阅读说明：本技术 激光处理装置 (Laser processing apparatus ) 是由 下地辉昭 伊藤大介 松岛达郎 清水良 于 2019-11-29 设计创作，主要内容包括：激光处理装置包括：载台(2),其可借由从表面喷射气体来悬浮搬运基板(3)；激光振荡器,其将激光(20a)照射至基板(3)；及气体喷射口,其用于喷射惰性气体,且配置于俯视下与激光(20a)的焦点位置重叠的位置。载台(2)的表面由上部结构(5a,5b)所构成,上部结构(5a,5b)配置为彼此分离且相对。于俯视下,上部结构(5a,5b)之间的间隙与激光(20a)的焦点位置重叠。填充组件(8)配置于上部结构(5a,5b)之间,且配置为填补上部结构(5a,5b)之间的间隙。(The laser processing apparatus includes: a stage (2) for floating and conveying the substrate (3) by ejecting gas from the surface; a laser oscillator that irradiates a substrate (3) with laser light (20 a); and a gas injection port for injecting an inert gas, and arranged at a position overlapping the focal position of the laser beam (20a) in a plan view. The surface of the stage (2) is formed by upper structures (5a,5b), and the upper structures (5a,5b) are arranged to be separated from and opposed to each other. The gap between the upper structures (5a,5b) overlaps the focal position of the laser light (20a) in a plan view. The filler element (8) is arranged between the upper structures (5a,5b) and is arranged to fill a gap between the upper structures (5a,5 b).)

1. A laser processing apparatus comprising:

a stage having a surface and an inner surface opposite to the surface, and capable of levitating and conveying a substrate by ejecting gas from the surface;

a laser oscillator that irradiates laser light to the substrate; and

a gas injection port for injecting an inert gas, the gas injection port being disposed above the stage and overlapping a focal position of the laser beam in a plan view,

here, the surface of the stage is composed of a first upper structure and a second upper structure,

the first and second upper structures are configured to be separated and opposite to each other,

a gap between the first upper structure and the second upper structure, in a plan view, overlapping a focal position of the laser light,

a filler component is disposed between the first and second superstructure and is configured to fill the gap.

2. The laser processing apparatus according to claim 1, wherein the inert gas ejected from the gas ejection port does not flow to a position lower than the filling assembly.

3. The laser processing apparatus of claim 1 or 2, wherein an upper surface of the filler component is located at a lower position than respective upper surfaces of the first and second upper structures.

4. The laser processing apparatus of claim 3, wherein the heights of the respective upper surfaces of the first and second upper structures are the same as each other.

5. The laser processing apparatus according to any one of claims 1 to 4, wherein the planar shape of the laser light on the stage is a rectangle having a major axis and a minor axis,

the filler component is disposed along a direction of the long axis.

6. The laser processing apparatus according to any one of claims 1 to 5, wherein the substrate is a glass substrate.

7. The laser processing apparatus according to any one of claims 1 to 6, wherein an amorphous semiconductor film is formed on the substrate, and the amorphous semiconductor film is transformed into a polycrystalline semiconductor film by irradiation of the laser light.

8. The laser processing apparatus according to any one of claims 1 to 7,

the first superstructure has a first surface side component ejecting the gas,

the second superstructure has a second surface side component for injecting the gas,

the filling assembly does not eject the gas.

9. The laser processing apparatus according to claim 8, wherein the first surface-side element and the second surface-side element are each formed of a porous body.

10. The laser processing apparatus according to any one of claims 1 to 9, wherein the laser is irradiated to the substrate through the gas ejection port.

11. The laser processing apparatus according to any one of claims 1 to 10, wherein the inert gas is ejected from the gas ejection port while the substrate is suspended on the stage and conveyed, and the laser light is irradiated to the substrate.

12. The laser processing apparatus according to any one of claims 1 to 11, wherein the laser light is irradiated to the substrate in an atmosphere formed by the inert gas ejected from the gas ejection port.

Technical Field

The present application relates to a laser processing apparatus.

Background

The technique described in international patent publication No. WO2015/174347 (patent document 1) relates to a laser annealing apparatus that irradiates a processing object with laser light to perform an annealing process.

Documents of the prior art

Patent document

Patent document 1: international patent publication No. WO2015/174347

Disclosure of Invention

Technical problem to be solved by the present application

The present inventors have now studied a laser processing apparatus that moves a processing object while suspending the processing object on a stage of the laser processing apparatus, and irradiates the moving processing object with laser light. In such a laser processing apparatus, it is desirable to suppress or prevent the laser processing conditions applied to the processing object from being changed.

Other problems and novel features will become apparent from the following description and drawings.

Means for solving the problems

According to one embodiment, a laser processing apparatus includes: a stage for floating and conveying the substrate by ejecting gas from the surface; a laser oscillator that irradiates laser light to the substrate; and a gas ejection port for ejecting an inert gas, the gas ejection port being disposed at a position overlapping the laser beam in a plan view. The surface of the stage is constituted by a first upper structure and a second upper structure, which are arranged to be separated from and opposed to each other. A gap between the first and second upper structures overlaps a focal position of the laser in a top view, and a filling assembly is configured to fill the gap between the first and second upper structures.

Effect of the invention

According to one embodiment, variation in laser processing conditions applied to a processing object can be suppressed or prevented.

Drawings

Fig. 1 is a cross-sectional view showing a schematic configuration of a laser processing apparatus according to an embodiment.

Fig. 2 is a plan view for explaining the operation of the laser processing apparatus according to the embodiment.

Fig. 3 is a plan view of a main part of a laser processing apparatus according to an embodiment.

Fig. 4 is a sectional view of a main part of a laser processing apparatus according to an embodiment.

Fig. 5 is a sectional view of a main part of a laser processing apparatus according to an embodiment.

Fig. 6 is a cross-sectional view of a schematic structure of a laser processing apparatus according to a first study example.

Fig. 7 is a cross-sectional view of a schematic configuration of a laser processing apparatus according to a second study example.

Fig. 8 is a sectional view of a main part of a laser processing apparatus according to a second research example.

Fig. 9 is an explanatory view for explaining a problem to be solved in the laser processing apparatus according to the second study example.

Fig. 10 is an explanatory view for explaining a problem to be solved in the laser processing apparatus according to the second study example.

Fig. 11 is an explanatory view for explaining a problem to be solved in the laser processing apparatus according to the second study example.

Fig. 12 is an explanatory view for explaining the efficacy of the laser processing apparatus according to the embodiment.

Fig. 13 is an explanatory view for explaining the efficacy of the laser processing apparatus according to the embodiment.

Fig. 14 is an explanatory view for explaining the efficacy of the laser processing apparatus according to the embodiment.

Fig. 15 is an external view showing a large-screen television as a liquid crystal display device.

Fig. 16 is an external view showing a mobile communication device as a liquid crystal display device.

Fig. 17 is a flowchart showing a flow of manufacturing steps for manufacturing a display device according to an embodiment.

Fig. 18 is a diagram showing a configuration example of a display device according to an embodiment.

Fig. 19 is a diagram showing an example of the structure of the pixel shown in fig. 13.

Fig. 20 is a cross-sectional view showing a device structure of a thin film transistor.

Fig. 21 is a flowchart showing a flow of manufacturing steps of the thin film transistor.

Fig. 22 is a flowchart illustrating a flow of a channel film forming step.

Fig. 23 is a plan view of a main part of a laser processing apparatus according to a first modification.

Fig. 24 is a plan view of a stage of a laser processing apparatus according to a second modification.

Fig. 25 is a plan view of a main part of a laser processing apparatus according to a second modification.

Fig. 26 is a sectional view of a main part of a laser processing apparatus according to a second modification.

Fig. 27 is a sectional view of a main part of a laser processing apparatus according to a third modification.

Fig. 28 is a sectional view of a main part of a laser processing apparatus according to a third modification.

Reference numerals

1,101 laser processing apparatus

2,102,202 stage

3,103 substrate

3a,103a amorphous silicon film

4 seat board

5,5a,5b,5c superstructure

6 surface side assembly

7 base

8 fill assembly

10 middle plate

11a,11b,11c adhesive layer

12a,12b space

13a,13b through the hole

20,20a laser

20b laser irradiation region

21 laser generating part

22 optical attenuator

23 optical system module

23a mirror

23b sealed window

24 closed shell

24a sealed window

25 processing chamber

26 sealed box

27 opening part

28 substrate heating zone

Region 29

31 large picture TV set

32 smart phone

40 pixels

41 pixel part

42 scanning line driving circuit

43 signal line drive circuit

44,45,45A line

46 thin film transistor

47 liquid crystal element

50 base plate

51 channel membranes

52 gate insulating film

53 gate electrode

54 interlayer insulating film

55a source electrode

55b drain electrode

56 protective film

Detailed Description

The embodiments are described below in detail with reference to the drawings. In all the drawings for describing the embodiments, the same reference numerals are given to elements having the same functions, and redundant description is omitted. In addition, in the following embodiments, descriptions of the same or equivalent portions are not repeated in principle unless necessary.

(embodiment mode 1)

< integral constitution of laser processing apparatus >

The overall configuration of the laser processing apparatus 1 according to the present embodiment will be described with reference to fig. 1. Fig. 1 is a cross-sectional view showing a schematic configuration of a laser processing apparatus according to an embodiment.

As shown in fig. 1, a laser processing apparatus 1 of the present embodiment includes: a laser generating section 21; an optical attenuator 22; an optical system module 23; a hermetic case 24; and a processing chamber 25.

The laser generation unit (laser oscillator) 21 is composed of a laser oscillator (laser source) that outputs laser light (for example, excimer laser light), and an optical attenuator (attenuator)22 for adjusting the output of the laser light is disposed at the output end of the laser generation unit 21. The optical attenuator 22 has a function of adjusting the output of the laser light by adjusting the transmittance of the laser light.

An optical system module 23 is disposed at the end where the laser beam whose output is adjusted by the optical attenuator 22 travels. The optical system module 23 is configured by a mirror 23a, a lens (not shown), and the like, and has a function of shaping the laser light input from the optical attenuator 22 to the optical system module 23 into beam-like laser light. A sealing window 23b that is transmissive to laser light is provided in the output portion of the optical system module 23. The laser beam formed by the optical system module 23 is output from the optical system module 23 through the sealing window 23 b.

A hermetic case 24 is provided at the end of the optical system module 23 where the laser beam is to travel (here, the lower side of the optical system module 23). The inside of the sealed case 24 is a sealed space, and the laser travels through the sealed space. A sealing window 24a that is transmissive to laser light is provided in the output portion of the sealed case 24.

A processing chamber 25 is disposed at the end on which the laser light outputted from the sealed casing 24 travels (here, the lower side of the sealed casing 24). The processing chamber 25 is provided with a seal box 26 connected to a seal window 24a provided in an output portion of the sealed casing. For example, an inert gas typified by nitrogen gas is supplied to the seal box 26. As shown in fig. 1, the upper side of the seal box 26 is sealed by a seal window 24a provided in the sealed case 24, and an opening (gas injection port) 27 is provided on the lower side of the seal box 26. Therefore, the inert gas (e.g., nitrogen gas) supplied to the seal box 26 is ejected from the opening portion 27 to the lower side of the seal box 26 (i.e., toward the stage 2).

A stage 2 is disposed below this sealed box 26. The stage 2 is disposed below the seal box 26 in the processing chamber 25. The stage 2 has an upper surface (surface); and a back surface (lower surface) opposed thereto, and the substrate 3 is levitated and conveyed by jetting a gas (gas) from the upper surface (surface). A substrate 3 made of, for example, glass or quartz may be arranged on the upper surface of the stage 2, and the substrate 3 is conveyed in the horizontal direction (specifically, the X direction) while being suspended above the stage 2 by gas injected from the upper surface of the stage 2 (more specifically, the upper surfaces of the plurality of upper structures 5 constituting the stage 2).

An amorphous (amorphous) semiconductor film, more specifically, an amorphous silicon film 3a is formed on the surface (upper surface) of the substrate 3. An inert gas (for example, nitrogen gas) injected (discharged) from an opening 27 provided in the seal box 26 is injected to the amorphous silicon film 3a formed on the surface of the substrate 3.

The amorphous semiconductor film (here, the amorphous silicon film 3a) formed on the substrate 3 is changed (changed) into a polycrystalline semiconductor film (here, a polycrystalline silicon film) by laser processing (laser annealing processing) using the laser processing apparatus 1, as will be described later. The following description will be made based on a case where the amorphous semiconductor film formed on the surface of the substrate 3 is the amorphous silicon film 3 a. The substrate 3 on which the amorphous semiconductor film (amorphous silicon film 3a) is formed can be regarded as a processing object.

The stage 2 includes: a seat plate (base member) 4; a plurality of upper structures (substrate floating structure, stage assembly, substrate floating stage assembly, floating unit) 5. The upper surfaces of the plurality of upper structures 5 constitute the upper surface of the stage 2. Therefore, the plurality of upper structures 5 are not stacked on top of each other, but arranged in a horizontal direction, and these plurality of upper structures 5 constitute the upper part of the stage 2. The plurality of upper structures 5 are arranged in line and supported on the seat plate 4.

In fig. 1, it is shown that not only the upper structures 5a and 5b described later but also the upper structures 5c other than the upper structures 5a and 5b are disposed on the common seat plate 4, but the upper structure 5c may be supported by a different member from the seat plate 4 on which the upper structures 5a and 5b are disposed, instead of the upper structure 5c being mounted on the seat plate 4. However, in this case, the upper structures 5a,5b and the filling assembly 8 between the upper structures 5a,5b are preferably still arranged on a common seat plate 4. The seat plate 4 on which the superstructure 5a,5b is mounted can be formed, for example, of stone (granite, etc.), on the other hand, the components supporting the superstructure 5c can be formed, for example, by means of metal materials.

Each upper structure 5 is configured to eject gas from its upper surface (surface). That is, gas (gas) is jetted from the upper surface (front surface) of the upper structure 5, and the substrate 3 is floated by the jetted gas. Therefore, the upper structure 5 functions as a structure (component) for ejecting gas from the upper surface (front surface) thereof to suspend the substrate 3, that is, a structure for suspending the substrate.

Specifically, a plurality of (many) fine holes are present on the upper surface (surface) of the upper structure 5, and gas can be injected from the fine holes. When the substrate 3 moves while being suspended on the stage 2, the upper surface (front surface) of the upper structure 5 faces the lower surface of the substrate 3, and the gas (hereinafter referred to as substrate suspension gas) injected from the plurality (numerous) of pores on the upper surface (front surface) of the upper structure 5 collides with the lower surface of the substrate 3 to suspend the substrate 3.

Next, the operation of the laser processing apparatus 1 will be described with reference to fig. 1 and 2. Fig. 2 is a plan view for explaining the operation of the laser processing apparatus 1, and shows the stage 2 of the laser processing apparatus 1; a substrate 3 which is transported while being suspended on the stage 2.

In fig. 1, a laser beam (laser beam) 20 output from a laser generating unit (laser oscillator) 21 is adjusted in optical output by an optical attenuator 22 and then input to an optical system module 23. The laser beam 20 input to the optical system module 23 is shaped into a beam shape (rectangular shape) by a lens system provided inside the optical system module 23. The laser beam 20 formed into a linear shape is reflected by a mirror 23a disposed inside the optical system module 23, for example, and then enters the sealed case 24 through a sealing window 23 b. The laser beam 20 incident on the sealed casing 24 travels through the internal space of the sealed casing 24, and then enters the sealed box 26 provided in the processing chamber 25 through the sealed window 24 a. Next, the laser light 20 incident on the seal box 26 travels toward the stage 2 through the opening 27 provided in the seal box 26. Here, the laser beam 20 traveling toward the stage 2 (substrate 3) through the opening 27 of the seal box 26 is denoted by reference numeral 20a and is referred to as a laser beam 20 a. The laser light 20a is irradiated onto the substrate 3 (more specifically, the amorphous silicon film 3a on the substrate 3) which moves while being suspended on the stage 2. The laser irradiated region in the amorphous silicon film 3a is locally heated and changed (altered) into a polysilicon film (polysilicon film).

The laser beam 20a is formed into a beam shape having a long axis direction (longitudinal direction) in the Y direction. In fig. 2 and fig. 3 and 25 described later, a region (planar region) where the laser beam 20a can be irradiated is denoted by a reference numeral 20b to denote a laser-irradiated region 20 b. The laser irradiation region 20b is a rectangle having a major axis (long side) and a minor axis (short side), the major axis (long side) is larger than the minor axis (short side), the major axis (long side) direction is the Y direction, and the minor axis (short side) direction is the X direction. That is, the planar shape of the laser beam 20a on the surface (upper surface) of the stage 2 is a rectangle having a major axis (long side) and a minor axis (short side), the major axis (long side) direction is the Y direction, and the minor axis (short side) direction is the X direction. From another perspective, the planar shape of the laser beam 20a irradiated onto the substrate 3 (amorphous silicon film 3a) is a rectangle having a major axis (long side) and a minor axis (short side), the major axis (long side) direction is the Y direction, and the minor axis (short side) direction is the X direction. That is, the planar shape of laser light 20a on the surface of substrate 3 (amorphous silicon film 3a) or on the surface of stage 2 is a rectangle having a major axis (long side) and a minor axis (short side), and the direction of the major axis (long side) is the Y direction. The length of the long side of the laser irradiation region 20b (the length in the Y direction) may be substantially the same as the length of the substrate 3 in the Y direction, for example. On the other hand, the length of the short side of the laser irradiation region 20b (the length in the X direction) is much smaller than the length of the substrate 3 in the X direction.

Here, the X direction and the Y direction are directions intersecting each other, and preferably, directions intersecting each other perpendicularly. The X direction and the Y direction are substantially parallel to the upper surface of the stage 2, and therefore, are substantially parallel to the upper surface of the substrate 3 floating on the stage 2.

When the substrate 3 is subjected to laser processing, the stage 2 itself does not move, and the substrate 3 is conveyed (moved) while being suspended on the fixed stage 2. That is, the state of fig. 2 (a), the state of fig. 2(b), and the state of fig. 2 (c) are sequentially transferred. Fig. 2 (a) corresponds to a state before the substrate 3 starts moving, fig. 2(b) corresponds to a state when the substrate 3 is moving, and fig. 2 (c) corresponds to a state when the substrate 3 has finished moving. The substrate 3 arranged on the stage 2 can be floated from the stage 2 by a gas ejected from the upper surface of the stage 2 (that is, the upper surfaces of the plurality of upper structures 5 constituting the stage 2). Further, the substrate 3 suspended on the stage 2 may be moved in the X direction by holding the substrate 3 to move in the X direction by a robot arm (not shown) for substrate conveyance.

When the substrate 3 is laser-processed, the stage 2 itself does not move, and the irradiation position of the laser beam 20 does not move. Therefore, the irradiation position of the laser beam 20a with respect to the stage 2 is fixed. That is, the laser irradiation area 20b is fixed when viewed from the stage 2. However, since the substrate 3 is moved in the X direction while being suspended on the stage 2, the irradiation position (irradiation region) of the laser light 20a on the substrate 3 (amorphous silicon film 3a) is moved in accordance with the movement of the substrate 3. That is, by moving the substrate 3 relative to the stage 2 and the laser beam 20a whose positions are fixed, the irradiation position (irradiation region) of the laser beam 20a on the substrate 3 (amorphous silicon film 3a) is moved in accordance with the movement of the substrate 3. Thereby, the laser light irradiation region in the amorphous silicon film 3a can be scanned, and the irradiation processing of the laser light 20a can be applied to the entire amorphous silicon film 3 a. In addition, the laser 20 may be a continuous laser or a pulsed laser with a specific frequency.

Further, an inert gas (e.g., nitrogen gas) is supplied to the seal box 26 so that the inert gas is ejected (discharged, exhausted) from an opening 27 provided in a lower portion of the seal box 26. The inert gas ejected from the opening 27 provided in the seal box 26 is ejected onto the upper surface of the substrate 3 (more specifically, the amorphous silicon film 3 on the substrate 3) that moves in the X direction while being suspended on the stage 2. Therefore, the opening 27 provided in the seal box 26 can be regarded as a gas injection port for injecting the inert gas.

The inert gas is injected from the opening 27 of the seal box 26 to the amorphous silicon film 3a on the substrate 3 in order to avoid unnecessary reaction (for example, to avoid generation of a silicon oxide film on the surface of a polysilicon film) when the amorphous silicon film 3a is converted into a polysilicon film by irradiating laser light to the amorphous silicon film 3a on the substrate 3. That is, the laser beam is irradiated to the amorphous silicon film 3a in the atmosphere of the inert gas ejected from the opening 27 of the seal box 26 to convert the amorphous silicon film 3a into a polysilicon film.

That is, while the substrate 3 is suspended on the stage 2 and moved in the X direction, the laser beam 20a formed into a beam shape is irradiated while an inert gas (for example, nitrogen gas) is jetted to the amorphous silicon film 3a formed on the surface of the substrate 3. As a result, the amorphous silicon film 3a formed on the substrate 3 is locally heated, whereby the laser irradiated region of the amorphous silicon film 3a can be changed to a polysilicon film and the laser irradiated region of the amorphous silicon film 3a can be scanned. By applying laser processing (laser annealing processing) to the entire amorphous silicon film 3a in this manner, the entire amorphous silicon film 3a can be converted into a polysilicon film. That is, the amorphous semiconductor film (here, the amorphous silicon film 3a) formed on the substrate 3 can be changed (converted) into a polycrystalline semiconductor film (here, a polycrystalline silicon film).

In this way, when performing laser processing using the laser processing apparatus 1, the substrate 3 (amorphous silicon film 3a) is irradiated with the laser light 20a by injecting an inert gas from the opening 27 of the seal box 26 while floating and transporting the substrate 3 on the stage 2.

Detailed description of the laser processing apparatus

Next, a detailed configuration of stage 2 of laser processing apparatus 1 according to the present embodiment will be described with reference to fig. 3 to 5.

Fig. 3 is a plan view of a main part of the laser processing apparatus 1 according to the present embodiment, and fig. 4 and 5 are sectional views of a main part of the laser processing apparatus 1 according to the present embodiment. Fig. 3 is a plan view of a part of stage 2 included in laser processing apparatus 1 according to the present embodiment, and the plan view area shown in fig. 3 corresponds approximately to area 29 of fig. 2 (B). In addition, in fig. 3, the laser irradiation region 20b is hatched. FIG. 4 is a cross-sectional view generally corresponding to the position indicated by line A1-A1 in FIG. 3, and FIG. 5 is a cross-sectional view generally corresponding to the position indicated by line A2-A2 in FIG. 3. In addition, although the cross-sectional view of fig. 4 shows the laser beam 20a, the laser beam 20a is not shown in the cross-sectional view of fig. 5 since the laser beam 20a is irradiated on the entire upper surface of the amorphous silicon film 3 a.

As described above, the stage 2 of the laser processing apparatus 1 of the present embodiment includes: a seat plate 4; and a plurality of upper structures 5 arranged on the seat plate 4. The upper surface (surface) of the carrier 2 is constituted by a plurality of upper structures 5, that is, the upper surfaces (surfaces) of the plurality of upper structures 5 constitute the upper surface of the carrier 2. The plurality of upper structures 5 of the stage 2 each eject gas from the upper surface (front surface) thereof, and the substrate 3 is floated by the ejected gas. The stage 2 of the laser processing apparatus 1 of the present embodiment further includes a filler block 8.

The plurality of upper structures 5 constituting the stage 2 include upper structures 5a and 5b, which are adjacent to each other in the X direction with a laser irradiation region 20b therebetween in a plan view (see fig. 2 and 3). The upper structure 5a and the upper structure 5b are disposed apart from and opposite to each other in the X direction. Therefore, the upper structure 5a and the upper structure 5b are arranged at a specific interval along the X direction, and the filler unit 8 is arranged between the upper structure 5a and the upper structure 5b in the X direction. That is, the upper structure 5a and the upper structure 5b are adjacent to each other in the X direction with the filler unit 8 interposed therebetween, and the filler unit 8 is disposed between the side surfaces of the upper structure 5a and the upper structure 5b facing each other. The upper structures 5a,5b and the packing member 8 disposed between the upper structures 5a,5b are disposed (mounted) on the upper surface of the seat plate 4. The filler assembly 8 may be mounted to the superstructure 5a or superstructure 5b using screws or the like.

The filling member 8 is a member for closing (filling up) the gap between the upper structure 5a and the upper structure 5 b. Thus, the filling assembly 8 is configured to fill the gap between the superstructure 5a and the superstructure 5 b. The upper structures 5a,5b preferably contact the packing assembly 8 between the upper structures 5a,5 b. Unlike the upper structure 5, the filling unit 8 does not eject gas for floating the substrate 3 (substrate floating gas), and therefore does not function as a unit for floating the substrate 3. Since no other upper structure 5 is disposed between the upper structure 5a and the upper structure 5b adjacent to each other in the X direction with the filling module 8 interposed therebetween, no gas for floating the substrate 3 (substrate-floating gas) is ejected in the region between the upper structure 5a and the upper structure 5 b.

Since the filling unit 8 is disposed between the upper structure 5a and the upper structure 5b and is disposed to fill the gap between the upper structure 5a and the upper structure 5b, the filling unit 8 has a function of preventing the inert gas injected from the opening 27 of the seal box 26 from flowing (flowing) to the lower side (lower side) than the filling unit 8 through the gap between the upper structure 5a and the upper structure 5 b. That is, by having the filling member 8 between the upper structure 5a and the upper structure 5b, the inert gas injected from the opening portion 27 of the seal box 26 does not flow to a position below the filling member 8 (more specifically, below the upper surface of the filling member 8).

The filling assembly 8 may be constructed of, for example, a metallic material. For example, stainless steel (SUS) or the like may be used as the material of the packing member 8. Furthermore, the filling member 8 may have a plate-like shape, for example, to be arranged between the upper structures 5a,5 b. Therefore, the filling member 8 can be formed by processing a plate-shaped metal member (metal plate).

Since the structure of the upper structure 5a and the structure of the upper structure 5b are basically the same, the description of the upper structure 5a is described herein, but the description of the structure of the upper structure 5a can be applied to the structure of the upper structure 5 b.

The upper structure 5a includes a front side member 6 and a base portion (base portion) 7, and the front side member 6 is disposed on and supported by the base portion 7. The upper surface (surface) of the front surface side member 6 constitutes the upper surface (surface) of the upper structure 5a, and thus constitutes a part of the upper surface (surface) of the stage 2.

The surface-side member 6 is preferably formed of a porous body (porous material). The porous body has many fine pores (i.e., pores). Examples of the porous material used include porous carbon, porous ceramic, and porous metal. Further, the surface side member 6 may be a plate-like member. Therefore, a porous plate (plate-shaped member formed of a porous body) can be suitably used as the surface side member 6, in which case the gas for suspending the substrate 3 can pass through many pores of the porous plate and be ejected from the upper surface of the porous plate. In this case, the pores of the porous plate correspond to the above-described "fine pores" of the upper surface of the upper structure 5 a.

The base 7 may be formed of a metal material, and preferably may be formed of aluminum or an aluminum alloy. The base 7 can be formed by processing a plate-like member (metal plate), for example. The seat plate 4 has a flat upper surface, and the upper structures 5a and 5b and the filler block 8 are disposed on the upper surface of the seat plate. The outer shape of each of the upper structures 5a,5b may be, for example, a substantially rectangular parallelepiped.

The upper structure 5a includes a structure for ejecting a substrate levitation gas from the upper surface (surface side member 6) of the upper structure 5a, and specifically includes the following structure.

As shown in fig. 4, the upper structure 5a includes an intermediate plate 10 disposed between the base 7 and the front side module 6, in addition to the base 7 and the front side module 6. The intermediate plate 10 may be a plate-like member thinner than the base 7, and may be formed of, for example, a metal material (aluminum or the like). In the upper structure 5a, the intermediate plate 10 is bonded and fixed to the base 7 by an adhesive layer (adhesive material) 11b, and further, the front side member 6 is bonded and fixed to the base 7 by an adhesive layer (adhesive material) 11 a. In the upper structure 5a, the intermediate plate 10 is disposed between the base 7 and the front side module 6, a space (pressure-applying space) 12a is provided between the front side module 6 and the intermediate plate 10, and a space (pressure-reducing space) 12b is provided between the base 7 and the intermediate plate 10. The space 12a is surrounded by the intermediate plate 10, the front side module 6, and the adhesive layer 11a, and the space 12b is surrounded by the base 7, the intermediate plate 10, and the adhesive layer 11 b.

The intermediate plate 10 is provided with a plurality of (many) through holes 13b, and similarly, the front side module 6 is provided with a plurality of (many) through holes 13a at positions corresponding to the through holes 13b of the intermediate plate 10. The peripheries of the through holes 13a in the lower surface of the front side member 6 and the peripheries of the through holes 13b in the upper surface of the intermediate plate 10 are bonded to each other by an annular adhesive layer 11 c. Therefore, the through holes 13a of the front surface side unit 6 and the through holes 13b of the intermediate plate 10 are connected to each other through the space in the annular adhesive layer 11 c. Therefore, the front surface side member 6 formed of the porous body (porous plate) has a plurality of (many) through-holes 13a formed mechanically in addition to the pores of the porous body itself. In consideration of workability, the through-holes 13a preferably have a diameter larger than the pores of the porous body.

The pressurized gas is introduced into the space 12a through-hole (not shown) or the like provided in the base 7, and the pressurized gas introduced into the space 12a is ejected from the upper surface of the front surface side member 6 through the plurality of fine holes (fine holes constituting the porous body) of the front surface side member 6, and the substrate 3 is levitated by the ejected gas. In fig. 4, the gas ejected from the upper surface of the front surface side element 6 is schematically shown by an upward arrow. The gas ejected from the upper surface of the surface side member 6 may be, for example, an inert gas typified by nitrogen. Further, the space 12b is decompressed by a through-hole (not shown) provided in the base 7, whereby the gas on the front side member 6 is sucked into the space 12b through the through-hole 13a of the front side member 6, the space in the annular adhesive layer 11c, and the through-hole 13b of the intermediate plate 10. In fig. 4, the gas sucked from the upper surface (through-hole 13a) of the surface side member 6 is schematically shown by a downward arrow.

Therefore, while the gas is ejected from the micropores (in this case, pores constituting a porous body) of the front surface side module 6 to suspend the substrate 3, the gas on the front surface side module 6 is sucked from the through holes 13a of the front surface side module 6 to adsorb the substrate 3. Therefore, by adjusting the gas ejection and gas adsorption from the front surface side unit 6, the height position of the floating substrate 3 can be controlled with high accuracy.

Here, as an example, a structure for performing gas injection and gas suction from the upper surface of the upper structure 5a by using the intermediate plate 10, the adhesive layers 11a,11b,11c, the spaces 12a,12b, the through holes 13a,13b, and the like will be described, but the structure is not limited thereto. The upper structures 5a,5b may also have a structure for gas (substrate levitation gas) ejection and gas suction from the upper surfaces thereof.

The laser 20a is irradiated to the substrate 3 (more specifically, the amorphous silicon film 3a formed on the substrate 3), and if the substrate 3 and the amorphous silicon film 3a are absent, the laser 20a is irradiated to the region between the upper structure 5a and the upper structure 5b (i.e., the filling member 8). That is, the laser light 20a travels toward the region between the upper structure 5a and the upper structure 5 b. Therefore, the laser irradiation region 20b (region irradiated with the laser light 20a) in the substrate 3 (amorphous silicon film 3a) is located above the region between the upper structure 5a and the upper structure 5b (i.e., above the filler element 8), and overlaps with the region between the upper structure 5a and the upper structure 5b (i.e., the filler element 8) in a plan view. Therefore, the gap (filling member 8) between the upper structure 5a and the upper structure 5b and the focal position of the laser light 20a overlap each other in a plan view.

An opening 27 as a gas ejection port is disposed above the stage 2. The opening 27 serving as a gas injection port is disposed at a position overlapping the focal position of the laser beam 20a in a plan view. That is, the opening 27 overlaps the laser irradiation region 20b in a plan view. Preferably, the laser irradiation region 20b is surrounded by the opening 27 in a plan view. This is because the laser beam 20a is irradiated to the substrate 3 (amorphous silicon film 3a) in an atmosphere formed by an inert gas injected (discharged) from the opening 27 of the sealing box 26 while forming the vicinity of the laser irradiation region 20 as an inert gas atmosphere.

Therefore, the opening 27 as a gas injection port overlaps with the gap (filling block 8) between the upper structure 5a and the upper structure 5b in a plan view. That is, at least a part of the opening 27 overlaps with the gap (the filler member 8) between the upper structure 5a and the upper structure 5b in a plan view.

The opening 27 serving as a gas ejection port is disposed above the stage 2 in the processing chamber 25, and is disposed below (at a lower position than) the laser beam generating unit 21, the optical attenuator 22, the optical system module 23, and the sealed case 24.

< research Process >

Fig. 6 is a cross-sectional view showing a schematic configuration of a laser processing apparatus 101 according to a first example of the present inventors, which corresponds to fig. 1.

In the laser processing apparatus 101 of the first study example shown in fig. 6, the substrate 103 corresponding to the substrate 3 is arranged on the stage 102 and contacts the stage 102. The laser beam 20 is irradiated to the substrate 103 while moving the substrate 103 together with the stage 102 by moving the stage 102. That is, in the laser processing apparatus 101 according to the first study example, the substrate 103 is not moved while being suspended on the stage 102, but is arranged and fixed on the stage 102 so that the stage 102 moves together with the substrate 103. By moving the substrate 103 together with the stage 102, a laser light irradiation region in the amorphous silicon film 103a formed on the substrate 103 can be scanned, and the amorphous silicon film 103a can be entirely converted into a polysilicon film.

However, in the laser processing apparatus 101 according to the first study example, since the stage 102 must be moved together with the substrate 103, after laser processing is performed on a certain substrate 103, the stage 102 moved to the end position of the laser processing must be reset to the initial position. After that, it is necessary to dispose the next substrate 103 on the stage 102, and then perform laser processing on the substrate 103 while moving the stage 102 together with the substrate 103. In this case, since it is necessary to detach the substrate 103, on which the laser processing has been completed, from the stage 102 and then to perform an operation of resetting the stage 102 to the initial position, when the laser processing is performed on a plurality of substrates 103, the processing time per one substrate 103 becomes long on average, and the throughput becomes low.

Therefore, the present inventors have studied a method of moving a substrate in a horizontal direction while suspending the substrate on a stage of a laser processing apparatus and irradiating the moving substrate with a laser beam. Since the stage does not need to be moved in this case, when applying laser processing to a plurality of substrates, the processing time for leveling a single substrate can be shortened, so that the throughput is improved.

Fig. 7 shows a schematic configuration of a laser processing apparatus 201 according to a second example of the present inventors, which corresponds to the above-described fig. 1. Fig. 8 is a sectional view of a main part of a laser processing apparatus 201 according to a second study example, which corresponds to the above-described fig. 4.

The laser processing apparatus 201 (fig. 7 and 8) of the second research example differs from the laser processing apparatus 1 (fig. 1 and 4) of the present embodiment in that the stage 2 (fig. 1 and 4) of the laser processing apparatus 1 of the present embodiment has the filler block 8, whereas the stage 201 (fig. 7 and 8) of the laser processing apparatus 201 of the second research example does not have a substance corresponding to the filler block 8. That is, in stage 202 of laser processing apparatus 201 according to the second study example, nothing corresponding to filler block 8 is disposed between upper structure 5a and upper structure 5 b.

First, the reason why the upper structure 5a and the upper structure 5b are separated in the laser processing apparatus 201 of the second study example shown in fig. 7 and 8 and the laser processing apparatus 1 (fig. 1 and 4) of the present embodiment will be described.

In the laser processing apparatus 201 (fig. 7 and 8) of the second study example and the laser processing apparatus 1 (fig. 1 and 4) of the present embodiment, the laser 20a is irradiated to the moving substrate 3 while the substrate is suspended on the fixed stages (2,202) and moved in the horizontal direction. Thereby, the laser light irradiation region in the amorphous silicon film 3a formed on the substrate 3 can be scanned, and the amorphous silicon film 3a as a whole can be converted into a polysilicon film.

However, in the laser processing apparatus 201 (fig. 7 and 8) of the second study example and the laser processing apparatus 1 (fig. 1 and 4) of the present embodiment, the stages (2,202) are fixed as the substrate 3 is moved, so that the laser irradiation position in the substrate 3 is fixed as viewed from the stages (2,202), and there is a risk that the stages (2,202) are locally heated.

That is, in fig. 4 and 7, the region irradiated with the laser beam 20a and the vicinity thereof of the substrate 3 and the amorphous silicon film 3a thereon are locally heated, and therefore, the region enclosed by the broken line of the reference numeral 28 (hereinafter referred to as a substrate heating region 28) is locally heated to a considerably high temperature. Since the substrate 3 is moved and irradiated with the laser beam, the substrate heating region 28 moves along with the movement of the substrate 3 in the substrate 3 and the amorphous silicon film 3a thereon. However, since the stages (2,202) are fixed, the position of the substrate heating region 28 is fixed without moving as viewed from the stages (2, 202). Therefore, during the laser processing of the substrate 3, the region of the stages (2,202) located below the substrate heating region 28 is fixed.

Therefore, during the laser processing of the substrate 3, the region located below the substrate heating region 28 and the vicinity thereof among the stages (2,202) are continuously heated by the heat transferred from the substrate heating region 28, and therefore, the heat transferred from the substrate heating region 28 is accumulated, which may cause local heating and local temperature increase. When the temperature of the stage (2,202) is locally heated and locally rises, thermal strain (deformation due to heat) occurs in the stage 2, and the stage (2,202) may be deformed.

If the stages (2,202) are locally deformed, the height position at which the substrate 3 is suspended on the stages (2,202) may vary, and therefore, the conditions for laser processing of the substrate 3 may vary. That is, since the substrate 3 moves while being suspended on the stages (2,202), when the stages (2,202) deform, the height position of the substrate 3 suspended on the stages (2,202) changes, and when the height position of the substrate 3 changes, the distance between the focal position of the laser irradiated to the substrate 3 and the substrate 3 changes, which causes the conditions for the laser processing performed on the substrate 3 to fluctuate.

For example, even before the stage (2,202) deforms due to thermal strain, if the height position of the substrate 3 that is originally suspended on the stage (2,202) coincides with the focal position of the laser beam 20a, the stage (2,202) deforms due to the influence of heat conduction from the substrate heating region 28, and the height position of the substrate 3 that is suspended on the stage (2,202) deviates from the focal position of the laser beam 20 a. This causes a change in the conditions of the laser processing performed on the substrate 3 before and after the stages (2,202) are locally deformed by the influence of thermal strain.

Before and after the stages (2,202) are deformed by the influence of thermal strain, the conditions of the laser processing performed on the substrate 3 are changed, and the characteristics of the polysilicon film may be changed when the amorphous silicon film 3a formed on the substrate 3 is changed into the polysilicon film by the laser processing. For example, a variation in the crystalline state of the polysilicon film may be caused. Therefore, in order to suppress the variation in the characteristics of the polysilicon film formed in one substrate 3; or the characteristics of the polysilicon films formed on the plurality of substrates 3 are varied, and it is desirable to suppress the occurrence of deformation of the stages (2,202) due to heat conduction from the substrate heating region 28.

Here, unlike the second study example (fig. 7 and 8) and the present embodiment (fig. 1 and 4), an arrangement in which the upper structure 5a and the upper structure 5b are integrally formed in contact with each other may be evaluated. However, in this case, the upper structure of the stage exists directly below the laser irradiation region in the substrate 3 (amorphous silicon film 3a) and also directly below the substrate heating region 28, so that heat is easily transferred from the substrate heating region 28 to the upper structure of the stage. Therefore, the upper structure (particularly, the structure corresponding to the front surface side element 6) existing just below the substrate heating region 28 may be deformed by the influence of heat conduction from the substrate heating region 28.

In contrast, in the second study example (fig. 7 and 8) and the present embodiment (fig. 1 and 4), the upper structure 5a and the upper structure 5b constituting the stage are separated by a specific interval, and the focal position of the laser light 20a overlaps with the gap (area) between the upper structure 5a and the upper structure 5b in a plan view. From another point of view, the laser irradiated region in the substrate 3 (amorphous silicon film 3a) overlaps with the gap (region) between the upper structure 5a and the upper structure 5b in a plan view. Thereby making it difficult to transfer heat from the substrate heating region 28 to the upper structures 5a,5b (particularly, the surface side members 6 of the upper structures 5a,5b) during the laser processing of the substrate 3 (amorphous silicon film 3 a). That is, since the upper structure (5a,5b) becomes absent immediately below the laser light irradiation region in the substrate 3 (amorphous silicon film 3a), it is difficult to transfer heat from the substrate heating region 28 to the upper structure (5a,5b), so that it is possible to reduce the risk that the surface side component 6 constituting the upper structure (5a,5b) is deformed by the influence of heat conduction from the substrate heating region 28. This reduces the risk of variation in the height position of the substrate 3 that moves while being suspended on the stage 2.

For this reason, in the second study example (fig. 7 and 8) and the present embodiment (fig. 1 and 4), the upper structure 5a and the upper structure 5b constituting the stages (2,202) are separated, and the focal position of the laser light 20a overlaps with the gap (area) between the upper structure 5a and the upper structure 5b in a plan view.

In the second study example (fig. 7 and 8) and the present embodiment (fig. 1 and 4), during the laser processing, the inert gas is injected from the opening 27 of the sealing box 26 to the substrate 3 (amorphous silicon film 3a) as described above. This is to prevent unnecessary reaction from occurring when the laser beam 20a is irradiated to the amorphous silicon film 3a on the substrate 3 to convert the amorphous silicon film 3a into a polysilicon film. That is, the laser beam 20a is irradiated to the amorphous silicon film 3a in the atmosphere of the inert gas ejected from the opening 27 of the seal box 26 to convert the amorphous silicon film 3a into a polysilicon film.

Therefore, in the second study example (fig. 7 and 8) and the present embodiment (fig. 1 and 4), the laser beam 20a is irradiated while the substrate 3 is suspended on the stages (2,202) and moved in the horizontal direction, and the amorphous silicon film 3a formed on the surface of the substrate 3 is sprayed with an inert gas (e.g., nitrogen gas). Accordingly, based on the studies of the present inventors, it was found that the following problems described with reference to fig. 9 to 11 occur in the case of the laser processing apparatus 201 (fig. 7 and 8) of the second study example. Fig. 9 to 11 are explanatory views for explaining problems in the laser processing apparatus 201 according to the second study example, and show cross-sectional views corresponding to the positions of fig. 8.

In fig. 9 to 11 and fig. 12 to 14 described later, an inert gas atmosphere formed by an inert gas (e.g., nitrogen gas) injected from the opening 27 of the seal box 26 is schematically indicated by dot hatching. Note that arrows (upward arrows in fig. 4 and 8) indicating gas ejected from the upper surface of the front surface side module 6 constituting the upper structures 5a and 5b and arrows (downward arrows in fig. 4 and 8) indicating gas sucked from the upper surface (through-holes 13a) of the front surface side module 6 constituting the upper structures 5a and 5b are not shown in fig. 9 to 11 and fig. 12 to 14 described later.

As shown in fig. 9, during the laser processing (the processing of irradiating the laser beam 20a) performed on a certain substrate 3, the inert gas ejected from the opening 27 of the seal box 26 is ejected to the substrate 3 (the amorphous silicon film 3a) and spreads in the horizontal direction in the space above the substrate 3. At this time, the inert gas ejected from the opening 27 of the seal box 26 is not supplied to the gap between the upper structure 5a and the upper structure 5b because it is shielded by the substrate 3.

On the other hand, during the period from the end of laser processing on a certain substrate 3 to the start of laser processing on the next substrate 3, as shown in fig. 10, no substrate 3 is present above the gap between the upper structure 5a and the upper structure 5 b. At this time, since the substrate 3 does not exist at the end where the gas travels, the inert gas injected from the opening 27 of the seal box 26 travels toward the stage 2 without being blocked by the substrate 3, and is supplied to the gap between the upper structure 5a and the upper structure 5 b. As shown in fig. 10, in the second research example, since the filling member 8 is not disposed between the upper structure 5a and the upper structure 5b, the inert gas supplied from the opening 27 of the seal box 26 to the gap between the upper structure 5a and the upper structure 5b flows downward between the upper structure 5a and the upper structure 5 b. The inert gas flows downward between the upper structure 5a and the upper structure 5b and does not diffuse in the horizontal direction (particularly, the X direction) at the upper surfaces of the upper structures 5a,5b, so that the range of the inert gas atmosphere is limited to the gap between the upper structure 5a and the upper structure 5b and the vicinity thereof in a plan view, so that the range of the inert gas atmosphere becomes narrow in a plan view (refer to fig. 10).

The next substrate 3 is moved while being suspended on the stage 2, and as shown in fig. 11, when the end of the substrate 3 reaches above the gap between the upper structure 5a and the upper structure 5b, the laser processing (the processing of irradiating the laser beam 20a) on the substrate 3 is started. At this time, at the stage immediately after the start of the laser processing on the substrate 3 (i.e., at the stage of irradiating the laser beam 20a to the vicinity of the end of the substrate 3 as shown in fig. 11), the inert gas in the vicinity of the laser irradiation region (20b) is unstable and the atmospheric components are easily mixed therein due to the influence of the narrow range of the inert gas atmosphere in the plan view as described above. Therefore, in a stage immediately after the start of the laser processing for the substrate 3 (i.e., the stage of fig. 11), the laser light 20a may be irradiated to the substrate 3 (amorphous silicon film 3a) in an atmosphere containing an inert gas but also mixed with atmospheric components.

When the substrate 3 further continues to move from the state of fig. 11 to the state of fig. 9, the inert gas injected from the opening 27 of the seal box 26 diffuses in the horizontal direction (particularly, the X direction) on the substrate 3, so that the range of the inert gas atmosphere is widened in a plan view, the inert gas atmosphere in the vicinity of the laser irradiation region (20b) is stable, and the air components are less likely to be mixed therein. Therefore, in the state of fig. 9, the laser light 20a is irradiated to the substrate 3 (amorphous silicon film 3a) in an inert gas atmosphere in which almost no atmospheric components are mixed.

Therefore, in the case of the second study example, the laser processing conditions applied to the substrate 3 may vary in the vicinity of the end portion of the substrate 3 and in a position away from the end portion. Specifically, there is a possibility that the degree of crystallization when the amorphous silicon film 3a is converted into a polysilicon film varies depending on the difference between the atmosphere when the substrate 3 is irradiated with the laser light 20a (the atmosphere in the vicinity of the laser irradiation region 20b) in the vicinity of the end portion and in the position away from the end portion. For example, when the amorphous silicon film 3a on the substrate 3 is converted into a polysilicon film by laser processing, the crystal grain size of the polysilicon film near the end of the substrate 3 and the crystal grain size of the polysilicon film at a position distant from the end of the substrate 3 (for example, near the center of the substrate 3) are different, so that a difference (unevenness) occurs in the crystal grain size of the polysilicon film on the substrate 3. Since this causes a problem that the reliability of an element (e.g., a thin film transistor element) or a device (e.g., a display device) using the polysilicon film is deteriorated, it is desirable to prevent this.

Further, irradiating the laser light 20a to the amorphous silicon film 3a in an atmosphere mixed with an atmospheric component may cause an unnecessary reaction when converting the amorphous silicon film 3a into a polycrystalline silicon film. Since this case leads to deterioration in reliability of an element (e.g., a thin film transistor element) or a device (e.g., a display device) using the polysilicon film, it is desirable to prevent this.

< about the main features and effects >

Next, the main features of the laser processing apparatus according to the present embodiment will be described. Fig. 12 to 14 are explanatory views for explaining the efficacy of the laser processing apparatus 1 according to the present embodiment, and show cross-sectional views corresponding to the positions of fig. 8.

In the present embodiment, the upper structure 5a and the upper structure 5b are separated at a specific interval, and the filler member 8 is disposed between the upper structure 5a and the upper structure 5b such that the focal position of the laser light 20a (laser light irradiation region in the substrate 3) overlaps with the gap (filler member 8) between the upper structure 5a and the upper structure 5b in a plan view. Thereby, the filling member 8 is made to exist in a region where heat is easily transferred from the substrate heating region 28, that is, in a region directly below the laser irradiation region of the substrate 3, instead of the upper members 5a,5b, and therefore, it is possible to suppress or prevent the upper structures 5a,5b (particularly, the surface side members 6) from being deformed by thermal strain. Therefore, the variation in the height position of the substrate 3 that moves while being suspended on the substrate 2 can be suppressed or prevented.

Since the upper structures 5a and 5b have a function of ejecting gas (substrate levitation gas) from the upper surfaces thereof to levitate the substrate 3, the upper structures 5a and 5b (particularly, the front surface side member 6) are deformed by thermal strain, which affects the fluctuation of the height position of the substrate 3 moving while levitating on the stage 2. In contrast, the filling unit 8 is not a unit for ejecting gas (substrate levitation gas) from the upper surface thereof, that is, a unit having a function of levitating the substrate. Therefore, even if the filler member 8 is deformed by thermal strain due to the influence of heat conduction from the substrate heating region 28, the risk of its influence on the height position of the substrate 3 is smaller than in the case where the upper structures 5a,5b (particularly, the surface-side member 6) are deformed by thermal strain. Therefore, by separating the upper structure 5a and the upper structure 5b at a specific interval and disposing the filling member 8 between the upper structure 5a and the upper structure 5b, the risk of deformation of the member for ejecting gas for suspending the substrate 3 due to the influence of heat conduction from the substrate heating region 28 can be reduced, and therefore, variation in the height position of the substrate 3 moving while being suspended on the stage 2 can be suppressed or prevented.

In the second example, since the filling member 8 is not disposed between the upper structures 5a and 5b, the inert gas injected from the opening 27 of the seal box 26 flows downward between the upper structure 5a and the upper structure 5b when the substrate 3 is not present above the gap between the upper structure 5a and the upper structure 5b (stage of fig. 10), as described with reference to fig. 9 to 11. In this case, the inert gas is less likely to diffuse in the horizontal direction (particularly, the X direction) on the upper surfaces of the upper structures 5a,5b, and therefore, the inert gas atmosphere in a plan view is not stable, so that the laser light 20a may be irradiated to the substrate 3 (amorphous silicon film 3a) in an atmosphere mixed with atmospheric components.

In the present embodiment, as shown in fig. 12, while a laser process (a process of irradiating a laser beam 20a) is performed on a certain substrate 3, an inert gas injected from the opening 27 of the seal box 26 is injected to the substrate 3 (amorphous silicon film 3a) and spreads in a horizontal direction in a space above the substrate 3. In addition, during the period from the end of laser processing on a certain substrate 3 to the start of laser processing on the next substrate 3, as shown in fig. 13, the substrate 3 does not exist above the gap between the upper structure 5a and the upper structure 5b, and the filler block 8 is disposed between the upper structure 5a and the upper structure 5 b. At this time, as is clear from fig. 13, since the end where the gas travels does not exist in the substrate 3, the inert gas injected from the opening 27 of the seal box 26 travels toward the stage 2 without being blocked by the substrate 3, and therefore, although the inert gas can travel toward the gap between the upper structure 5a and the upper structure 5b, the flow of the gas is restricted by the filling member 8. That is, in the present embodiment, the inert gas injected from the opening 27 of the seal box 26 does not need to flow between the upper structure 5a and the upper structure 5b to a position below the filling unit 8 (more specifically, below the upper surface of the filling unit 8). Therefore, the inert gas injected from the opening 27 of the seal box 26 does not need to flow downward between the upper structure 5a and the upper structure 5b, and is easily diffused in the horizontal direction (particularly, the X direction) on the upper surfaces of the upper structures 5a and 5b, and therefore, the inert gas atmosphere can reach a position (refer to fig. 13) separated from the gap between the upper structures 5a and 5b to a certain extent (separated from each other in the X direction) in a plan view. Therefore, the range of the inert gas atmosphere in a plan view is widened.

The next substrate 3 is moved while being suspended on the stage 2, and as shown in fig. 14, when the end of the substrate 3 reaches above the gap between the upper structure 5a and the upper structure 5b, the laser processing (processing of irradiating the laser beam 20a) on the substrate 3 is started. At this time, the range of the inert gas is widened in the plan view as described above also in the stage immediately after the start of the laser processing on the substrate 3 (i.e., the stage of irradiating the end portion of the substrate 3 with the laser beam 20a as shown in fig. 14), and therefore the inert gas atmosphere in the vicinity of the laser irradiation region (20b) is stable, and the atmospheric components are less likely to be mixed. Therefore, in the same manner as in the stage immediately after the start of the laser processing on the substrate 3 (i.e., the stage shown in fig. 4), the laser beam 20a is irradiated to the substrate 3 (amorphous silicon film 3a) in an inert gas atmosphere in which almost no atmospheric component is mixed.

When the substrate 3 is continuously moved further from the state of fig. 14 to the state of fig. 12, the inert gas injected from the opening 27 of the seal box 26 is diffused in the horizontal direction on the substrate 3. At this stage (stage of fig. 12), too, the range of the inert gas atmosphere is widened in the plan view, and therefore, the inert gas atmosphere in the vicinity of the laser light irradiation region (20a) is stable, and the atmosphere component is hard to be mixed, so that the laser light 20a is irradiated to the substrate 3 (amorphous silicon film 3a) in the atmosphere in which the inert gas is hardly mixed.

Therefore, in the present embodiment, it is possible to suppress or prevent the laser processing conditions for the substrate 3 (amorphous silicon film 3a) from varying in the vicinity of the end portion of the substrate 3 and in the position away from the end portion. Specifically, in the case of performing laser processing on the plurality of substrates 3, the laser light 20a may be irradiated to the substrate 3 (amorphous silicon film 3a) in an atmosphere in which an inert gas is hardly mixed during a period from the start of the laser processing performed on each substrate 3 until the end of the laser processing performed on the plurality of substrates 3. Therefore, the atmosphere when the laser light 20a is irradiated (the atmosphere in the vicinity of the laser irradiation region 20b) can be made the same in the vicinity of the end portion of the substrate 3 and the position distant from the end portion, so that the degree of crystallization when the amorphous silicon film 3a is converted into a polysilicon film can be made the same (uniform) for each substrate 3. For example, when the amorphous silicon film 3a on the substrate 3 is converted into a polysilicon film by laser processing, the crystal grain size of the polysilicon film near the end of the substrate 3 and the crystal grain size of the polysilicon film at a position distant from the end of the substrate 3 (for example, near the center of the substrate 3) can be made the same, and the crystal grain sizes in the polysilicon film on the substrate 3 can be made uniform. Therefore, the reliability of an element (e.g., a thin film transistor) or a device (e.g., a display device) using the polysilicon film can be improved.

In addition, in the present embodiment, since the laser light 20a is prevented from being irradiated to the amorphous silicon film 3a in the atmosphere mixed with the atmospheric components, it is possible to prevent the occurrence of an unnecessary reaction when the amorphous silicon film 3a is converted into a polysilicon film. Thereby, the reliability of an element (e.g., a thin film transistor) or a device (e.g., a display device) using the polysilicon film can be improved.

Further, it is preferable that the upper surface of the filling member 8 disposed between the upper structures 5a and 5b is lower than the respective upper surfaces of the upper structures 5a and 5b (i.e., the upper surfaces of the surface-side members 6 constituting the upper structures 5a and 5b, respectively). The reason for this is as follows.

If the upper surface of the fill assembly 8 is located higher than the respective upper surfaces of the upper structures 5a,5b, a state is created in which a portion of the fill assembly 8 protrudes from the respective upper surfaces of the upper structures 5a,5b, so that the fill assembly 8 may hinder the movement of the substrate 3 moving in the horizontal direction while being suspended on the stage 2. Therefore, by setting the height position of the upper surface of the filler block 8 lower than the respective upper surfaces of the upper structures 5a,5b, it is possible to avoid the filler block 8 from interfering with the movement of the substrate 3 moving in the horizontal direction while being suspended on the stage 2.

Furthermore, if the height position of the upper surface of the fill assembly 8 is made lower than the respective upper surfaces of the upper structures 5a,5b, the distance from the substrate heating zone 28 to the upper surface of the fill assembly 8 can be increased without changing the spacing between the upper surfaces of the upper structures 5a,5b (surface side assembly 6) and the lower surface of the substrate 3. This reduces the height of the upper surface of the fill assembly 8 below the substrate heating region 28, and prevents heat from being transferred from the substrate heating region 28 to the stage 2, thereby reducing the risk of deformation of the stage 2 due to the influence of heat conduction from the substrate heating region 28.

That is, since the heat transferred from the substrate heating region 28 to the filling member 8 is also transferred from the filling member 8 to the upper structures 5a and 5b, the heat is not easily transferred from the substrate heating region 28 to the filling member 8, and therefore, the temperature rise of the upper structures 5a and 5b is suppressed, and the risk of deformation of the upper structures 5a and 5b (particularly, the surface side member 6) is reduced. Therefore, by making the height position of the upper surface of the filling member 8 lower than the respective upper surfaces of the upper structures 5a,5b, heat is made less likely to be transferred from the substrate heating region 28 to the filling member 8, whereby temperature rise of the upper structures 5a,5b can be suppressed, and therefore the risk of deformation of the upper structures 5a,5b (particularly the surface-side member 6) can be reduced. Further, since the filling unit 8 is not a unit for ejecting gas for floating the substrate 3, even if the height position of the upper surface of the filling unit 8 is made lower than the respective upper surfaces of the upper structures 5a,5b, the phenomenon that the substrate 3 is floated and moved is not adversely affected.

Furthermore, the height difference h1 between the upper surface of the packing element 8 and the respective upper surface of the superstructure 5a,5b is preferably 40mm or less (h1 ≦ 40 mm). Whereby the effect of restricting the flow of the inert gas can be easily obtained by the packing member 8. Therefore, when the substrate 3 is not present above the gap between the upper structure 5a and the upper structure 5b, the inert gas injected from the opening 27 can be diffused in the horizontal direction (particularly, the X direction) on the upper surfaces of the upper structures 5a and 5b, and the range of the inert gas atmosphere in a plan view can be expanded more reliably.

Further, the upper surface of the upper structure 5a and the upper surface of the upper structure 5b are preferably located at the same height position with each other. Thereby, it is possible to make it easy to control the height position of the substrate 3 at the position irradiated with the laser light 20a to a specific height, and to control the laser processing conditions to the substrate 3 (amorphous silicon film 3a) to specific conditions.

The filling unit 8 also has a function of preventing the inert gas injected from the opening 27 of the seal box 26 from flowing (flowing) between the upper structure 5a and the upper structure 5b to a lower side than the filling unit 8. The filling member 8 is therefore preferably in contact with the superstructure 5a,5b, and therefore, preferably, the side of the filling member 8 (the side facing the superstructure 5a) is in contact with the side of the superstructure 5a (the side facing the filling member 8), and the side of the filling member 8 (the side facing the superstructure 5b) is in contact with the side of the superstructure 5b (the side facing the filling member 8). This can more reliably prevent the inert gas injected from the opening 27 of the seal box 26 from flowing between the upper structure 5a and the upper structure 5b to the lower side than the filling unit 8. In the case where the filler member 8 contacts the upper structures 5a,5b, the dimension of the filler member 8 in the X direction substantially coincides with the interval between the upper structures 5a and 5b (the interval in the X direction).

Further, in a plan view, the filler unit 8 is preferably disposed over the entire region between the upper structures 5a and 5 b. That is, preferably, in a plan view, the filling member 8 is present not only at a part of the position along the Y direction between the upper structure 5a and the upper structure 5b, but the filling member 8 is present (extends) throughout the entirety of the position along the Y direction between the upper structure 5a and the upper structure 5 b. Thereby, the effect of restricting the flow of the inert gas by the packing member 8 can be obtained over the entire area between the upper structures 5a and 5 b. Therefore, when the substrate 3 is not present above the gap between the upper structure 5a and the upper structure 5b, the inert gas injected from the opening 27 is easily diffused in the horizontal direction (particularly, the X direction) from the upper surfaces of the upper structures 5a and 5b, and the range of the inert gas atmosphere in a plan view can be more reliably widened.

Furthermore, the filling element 8 extends between the upper structure 5a and the upper structure 5b along the Y direction, that is to say is arranged along the Y direction. The Y direction is the longitudinal direction of the laser beam 20a irradiated to the substrate 3 (amorphous silicon film 3 a). That is, the filling member 8 is disposed between the upper structure 5a and the upper structure 5b along the longitudinal direction of the laser beam 20a (laser irradiation region 20 b). This makes it possible to easily fill the gap between the upper structure 5a and the upper structure 5b separated in the X direction with the filling member 8 in the Y direction, and the filling member 8 can surely obtain the effect of restricting the flow of the inert gas in the Y direction.

The opening 27 of the seal box 26 also functions as an injection port (ejection port) for the inert gas. The inert gas injected from the opening 27 of the seal box 26 should be supplied to the laser irradiation region 20b and its vicinity. The reason for this is that the inert gas ejected from the opening 27 of the sealing box 26 is used to change the atmosphere in the laser light irradiation region 20b and the vicinity thereof to the inert gas atmosphere, and the laser light 20a is irradiated to the substrate 3 (amorphous silicon film 3a) in the inert gas atmosphere. Therefore, the opening 27 of the seal box 26 is made to overlap the laser irradiation region 20b and thus the focal position of the laser light 20a in a plan view. In a plan view, it is more preferable that the laser irradiation region 20b is surrounded by the opening 27 of the seal box 26. Thereby making it easy to supply the inert gas from the opening portion 27 of the inert gas sealing box 26 to the laser irradiation region 20b and the vicinity thereof. In addition, when the opening 27 of the seal box 26 overlaps the laser irradiation region 20b in a plan view, the opening 27 of the seal box 26 overlaps the gap (the filling block 8) between the upper structure 5a and the upper structure 5b in a plan view.

The plurality of upper structures 5 having the stage 2 include an upper structure 5c in addition to the upper structures 5a and 5 b. In the case of fig. 2, the superstructure 5c is arranged in the X direction with the superstructures 5a,5b adjacent to each other in the X direction being interposed therebetween, the superstructure 5c being adjacent to the superstructure 5a in the X direction, the superstructure 5a being adjacent to the superstructure 5b in the X direction, and the superstructure 5b being adjacent to the superstructure 5c in the X direction.

The filler member 8 is disposed between the upper structures 5a and 5b adjacent to each other in the X direction as described above. However, between adjacent superstructure 5c,5 a; and between the adjacent upper structures 5b,5c, whether or not the filling member 8 is provided. This is because, in a plan view, the region between the upper structures 5a and 5b overlaps the laser irradiation region 20b, but in a plan view, the region between the upper structures 5a and 5c and the region between the upper structures 5b and 5c do not overlap the laser irradiation region 20b and are spaced from the laser irradiation region 20b to some extent.

That is, the inert gas injected from the opening portion 27 of the seal box 26 should be supplied to the laser irradiation region 20b and the vicinity thereof, and therefore, the inert gas is injected from the opening portion 27 of the seal box 26 toward the laser irradiation region 20 b; in other words, the jet is directed from the opening 27 of the seal box 26 towards the gap between the upper structures 5a,5 b. Therefore, without the filler element 8 between the upper structures 5a,5b, the problems described above with reference to fig. 9 to 11 arise; the problem described with reference to fig. 9 to 11 does not occur between the adjacent upper structures 5c,5a and between the adjacent upper structures 5b,5c even if the filling member 8 does not exist. Therefore, even in the case where no filler member 8 is provided between the upper structures 5a,5c and between the upper structures 5b,5c, the problem described above with reference to fig. 9 to 11 can be improved or solved by providing the filler member 8 between the upper structures 5a,5 b. In addition, in the case where nothing corresponding to the filler member 8 is provided between the upper structures 5a,5c and between the upper structures 5b,5c, the structure of the stage 2 can be further simplified, so that the stage 2 can be easily assembled. The adjacent upper structures 5c may be arranged between each other, between the adjacent upper structures 5a and 5c, and between the adjacent upper structures 5b and 5c, similarly, without providing the filler 8.

The upper structures 5a,5b, and 5c each have a function of ejecting gas (gas) from the upper surface (front surface) and levitating the substrate 3 by the ejected gas. However, the mechanism of the upper structure 5c for injecting gas may also be different from the upper structures 5a,5 b. For example, as described above, the upper structures 5a and 5b can suck the gas on the front surface side module 6 from the through-holes 13a of the front surface side module 6 to adsorb the substrate 3 while ejecting the gas from the micropores (pores constituting the porous body) of the front surface side module 6 constituting the upper structures 5a and 5b to suspend the substrate 3. That is, in the upper structures 5a and 5b, two operations of gas injection and gas suction are performed from the upper surface, and the balance thereof is adjusted. On the other hand, in the upper structure 5c, although the gas is ejected from the plurality of through holes provided in the surface side member (corresponding to the surface side member 6) constituting the upper structure 5c, the upper structure 5c is not provided with a mechanism for sucking the gas on the surface side member. Therefore, the surface-side member constituting the upper structure 5c may not be a porous body, and for example, a metal plate in which a plurality of (many) through-holes are formed may be used.

So that it is easy to control the height position of the substrate 3 suspended on the stage 2, not the upper structure 5c that ejects gas from the upper surface but does not suck gas, but the upper structures 5a,5b that can perform both gas ejection and gas suction from the upper surface. On the other hand, it is desirable that the portion where the height position of the substrate 3 suspended on the stage 2 is accurately controlled be the area near the laser irradiation area 20 b. Therefore, with respect to the upper structures 5a,5b close to the laser irradiation region 20b, it is possible to more accurately control the height position of the substrate 3 at the position where the laser light 20a is irradiated by enabling both gas ejection and gas suction from the upper surface, so that it is easy to control the laser processing conditions. On the other hand, the upper structure 5c located away from the position irradiated with the laser beam 20a is configured to be simplified in structure by performing gas ejection from the upper surface but not performing gas suction. This makes it easy to prepare the upper structure 5c, and therefore, the manufacturing cost of the laser processing apparatus can be reduced.

< example of display device >

The laser processing apparatus 1 of the present embodiment is applicable to, for example, a manufacturing process of a display device.

Fig. 15 is an external view showing a large-screen television as a liquid crystal display device; fig. 16 is an external view showing a mobile communication device as a liquid crystal display device. A large-screen television 31 shown in fig. 15 and a smartphone 32 as a mobile communication device shown in fig. 16 are examples of display devices in the present embodiment.

The display devices of the present embodiment described above are intended for display devices of various sizes. The display device in this embodiment is not limited to a liquid crystal display device, and an organic EL display device, for example, may be used.

< manufacturing Process of display device >

Next, the outline of the manufacturing process of the display device in this embodiment will be briefly described with reference to fig. 17, taking the manufacturing process of the liquid crystal display device as an example. Fig. 17 is a flowchart showing a flow of a manufacturing process for manufacturing the display device of the present embodiment.

First, a Thin Film Transistor (TFT) glass substrate and a color filter glass substrate are formed, respectively.

Specifically, a glass substrate is prepared, and a Thin Film Transistor (TFT) is formed on the glass substrate, thereby obtaining a TFT glass substrate (a TFT-formed glass substrate) (step S1 in fig. 17). The thin film transistor forming step includes laser processing using the laser processing apparatus 1, and the glass substrate corresponds to the substrate 3 and a substrate 50 described later.

Next, after the alignment film is applied to the surface of the TFT glass substrate (step S2 of fig. 17), a rubbing process is applied (step S3 of fig. 17). Thereafter, a sealant is applied to the surface of the TFT glass substrate (step S4 of fig. 17).

On the other hand, another glass substrate is prepared, and a color filter is formed on the glass substrate to obtain a color filter substrate (a glass substrate on which a color filter is formed) (step S5 of fig. 17).

Next, after the surface of the color filter glass substrate is coated with the alignment film (step S6 in fig. 17), a rubbing process is applied (step S7 in fig. 17). Thereafter, a gap agent is applied to the surface of the color filter substrate (step S8 of fig. 17).

Next, after the TFT glass substrate and the color filter glass substrate are bonded (step S9 in fig. 17), a dicing (scriber) process is performed (step S10 in fig. 17). Thereby, the attached TFT glass substrate and color filter glass substrate are cut into the size of each liquid crystal display device.

Then, after injecting the liquid crystal into the gap between the TFT glass substrate and the color filter glass substrate secured with the sealant and the gap agent (step S11 in fig. 17), the gap is sealed (step S12 in fig. 17).

Next, a pair of polarizing plates are bonded so as to sandwich the bonded TFT glass substrate and color filter glass substrate (step S13 in fig. 17). A liquid crystal display panel can be manufactured in this manner. After the liquid crystal display panel is subjected to the press driving (step S14 in fig. 17), a backlight is further mounted (step S15 in fig. 17). The liquid crystal display device is completed in this way (step S16 of fig. 17).

Detailed construction of display device

Next, a detailed configuration of the display device according to the present embodiment will be described. Fig. 18 is a diagram showing a configuration example of the display device of the present embodiment.

In the configuration example shown in fig. 18, the display device includes: a pixel unit (pixel region) 41 in which a plurality of pixels 40 are arranged in a matrix (row and column); the scanning line drive circuit 42; the signal line driver circuit 43. The pixel 40 determines each of the row selecting states or the non-selecting states by a scanning signal supplied through a line 44 (scanning line) electrically connected to the scanning line driving circuit 42. Further, a pixel signal (image signal) is supplied to the pixel 40 selected by the scanning signal via a wiring 45 (signal line) electrically connected to the signal line driver circuit 43.

Fig. 19 is a diagram showing an example of the structure of the pixel shown in fig. 18. As shown in fig. 19, the pixel 40 includes: a thin film transistor 46 functioning as a switching element for controlling a pixel; and a liquid crystal element 47 functioning as a display unit. For example, the liquid crystal element 47 has a structure in which a liquid crystal material is sandwiched between a pair of electrodes (a pixel electrode and an opposite electrode).

In the thin film transistor 46, a gate electrode is electrically connected to a wiring 44 (scanning line), one of a source and a drain is electrically connected to a wiring 45A (signal line), and the other is electrically connected to a pixel electrode of the liquid crystal element 47.

< device Structure of thin film transistor >

The device structure of the thin film transistor 46 will be described next. Fig. 20 is a cross-sectional view showing a device structure of a thin film transistor.

The thin film transistor 46 shown in fig. 20 has a top gate type structure. The thin film transistor 46 has a channel film 51 formed on a substrate 50 (e.g., a glass substrate) having an insulating surface. The channel film 51 is formed of a polycrystalline silicon film as a polycrystalline semiconductor film. Further, a gate insulating film 52 is formed on the substrate 50 so as to cover the channel film 51, and a gate electrode 53 is formed on the gate insulating film 52. An interlayer insulating film 54 is formed on the gate insulating film 52 so as to cover the gate electrode 53, and a source electrode 55a and a drain electrode 55b are formed on the interlayer insulating film 54. The source electrode 55a and the drain electrode 55b are connected to the channel film 51 through via holes provided in the interlayer insulating film 54 and the gate insulating film 52, respectively. The protective film 56 is formed so as to cover the interlayer insulating film 54, the source electrode 54, and the drain electrode 55 b. The thin film transistor 46 is formed in the above manner.

In addition, although the thin film transistor 46 has a top gate structure, the thin film transistor 46 may have a bottom gate structure as another type.

< manufacturing Process of thin film transistor >

The following describes the manufacturing steps for the thin film transistor (46). Fig. 21 is a flowchart showing a flow of manufacturing steps of the thin film transistor.

First, for example, a channel film (51) is formed on a glass substrate (corresponding to the above-described substrates 3,50), which is a substrate formed of glass (step S21 of fig. 21). Next, a gate insulating film (52) is formed on the glass substrate (3,50) so as to cover the channel film (51) (step S22 in fig. 21). Next, a gate electrode (53) is formed on the gate insulating film (52) (step S23 in FIG. 21). After the gate electrode (53) is formed, impurities for a source and a drain may be implanted into the channel film (51). An interlayer insulating film (54) is then formed (step S24 in fig. 21). Next, a via hole is formed prior to the interlayer insulating film (54) and the gate insulating film (52), and then a source electrode (55a) and a drain electrode (55b) are formed (step S25 of fig. 21). Next, the protective film (56) is formed (step S26 in fig. 21). A thin film transistor can be manufactured in the above manner.

< channel film formation step >

The details of the step of forming the channel film (51) are described herein. Fig. 22 is a flowchart illustrating a flow of a channel film forming step.

First, an amorphous silicon film is formed on a glass substrate (3,50) (step S31 in fig. 22). Thereafter, the amorphous silicon film is irradiated with laser light (20a) to perform laser annealing (step S32 in fig. 22). Thereby causing the amorphous silicon film to be heated, with the result that a polysilicon film is formed from the amorphous silicon film (step S33 of fig. 22). That is, the amorphous silicon film is transformed (degenerated) into a polycrystalline silicon film. In this way, a channel film (51) in which an amorphous silicon film is transformed (degenerated) can be formed. After the laser annealing treatment, the channel film (51) formed of the polysilicon film may be patterned into a specific shape by using a photolithography technique, an etching technique, or the like.

Since the channel film has a function as a channel for electrons, the characteristics of the channel film affect the performance of the thin film transistor. Since polysilicon has higher mobility than amorphous silicon, the performance of the thin film transistor can be improved by forming the channel film from a polysilicon film. Therefore, in the present embodiment, the channel film is formed of a polysilicon film. Specifically, as described above, after the amorphous silicon film is formed, laser annealing is applied to the amorphous silicon film, whereby the amorphous silicon film is converted into a polysilicon film. Therefore, laser annealing (heat treatment) is necessary to form the channel film from the polysilicon film, and a laser processing apparatus is necessary to perform the laser annealing. In the present embodiment, the laser processing apparatus 1 can be used to perform the laser annealing process.

In the case of using the laser processing apparatus 1 of the present embodiment, the substrate 3 is moved (conveyed) in the horizontal direction while suspending the substrate 3 on the stage 2, and the laser light 20a is irradiated to the moved substrate 3 (more specifically, the amorphous silicon film 3a on the substrate 3), whereby the amorphous silicon film 3a formed on the substrate 3 is converted into a polysilicon film. The polysilicon film corresponds to the channel film (51). Since it is not necessary to move the stage 2, when laser processing is applied to a plurality of substrates, the processing time for leveling a single substrate can be shortened, and the throughput can be improved.

In the laser processing apparatus 1 of the present embodiment, the upper structure 5a and the upper structure 5b are separated from each other, and the focal position of the laser beam 20a (the laser beam irradiation region in the substrate 3) is overlapped with the gap (the filling member 8) between the upper structure 5a and the upper structure 5b in a plan view, whereby the upper structures 5a and 5b are suppressed or prevented from being deformed by thermal strain. This can suppress or prevent the variation in the height position of the substrate 3 that moves while being suspended on the stage 2. In the laser processing apparatus 1 of the present embodiment, as described above, the filling member 8 is disposed so as to fill the gap between the upper structure 5a and the upper structure 5b, whereby the problems described above with reference to fig. 9 to 11 can be solved or improved.

Therefore, by using the laser processing apparatus 1 of the present embodiment, it is possible to suppress or prevent the conditions of the laser processing performed on the substrate 3 (amorphous silicon film 3a) from varying. This can suppress or prevent the characteristic fluctuation of the polysilicon film when the amorphous silicon film 3a formed on the substrate 3 by the laser processing is converted to the polysilicon film. Therefore, the variation of the characteristics of the channel film (51) formed of the polysilicon film can be suppressed or prevented, and the variation of the characteristics of the thin film transistor (46) can be suppressed or prevented. Therefore, the performance and reliability of the display device with the thin film transistor (46) can be improved.

< modification example >

Next, a first modification of the laser processing apparatus 1 according to the present embodiment will be described.

Fig. 23 is a sectional view of a main part showing a first modification of the laser processing apparatus 1 according to the present embodiment, which corresponds to fig. 4.

In the case of fig. 4 described above, the upper structures 5a,5b and the packing member 8 disposed between the upper structures 5a,5b are disposed on the upper surface of the seat plate 4, and the respective lower surfaces of the upper structures 5a,5b and the packing member 8 are in contact with the upper surface of the seat plate 4.

In contrast, in the case of fig. 23 (first modification), the lower surface of the packing member 8 is a predetermined distance away, and a predetermined space in which the packing member 8 does not exist exists between the packing member 8 disposed between the upper structures 5a and 5b and the upper portion of the upper surface of the seat plate 4. That is, in the case of fig. 4 and 23, although the height positions of the respective upper surfaces of the upper structures 5a,5b and the fill elements 8 are the same, the fill elements of fig. 23 are smaller than the fill elements 8 of fig. 4 with respect to the dimension in the height direction (Z direction) of the fill elements 8, and therefore the lower surface of the fill elements 8 of fig. 23 is higher than the lower surface of the fill elements 8 of fig. 4 with respect to the height positions of the lower surfaces of the fill elements 8.

In the same manner as in the case of fig. 23 (first modification), the filling unit 8 has a function of preventing the inert gas ejected from the opening 27 of the seal box 26 from flowing (flowing) between the upper structure 5a and the upper structure 5b to a lower side than the filling unit 8. That is, in the case of fig. 23 (first modification), similarly, the filling unit 8 is present between the upper structure 5a and the upper structure 5b, whereby the inert gas injected from the opening 27 of the seal box 26 does not flow to a position below the filling unit 8 (more specifically, below the upper surface of the filling unit 8). Therefore, even if a space where the filling unit 8 does not exist exists between the filling unit 8 and the seat plate 4 between the upper structure 5a and the upper structure 5b, the flow of the inert gas ejected from the opening 27 of the seal box 26 is not affected. In the case of fig. 23 (first modification), too, the filler member 8 is preferably in contact with the upper structures 5a,5b, and therefore, it is preferable that the side of the filler member 8 (the side facing the upper structure 5a) is in contact with the side of the upper structure 5a (the side facing the filler member 8), and the side of the filler member 8 (the side facing the upper structure 5b) is in contact with the side of the upper structure 5b (the side facing the filler member 8).

As a further modification, the filler unit 8 may be present not only between the upper structures 5a and 5b but also below the upper structures 5a and 5b (i.e., between the upper structures 5a and 5b and the seat plate 4). In this case, the filling assembly 8 extends from between the superstructure 5a and the superstructure 5b up to between the superstructures 5a,5b and the seat plate 4. In any case, the filler assembly 8 has a portion disposed between (sandwiched by) the upper structures 5a,5 b.

Next, a second modification of the laser processing apparatus 1 according to the present embodiment will be described.

Fig. 24 is a plan view showing stage 2 of laser processing apparatus 1 according to the second modification, fig. 25 is a plan view of a main part of laser processing apparatus 1 according to the second modification, and fig. 26 is a sectional view of a main part of laser processing apparatus 1 according to the second modification. Fig. 24 is a plan view corresponding to fig. 2 (a). Fig. 25 is a partially enlarged plan view showing a part of fig. 24 in an enlarged manner, and corresponds to fig. 3. In fig. 25, the laser irradiation region 20b is hatched. FIG. 26 is a cross-sectional view generally corresponding to the position indicated by line C1-C1 in FIG. 25. In addition, the cross-sectional view taken along line C2-C2, the cross-sectional view taken along line C3-C3, the cross-sectional view taken along line C4-C4, and the cross-sectional view taken along line C5-C5 shown in FIG. 26 are almost the same as those shown in FIG. 4, and redundant drawings are omitted here.

In the case of fig. 2, the dimensions of the upper structures 5a,5b, and 5c in the Y direction are respectively larger than or equal to the dimensions of the substrate 3 in the Y direction, and the substrate 3 is moved in the X direction while being suspended on a pair of upper structures 5a and 5b adjacent to each other in the X direction, and the laser beam 20a is irradiated onto the moving substrate 3 (more specifically, the amorphous silicon film 3a on the substrate 3). The filler block 8 described in embodiment 1 is disposed between the adjacent upper structures 5a and 5b in the X direction.

In contrast, in the case of fig. 24 to 26 (second modification), the dimensions of the upper structures 5a,5b,5 in the Y direction are respectively smaller than the dimensions of the substrate 3 in the Y direction. In addition, a plurality of pairs of upper structures 5a,5b are arranged in the Y direction so as to be adjacent to each other in the X direction with the filler block 8 interposed therebetween. Since the filler members 8 are disposed between the adjacent upper structures 5a,5b in the X direction, the filler members 8 between the upper structures 5a,5b are also aligned in the Y direction corresponding to the alignment of the plurality of pairs of upper structures 5a,5b in the Y direction. That is, in the case of fig. 24 to 26, the upper structure 5a, the upper structure 5b and the filling members 8 therebetween are 1 set, and a plurality of sets are arranged in the Y direction. In the cases of fig. 24 to 26, 4 groups are arranged in the Y direction, and the number of groups arranged in the Y direction is not limited to 4 groups. Further, in the case of fig. 24, since not only the upper structures 5a,5b but also the upper structures 5c other than the upper structures 5a,5b are smaller in size in the Y direction than the substrate 3, a plurality of upper structures 5c are also arranged in the Y direction.

Since the respective configurations of the upper structures 5a and 5b and the filler block 8 are substantially the same as those described with reference to fig. 3 to 5 in the case of fig. 24 to 26, redundant description thereof will be omitted here.

In the case of fig. 24 to 26 (second modification), the size (planar area) of each of the upper structures 5a,5b,5c can be made small, and therefore, the upper structures 5a,5b,5c are easily prepared, and the stage 2 is easily assembled. Therefore, the laser processing apparatus is easily manufactured.

In fig. 24 to 26 (second modification), the filling members 8 arranged in the Y direction may be integrated. In this case, a plurality of upper structures 5a are formed arranged on the side of one side of the common filling member 8 extending in the Y direction; and a plurality of upper structures 5b are arranged on the other side surface. That is, a plurality of sets of the upper structures 5a,5b are arranged, and a common filling member 8 extending in the Y direction is disposed therebetween.

Further, the filling assembly 8 in the case of fig. 23 (first modification) described above may also be applied to the case of fig. 24 to 26 (second modification).

Next, a third modification of the laser processing apparatus 1 according to the present embodiment will be described. The height of the packing member 8 (height position of the upper surface) may not be fixed. Fig. 27 and 28 are sectional views of essential parts of a laser processing apparatus 1 according to a third modification, and show an example in which the height of the filler block 8 is not fixed. Fig. 27 is a cross-sectional view corresponding to fig. 5; fig. 28 is a cross-sectional view corresponding to fig. 26. The top view in section of fig. 27 is substantially the same as that of fig. 3; the plan view in fig. 28 is substantially the same as that of fig. 25.

In the case of fig. 27, the filler unit 8 is arranged between the upper structures 5a,5b of one set, as in the case of fig. 3 to 5 described above. In the case of fig. 5 described above, the height of the filler member 8 (the height position of the upper surface) is substantially constant irrespective of the position in the Y direction, and in the case of fig. 27, the height of the filler member 8 (the height position of the upper surface) is not constant. Specifically, in the case of fig. 27, the height of the packing member 8 (the height position of the upper surface) is increased at both ends in the Y direction, and the height of the packing member 8 (the height position of the upper surface) is set lower than both ends in the Y direction at positions other than both ends (i.e., more inward than both ends in the Y direction). Further, when the substrate 3 is moved in the Y direction while being floated, it is preferable that the regions (both ends in the Y direction) where the height of the filling member 8 is high do not overlap with the substrate 3 in a plan view.

In the case of fig. 28, similarly to the case of fig. 25 and 26, a plurality of upper structures 5a and 5b corresponding to a plurality of pairs are arranged in the Y direction, and a plurality of packing elements 8 are arranged between the upper structures 5a and 5b in the Y direction. That is, in the case of fig. 28, the upper structure 5a, the upper structure 5b, and the filling members 8 therebetween are 1 set, and are arranged in plural sets in the Y direction, as in the case of fig. 25 and 26 described above. In the case of fig. 26, the heights (height positions of the upper surfaces) of the plurality of packing elements 8 arranged in the Y direction are substantially constant regardless of the position in the Y direction, and in the case of fig. 28, the heights (height positions of the upper surfaces) of the plurality of packing elements 8 arranged in the Y direction are not constant. Specifically, in the case of fig. 28, the height of the filling member 8 (the height position of the upper surface) is raised at both ends in the Y direction of the plurality of filling members 8 arranged in the Y direction as a whole, and the filling members 8 are set lower than both ends at positions outside both ends in the Y direction (i.e., inside both ends in the Y direction). Further, when the substrate 3 is moved in the Y direction while being floated, it is preferable that the regions (both ends in the Y direction) where the height of the filling member 8 is increased do not overlap with the substrate 3 in a plan view.

In the case of fig. 27 and the case of fig. 28, by making the height of the filling member 8 at both ends in the Y direction (height position of the upper surface) higher, the effect of restricting the flow of the inert gas supplied from the opening portion 27 in the Y direction is obtained with the region where the height of the filling member 8 is higher (both ends in the Y direction). This makes it easy for the inert gas ejected from the opening 27 to diffuse in the horizontal direction (particularly, the X direction) from the upper surfaces of the upper structures 5a,5b when there is no substrate 3 above the gap between the upper structures 5a and 5 b.

Next, a fourth modification of the laser processing apparatus 1 according to the present embodiment will be described. The fourth modification can be applied to any of the cases of fig. 3 to 5 described above, fig. 23 (first modification) described above, fig. 24 to 26 (second modification), and fig. 27 and 28 (third modification).

The fourth modification corresponds to the case where the filling member 8 has a structure capable of ejecting gas from the upper surface thereof. As for the gas ejected from the upper surface of the filling member 8, for example, an inert gas typified by nitrogen gas can be used.

In the case of the fourth modification, since the effect of restricting the flow (downward flow) of the inert gas injected from the opening portion 27 of the seal box 26 can be obtained by the gas injected from the upper surface of the filling member 8, when the substrate 3 is not present above the gap between the upper structure 5a and the upper structure 5b, the inert gas injected from the opening portion 27 is more likely to be diffused in the horizontal direction (particularly, the X direction) on the upper surfaces of the upper structures 5a,5 b.

On the other hand, when the filling member 8 does not have a structure in which gas can be ejected from the upper surface thereof, that is, when gas is not ejected from the upper surface of the filling member 8, there is no case in which the gas ejected from the upper surface of the filling member 8 collides with the substrate 3. Since the influence of the gas ejected from the upper surface of the filling member 8 can be thereby eliminated, the height position of the substrate 3 at the position of the irradiation laser 20a can be controlled with certainty by gas ejection and suction from the upper surfaces of the upper structures 5a,5 b. It is easy to control the laser processing conditions.

As described above, although the application completed by the present inventors is specifically described based on the embodiments thereof, the present application is not limited to the embodiments described above, and it is apparent that various modifications can be made without departing from the scope of the present invention.