WO2005108638A1

WO2005108638A1 - Substrate dome

Info

Publication number: WO2005108638A1
Application number: PCT/JP2005/000848
Authority: WO
Inventors: Masayuki Takimoto; Hiroyuki Komuro; Tatsumi Abe; Yutaka Fuse; Kazuhito Aonahata
Original assignee: Showa Shinku Co., Ltd.
Priority date: 2004-05-11
Filing date: 2005-01-24
Publication date: 2005-11-17
Also published as: JP3966869B2; CN1977066A; KR20070010153A; JP2005320605A

Abstract

Substrate domes capable of suppressing the lowering of the accuracy of film thickness distribution on substrates disposed thereon by a thermal expansion and centrifugal force by the rotation of the substrate dome during film formation in the substrate dome. A vacuum device comprises a vacuum chamber and the substrate domes on which the film formation substrates are mounted and which are oppositely disposed at the bottom of the vacuum chamber. The substrate domes formed of titan or a titan alloy is formed in the vacuum device.

Description

Specification

Board dome

Technical field

The present invention relates to prevention of deformation of a substrate dome when a substrate is placed on the substrate dome and a film is formed.

Background art

[0002] In general, a substrate dome on which a substrate is mounted has a dome shape because it is designed so that a film having the same thickness is deposited at all positions where the substrate is arranged. Further, when depositing the film forming material, the substrate dome is rotated in order to make the film thickness distribution in the circumferential direction inside the substrate dome uniform.

[0003] The present invention relates to a structure necessary for suppressing a decrease in accuracy of film thickness distribution on a substrate disposed on a substrate dome due to a centrifugal force due to thermal expansion and rotation during film formation on the substrate dome. It is.

FIG. 2 shows a vapor deposition apparatus for forming an optical thin film, and an outline of thin film formation by the same method will be described below.

[0005] In the apparatus shown in Fig. 2, a vapor deposition material 29 is placed in a bottom plate of a vacuum chamber 30 having an exhaust system (not shown), a crucible 28, an electron gun 27 for heating the vapor deposition material 29 to an evaporation temperature, and a shutter 26 for closing when the vapor deposition is completed. And a substrate dome 20 on which a substrate 21 is disposed on a top plate, and a bearing 22 for rotating the substrate dome, a dome side gear 23, a motor side gear 24, and a motor 25 are arranged. In addition, a heater 31 for heating the substrate 21 is provided to improve the packing density of a film deposited on the substrate, and the manner of evaporation differs depending on the type of evaporation material. A film thickness correction plate 32 for correcting the film thickness distribution generated in the direction is provided.

[0006] When vapor deposition is performed by this apparatus, first, a substrate 21 to be vapor-deposited is placed on a substrate dome 20, and the substrate dome 20 is placed in a vacuum chamber, or the substrate dome 20 is placed in a vacuum chamber. After that, the substrate 21 is set on the substrate dome 20. Then, the evaporation material 29 is put into the crucible 28. When the inside of the vacuum chamber is evacuated to maintain a vacuum state, the substrate dome 20 is rotated, and the substrate 21 is heated by the heater 31. When the substrate temperature reaches the target temperature, the electron gun 27 The beam is irradiated to the evaporation material 29 and heated to the evaporation temperature. Depending on the type of the vapor deposition material, an automatic tilting type or fixed type film thickness correction plate 32 is arranged between the evaporation source and the substrate 21 to correct the film thickness distribution in the substrate dome 20. When the shutter 26 is opened, the vapor deposition material 29 scatters, and the vapor deposition material 29 is deposited on the substrate 21. When the deposition is completed, the shutter 26 is closed, the heater 31, the electron gun 27, and the substrate rotation motor 25 are stopped. After cooling, the atmosphere is introduced into the vacuum chamber.

[0007] Fig. 3 shows a conventional substrate dome 20 used in the above-described vapor deposition apparatus, and a dome shape is generally formed by subjecting stainless steel or aluminum or the like to drawing according to the application. Inside the substrate dome 20, holes 40 for arranging the substrates that match the shape of the substrate 21 are arranged on the contour lines. In some cases, a hole 41 for a film thickness measuring device is formed in the center of the substrate dome 20. Although the thickness of the substrate dome 20 varies depending on the dome diameter, the thickness of the substrate dome 20 of φ800 mm-φ1200 is about 2 mm and 4 mm.

[0008] At present, very strict accuracy standards and high production efficiency are simultaneously required for thin film formation. In order to increase production efficiency, it is necessary to increase the reproducibility of the film thickness and the film thickness distribution as much as possible. To achieve this, the distance between the film-forming material and the substrate must always be kept constant. In order to keep the distance constant, deformation of the substrate dome due to heat or the like must be minimized.

[0009] Further, the substrate temperature varies depending on the intended use of the film to be formed, the film-forming material, and the like, and the substrate temperature varies from a temperature close to room temperature to a temperature heated to about 300 ° C. Further, in both cases, since the evaporation temperature and the thermal conductivity differ depending on the type of the film forming material, the amount of radiant heat emitted from the evaporation source differs depending on the film forming material. Therefore, the amount of radiant heat transmitted to the substrate during multilayer film formation is constantly changing. As a result, the temperature of the substrate during film formation changes at least about 30 ° C, and the change in heat changes the amount of thermal expansion of the substrate dome, making it difficult to maintain a constant distance between the substrate and the evaporation source. I got it.

[0010] As described above, in addition to the problem that the deformation due to the thermal expansion of the substrate dome during the film formation changes the distance between the substrate and the evaporation source, the deposition conditions and the film thickness correction plate depend on the type of the film to be formed. There is a problem that must be used properly. Two types of film formation: certain film forming material A and film forming material B When performing multi-layer deposition of materials (1), the substrate temperature is set to 300 ° C. In addition, when performing multi-layer film formation (2) with two kinds of film formation materials B and C, the substrate temperature is set to 100 ° C. When comparing these two types of multilayer film formation, the substrate temperature is greatly different, so the amount of thermal expansion of the dome is different, resulting in a difference in the distance between the substrate and the evaporation source. Therefore, the film thickness compensating plate used for film forming material B in multilayer film forming (1) cannot be used for film forming material B in multilayer film forming (2), and film forming for multilayer film forming (2) A film thickness compensator for Material B must be manufactured separately.

FIG. 4 shows the calculated values of the films deposited on the substrate 21 when the substrate dome 20 is not deformed in the apparatus shown in FIGS. The distance from the center point of the evaporation material 29, which is the evaporation source, to each substrate is Dl, D2, D3, D4, and the horizontal distance from the center of the substrate dome 20 is XI, X2, X3, X4. , And the angles between the line connecting the center of the substrate dome 20 and the center of the vapor deposition material 29 and Dl, D2, D3, and D4 are Θ1, Θ2, and 角度. 3, Θ4. At this time, the film thickness deposited on each substrate is generally dl, d2, d3, and d4, and the amount of the evaporation material 29 evaporated from the evaporation source is k.

cos

d, = k 1 + 1

Hubby, ²

cosS ₂

^X 2 + 2)

C J

= ^Χ 3 + Υ3)

COS 0 ₄

= χι + y).

When there is no deformation of the substrate dome, dl = d2 because XI = Χ2, Υ1 = Υ2, and θ1 = θ2. Let this be dl 2. Also, since Χ3 = Χ4, Υ3 = Υ4, and θ3 = θ4, d3 = d4. This is d34. Therefore, the curvature of the substrate dome 20 is designed so that dl 2 = d34. Since k shown in [Equation 1] is a unique value that differs depending on the deposition material, If dl2 = d34 depending on the type of 29, dl2 = d34 using the thickness correction plate 32.

FIG. 5 shows the force applied to an arbitrary point A on the substrate dome 20 during vapor deposition. Since the dome is rotating, a centrifugal force S is applied to point A, so a force extending in the direction of i is applied. At point A, a gravitational force S is applied, so a force that extends in the direction of h is also applied. The sum of these two forces is j. The same applies to j since i and h are both proportional to the temperature, coefficient of thermal expansion and weight of the substrate dome 20.

[0013] Fig. 6 shows the calculated elongation of a stainless steel substrate dome 20 having a radius of curvature of 900mm and a substrate dome diameter of 1100mm due to thermal expansion. Here, a comparison is made between room temperature (25 ° C) and 300 ° C. The length of the arc cross-section of the substrate dome 20 takes the force of heat S彭張I system number 17.3 X 10- ⁶ temperature variations I匕量and stainless thereto since it is 1182.8Mm the 1182.8mm X 17. 3 X 10- ⁶ X (300 ° C-25 ° C) = 5.63mm. In other words, when the temperature of the substrate dome rises from room temperature to 300 ° C, the distance of the arc of the dome cross section increases by 118.88 mm to 5.63 mm.

Here, for example, in an in-line type sputtering apparatus, there has been proposed an apparatus in which a substrate holder is formed of titanium or a titanium alloy so that a substrate holder to be detached is not plastically deformed even in a heated atmosphere.

Patent Document 1: Japanese Patent Application Laid-Open No. 4-325679

Disclosure of the invention

Problems to be solved by the invention

[0015] As described above, when the distance of the arc of the cross section of the substrate dome 20 increases, X and Y in FIG.

Since Θ changes, it becomes dl 2 ≠ d34. As a result, it becomes necessary to use the film thickness correction plate 32 properly depending on the temperature. In addition, the ratio of dl2 to d34 changes due to the temperature change of the substrate dome 20 during vapor deposition, so that even if the film thickness compensator is properly used depending on the temperature, the change in the film thickness distribution during vapor deposition cannot be corrected. There is a problem.

FIG. 7 shows a structure in which the rotation mechanism of the substrate dome 20 is arranged not at the center as in FIG. When the outer peripheral ring 42 is arranged on the rotating mechanism and the substrate dome 20 is installed, the extension of the substrate dome 20 in the outer peripheral direction can be suppressed to some extent. It will grow. Therefore, even if this method is used, the heat of the substrate dome 20 The problem cannot be solved fundamentally unless expansion is suppressed.

[0017] In addition to the above, there is also a problem of a load on the substrate rotating mechanism. Even in the case of FIG. 2, even in the case of FIG. 7, the load on the bearing 22 increases as the weight of the substrate dome 20 increases. (I> When installing 70mm x 70mm x t2 glass substrates on a substrate 20 with a substrate radius of 1100mm and a radius of curvature of 900mm, the number of glass substrates will be at least about 110. Since the specific gravity of glass is 2.5, 1 glass The weight per thread is 24.5 g, which is about 24.5 g X l 10 = 2.7 kg when 110 pieces are in total.The weight of this substrate dome is 110 holes in the case of stainless steel. Approximately 13.2 kg when calculated with a specific gravity of 7.93 after leaving space for each sheet, so a total weight of at least 13.2 kg + 2.7 kg = 15.9 kg is applied to the bearing 22. Of the weight, the weight of the substrate dome 20 is about 83%, and there is no solution other than reducing the weight of the substrate dome 20 to reduce the load on the bearing 22 and extend the maintenance cycle.

As described above, the total weight of the substrate 21 and the substrate dome 20 is at least about 16 kg. Since it is heavy, it is difficult to attach and detach it to and from the device, and deformation may occur due to weight during storage. In addition, as described above, the larger the weight, the greater the centrifugal force and gravity applied to the substrate dome 20 during vapor deposition, thereby promoting deformation.

The present invention has been made in order to solve the above problems, and provides a substrate dome and a film forming method having the following aspects.

A first aspect of the present invention is directed to a vacuum apparatus including a vacuum chamber and a substrate dome on which a film-forming substrate is mounted and which is opposed to the bottom of the vacuum chamber, and has a thermal expansion coefficient of 17.3 × 10 ^6. The substrate dome is formed by using a material having a size less than or equal to.

According to a second aspect of the present invention, there is provided a vacuum apparatus comprising a vacuum chamber and a substrate dome on which a film-forming substrate is mounted and which is opposed to the bottom of the vacuum chamber, and has a longitudinal elastic modulus of 19.7 × 10 ^3. The substrate dome was formed using a material having a size less than that of the substrate dome.

A third aspect of the present invention is directed to a vacuum apparatus including a vacuum chamber and a substrate dome on which a film formation substrate is mounted and opposed to the bottom of the vacuum chamber, wherein a material having a specific gravity of less than 7.93 is used. It was used to form a substrate dome. According to a fourth aspect of the present invention, there is provided a vacuum apparatus comprising a vacuum chamber and a substrate dome on which a film-forming substrate is mounted and disposed opposite to the bottom of the vacuum chamber, wherein the substrate dome is formed using a material made of titanium or a titanium alloy. It was formed. The substrate dome was formed by drawing.

According to a fifth aspect of the present invention, there is provided a vacuum chamber comprising a vacuum chamber, a crucible for placing a film-forming material disposed at the bottom of the vacuum chamber, and a substrate dome on which a film-forming substrate is mounted and which is arranged to face the film-forming material In the apparatus, in a film forming method of depositing a film forming material on a film forming substrate while rotating a substrate dome, a deformation due to a centrifugal force applied to the substrate dome, or its own weight or thermal expansion is adjusted. The distance between the substrate and the film formation substrate was kept constant to improve the film thickness distribution accuracy.

[0025] At least a substrate dome, an evaporation source, and a substrate heating means are provided inside the vacuum chamber, and the film deposition substrate is attached to the substrate dome and rotated, and an electron beam is irradiated to the evaporation source arranged opposite to the film deposition substrate to form a film. In an optical thin film forming apparatus for depositing an evaporating substance on a substrate, the substrate dome is made of titanium or a titanium alloy.

The invention's effect

[0026] By suppressing deformation of the substrate dome during film formation according to the present invention, the distance between the film formation material and the film formation substrate is kept constant, and the film thickness distribution accuracy and film formation reproducibility are significantly improved. This is possible.

Brief Description of Drawings

FIG. 1 is a diagram showing a pure titanium substrate dome of the present invention.

FIG. 2 is a schematic view of a vacuum evaporation apparatus.

FIG. 3 is a view showing a conventional substrate dome.

FIG. 4 is a view for explaining the effect of the distance and angle between the substrate and the evaporation source on the film thickness.

FIG. 5 is a view for explaining a force applied to a substrate dome during vapor deposition.

FIG. 6 is a view for explaining an amount of expansion due to substrate heating.

FIG. 7 is a schematic view of a vacuum evaporation apparatus.

Explanation of symbols

[0028] 1 Pure titanium substrate dome of the present invention 20 Conventional stainless steel substrate dome

21 substrate

22 Bearing

23 Dome side gear

24 Motor side gear

25 motor

26 Shutter

27 electron gun

28 crucible

29 Evaporation material

30 vacuum chamber

31 heater

32 Film thickness compensator

40 Board placement hole

41 Thickness measurement hole

42 Outer ring

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 shows a plan view and a cross-sectional view illustrating an embodiment of the substrate dome of the present invention.

Hereinafter, it is assumed that the substrate dome 1 according to the present invention is mounted on a vacuum device similar to the device shown in FIGS. 2 and 7 except for the substrate dome 20. It is not limited to this.

The shape and dimensions of the substrate dome 1 are equal to those of the conventional substrate dome 20, and the drawing method is the same as the conventional method. The material is pure titanium instead of the conventional stainless steel or aluminum of the substrate dome 20. The material of the substrate dome in which the present invention can be implemented may be any material as long as it has a small coefficient of thermal expansion, a coefficient of longitudinal elasticity, and a small specific gravity. Pure titanium has the ability to ensure more desirable performance For example, it is possible to improve performance by using a titanium alloy.

[0030] When substrate dome 1 is made of pure titanium or a titanium alloy, titanium Since the coefficient of expansion is low, it is possible to control the amount of thermal expansion due to temperature changes during substrate heating and vapor deposition. As a result, the change in the mounting position of the substrate 21 becomes smaller than that of a conventional stainless steel dome or the like, so that the reproducibility and distribution of the film deposited on the substrate are close to the calculated values, and the productivity is remarkably improved. Further, since titanium has a very low specific gravity as compared with stainless steel, the weight of the substrate dome is reduced, and the load on the bearing 22 is also reduced. As a result, the maintenance cycle is extended and the influence of the centrifugal force and the gravity applied to the substrate dome during vapor deposition is reduced by the reduced weight, so that the deformation of the substrate dome 1 can be further suppressed. Further, since the weight is reduced, the detachability of the substrate dome 1 is improved, and deformation due to the weight during storage is suppressed.

Therefore, a concrete comparison between the substrate dome 1 of the present invention and the conventional substrate dome 20 will be made. Since the thermal expansion coefficient of pure titanium is a ^{8. 8 X 10- 6, 1182. 8mm} X 8. 8 X 10- 6 X (300 ° C-25 and which calculates the amount of expansion as in the case of FIG. 6 ° C) = 2.86mm, which is about 50% less in expansion than stainless dome. As described with reference to FIG. 4, the thickness of the film deposited on the substrate 21 is inversely proportional to the square of the distance between the substrate 21 and the evaporation source. % Or less.

Next, the load on the substrate rotating mechanism will be compared. When 110 glass substrates of 70 mm x 70 mm x t2 are installed on a substrate dome with a diameter of 1100 mm and a radius of curvature of 900 mm, the conventional substrate dome 20 made of stainless steel weighs about 13.2 kg and has 110 glass substrates. The total weight was 15.9 kg. When the substrate dome 1 is made of pure titanium, the specific gravity is 4.51 and the weight of the substrate dome is about 7.6 kg. Similarly, if 110 boards are added in weight, the total weight is 10.3 kg, compared to the conventional board dome 20, the weight of the board dome alone is reduced by about 42%, and the total weight is reduced by about 35% . Therefore, the load on the bearing 22 is greatly reduced, so that the maintenance cycle can be significantly extended. In addition to the low coefficient of thermal expansion, the reduced weight also reduces the centrifugal force and gravity applied to the substrate dome itself, so that deformation can be greatly suppressed.

[0033] As described above, since the total weight is reduced by about 35%, the detachability with the apparatus is improved, and the deformation S due to the weight during storage can be suppressed. The substrate dough during transportation because the modulus of longitudinal elasticity 19. 7 X 10 ³ and compared to the longitudinal elastic coefficient of the pure titanium stainless steel is approximately half as 11. 6 X 10 ³ Deformation due to external force is small even when the robot is dropped.

[0034] Therefore, as described above, when the substrate dome 1 of pure titanium or a titanium alloy of the present invention is used, the temperature change and rotation during substrate heating and vapor deposition are compared with the case where the conventional substrate dome 20 is used. Deformation due to the influence of driving is suppressed, and changes in the substrate mounting position are suppressed as much as possible, so that the reproducibility of film formation is significantly improved. In addition, the reduced weight reduces the load on the bearing 22, etc., improving maintainability and improving detachability. In addition, deformation due to external forces such as falling during transportation is small, so it is possible to maintain high productivity continuously.

[0035] In the above-described embodiment, the film formation using the vapor deposition method has been described. However, the film formation method capable of implementing the apparatus and method of the present invention is not limited to the vapor deposition method, but includes the sputtering method and the ion plating method. And many others.

Claims

The scope of the claims

[1] A vacuum apparatus comprising: a vacuum chamber; and a substrate dome on which a film forming substrate is mounted and opposed to a bottom of the vacuum chamber,

Vacuum and wherein the thermal expansion coefficient of the material forming the substrate dome 17. less than 3 X 10_ ^6.

[2] A vacuum apparatus comprising a vacuum chamber and a substrate dome on which a film forming substrate is mounted and opposed to the bottom of the vacuum chamber,

A vacuum device characterized in that the material forming the substrate dome has a modulus of longitudinal elasticity of less than 19.7 × 10 ³ .

[3] A vacuum apparatus comprising a vacuum chamber and a substrate dome on which a film forming substrate is mounted and opposed to the bottom of the vacuum chamber,

A vacuum device characterized in that the specific gravity of the material forming the substrate dome is less than 7.93.

[4] A vacuum apparatus comprising a vacuum chamber, a substrate dome on which a film forming substrate is mounted, and a substrate dome opposed to the bottom of the vacuum chamber,

A vacuum device in which the material forming the substrate dome is titanium or titanium alloy.

5. The vacuum device according to claim 4, wherein the shape of the substrate dome is formed by drawing titanium or a titanium alloy.

[6] In a vacuum apparatus comprising a vacuum tank, a crucible on which a film-forming material placed on the bottom of the vacuum tank is placed, and a substrate dome on which a film-forming substrate is mounted and opposed to the film-forming material, the substrate dome A film forming method for depositing the film forming material on the film forming substrate in a state in which the film forming material is rotated. The film forming material and the film forming method are adjusted by controlling deformation due to centrifugal force or own weight or thermal expansion applied to the substrate dome. A film forming method characterized by maintaining a constant distance from a substrate and improving the film thickness distribution accuracy.

[7] At least a substrate dome, an evaporation source, and a substrate heating means are provided inside the vacuum chamber, and a film formation substrate is mounted on the substrate dome and rotated, and an electron beam is applied to the evaporation source arranged opposite to the film formation substrate. And an optical thin film forming apparatus for depositing a vaporized substance on the film forming substrate. And

An apparatus for forming an optical thin film, wherein the substrate dome is formed of titanium or a titanium alloy.