阅读说明：本技术 曝光装置 (Exposure device ) 是由 神田宽行 原望 于 2021-03-22 设计创作，主要内容包括：本发明提供一种曝光装置,该曝光装置具有：曝光部,在基体材料(9)上曝光图案；工作台(41),具有与基体材料(9)的一个主面接触的保持板(43),所述工作台(41)保持基体材料(9)；光学单元(5),通过经由设置于保持板(43)的开口(432)向基体材料(9)的该主面照射光,使在曝光部曝光图案中所参照的参照标记形成于该主面；以及气体供给部(71),向光学单元(5)中配置在最靠近保持板(43)侧的透光构件(541)与保持板(43)之间供给规定的气体。由气体供给部(71)供给的气体在透光构件(541)与保持板(43)之间横穿开口(432)而流动。由此,能够抑制不必要物质附着在透光构件(541)的表面。(The present invention provides an exposure apparatus, comprising: an exposure section that exposes a pattern on the base material (9); a table (41) having a holding plate (43) that is in contact with one main surface of a base material (9), the table (41) holding the base material (9); an optical unit (5) for forming a reference mark, which is referred to in an exposure pattern of an exposure section, on the main surface of the base material (9) by irradiating the main surface with light through an opening (432) provided in the holding plate (43); and a gas supply unit (71) that supplies a predetermined gas between the holding plate (43) and a light-transmitting member (541) disposed closest to the holding plate (43) in the optical unit (5). The gas supplied from the gas supply unit (71) flows between the light-transmitting member (541) and the holding plate (43) across the opening (432). This can prevent adhesion of unnecessary substances to the surface of the light-transmitting member (541).)

1. An exposure apparatus, wherein,

comprising:

an exposure section that exposes a pattern on a plate-like or film-like base material;

a table having a holding plate in contact with one main surface of the base material, the table holding the base material;

an optical unit configured to form a reference mark referred to in the exposure pattern of the exposure portion on the main surface of the base material by irradiating light to the main surface of the base material through an opening provided in the holding plate, or to photograph the reference mark formed on the main surface of the base material through the opening; and

a gas supply unit configured to supply a predetermined gas between the holding plate and a light-transmitting member disposed on the side closest to the holding plate in the optical unit,

the gas supplied by the gas supply portion flows across the opening between the light-transmitting member and the holding plate.

2. The exposure apparatus according to claim 1,

between the light transmitting member and the holding plate, a gas flow path that extends in one direction along the holding plate and through which the gas flows is provided.

3. The exposure apparatus according to claim 2,

the flow path area of the gas flow path is smaller than the area of the opening.

4. The exposure apparatus according to any one of claims 1 to 3,

the holding plate is an adsorption plate for adsorbing and holding the base material through a plurality of suction ports connected to the negative pressure space,

the gas crossing the opening flows into the negative pressure space.

5. The exposure apparatus according to any one of claims 1 to 3,

the optical unit is a mark forming part for forming the reference mark on the main surface of the base material,

the optical unit forms the reference mark on the other principal surface of the base material held by the stage when the exposure section exposes a pattern on the principal surface,

the exposure section refers to the reference mark when exposing the pattern on the main surface.

6. The exposure apparatus according to any one of claims 1 to 3,

the exposure apparatus further includes another optical unit having the same configuration as the optical unit, and configured to form a reference mark on the substrate through another opening provided in the holding plate or to photograph the reference mark of the substrate,

the optical unit is used for one kind of base material, and the other optical unit is used for other kinds of base materials.

7. An exposure apparatus, wherein,

comprising:

an exposure section that exposes a pattern on a plate-like or film-like base material;

a table having a holding plate in contact with one main surface of the base material, the table holding the base material;

an optical unit configured to form a reference mark, which is referred to in the exposure pattern of the exposure portion, on the main surface of the base material by irradiating light to the main surface of the base material through an opening provided in the holding plate; and

and a gas supply unit configured to supply a predetermined gas between the light-transmitting member disposed closest to the holding plate side in the optical unit and the holding plate, thereby making the inside of the opening positive in pressure.

Technical Field

The present invention relates to an exposure apparatus.

Background

Conventionally, an exposure apparatus for exposing a pattern on a substrate such as a printed circuit board is used. In the exposure apparatus, the position of an exposure pattern is determined on a base material based on a reference mark (alignment mark) formed in advance on the base material. Further, japanese patent application laid-open No. 2008-292915 discloses an exposure writing apparatus including: a mark forming part for forming alignment marks on two main surfaces of the substrate; and a drawing section that draws the circuit pattern on the substrate based on the alignment mark. In this apparatus, the circuit patterns on the two main surfaces are drawn in an accurate correspondence by the alignment marks on the two main surfaces.

Further, japanese patent No. 5793410 discloses a pattern forming apparatus for transferring a pattern carried on one main surface of a transparent flat plate body onto a substrate. In this apparatus, a holding stage is provided, which holds the flat plate body by vacuum suction while being in contact with the other main surface of the flat plate body. The holding stage has a light guide hole formed therein, and a transparent window member is provided inside the light guide hole. In the imaging unit, the flat plate body is imaged through the window member in order to align the flat plate body with the substrate. Further, the air pressure in the gap space surrounded by the other main surface of the flat plate body, the surface of the window member, and the side wall surface of the light guide hole is increased. This prevents the flat plate body from being deflected into the gap space.

In an exposure apparatus for holding a substrate on a holding plate, it is generally considered that when exposing a pattern on a first main surface of the substrate, a reference mark is formed on a second main surface in contact with the holding plate, and then the substrate is inverted and the reference mark is referred to, thereby exposing the pattern on the second main surface in accordance with the position of the pattern on the first main surface. In this case, an opening for forming the reference mark is provided in the holding plate, and a mark forming portion as an optical unit is disposed at a position facing the base material via the opening.

However, in such an exposure apparatus, there is a possibility that unnecessary substances such as dust enter the opening, and there is a possibility that the unnecessary substances adhere to the surface of the light-transmitting member disposed closest to the holding plate side in the mark forming portion. If an unnecessary substance adheres to the light-transmitting member, the reference mark cannot be formed properly. In addition, the same problem occurs in an exposure apparatus in which a mark imaging unit as another optical unit is disposed instead of the mark forming unit, and the reference mark on the main surface on the holding plate side is imaged by the mark imaging unit, and the pattern is exposed on the main surface on the opposite side.

Disclosure of Invention

The invention relates to an exposure apparatus, which aims to prevent unnecessary substances from attaching on the surface of a light-transmitting member in an optical unit.

In an exposure apparatus according to a preferred embodiment of the present invention, an exposure section exposes a pattern on a plate-like or film-like base material; a table having a holding plate in contact with one main surface of the base material, the table holding the base material; an optical unit configured to form a reference mark referred to in the exposure pattern of the exposure portion on the main surface of the base material by irradiating light to the main surface of the base material through an opening provided in the holding plate, or to photograph the reference mark formed on the main surface of the base material through the opening; and a gas supply unit configured to supply a predetermined gas between the holding plate and a light transmitting member disposed closest to the holding plate side in the optical unit, wherein the gas supplied by the gas supply unit flows between the light transmitting member and the holding plate across the opening.

In the exposure apparatus, it is possible to suppress adhesion of unnecessary substances to the surface of the light-transmitting member in the optical unit.

Preferably, between the light transmitting member and the holding plate, a gas flow path that extends in one direction along the holding plate and through which the gas flows is provided.

Preferably, the gas flow path has a flow path area smaller than an area of the opening.

Preferably, the holding plate is an adsorption plate that adsorbs and holds the base material through a plurality of suction ports connected to a negative pressure space into which the gas that has traversed the opening flows.

Preferably, the optical unit is a mark forming section that forms the reference mark on the main surface of the base material, the optical unit forms the reference mark on the main surface when the exposure section exposes a pattern on the other main surface of the base material held on the stage, and the exposure section refers to the reference mark when exposing the pattern on the main surface.

Preferably, the exposure apparatus further includes another optical unit having the same configuration as the optical unit, and the reference mark is formed on the base material through another opening provided in the holding plate, or the reference mark of the base material is photographed,

the optical unit is used for one kind of base material, and the other optical unit is used for other kinds of base materials.

An exposure apparatus according to another preferred embodiment of the present invention includes: an exposure section that exposes a pattern on a plate-like or film-like base material; a table having a holding plate in contact with one main surface of the base material, the table holding the base material; an optical unit configured to form a reference mark, which is referred to in the exposure pattern of the exposure portion, on the main surface of the base material by irradiating light to the main surface of the base material through an opening provided in the holding plate; and a gas supply unit configured to supply a predetermined gas between the light-transmitting member disposed closest to the holding plate side in the optical unit and the holding plate, thereby making the inside of the opening positive in pressure. In the exposure apparatus, it is possible to suppress adhesion of unnecessary substances to the surface of the light-transmitting member in the optical unit.

The above objects, other objects, features, aspects and advantages will become more apparent from the following detailed description of the present invention with reference to the accompanying drawings.

Drawings

Fig. 1 is a diagram showing a configuration of an exposure apparatus.

Fig. 2 is a plan view showing the table unit.

Fig. 3 is a diagram showing the inside of the table unit.

Fig. 4 is a sectional view of the table unit.

Fig. 5 is a sectional view of the table unit.

Fig. 6 is an enlarged view of the vicinity of the annular cover.

Fig. 7 is a diagram showing a flow of an operation of exposing a pattern on a base material.

Fig. 8 is a diagram showing the base material on the table unit.

Fig. 9 is a diagram showing a base material on the table unit.

Fig. 10 is a diagram showing a table unit in another example of the exposure apparatus.

Fig. 11 is a diagram showing a base material on the table unit.

Fig. 12 is a diagram showing a base material on the table unit.

Description of the reference numerals:

1: exposure device

3: exposure portion

5: mark forming part

5 a: mark shooting part

9: base material

41: working table

43: retaining plate

71: gas supply unit

91: first main surface

92: second main surface

421: negative pressure space

431: suction port

432: plate opening

541: outermost lens

583: trough part

911: pattern(s)

921: reference mark

Detailed Description

Fig. 1 is a diagram showing a configuration of an exposure apparatus 1 according to an embodiment of the present invention. In fig. 1, 3 directions orthogonal to each other are indicated by arrows as an X direction, a Y direction, and a Z direction. (the same applies to other figures). In the example of fig. 1, the X direction and the Y direction are horizontal directions, and the Z direction is a vertical direction. In the following description, the Z direction is referred to as the "up-down direction", but the Z direction may be a direction inclined with respect to the vertical direction or the like depending on the design of the exposure apparatus 1.

The exposure apparatus 1 is a direct writing apparatus that irradiates light onto a photosensitive material on a base material 9 and writes a pattern such as a wiring on the photosensitive material. The base member 9 is a printed board or the like, and is, for example, plate-shaped. The exposure apparatus 1 includes: a control unit 2, an exposure unit 3, a table unit 4, a table lifting mechanism 61, and a table moving mechanism 62. The control unit 2 is a computer having a CPU or the like, for example. The controller 2 controls the exposure unit 3, the table unit 4, the table lifting mechanism 61, and the table moving mechanism 62. The stage unit 4 holds the base material 9 below (on the (-Z) side) the exposure section 3. The table unit 4 will be described in detail later.

The exposure section 3 includes a plurality of scanning heads 31 and a plurality of imaging sections 36. The plurality of drawing heads 31 and the plurality of imaging units 36 are supported by a support portion, not shown, and are disposed above (on the (+ Z) side) the table unit 4. The plurality of drawing heads 31 are arranged in the X direction (hereinafter, referred to as "width direction"). Each of the drawing heads 31 has a light source 32 and a light modulation unit 33. The light source 32 includes, for example, a semiconductor laser, a solid-state laser, a gas laser, or the like, and emits laser light toward the light modulation section 33. The light modulation unit 33 modulates light from the light source 32. The light modulated by the light modulation unit 33 is irradiated to an upward main surface 91 (hereinafter referred to as "first main surface 91") of the substrate 9 held by the table unit 4. As the light modulation section 33, for example, a DMD (digital micromirror device) or the like in which a plurality of light modulation elements are two-dimensionally arranged can be used. The light modulation unit 33 may be a modulator in which a plurality of light modulation elements are one-dimensionally arranged.

The plurality of imaging units 36 are arranged in the width direction on the (-Y) side of the drawing head 31. In the example of fig. 1, two imaging units 36 are provided. Each imaging unit 36 is supported by the support portion via an imaging unit moving mechanism 37. The imaging unit 36 can be moved in the width direction by the imaging unit moving mechanism 37. In an exposure operation described later, reference marks 921 (see fig. 9) serving as alignment marks are formed on each side portion (end portion in the width direction) of the base material 9. The two imaging units 36 are disposed at the same positions in the width direction as the reference marks 921 on both sides of the base material 9, and the reference marks 921 are imaged by the imaging units 36.

The table lifting mechanism 61 has a motor, an air cylinder, or the like, and moves the table unit 4 in the Z direction (i.e., the up-down direction). The table moving mechanism 62 includes a guide rail, a guide block, a motor (e.g., a linear motor), a linear scale, and the like. The table moving mechanism 62 moves the table unit 4 in the Y direction (hereinafter, referred to as "moving direction") together with the table lifting mechanism 61. Thereby, the irradiation positions of the light from the plurality of scanning heads 31 are scanned in the moving direction on the first main surface 91 of the base material 9 held by the table unit 4. In the exposure apparatus 1, the writing (exposure) pattern is written on the first main surface 91 of the base material 9 by controlling each writing head 31 in synchronization with the movement of the table unit 4 by the table moving mechanism 62. In the exposure apparatus 1, the stage elevating mechanism 61 may be omitted, or a rotation mechanism that rotates the stage unit 4 about an axis parallel to the Z direction may be provided.

Fig. 2 is a plan view showing a part of the table unit 4. The table unit 4 has a table 41 and a plurality of mark forming portions 5. The table 41 has a table main body 42 and a holding plate 43. The table main body 42 is substantially plate-shaped and has a negative pressure space 421 (see fig. 5) formed therein. The mark forming portions 5 are held by the table main body 42 and covered with a holding plate 43. In the example of fig. 2, a plurality of mark forming portions 5 are arranged in the width direction (X direction) at the end portion on the (+ Y) side of the table main body 42.

Specifically, a pair of mark forming portions 5 are disposed at positions separated from the center of the table 41 in the width direction by the same distance, and the other pair of mark forming portions 5 are disposed at positions separated by a distance different from the distance. In the table unit 4 of fig. 2, a plurality of pairs of mark forming portions 5 are provided. The mark forming portions 5 may be provided at the end portion on the (-Y) side of the table main body 42. The internal structure of the table main body 42 and the structure of the mark forming part 5 will be described in detail later.

The holding plate 43 is a thin plate and is made of metal such as aluminum. The holding plate 43 is placed on the upper surface of the table main body 42. The holding plate 43 covers substantially the entire table main body 42. The holding plate 43 is similarly provided with a plurality of (a plurality of) suction ports 431 throughout. The plurality of suction ports 431 are connected to the negative pressure space 421. When the pattern is exposed on the first main surface 91 of the substrate 9, a second main surface 92 (see fig. 1) on the opposite side of the first main surface 91 of the substrate 9 is in contact with the holding plate 43. The second main surface 92 is attracted by the plurality of suction ports 431. Thus, the holding plate 43 is an adsorption plate for adsorbing and holding the base material 9 through the plurality of suction ports 431.

Fig. 3 is an enlarged view showing an area a1 surrounded by a broken line in fig. 2, showing the inside of the table unit 4 with the holding plate 43 removed. Fig. 4 is a sectional view of table unit 4 at the position of IV-IV in fig. 3, and fig. 5 is a sectional view of table unit 4 at the position of V-V in fig. 3.

A negative pressure space 421 is formed in the table main body 42 shown in fig. 3. The negative pressure space 421 is a recess recessed downward in the upper (+ Z side) surface of the table main body 42. The negative pressure space 421 is connected to a pressure reducing mechanism having a pump or the like, and the negative pressure space 421 is reduced in pressure. Thereby, the substrate 9 placed on the holding plate 43 is sucked and held through the plurality of suction ports 431. For example, a plurality of negative pressure spaces 421 independent of each other are provided in the table main body 42, and the negative pressure space 421 to be actually depressurized is selected in accordance with the size of the substrate 9 placed on the holding plate 43. Further, a plurality of holding holes 422 penetrating in the vertical direction are formed in the table main body 42. Each mark forming portion 5 has a substantially cylindrical shape, and is inserted into the holding hole 422 and fixed to the table main body 42. In the example of fig. 3, a plurality of projections 423 projecting from the bottom surface of the negative pressure space 421 are provided, and the upper portion of the mark forming portion 5 is supported by the projections 423.

The plurality of mark forming parts 5 are optical units for forming the reference mark 921, and have the same structure as each other. As shown in fig. 4 and 5, each mark forming portion 5 includes a light source 51, an illumination optical system 52, a mask 53, a projection optical system 54, and a lens barrel 55. The lens barrel 55 is a bottomed substantially cylindrical shape, and houses the light source 51, the illumination optical system 52, the mask 53, and the projection optical system 54. The light source 51 is attached to the bottom 551 of the barrel 55. Inside the barrel 55, the light source 51, the illumination optical system 52, the mask 53, and the projection optical system 54 are arranged in this order from the bottom 551 toward the holding plate 43 along the optical axis J1. The light source 51 is, for example, a semiconductor laser, and emits laser light. The light source 51 may be an LED other than a semiconductor laser. The wavelength band of light emitted from the light source 51 is substantially the same as the wavelength band of light emitted from the light source 32 of the drawing head 31, for example, and in the present embodiment, the light emitted from the light source 51 and the light source 32 is ultraviolet light. The illumination optical system 52 irradiates light from the light source 51 to the mask 53.

In the mask 53, a predetermined pattern is formed using a material that blocks the light. The projection optical system 54 guides the light having passed through the mask 53 to the holding plate 43 side along the optical axis J1. An opening 432 (hereinafter referred to as "plate opening 432") is provided in the holding plate 43 at a position intersecting the optical axis J1. The light from the mask 53 is irradiated to the second main surface 92 of the base material 9 through the plate opening 432. In practice, an image of the mask 53 is formed on the second main surface 92 by the projection optical system 54. In fig. 4 and 5, the base material 9 is indicated by a two-dot chain line.

In the present embodiment, the lens barrel 55 can be separated into a plurality of parts, and the part closest to the holding plate 43 is the substantially annular cover 56 centered on the optical axis J1. Fig. 6 is an enlarged view of the vicinity of the annular cover 56 in fig. 4.

The annular cover 56 has a cover body 57 and a central annular portion 58. The cover main body 57 is substantially annular about the optical axis J1. The lid body 57 has an upper portion with a larger inner diameter than a lower portion. That is, the cap main body 57 is provided with a large-diameter hole 571 located on the upper side and a small-diameter hole 572 located on the lower side, and the diameter of the large-diameter hole 571 is larger than that of the small-diameter hole 572.

As shown in fig. 3 and 5, two arc-shaped projections 573 projecting upward are provided on the upper surface of the lid main body 57 around the large-diameter hole 571. The two arcuate projections 573 are arcuate portions centered on the optical axis J1 and having the same radius, and the angle of the arcuate portions is less than 180 degrees. The two circular arc-shaped protrusions 573 are symmetrical with respect to a plane perpendicular to the X direction and including the optical axis J1. The upper ends of the two arcuate projections 573 contact the lower surface of the retainer plate 43. As shown in fig. 3, gaps 574 are provided between both ends on the (+ Y) side and both ends on the (-Y) side of the two arcuate projections 573, respectively. As shown in fig. 5, on the upper surface of the cover main body 57, annular regions around the two arcuate projections 573 are slightly separated from the lower surface of the holding plate 43. The space between the annular region and the lower surface of the holding plate 43 is directly connected to the negative pressure space 421.

In the projection optical system 54 shown in fig. 6, a lens 541 (hereinafter, referred to as "outermost lens 541") disposed closest to the holding plate 43 is disposed in the large-diameter hole 571. The outermost lens 541 is a light-transmitting member disposed on the side closest to the holding plate 43 in the mark forming portion 5. The outer peripheral portion of the lower surface of the outermost lens 541 contacts the upper edge of the small-diameter hole 572.

The central annular portion 58 is substantially annular about the optical axis J1, and is inserted into the large-diameter hole 571. In the central annular portion 58, the inner diameter of the upper portion is smaller than the inner diameter of the lower portion. That is, the central annular portion 58 is provided with a small-diameter hole portion 581 located on the upper side and a large-diameter hole portion 582 located on the lower side, and the diameter of the small-diameter hole portion 581 is smaller than the diameter of the large-diameter hole portion 582. The small-diameter hole portion 581 faces the plate opening 432 of the holding plate 43 in the vertical direction. In the central annular portion 58, the outer peripheral portion of the upper surface of the outermost lens 541 is in contact with a substantially annular surface extending radially outward (radially about the optical axis J1) from the lower end of the small-diameter hole 581 to the upper end of the large-diameter hole 582. Thus, the outermost lens 541 is sandwiched between the lid main body 57 and the central annular portion 58 in the vertical direction.

As shown in fig. 3, a groove 583 extending in the Y direction is provided on the upper surface of the central annular portion 58. A part of the groove 583 overlaps the small-diameter hole 581. For example, the groove 583 has a depth smaller than the depth of the small-diameter hole 581 in the vertical direction. The width of the groove portion 583 in the X direction is smaller than the diameter of the small-diameter hole portion 581. Both ends of the longitudinal groove portion 583 are connected to two gaps 574 provided between the two arcuate projections 573, respectively. Preferably, the width of the gap 574 in the X direction is greater than the width of the groove portion 583.

The upper surface of the central annular portion 58 is close to the lower surface of the holding plate 43 except for the groove portion 583 and the small-diameter hole portion 581. In other words, the upper side of the groove portion 583 is substantially closed by the holding plate 43 except for the position opposing the plate opening 432. As described later, a predetermined gas is supplied to the groove 583, and the gas flows along the groove 583. In this way, the gas flow path defined by the groove 583 of the central annular portion 58 is provided between the outermost lens 541 and the holding plate 43. In the present embodiment, the flow path area (cross-sectional area perpendicular to the longitudinal direction of the groove 583) of the gas flow path is smaller than the opening area of the plate opening 432. The gas flow path may extend in a direction other than the Y direction on the upper surface of the central annular portion 58.

As shown in fig. 3, a communication hole 584 extending in the vertical direction is provided in the bottom surface of the groove 583. As shown in fig. 6, an annular space 585 is formed between the outer periphery of the outermost lens 541 and the inner peripheral surface of the large-diameter hole portion 582, and the communication hole 584 is connected to the annular space 585. Further, a communication hole 576 extending in the horizontal direction toward the optical axis J1 is provided on the outer peripheral surface of the cover main body 57. The connecting hole 576 is connected to the inner circumferential surface of the small-diameter hole portion 572. In the cap main body 57, a substantially annular surface extending radially inward from the lower end of the large-diameter hole 571 to the upper end of the small-diameter hole 572 is provided with a downwardly extending communication hole 577. Both ends of the contact hole 577 are connected to the annular space 585 and the contact hole 576. In the lens barrel 55, a communication hole 552 connected to the communication hole 576 is provided. As shown in fig. 4, the table main body 42 is provided with a connection hole 424 connected to the connection hole 552.

The exposure apparatus 1 further includes a gas supply unit 71. The gas supply unit 71 includes a pump and the like, and supplies a predetermined clean gas (hereinafter referred to as "clean gas") to the connection hole 424 of the table main body 42. The clean gas is, for example, clean air after passing through a filter or the like. The clean gas may be a gas other than air containing no unnecessary substances. In the present embodiment, the gas supply portion 71 supplies the purge gas to the communication hole 424 at a constant flow rate. The flow rate of the cleaning gas may be changed as necessary. The cleaning gas supplied to the connection hole 424 is filled into the annular space 585 through the connection holes 552, 576, and 577 of fig. 6, and further supplied into the groove portion 583 through the connection hole 584. The cleaning gas flows from the communication hole 584 along the groove 583 to both ends of the groove 583.

When the substrate 9 is not held by the holding plate 43, a part of the clean gas flowing from the communication hole 584 toward the optical axis J1 in the groove 583 is discharged (blown) to the outside from the plate opening 432 of the holding plate 43. In other words, the interior of the plate opening 432 is at a positive pressure higher than atmospheric pressure. This prevents or suppresses entry of unnecessary substances into the plate opening 432 from the upper surface side of the holding plate 43. The remaining clean gas passes between the small-diameter hole 581 of the central annular portion 58 and the plate opening 432, i.e., passes across the plate opening 432 on the lower surface side of the holding plate 43. Therefore, even if an unnecessary substance enters inside the plate opening 432, the unnecessary substance flows along the groove portion 583 together with the clean gas crossing the plate opening 432.

The clean gas that has traversed plate opening 432 passes through one gap 574 between arcuate projections 573, reaches the space between the upper surface of lid main body 57 and retaining plate 43, and is discharged into negative pressure space 421. The clean gas flowing from the communication hole 584 toward the side opposite to the optical axis J1 in the groove 583 is discharged into the negative pressure space 421 through the other gap 574 between the arcuate projections 573 and the space between the cover main body 57 and the holding plate 43.

When the substrate 9 is held by the holding plate 43, since the plate opening 432 is closed by the substrate 9, almost all of the clean gas flowing from the communication hole 584 toward the optical axis J1 in the groove 583 passes through the plate opening 432. The cleaning gas passes through one gap 574 between the arcuate projections 573 and the upper surface of the cover main body 57, and is discharged into the negative pressure space 421. By providing the purge gas discharge path in this way, the pressure inside the plate opening 432 can be prevented from becoming too high, and the substrate 9 on the holding plate 43 can be prevented or suppressed from being lifted up. In other words, in the stage 41, by providing a structure for releasing the pressure of the purge gas supplied between the mark forming portion 5 and the holding plate 43, it is possible to prevent or suppress a decrease in the flatness of the base material 9 in the exposure of the pattern. The clean gas flowing from the communication hole 584 to the opposite side of the optical axis J1 in the groove 583 is the same as in the case where the substrate 9 is not held by the holding plate 43.

In fact, when the sectional area of the groove 583 as a gas flow path is too small relative to the opening area of the plate opening 432, the substrate 9 is easily lifted. In addition, when the cross-sectional area of the groove portion 583 is too large relative to the opening area of the plate opening 432, the internal pressure of the plate opening 432 becomes low, and thus unnecessary substances easily enter the plate opening 432, or a large amount of clean gas needs to be supplied in order to make the internal pressure of the plate opening 432 a predetermined positive pressure. Therefore, it is preferable to determine the ratio of the opening area of the plate opening 432 to the sectional area of the groove portion 583 in consideration of the above-described case. In one example, the above ratio is 1: 0.8.

Fig. 7 is a diagram showing a flow of an operation of the exposure apparatus 1 to expose a pattern on the base material 9. When the exposure apparatus 1 of fig. 1 exposes a pattern on the substrate 9, first, the substrate 9 is placed and held on the table 41 arranged on the (-Y) side of the exposure unit 3 (hereinafter, referred to as a "transfer position") by an external conveyance mechanism (step S11). At this time, the position of the base material 9 with respect to the holding plate 43 is adjusted to some extent by the abutting plate 49 or the like provided on the holding plate 43 shown in fig. 2. Here, it is assumed that the second main surface 92 of the substrate 9 is in contact with the holding plate 43 and the first main surface 91 is opposed to the exposure portion 3. In the base 9, photosensitive materials are provided on both the first main surface 91 and the second main surface 92.

Next, the table moving mechanism 62 of fig. 1 starts the continuous movement of the table 41 in the moving direction. In addition, the plurality of scanning heads 31 are controlled in synchronization with the movement of the table 41, and the modulated light is emitted toward the first main surface 91 of the base material 9. Thereby, as shown in fig. 8, the pattern 911 is exposed on the first main surface 91 of the base material 9 (step S12). Fig. 8 schematically shows a pattern 911, a reference mark 921 described later, and the like for convenience of illustration (the same applies to fig. 9, 11, and 12 described later).

When the pattern 911 is exposed to substantially the entire first main surface 91, the movement of the table 41 in the moving direction is stopped. Further, the exposure apparatus 1 may be provided with a mechanism for moving the plurality of scanning heads 31 or the table 41 in the width direction, and each time the movement of the table 41 in the moving direction (main scanning) is completed, the plurality of scanning heads 31 or the table 41 may be intermittently moved in the width direction (sub-scanning), thereby exposing the pattern 911 to the first main surface 91.

In addition, a pair of mark forming portions 5 facing both side portions (both end portions in the width direction) of the base member 9 is selected from the plurality of pairs of mark forming portions 5 shown in fig. 2. Then, in each of the pair of mark forming portions 5, laser light is emitted from the light source 51 (see fig. 4), whereby an image of the mask 53 is formed at a position of the second main surface 92 that faces the board opening 432. As a result, as shown in fig. 8, a pair of reference marks 921 are formed on the second main surface 92 (step S13).

In the exposure apparatus 1, the positions of the exposure section 3 and the mark forming sections 5 are corrected in advance, and the relative positions (the positions in the X direction and the Y direction) between the pattern 911 on the first main surface 91 and the reference mark 921 on the second main surface 92 in the substrate 9 on the table 41 are set in advance. Preferably, the formation of the reference mark 921 on the second main surface 92 is performed in parallel with the exposure of the pattern 911 on the first main surface 91. The reference mark 921 may be formed before or after the exposure of the pattern 911 without moving the position of the base material 9 on the table 41 between the exposure of the pattern 911 and the formation of the reference mark 921.

When the exposure of the pattern 911 with respect to the first main surface 91 and the formation of the reference mark 921 with respect to the second main surface 92 are completed, the table 41 is disposed at the transfer position, and the substrate 9 is taken out from the table 41 by the external conveyance mechanism. After the substrate 9 is turned over by the conveyance mechanism, it is placed on and held by the table 41 (step S14). Thereby, as shown in fig. 9, the first main surface 91 is in contact with the holding plate 43, and the second main surface 92 faces the exposure section 3.

Next, the table 41 is moved in the moving direction by the table moving mechanism 62, and the pair of reference marks 921 are arranged below the two imaging units 36. In fig. 9, the imaging unit 36 is indicated by a two-dot chain line. The two image pickup units 36 are arranged at the same positions in the width direction as the pair of mark forming units 5 used in step S13, and each image pickup unit 36 picks up an image of the reference mark 921 on the second main surface 92 (step S15). The control unit 2 acquires the position and inclination of the pair of reference marks 921 with respect to the table 41 based on the captured images of the two imaging units 36. Thereby, the position and inclination of the pattern 911 of the first main surface 91 with respect to the table 41 are acquired. In the case where the reference mark 921 of the photosensitive material formed on the second main surface 92 cannot be confirmed in the captured image of the image capturing unit 36, the reference mark 921 may be developed in step S14. In addition, only one reference mark 921 may be used depending on the accuracy required to acquire the position of the pattern 911 on the first main surface 91.

Then, the plurality of writing heads 31 are controlled to expose the pattern on the second main surface 92 of the substrate 9 while continuously moving the table 41 in the moving direction (step S16). At this time, the drawing data for exposure of the pattern is corrected based on the position and inclination of the pattern 911 on the first main surface 91. Thereby, the position and inclination of the pattern of the second main surface 92 are accurately aligned with the pattern 911 of the first main surface 91. When the exposure of the pattern to the second main surface 92 is completed, the table 41 is disposed at the transfer position, and the substrate 9 is taken out from the table 41 by the external conveyance mechanism (step S17). By the above operation, the exposure operation of the pattern by the exposure apparatus 1 is ended.

In the exposure apparatus 1, when the pattern is exposed on the other substrate 9 having a width different from the width of the substrate 9 in the width direction, the other pair of mark forming portions 5 are used to form the reference mark 921 in step S13. The other pair of mark forming portions 5 face both side portions of the other base member 9 on the table 41. Then, in step S15, the reference mark 921 on the second main surface 92 is imaged by the two imaging units 36 arranged at the same positions in the width direction as the other pair of mark forming units 5, and alignment (registration) with the pattern 911 on the first main surface 91 is performed in the exposure of the pattern to the second main surface 92. In this way, by using one mark forming section 5 for one kind of substrate 9 and using another mark forming section 5 for another kind of substrate 9, it is possible to expose patterns to various kinds of substrates 9 in the exposure apparatus 1.

As described above, the exposure apparatus 1 is provided with the mark forming portion 5, and the mark forming portion 5 irradiates light to the main surface of the substrate 9 through the plate opening 432 provided in the holding plate 43, thereby forming the reference mark 921 on the main surface. In the exposure operation in the exposure apparatus 1, when the exposure section 3 exposes a pattern on the first main surface 91 of the substrate 9 held on the stage 41, the mark forming section 5 forms the reference mark 921 on the second main surface 92. In addition, the reference mark 921 is referred to when the exposure section 3 exposes a pattern on the second main surface 92. This enables the pattern on the second main surface 92 to be accurately aligned in position and inclination with the pattern 911 on the first main surface 91. In addition, the reference mark 921 can be formed efficiently.

Further, the gas supply portion 71 supplies the cleaning gas between the outermost lens 541 and the holding plate 43, and the cleaning gas flows between the outermost lens 541 and the holding plate 43 across the plate opening 432. This can prevent the adhesion of unnecessary substances to the surface of the outermost lens 541 in the mark forming portion 5. Further, by making the inside of the plate opening 432 positive pressure, it becomes difficult for unnecessary substances to enter the plate opening 432, so that it is possible to further suppress adhesion of unnecessary substances to the surface of the outermost lens 541. When the substrate 9 is held on the holding plate 43, the cleaning gas flows across the plate opening 432, that is, the cleaning gas is discharged from between the outermost lens 541 and the holding plate 43, whereby the pressure in the plate opening 432 can be prevented from becoming too high. As a result, the substrate 9 can be prevented or suppressed from being lifted up and the flatness of the substrate 9 can be prevented from being lowered, and thus, the pattern can be appropriately exposed.

In the exposure apparatus 1, a gas flow path (groove portion 583) extending in one direction along the holding plate 43 is provided between the outermost lens 541 and the holding plate 43, and a clean gas flows through the gas flow path. As described above, by allowing the clean gas to flow through the dedicated gas flow path, the flow rate of the clean gas passing through the plate opening 432 can be easily increased as compared with the case where no gas flow path is provided. As a result, the adhesion of the unnecessary substance to the outermost lens 541 can be more reliably suppressed.

Further, since the flow path area of the gas flow path is smaller than the area of the plate opening 432, a certain amount of clean gas is ejected from the plate opening 432, and entry of unnecessary substances into the plate opening 432 can be further suppressed. The purge gas that has passed through the plate opening 432 flows into the negative pressure space 421 of the table main body 42, and the purge gas can be appropriately discharged.

Fig. 10 is a diagram showing another example of the exposure apparatus, which shows the table unit 4 a. The table unit 4a in fig. 10 is different from the table unit 4 in fig. 2 in that a mark imaging unit 5a is provided instead of the mark forming unit 5. The other configurations of the exposure apparatus 1 having the stage unit 4a are the same as those of fig. 1, and the same reference numerals are given to the same configurations.

The mark imaging unit 5a is an optical unit for imaging with reference to the mark 921, and the light source 51 in the mark forming unit 5 of fig. 4 is replaced with an imaging element. The mask 53 and the illumination optical system 52 are omitted, and an image of a region facing the plate opening 432 on the principal surface of the base material 9 is formed on the imaging surface of the imaging element by the projection optical system 54. The structure around the outermost lens 541 of the projection optical system 54, that is, the structure of the annular cover 56 is the same as that of fig. 6. In the mark imaging unit 5a, a light source for illumination (a light source in a wavelength band that does not receive light from the photosensitive material of the base material 9) may be provided as necessary.

In an example of an exposure operation in the exposure apparatus 1 having the stage unit 4a, as shown in fig. 11, a pattern 911 is exposed on the first main surface 91 of the base material 9 by the exposure unit 3. In addition, a plurality of (two in fig. 11) reference marks 921 are formed on the first main surface 91 by the exposure section 3. Next, the base material 9 is turned over so that the first main surface 91 comes into contact with the holding plate 43. At this time, as shown in fig. 12, the reference marks 921 are arranged at positions facing the plate openings 432, and the reference marks 921 are imaged by the mark imaging unit 5 a. Further, in the table unit 4a, it is preferable that the plate opening 432 is larger than the table unit 4, and in the base material 9, a wide imaging area of the mark imaging part 5a is secured.

The control unit 2 acquires the positions and inclinations of the plurality of reference marks 921 with respect to the table 41 based on the captured images of the plurality of mark capturing units 5 a. Thereby, the position and inclination of the pattern 911 of the first main surface 91 with respect to the table 41 are acquired. Then, a pattern is exposed on the second main surface 92 of the base material 9. At this time, the drawing data of the exposure of the pattern is corrected based on the position and inclination of the pattern 911 on the first main surface 91. This enables the position and inclination of the pattern on the second main surface 92 to be accurately aligned with the pattern 911 on the first main surface 91.

As described above, the exposure apparatus 1 is provided with the mark imaging section 5a that images the reference mark 921 formed on the main surface of the substrate 9 through the plate opening 432. In the exposure operation in the exposure apparatus 1, when the exposure section 3 exposes a pattern on the first main surface 91 of the substrate 9 held on the stage 41, the reference mark 921 is also formed on the first main surface 91. When the exposure unit 3 exposes a pattern on the second main surface 92, the reference mark 921 is imaged by the mark imaging unit 5a, and the pattern is referred to for exposure. This enables the position and inclination of the pattern on the second main surface 92 to be accurately aligned with the pattern 911 on the first main surface 91.

In the stage unit 4a, a cleaning gas is also supplied between the outermost lens 541 and the holding plate 43 by the gas supply portion 71, and the cleaning gas flows between the outermost lens 541 and the holding plate 43 across the plate opening 432. This can prevent the adhesion of unnecessary substances to the surface of the outermost lens 541 in the marker imaging section 5 a. Further, by making the inside of the plate opening 432 positive pressure, it becomes difficult for unnecessary substances to enter the plate opening 432, so that it is possible to further suppress adhesion of unnecessary substances to the surface of the outermost lens 541.

Various modifications can be made to the exposure apparatus 1.

In the mark forming section 5 and the mark imaging section 5a as the optical unit, another light-transmitting member such as a light-transmitting plate may be provided between the outermost lens 541 and the holding plate 43. In this case, in order to suppress adhesion of unnecessary substances to the surface of the light-transmitting member, a clean gas is supplied between the light-transmitting member and the holding plate 43. As described above, in the exposure apparatus 1, it is important that the gas supply section 71 supplies the clean gas between the light-transmitting member disposed closest to the holding plate 43 in the optical unit and the holding plate 43, the clean gas flows between the light-transmitting member and the holding plate 43 across the plate opening 432, and/or the inside of the plate opening 432 is made positive pressure by the clean gas.

The groove 583 forming the gas flow path may be omitted from the annular cover 56 in fig. 3. Even in this case, since the clean gas supplied from the communication hole 584 to the upper surface of the central annular portion 58 is diffused around along the upper surface, the clean gas can flow so as to cross the plate openings 432, and the inside of the plate openings 432 can be set to a positive pressure.

When the table 41 holds the substrate 9 by a method other than suction (for example, a mechanical chuck), a dedicated discharge flow path into which the clean gas having traversed the plate opening 432 flows may be provided in the table main body 42 or the like.

In the exposure apparatus 1 described above, the optical unit is provided on the stage 41 for exposure which faces the exposure section 3 through the substrate 9, but the optical unit may be provided on another stage for forming the reference mark 921 or for imaging the reference mark 921, for example. In this case, in a state where the substrate 9 is held on the holding plate of the other stage, light is irradiated to the main surface of the substrate 9 or an image of the main surface is taken by the optical unit through the plate opening of the holding plate.

In the mark forming portion 5 described above, the reference mark 921 is formed by irradiating light to the second main surface 92 on which the photosensitive material is provided, but the reference mark 921 may be formed by emitting high-intensity laser light from the mark forming portion 5 and partially cutting off the second main surface 92 on which the photosensitive material is not provided.

The reference mark 921 imaged by the mark imaging unit 5a may be a mark formed in another device. In this case, for example, when the pattern is exposed on the first main surface 91, the reference mark 921 is imaged by the imaging unit 36 that images the first main surface 91, and when the pattern is exposed on the second main surface 92, the reference mark 921 is imaged by the mark imaging unit 5 a. This enables the pattern of the second main surface 92 to be accurately aligned in position and inclination with the pattern 911 of the first main surface 91.

In the above-described embodiment, the case where the exposure apparatus 1 is a direct writing apparatus has been described, but the exposure unit 3 of the exposure apparatus 1 may be a device that projects a pattern formed on a mask or the like onto the base material 9 to expose the pattern.

In the exposure apparatus 1, when the position of the stage unit 4 is fixed and a pattern is exposed on the base material 9, the exposure section 3 may also be moved in the moving direction.

The base material 9 of the exposure pattern may be a semiconductor substrate, a glass substrate, or the like other than the printed board. The base member 9 may be a film such as a flexible substrate.

The configurations in the above-described embodiment and the modifications may be appropriately combined as long as they are not contradictory to each other.

While the invention has been described in detail, the foregoing description is illustrative and not restrictive. Accordingly, many modifications and variations may be made without departing from the scope of the invention.