阅读说明：本技术 成膜装置及成膜方法 (Film forming apparatus and film forming method ) 是由 市原正浩 于 2019-12-19 设计创作，主要内容包括：本发明提供一种能够兼顾膜厚分布的均匀化和材料收获率的提高的成膜装置。蒸发源容器进行从在与成膜对象物的旋转轴正交的方向上离开旋转轴的分离位置向接近旋转轴的接近位置移动、并再次返回分离位置的往复移动,石英振荡器以维持与进行往复移动的蒸发源容器的相向状态的方式在腔室内移动,所述蒸发源容器在腔室内收纳成膜材料,配置于成膜对象物的下方,具有向上方开口的喷射口,所述石英振荡器设置于成膜监视器,所述成膜监视器获取从蒸发源容器蒸发的成膜材料相对于成膜对象物的成膜速率。(The invention provides a film forming apparatus which can make the uniformity of film thickness distribution and the improvement of material yield compatible. The evaporation source container performs reciprocating movement of moving from a separation position away from the rotation axis in a direction orthogonal to the rotation axis of the film formation object to an approach position close to the rotation axis and returning to the separation position again, the quartz oscillator moves in the chamber so as to maintain an opposing state with the evaporation source container performing reciprocating movement, the evaporation source container accommodates the film formation material in the chamber, is disposed below the film formation object, and has an injection port opening upward, the quartz oscillator is provided in a film formation monitor that acquires a film formation rate of the film formation material evaporated from the evaporation source container with respect to the film formation object.)

1. A film forming apparatus includes:

a chamber;

a rotation support portion that supports, in the chamber, the object to be film-formed so as to be rotatable about a rotation axis perpendicular to a film-formed surface of the object to be film-formed with the film-formed surface facing downward;

an evaporation source container that contains a film forming material in the chamber, is disposed below the object to be film formed, and has an ejection opening that opens upward;

a film formation monitor having a quartz oscillator to which the film formation material evaporated from the evaporation source container is attached, the film formation monitor acquiring a film formation rate of the film formation material evaporated from the evaporation source container with respect to the object to be film formed; and

a heating control unit having a heating source for heating the evaporation source container, and controlling power supplied to the heating source based on the film formation rate acquired by the film formation monitor,

it is characterized in that the preparation method is characterized in that,

the evaporation source container performs reciprocating movement of moving from a separation position away from the rotation axis in a direction orthogonal to the rotation axis to an approach position close to the rotation axis and returning to the separation position again,

the quartz oscillator moves so as to maintain a state of facing the evaporation source container which performs the reciprocating movement.

2. The film forming apparatus according to claim 1,

the separation position is a position at which the evaporation source container does not overlap the film formation object when viewed in the direction of the rotation axis.

3. The film forming apparatus according to claim 1 or 2,

the film forming apparatus further includes a movable support mechanism that integrally supports the evaporation source container and a monitor unit including the quartz oscillator, and moves the evaporation source container and the monitor unit in the chamber.

4. The film forming apparatus according to claim 3,

the movable support mechanism includes an arm portion that is swingable within the chamber about a second rotation axis parallel to a rotation axis of the object to be film-formed and extends in a direction orthogonal to the second rotation axis,

the evaporation source container is disposed on one side of the arm portion with respect to the second rotation axis, and the monitor unit is disposed on the other side.

5. The film forming apparatus according to claim 1 or 2,

the film forming apparatus further includes a shutter plate configured to be movable to a closed position covering the injection port and an open position not covering the injection port when the evaporation source container is located at the separation position.

6. The film forming apparatus according to claim 5,

the shutter plate has a cutout portion that allows adhesion of the film-forming material evaporated from the evaporation source container to the quartz oscillator when the shutter plate is in the closed position.

7. The film forming apparatus according to claim 1 or 2,

the evaporation source container includes a plurality of evaporation source containers and a plurality of film formation monitors.

8. A film forming method for forming a film of a film forming material on a film forming object by heating an evaporation source container disposed below the film forming object in a chamber and having an injection port opening upward, and evaporating the film forming material stored in the evaporation source container, the film forming object being rotated in the chamber about a rotation axis perpendicular to a film forming surface with the film forming surface facing downward, the method comprising:

a first step of positioning the evaporation source container at a separation position at which the evaporation source container does not overlap with the film formation object when viewed in a direction along the rotation axis;

a second step of moving the evaporation source container from the separation position to an approach position closer to the rotation axis than the separation position in a direction orthogonal to the rotation axis; and

a third step of moving the evaporation source container from the approach position to the separation position,

moving a quartz oscillator provided in a film formation monitor for acquiring a film formation rate of the film formation material evaporated from the evaporation source container with respect to the object to be film formed, in such a manner that a facing state of the quartz oscillator and the evaporation source container is maintained during the first to third steps.

Technical Field

The present invention relates to a film forming apparatus and a film forming method for forming a thin film on an object to be film formed by a vacuum deposition method.

Background

As a film forming apparatus for forming a thin film on a substrate as a film forming object, there is a film forming apparatus of a vacuum deposition method in which a container (crucible) containing a film forming material is heated in a vacuum chamber, and the film forming material is evaporated (sublimated or vaporized) and sprayed out of the container to be deposited on the surface of the substrate. In a structure in which a crucible having an upward opening for a film forming material is used as an evaporation source to form a film on a substrate that is rotated with a film formation surface facing downward, the film thickness distribution changes depending on the arrangement of the evaporation source with respect to the substrate. The deposition amount per unit time (film formation rate) of the film forming material to a horizontal surface disposed above the evaporation source becomes a peak immediately above the ejection opening, and a mountain-shaped distribution gradually decreasing in a gradual gradient from the center of the peak to the outer side in the radial direction is formed.

In the conventional apparatus design, a configuration in which the evaporation source is disposed so that the film formation surface of the substrate is located at a position deviated from a position directly above the evaporation source (injection port) is the mainstream, with importance placed on uniformity of the film thickness distribution. That is, the film formation is performed in a region where the gradient of the change in the film formation rate in the mountain-shaped film thickness distribution is gentle. However, the film formation material ejected from the ejection port directly above is mostly not used for film formation and is wasted, and therefore, the arrangement structure is not high in material yield.

In recent years, a material yield has been emphasized by using a vapor deposition material of a high-performance material (i.e., high cost). That is, there is a tendency to adopt a structure in which an evaporation source is disposed directly below a substrate (at a position where the evaporation source overlaps with the substrate (is included in the substrate) when projected in the vertical direction). However, in the vicinity of the portion immediately above the ejection opening of the crucible where the film formation rate reaches a peak, the gradient of the change in the film formation rate becomes steep (the change in the amount of adhesion per unit time with respect to the distance from the center of the peak is large), and therefore, a region in which it is difficult to form a uniform film thickness distribution is formed. That is, the film thickness distribution may be deteriorated and the production quality may be deteriorated.

Patent documents 1 and 2 describe an apparatus structure for equalizing the film thickness by changing the position of an evaporation source disposed directly below a substrate. However, in the apparatus described in patent document 1, since the relative position of the evaporation source with respect to a film formation rate monitor (quartz oscillator) fixed in the chamber changes, the monitor condition is reset every time the evaporation source is moved. The device described in patent document 2 is not described in a film formation rate monitor, and is not a structure of a monitor environment in consideration of a film formation rate.

Disclosure of Invention

Problems to be solved by the invention

The invention aims to provide a film forming apparatus which can balance uniformization of film thickness distribution and improvement of material yield.

Means for solving the problems

In order to achieve the above object, a film forming apparatus according to the present invention includes:

a chamber;

a rotation support portion that supports, in the chamber, the object to be film-formed so as to be rotatable about a rotation axis perpendicular to a film-formed surface of the object to be film-formed with the film-formed surface facing downward;

an evaporation source container that contains a film forming material in the chamber, is disposed below the object to be film formed, and has an ejection opening that opens upward;

a film formation monitor having a quartz oscillator to which the film formation material evaporated from the evaporation source container is attached, the film formation monitor acquiring a film formation rate of the film formation material evaporated from the evaporation source container with respect to the object to be film formed; and

a heating control unit having a heating source for heating the evaporation source container, and controlling power supplied to the heating source based on the film formation rate acquired by the film formation monitor,

it is characterized in that the preparation method is characterized in that,

the evaporation source container performs reciprocating movement of moving from a separation position away from the rotation axis in a direction orthogonal to the rotation axis to an approach position close to the rotation axis and returning to the separation position again,

the quartz oscillator moves so as to maintain a state of facing the evaporation source container which performs the reciprocating movement.

In order to achieve the above object, a film forming method of the present invention,

an evaporation source container configured to be disposed below a film formation object in a chamber and having an injection port opening upward, and to evaporate a film formation material stored in the evaporation source container by heating an evaporation source container, thereby forming a film of the film formation material on the film formation object, the film formation object being rotated in the chamber about a rotation axis perpendicular to a film formation surface with the film formation surface facing downward, the evaporation source container being characterized by comprising:

a first step of positioning the evaporation source container at a separation position at which the evaporation source container does not overlap with the film formation object when viewed in a direction along the rotation axis;

a second step of moving the evaporation source container from the separation position to an approach position that approaches the rotation axis in a direction orthogonal to the rotation axis; and

a third step of moving the evaporation source container from the approach position to the separation position,

moving a quartz oscillator provided in a film formation monitor for acquiring a film formation rate of the film formation material evaporated from the evaporation source container with respect to the object to be film formed, in such a manner that a facing state of the quartz oscillator and the evaporation source container is maintained during the first to third steps.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, the uniformity of the film thickness distribution and the improvement of the material yield can be both achieved.

Drawings

FIG. 1 is a schematic cross-sectional view of a film formation apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic view showing the structure of a film formation rate monitoring apparatus in an embodiment of the present invention.

Fig. 3 is a schematic view showing the structures of a quartz monitor head and a shield member in the embodiment of the present invention.

Fig. 4 is an explanatory view of a movable supporting mechanism of an evaporation source device in an embodiment of the present invention.

Fig. 5 is an explanatory diagram of differences in film thickness distribution and material yield depending on the arrangement of the substrate and the evaporation source apparatus.

Fig. 6 is a diagram showing a film thickness distribution in a film formation process of the film formation apparatus according to the embodiment of the present invention.

Fig. 7 is a structural explanatory diagram in the case where a plurality of evaporation source devices are provided in the embodiment of the present invention.

Detailed Description

Preferred embodiments and examples of the present invention will be described below with reference to the accompanying drawings. However, the following embodiments and examples merely illustrate preferred configurations of the present invention, and the scope of the present invention is not limited to these configurations. In the following description, unless otherwise specified, the hardware configuration and software configuration, the process flow, the manufacturing conditions, the dimensions, the materials, the shapes, and the like of the devices are not intended to limit the scope of the present invention to these descriptions.

[ example 1]

A film deposition apparatus according to an embodiment of the present invention will be described with reference to fig. 1 to 4. The film deposition apparatus of the present embodiment is a film deposition apparatus for forming a thin film on a substrate by vacuum deposition.

The film forming apparatus of the present embodiment is used for depositing and forming a thin film on a substrate (including a substrate on which a laminate is formed) in the manufacture of various electronic devices such as various semiconductor devices, magnetic devices, and electronic devices, optical devices, and the like. More specifically, the film formation apparatus of the present embodiment is preferably used for manufacturing electronic devices such as a light-emitting element, a photoelectric conversion element, and a touch panel. Among these, the film formation apparatus of the present embodiment is particularly preferably applicable to the production of organic light emitting elements such as organic el (electro luminescence) elements and organic photoelectric conversion elements such as organic thin film solar cells. The electronic device of the present invention further includes a display device (for example, an organic EL display device) including a light-emitting element, an illumination device (for example, an organic EL illumination device), and a sensor (for example, an organic CMOS image sensor) including a photoelectric conversion element. The film formation apparatus of the present embodiment can be used as a part of a film formation system including a sputtering apparatus and the like.

< schematic construction of film Forming apparatus >

Fig. 1 is a schematic view showing a structure of a film formation apparatus 1 according to an embodiment of the present invention. The film deposition apparatus 1 includes a vacuum chamber (film deposition chamber, vapor deposition chamber) 200 whose interior is maintained in a vacuum atmosphere or an inert gas atmosphere such as nitrogen gas by an exhaust device 24 and a gas supply device 25. In the present specification, "vacuum" refers to a state in a space filled with a gas having a pressure lower than atmospheric pressure.

When the substrate 100 as a film formation object is conveyed into the vacuum chamber 200 by a conveyance robot (not shown), the substrate is held by a substrate holding unit 210 provided in the vacuum chamber 200. The substrate holding unit 210 holds the substrate 100 horizontally with the film formation surface 100a, which is the surface to be processed of the substrate 100, facing downward. The substrate holding unit 210 is supported so as to be suspended above the inside of the vacuum chamber 200 via a rotation shaft 220. The rotating shaft 220 is provided so as to penetrate the top of the vacuum chamber 200 substantially vertically, and is supported by a shaft hole at the top of the vacuum chamber 200 by a bearing or the like, and a gap between the shaft hole and the shaft hole is sealed by a magnetic fluid seal. The rotation shaft 220 rotates by a driving force of a rotation driving unit 230 provided outside the vacuum chamber 200 and including a motor and the like, and rotates the substrate holding unit 210. By rotating the substrate holding unit 210 as a rotation support portion, the substrate 100 is rotated around a predetermined rotation center axis (rotation axis Y1) inside the vacuum chamber 200.

As a specific substrate 100 holding structure by the substrate holding unit 210, a conventionally known structure such as a structure for holding by gripping an end portion of the substrate 100 or a structure for holding by suction of the back surface of the substrate 100 can be suitably employed. Further, the substrate 100 may be held so that the film formation surface 100a of the substrate 100 is covered with a mask having an opening pattern corresponding to a thin film pattern formed on the film formation surface 100a (the substrate 100 is placed on the upper surface of the mask).

An evaporation source device 300 is provided below the substrate 100 inside the vacuum chamber 200. The evaporation source apparatus 300 generally includes an evaporation source container (crucible) 301 (hereinafter referred to as container 301) that contains a film forming material (vapor deposition material) 304, and a heater 302 that is a heating mechanism (heat source) that heats the film forming material 304 contained in the container 301. The film forming material 304 in the container 301 is evaporated in the container 301 by heating with the heater 302, and is ejected out of the container 301 through the nozzle 303 provided at the upper part of the container 301 and forming the ejection port of the film forming material 304. The film forming material 304 ejected out of the container 301 is deposited on the film formation surface 100a of the substrate 100 rotating at a predetermined rotation speed above the apparatus 300.

The structure of the container 301 does not necessarily include the nozzle 303, and may include no nozzle 303 and only an ejection opening.

The heater 302 is configured such that a single wire-shaped (wire-shaped) heating element that generates heat by energization is wound around the outer periphery of the cylindrical portion of the container 301 by a plurality of turns. Further, a plurality of heating elements may be wound. As the heater 302, a metal heating resistor such as stainless steel may be used as a heating element, or a graphite heater may be used.

In addition, although not shown, the evaporation source device 300 may include a reflector, a heat transfer member for improving the heating efficiency of the heater 302, a frame body for accommodating the entire evaporation source device 300 including these components, a baffle plate, and the like.

The film forming apparatus 1 of the present embodiment includes a film formation rate monitoring device 4 as a means for detecting the amount of vapor of the film forming material 304 ejected from the container 301 or the thickness of the thin film formed on the substrate 100. The film formation rate monitoring apparatus 4 causes a part of the film formation material 304 discharged from the container 301 to adhere to the quartz oscillator provided in the quartz monitoring head 41 while intermittently repeating the shielding state and the non-shielding state by the shielding member 42 as a rotating body. By detecting the amount of change (decrease) in the resonance frequency (natural frequency) of the quartz oscillator due to the deposition of the film formation material 304, the amount of deposition (deposition amount) of the film formation material 304 per unit time can be acquired as the film formation rate (deposition rate) corresponding to a predetermined control target temperature. The film formation rate can be arbitrarily controlled by feeding back the film formation rate to the setting of the control target temperature in the heating control of the heater 302. Therefore, the film formation rate monitoring device 4 can always monitor the amount of the film formation material 304 discharged or the thickness of the film on the substrate 100 during the film formation process, thereby enabling highly accurate film formation.

The control unit (arithmetic processing unit) 20 of the film forming apparatus 1 of the present embodiment includes a monitor control unit 21 and a heating control unit 22, the monitor control unit 21 controls the operation of the monitor unit 40 and measures and acquires the film forming rate, and the heating control unit 22 controls the heating of the evaporation source apparatus 300. The control unit 20 performs control of the reciprocating movement of the evaporation source device 300 by the movable support mechanism 50, the opening/closing movement of the shutter 60, and the like, which will be described later, in addition to control of the rotation of the substrate 100 by the rotation driving unit 230.

< apparatus for monitoring film Forming Rate >

Fig. 2 is a schematic diagram showing a schematic configuration of the film formation rate monitoring apparatus 4 of the present embodiment. As shown in fig. 2, the film formation rate monitoring apparatus 4 of the present embodiment includes a monitor unit 40 and a monitor control unit 21, and the monitor unit 40 includes a monitor head 41, a shielding member (shutter) 42, and the like. The monitor unit 40 includes a monitor head 41, a shielding member 42, a servo motor 46 as a rotation drive source of a quartz holder (rotation support body) 44 in which the monitor head 41 is incorporated, and a servo motor 45 as a rotation drive source of the shielding member 42. The monitoring and control unit 21 includes a shielding member control unit (rotation control unit) 212 that controls the rotational drive of the shielding member 42, a film formation rate acquisition unit 213 that acquires (the amount of change in) the resonance frequency of the quartz oscillator 43, and a holder control unit 214 that controls the rotational drive of the quartz holder 44.

Fig. 3 is a schematic diagram showing the arrangement relationship between the monitor head 41 (quartz holder 44) and the shield member 42 when viewed along the respective rotation axis directions. As shown in fig. 3, a quartz holder 44 for supporting a plurality of quartz oscillators 43(43a, 43b) arranged at equal intervals in the circumferential direction is incorporated in the monitoring head 41. The monitor head 41 is provided with a monitor opening 41a slightly larger than the quartz oscillator 43, and the quartz holder 44 supports one of the supported quartz oscillators 43 at a position (rotation phase) exposed to the outside (evaporation source apparatus 300) via the monitor opening 41 a.

As shown in fig. 2 and 3, the center of the quartz holder 44 is connected to a motor shaft 46a of a servo motor 46, and is rotationally driven by the servo motor 46. This allows the quartz oscillator 43 exposed to the outside through the monitor aperture 41a to be sequentially switched. That is, one crystal oscillator 43a of the plurality of crystal oscillators 43 supported by the crystal holder 44 is located at a position overlapping the phase of the monitor aperture 41a, and the other crystal oscillator 43b is located at a position hidden inside the monitor head 41 as a used or replacement crystal oscillator. When the deposition amount of the film formation material 304 of the quartz oscillator 43 exposed to the outside through the monitor opening 41a exceeds a predetermined amount and the quartz oscillator 43 reaches the lifetime, the quartz holder 44 rotates to move a new quartz oscillator 43 to an exposure position overlapping the monitor opening 41 a.

The rotation control of the servo motor 46 by the holder control unit 214 is performed based on the rotational position (rotational phase) of the quartz holder 44 detected by the phase position detection mechanism 48 including the detection unit 48a and the detection unit 48 b. As the position (phase) detection means, a known position sensor such as a rotary encoder may be used.

As shown in fig. 3, the shielding member 42 is a substantially disk-shaped member, the center of which is coupled to a motor shaft 45a of a servo motor 45, and is rotationally driven by the servo motor 45. The shielding member 42 is provided at a position where a fan-shaped opening slit (opening portion, non-shielding portion) 42a is separated from the rotation center, and at a position where its rotation orbit overlaps with the monitoring opening 41a of the monitoring head 41.

As shown in fig. 2 and 3, by the rotation of the shielding member 42, the relative position (relative phase) of the opening slit 42a with respect to the monitor opening 41a changes to a position (opening position, non-shielding position) overlapping with the monitor opening 41a and a position (non-opening position, shielding position) not overlapping. Thus, the region of the shielding member 42 other than the opening slit 42a becomes the shielding portion 42b, and when it is located at a position (phase) overlapping (covering) the monitor opening 41a, it becomes a shielding state (non-opening state) in which adhesion of the film forming material 304 to the quartz oscillator 43a is inhibited. When the opening slit 42a is located at a position (phase) overlapping the monitor opening 41a, the deposition of the film forming material 304 to the quartz oscillator 43a is allowed to be in a non-shielding state (open state).

The rotation control of the servo motor 45 by the shielding member control unit 212 is performed based on the rotational position (rotational phase) of the shielding member 42 detected by the phase position detection mechanism 47 including the detection unit 47a and the detection unit 47 b. As the position (phase) detection means, a known position sensor such as a rotary encoder may be used.

The opening slit 42a is a closed hole in the present embodiment, but may be a slit shape opened at the peripheral end of the shielding member 42. The number of slits may be two or more, and the slit shape is not limited to the fan shape shown in the present embodiment, and various shapes can be adopted. When a plurality of open slits 42a are provided, they may have different shapes.

The quartz oscillator 43a is connected to the external resonator 49 via an electrode, a coaxial cable, or the like. A transmission signal generated by applying a voltage between the thin film of the film forming material 304 deposited on the front surface of the quartz oscillator 43a and the electrode on the back surface is transmitted from the resonator 49 to the film formation rate obtaining unit 213 as (a change amount of) the resonance frequency of the quartz oscillator 43 and is obtained.

Although not shown, the monitor unit 40 is provided with a flow path through which cooling water flows for cooling heat of the motors 45 and 46 serving as heat sources.

The structure of the film formation rate monitoring apparatus shown here is merely an example, and is not limited thereto, and various known structures can be suitably employed.

< control of Power supply to Heater >

The amount of heat generated by the heater 302 is controlled by controlling the amount of electric power (current value) supplied to the heater 302 by the heating control unit 22 including a power supply circuit. The power supply amount is adjusted by PID control so that the temperature detected by, for example, a temperature detection means not shown is maintained at a value suitable for obtaining the power supply amountA predetermined control target temperature of a desired film formation rate. By maintaining the amount of heat generated by the heater 302 (the power supplied to the heater 302) for a predetermined time, which is capable of maintaining a predetermined film formation rate, a thin film having a desired film thickness can be formed on the film formation surface 100a of the substrate 100

The film forming apparatus 1 of the present embodiment is configured to be able to execute rate control and average power control in a switchable manner as a control method of power supply in heating control of the heater 302. The power control method is not limited to this.

In the rate control, the control target temperature is changed as appropriate so that the monitored value (actual measurement value) of the film formation rate acquired by the film formation rate monitoring apparatus 4 matches a desired target rate (theoretical value), and the amount of power supplied to the heater 302 is controlled based on the set control target temperature.

In the present embodiment, average power control is used as power control for determining the amount of power to be supplied to the heater 302 without using a monitored value (actual measurement value) of the film formation rate acquired by the film formation rate monitoring apparatus 4. The average power control is a control method as follows: the power supply to the heater 302 is controlled so as to maintain the target power amount by setting the moving average value of the past samples of the supplied power as the target power amount. Further, power control may be used in which power is supplied to the heater 302 so as to maintain a predetermined amount of power (target amount of power). In these power controls, the film thickness is controlled by controlling the film formation rate using a theoretical value set based on film formation conditions such as the type of film formation material and the relative speed between the substrate and the evaporation source.

< features of the present embodiment >

The film forming apparatus 1 of the present embodiment is characterized in that the film forming process is performed while relatively moving the evaporation source apparatus 300 with respect to the rotating substrate 100, and at this time, the relative positions of the evaporation source apparatus 300 and the monitor unit 40 are not changed. The evaporation source device 300 is also characterized by a method of moving relative to the substrate 100. The evaporation source device 300 is configured to reciprocate between a spaced position away from the rotation axis of the substrate 100 and an approaching position close to the rotation axis. The separation position is a position at which the evaporation source apparatus 300 (the opening of the nozzle 303) is displaced from directly below the substrate 100 when viewed in a direction perpendicular to the film formation surface 100a of the substrate 100 (the direction of the rotation axis Y1 of the substrate 100). The proximity position is a position where the evaporation source device 300 is hidden directly below the substrate 100 and is close to the rotation center (the rotation axis Y1) of the substrate 100 when viewed in the same direction. During the film forming step, the evaporation source apparatus 300 reciprocates at least once from the separation position to the proximity position and from the proximity position to the separation position again. During this period, the relative positions of the evaporation source device 300 and the monitor unit 40 (the relative states such as the facing direction and the facing distance of the evaporation source device 300 and the quartz oscillator 43) are maintained.

With reference to fig. 1, 4, 5, and 6, a characteristic configuration of the film deposition apparatus 1 of the present embodiment will be described.

Fig. 4 is a schematic diagram illustrating the structure of the movable support mechanism 50 of the evaporation source apparatus 300 in the film formation apparatus 1 according to the present embodiment, where (a) is a schematic perspective view of the movable support mechanism 50, and (b) is a schematic plan view illustrating the displacement of the evaporation source apparatus 300 by the movable support mechanism 50, and is a view when viewed along the rotation axis direction of the substrate 100.

The film forming apparatus 1 of the present embodiment includes a movable support mechanism 50, and the movable support mechanism 50 includes an arm (arm portion) 51 that supports the evaporation source device 300 and the monitor unit 40, a rotation shaft 52 that supports the arm 51, and a rotation driving portion 53 that rotates the rotation shaft 52.

As shown in fig. 4(a), the arm 51 extends in a substantially horizontal direction within the vacuum chamber 200, and the evaporation source device 300 is disposed on one end side and the monitor unit 40 is disposed on the other end side. The monitor unit 40 is supported by the arm 51 so that the quartz oscillator 43 faces the evaporation source device 300 at a predetermined relative position. The rotation shaft 52 is provided so as to penetrate substantially vertically through the bottom of the vacuum chamber 200, supports the arm 51 at the upper end inside the vacuum chamber 200, and is connected to the rotation driving unit 53 at the lower end outside the vacuum chamber 200. The rotating shaft 52 is supported by a shaft hole at the bottom of the vacuum chamber 200 by a bearing or the like, and a gap between the shaft hole and the rotating shaft is sealed by a magnetic fluid seal. The rotation driving unit 53 disposed outside the vacuum chamber 200 rotates the rotation shaft 52 by a rotation driving force obtained from a power source such as a motor under the control of the control unit 20. By the rotation of the rotating shaft 52, the evaporation source device 300 supported by the arm 51 and the monitor unit 40 rotate integrally inside the vacuum chamber 200. The rotation axis (second rotation axis) Y2 of the rotation shaft 52 is parallel to the rotation axis Y1 of the substrate 100. The evaporation source device 300 draws an arc-shaped trajectory around the rotation axis Y2 by the rotation of the rotation shaft 52, and moves back and forth in the horizontal direction with respect to the rotation axis Y1 of the substrate 100 (swinging about the rotation axis Y2 as a fulcrum). The rotation axis Y2 as a pivot of the arm 51 is located between one end where the evaporation source device 300 is disposed and the other end where the monitor unit 40 is disposed.

The solid line in fig. 4(b) shows the arrangement structure of each part when the evaporation source device 300 is located at a close position close to the rotation axis (rotation axis) Y1 of the substrate 100. The evaporation source device 300 is located directly below the substrate 100 when viewed in the direction of the rotation axis Y1, and the entire evaporation source device is shielded by the substrate 100 and disposed close to the rotation axis Y1.

The broken line in fig. 4(b) shows the arrangement structure of each part when the evaporation source device 300 is located at a separated position apart from the rotation axis Y1 of the substrate 100. When viewed in the direction of the rotation axis Y1, the evaporation source device 300 is located entirely outside the substrate 100 and is disposed at a distance from the rotation axis Y1.

As shown in fig. 4(b), the film formation apparatus 1 of the present embodiment includes a baffle plate 60, and the baffle plate 60 serves as a shielding mechanism for limiting adhesion of the film formation material 4 evaporated from the evaporation source apparatus 300 to the substrate 100. The baffle 60 is attached to one end of an arm 61 extending horizontally in the vacuum chamber 200, and can be changed in position in the horizontal direction in the vacuum chamber 200 by rotation of a rotating shaft 62 connected to the other end of the arm 61. The mechanism for rotating the rotary shaft 62 is the same as the movable support mechanism 50, and the description thereof is omitted. The shutter 60 is configured to be movable to a shielding position (closing position) for covering (blocking) the opening (ejection port) of the nozzle 303 and a non-shielding position (opening position) for not covering with respect to the evaporation source apparatus 300 located at the separation position by rotation of the rotary shaft 62 controlled by the control unit 20.

The shutter 60 is moved to the shielding position when it is desired to restrict the film forming material 304 evaporated from the evaporation source apparatus 300 from flying and adhering to the substrate 100, such as during a preparatory heating process for stabilizing the evaporation state of the film forming material 304 before the film forming process is started or after the film forming process is completed. In order to maintain the evaporation state of the film forming material 304 in a state suitable for vapor deposition, it is preferable that the crucible 301 is heated once until the film forming material 304 needs to be replenished, for example. That is, the heating of the crucible 301 may be continued even while the substrate 100 is being replaced. In order to restrict the film forming material 304 from scattering in such a non-film forming step, the shutter 60 is moved to the shielding position.

The baffle plate 60 is provided with a notch (cut-out portion) 60a, and the facing state of the quartz oscillator 43 with respect to the evaporation source device 300 is maintained through the notch 60a even when the baffle plate 60 is located at the shielding position. That is, the film formation rate of the evaporation source apparatus 300 can be continuously obtained by the monitor unit 40 even in the non-film formation step.

Fig. 5 is a schematic diagram illustrating differences in film thickness distribution and material yield due to differences in the arrangement of the substrate 100 and the evaporation source apparatus 300. Fig. 5(a) is a schematic plan view similar to fig. 4(b) when the evaporation source device 300 is located away from the rotation axis Y1 of the substrate 100. Fig. 5(b) is a schematic plan view similar to fig. 4(b) when the evaporation source device 300 is located close to the rotation axis Y1 of the substrate 100. Fig. 5(c) is a schematic perspective view showing the arrangement relationship when the evaporation source device 300 is located at a position separated from the rotation axis Y1 of the substrate 100. Fig. 5(d) is a schematic perspective view showing the arrangement relationship when the evaporation source device 300 is located at a position close to the rotation axis Y1 of the substrate 100.

In the film forming apparatus 1 of the present embodiment, the film forming process is started from the relative arrangement of the evaporation source apparatus 300 and the substrate 100 shown in fig. 5(a) and 5 (c). That is, in a state where the evaporation source apparatus 300 is located at the spaced-apart position as the origin position and the shutter 60 is located at the shielding position, the heating of the crucible 301 is started under the control of the control unit 20, and the heating state (evaporation state) of the film forming material 304 is monitored by the film formation rate monitoring apparatus 4. When the heated state of the crucible 301 (the state of evaporation of the film forming material 304) is ready, the controller 20 rotates the substrate 100 at a predetermined rotation speed and moves the shutter 60 from the shielding position to the non-shielding position, thereby starting the film forming process at the separation position shown in fig. 5(a) and 5(c) (first step).

Then, the movable supporting mechanism 50 starts the rotation of the arm 51 under the control of the control unit 20, and starts the relative movement of the evaporation source device 300 with respect to the substrate 100 from the spaced-apart position shown in fig. 5(a) and 5(c) to the close position shown in fig. 5(b) and 5(d) (second step). During this time, the film formation rate of the film forming material 304 is also monitored by the film formation rate monitoring apparatus 4. Then, the evaporation source device 300 reaches the proximity position shown in fig. 5(b) and 5(d) and a position at a predetermined proximity distance from the rotation center (the rotation axis Y1) of the substrate 100.

When the evaporation source device 300 reaches the close position shown in fig. 5(b) and 5(d), the movable support mechanism 50 reverses the rotation direction (swinging direction) of the arm 51 in the opposite direction, and reverses the direction of the relative movement of the evaporation source device 300 in the direction toward the separation position shown in fig. 5(a) and 5(c) (third step). During the return movement of the evaporation source apparatus 300 to the separated position shown in fig. 5(a) and 5(c), the film formation rate of the film formation material 304 is also monitored by the film formation rate monitoring apparatus 4. After the evaporation source apparatus 300 returns to the separation position shown in fig. 5(a) and 5(c), the shutter 60 is moved from the non-shielding position to the shielding position, and the film formation process is completed.

After the film formation process is completed as described above, the heating of the crucible 301 and the monitoring of the film formation rate by the film formation rate monitoring device 4 are continued in preparation for the next film formation process.

Fig. 6 is a graph showing experimental results of the inventors of the present application as an example of a film thickness distribution in a film formation process in the film formation apparatus 1 of the present embodiment. In fig. 6, the abscissa indicates the radial position of the film formation surface 100a of the substrate 100 with the position where the rotation axis Y1 passes as the origin, and the ordinate indicates the film thickness as a ratio to the peak value with the film thickness of the peak value as the reference ("1").

Make itThe Si wafer substrate 100 is rotated at 10 to 30rpm, the height h from the nozzle 303 (ejection port) to the substrate 100 is set to 300mm, the distance d1 in the horizontal direction between the nozzle 303 at the separation position and the rotation axis Y1 is set to 300mm, and the distance d2 in the horizontal direction between the nozzle 303 at the approach position and the rotation axis Y1 is set to 50 mm.

The distribution is shown as descending downward to the right as it goes away from the center (the rotation axis Y1) as a whole, but it is understood that the difference in film thickness between the center and the outer peripheral edge formed in the outward (single pass) film deposition from the separation position to the proximity position is reduced by the film deposition in the circuit from the proximity position to the separation position. Specifically, the film thickness distribution was ± 6.5% in a single pass, but decreased to ± 5.0% by reciprocation. In addition, the material yield based on the reciprocating film formation was 2.5%.

Here, the experimental results of the present example will be described in comparison with a comparative example in which the evaporation source apparatus 300 is not moved relative to the substrate 100 and film formation is performed while being fixed at a predetermined position as in the present example. A case where the evaporation source apparatus 300 is fixed at the separation position shown in fig. 5(a) and 5(c) relative to the substrate 100 to form a film is referred to as comparative example 1, and a case where the evaporation source apparatus is fixed at the proximity position shown in fig. 5(b) and 5(d) to form a film is referred to as comparative example 2. Comparative example 1 is a device configuration similar to the above prior art document in which importance is attached to the material yield. In addition, comparative example 2 is a device configuration similar to the above-described conventional art in which importance is placed on uniformity of film thickness distribution.

In comparative example 1, since the evaporation source apparatus 300 is located just above the outer peripheral end of the substrate 100, a distribution gently reaching the peak value from the center to the outer peripheral end was formed, and a better result than the present example was obtained in which the film thickness distribution was ± 3.7%. However, in the region directly above the evaporation source apparatus 300 where the amount of the film forming material 304 discharged is relatively large, the film formation surface 100a of the substrate 100 is deviated, and therefore the amount of the film forming material 304 consumed without contributing to film formation increases, resulting in a lower yield than the present embodiment, such that the material yield becomes 1.1%.

In comparative example 2, since the evaporation source apparatus 300 is located close to the rotation axis Y1 and the deposition surface 100a is disposed so as to cover the evaporation source 300 directly above, the rotation center of the substrate 100 has a peak, and a distribution in which the film thickness decreases with a steep gradient toward the outer peripheral end is formed. Since the film forming material 304 which did not contribute to film formation was decreased, the yield was 4.2%, which is a better result than the present example, but the film thickness distribution was ± 10.9%, which is a lower result than the present example.

< advantages of the present embodiment >

According to the present example, as described in comparison with comparative examples 1 and 2, film formation with a good balance can be achieved from the viewpoint of film thickness distribution and material yield. That is, by the reciprocating movement between the separation position and the proximity position, the time during which the evaporation source apparatus 300 is positioned below the substrate 100 (when viewed from the vertical direction, they overlap) in the film formation process becomes longer, and the amount of the film forming material 304 that does not contribute to film formation can be reduced as compared with comparative example 1. On the other hand, since the time during which the evaporation source apparatus 300 stays at the rotation center of the substrate 100 (in the vicinity of the rotation axis Y1) during the film formation process is shortened, the variation in the local deposition amount of the film forming material 304 is reduced, and the variation in the film thickness distribution is suppressed as compared with comparative example 2. Therefore, according to the present embodiment, it is possible to achieve both of the uniformity of the film thickness distribution and the improvement of the material yield.

In addition, according to the present embodiment, the following configuration is adopted: while the evaporation source device 300 is relatively moved with respect to the substrate 100, the monitor unit 40 is also moved so as to maintain the relative position with respect to the evaporation source device 300 (the facing state of the quartz oscillator 43 with respect to the evaporation source device 300). This makes it possible to maintain the film formation rate monitoring environment in a constant state, and to perform rate control with high accuracy. In the present embodiment, the notch 60a is provided in the shutter 60, and the film deposition rate can be monitored even during the non-film deposition process. This enables the film formation rate to be continuously obtained even in the non-film formation process, and enables more accurate rate control. For example, a highly accurate film formation rate can be obtained according to a temporal change in the evaporation state due to a change in the amount of the film formation material 304 stored in the crucible 301, a temporary change in the evaporation state due to the occurrence of bumping, or the like.

< others >

In the present embodiment, the number of reciprocating movements between the separation position and the approach position is set to one reciprocation, but the number of reciprocations is not limited. For example, the evaporation source apparatus 300 may be moved at a moving speed higher than that in the case of one reciprocation, and may be reciprocated twice or more.

The moving speed of the evaporation source device 300 in the reciprocating movement may be the same speed or different speeds in the outward path and the return path. Further, the speed may be constant or may be changed in the middle of the reciprocation. That is, the film forming conditions can be appropriately incorporated into the rate control, the average power control, and the like, and can be appropriately set according to the control content.

In the present embodiment, the movable support mechanism 50 is configured to reciprocate the evaporation source device 300 (and the monitor unit 40) on the circular arc orbit, but is not limited to this configuration. For example, the following structure is also possible: the evaporation source device 300 and the monitor unit 40 are supported at the tip of an arm mechanism capable of telescopic operation so that the facing distances are constant, and the relative position of the evaporation source device 300 with respect to the substrate 100 is changed on a linear orbit by telescopic operation of the arm.

In the present embodiment, the evaporation source device 300 and the monitor unit 40 are configured to be integrally movable in the vacuum chamber 200 by the single movable support mechanism 50, but the present invention is not limited to this configuration. That is, the mechanism for moving the evaporation source device 300 and the mechanism for moving the monitor unit 40 may be different mechanisms, and the relative arrangement between the evaporation source device 300 and the monitor unit 40 may be maintained in cooperation with each other.

The configuration of the regulating means for regulating the ejection of the film forming material 304 from the evaporation source apparatus 300 is not limited to the configuration of the baffle 60 shown in the present embodiment. The configuration may be such that at least the film forming material 304 ejected from the ejection port of the crucible 301 is prevented from adhering to the object to be film formed. That is, the ejection opening may not be completely closed, or a wall that blocks the flight of the film forming material may be locally formed only in a direction in which the flight of the film forming material is to be restricted, for example.

As shown in fig. 7, the present invention can also be applied to a film deposition apparatus including a plurality of evaporation source apparatuses 300. Fig. 7(a) shows a state in which the three evaporation source devices 300 are located at the respective separation positions (original positions) and the three shutters 60 are located at the respective shielding positions, that is, a standby state in which the film formation process is not performed. Fig. 7(b) shows a state in which the three evaporation source devices 300 are located at the respective separation positions (original positions) and the three shutters 60 are located at the respective non-shielding positions, that is, a state in which the film formation process is started. Fig. 7(b) shows a state in which the three evaporation source apparatuses 300 are located at respective close positions and at respective return points during the reciprocating movement of the film formation process.

The configuration example shown in fig. 7 is a configuration including three evaporation source devices 300, but may be a configuration including two evaporation source devices 300 or a configuration including four or more evaporation source devices 300.

Description of the reference numerals

1 … film forming apparatus, 100 … substrate, 20 … control part, 200 … vacuum chamber (film forming chamber), 300 … evaporation source apparatus, 301 … evaporation source container (crucible), 302 … heater (heating source), 303 … nozzle, 40 … monitor unit, 50 … movable supporting mechanism, 51 … arm, 52 … rotating shaft, 53 … rotating drive part, 60 … baffle plate, 60a … notch.