Substrate stage and magnetron sputtering apparatus equipped with a substrate stage

Abstract

This substrate stage provides a function that can simultaneously achieve both the ability to heat a rectangular substrate to a predetermined temperature with uniformity across the surface and the ability to create a predetermined temperature gradient between the center and the outer edge of the substrate. [Solution] The system comprises a stage body 6 on which a substrate is placed, and a heater 7 that heats the substrate by heat conduction. The upper surface of the stage body is divided into a central region Cz that is inward from its center and a peripheral region that surrounds this central region. The peripheral region has a first peripheral region Sz1 located on both sides of the central region in the Y-axis direction, and a second peripheral region Sz2 located on both sides of the central region in the X-axis direction. A heater 7 is provided for each of the central region, the first peripheral region, and the second peripheral region, and when each heater is operated to heat the substrate, the amount of heat generated in the first peripheral region is lower than the amount of heat generated in the central region, and the amount of heat generated in the second peripheral region is lower than the amount of heat generated in the first peripheral region.

Description

Technical Field

[0001] The present invention relates to a substrate stage including a stage body on which a substrate having a rectangular contour is installed on an upper surface, and a heater provided on the stage body for heating the substrate by heat conduction, and a magnetron sputtering apparatus including this substrate stage.

Background Art

[0002] In the manufacturing process of flat panel displays, there is a film forming process for forming various thin films on the surface of a glass substrate (hereinafter referred to as "substrate") having a rectangular contour. In the film forming process, for example, a magnetron sputtering apparatus in which a plurality of magnet units are arranged side by side at intervals in one direction on the side opposite to the sputtering surface of a single target may be used. The size of the substrate to be formed is increasing with the progress of generations (for example, 2300 mm × 2700 mm in the G8.7 generation), and its plate thickness is also thin (for example, 0.5 mm). In the vacuum chamber of a magnetron sputtering apparatus for forming a film on such a substrate, a substrate stage in which a heater is provided on a stage body on which the substrate is installed on the upper surface may be provided. And, the substrate can be heated to a predetermined temperature range (for example, a temperature range of 50°C to 200°C) by contact heat conduction from the stage body (for example, see Patent Documents 1 and 2). As the heater, for example, a sheath heater in which a heating element such as a nichrome wire that generates heat by energization is assembled in a metal pipe is used.

[0003] The calorific value of the sheath heater depends on the electric power (heater output) supplied by the energization power supply. Therefore, when incorporating a sheath heater into the stage body, it is known that the energization circuit (system) is divided into a plurality, and the calorific value can be adjusted for each energization circuit. And, if the heater output is adjusted for each energization circuit, even if the substrate has a large area, the substrate surface can be heated with good uniformity. However, when heating the substrate surface to a predetermined temperature with good uniformity, depending on the target type according to the thin film to be formed, although the uniformity of the film thickness distribution of the thin film after film formation does not change, it has been found that the in-plane uniformity of the film quality (sheet resistance value, film stress, etc.) deteriorates instead.

[0004] As a result of our diligent research, we have found that when depositing thin films, particularly tungsten and molybdenum films made of high-melting-point metals usable for electrode films, the film quality tends to deteriorate at the outer edges of the substrate, impairing the in-plane uniformity of the film quality. Normally, a frame-shaped anode plate is arranged around the target at ground potential. Therefore, when a plasma atmosphere is formed in the deposition space between the target and the substrate, depending on the position of the magnet unit, the plasma may spread to the vicinity of the anode plate. This is thought to be due to a localized increase in the amount of heat input caused by the plasma at the outer edges of the substrate (especially at both ends in the X-axis direction), resulting in a relatively high substrate temperature and a localized change in the crystal structure. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2023-69659 [Patent Document 2] Japanese Patent Publication No. 2023-183724 [Overview of the project] [Problems that the invention aims to solve]

[0006] In view of the above, the object of the present invention is to provide a substrate stage and a magnetron sputtering apparatus equipped with a substrate stage that can simultaneously achieve the function of heating a large-area substrate with a rectangular contour to a predetermined temperature with good in-plane uniformity and the function of creating a predetermined temperature gradient between the central part and the outer edge of the substrate. [Means for solving the problem]

[0007] To solve the above problems, the present invention provides a substrate stage comprising a stage body on which a substrate having a rectangular outline is placed on its upper surface, and a heater provided on the stage body for heating the substrate by heat conduction. The upper surface of the stage body is divided into a central region with its center inward and a peripheral region surrounding this central region. The peripheral region is located on both sides of the central region in the Y-axis direction and has a width that spans two sides of the substrate placed on the upper surface of the stage body that extend in the X-axis direction, and a second peripheral region is located on both sides of the central region in the X-axis direction and has a width that spans two sides of the substrate placed on the upper surface of the stage body that extend in the Y-axis direction. A heater is provided for each of these divided central region, first peripheral region, and second peripheral region, and when each heater is operated to heat the substrate, the amount of heat generated in the first peripheral region is lower than the amount of heat generated in the central region, and the amount of heat generated in the second peripheral region is lower than the amount of heat generated in the first peripheral region.

[0008] Furthermore, in order to solve the above problems, the magnetron sputtering apparatus of the present invention, which comprises a substrate stage according to claim 1 or claim 2 in a vacuum chamber, comprises a target positioned opposite to the substrate installed on the stage body, and a ground potential anode plate positioned around the target, wherein the target is a single unit larger than the contour of the substrate, a plurality of magnet units are arranged side by side with spacing in the X-axis direction on the side of the target facing away from the sputtering surface, and the apparatus further comprises a driving means that synchronizes the reciprocating motion of each magnet unit in the X-axis direction, and the amount of heat generated in the first peripheral region, second peripheral region and subdivided region is adjusted based on the amount of heat generated in the central region, according to the amount of heat input to the substrate due to plasma during film formation.

[0009] Based on the above, when the substrate is heated uniformly, the amount of heat generated in the central region of the stage body facing the central region of the substrate (i.e., the heater power density (W / cm²) corresponding to the area of ​​the central region) depends on the heating temperature at that time (e.g., 150°C). 2The heating temperature is determined. Then, the amount of heat generated in the first peripheral region is set to a range of, for example, 30% to 50% of the central region, and the amount of heat generated in the second peripheral region is set to a range of, for example, 80% to 99% of the first peripheral region. This allows the substrate to be heated uniformly across its entire surface (for example, within the range of 150°C ± 5°C), even if the substrate has a large surface area. As a result, this can be used to preheat the substrate to a predetermined temperature when depositing, for example, an aluminum film or a titanium film on the substrate surface.

[0010] On the other hand, when applying a predetermined temperature gradient (e.g., Δ100°C) to the substrate while considering localized heat input due to plasma, the amount of heat generated in the first peripheral region is set to 30% to 50% of the central region's heating temperature, and the amount of heat generated in the second peripheral region is set to 10% or less of the first peripheral region's heating temperature. This creates a temperature difference region where the temperature decreases towards the substrate edge, particularly on both ends in the X-axis direction, allowing the substrate to be heated while applying a predetermined temperature gradient. As a result, this can be used to heat a substrate while applying a predetermined temperature gradient, taking into account localized heat input due to plasma, when depositing a tungsten film or a molybdenum film on the substrate surface. Here, the divisions of the substrate stage between the central region and the first and second peripheral regions surrounding this central region (the areas of the central region, the first peripheral region, and the second peripheral region) are determined experimentally in advance. For example, a high-melting-point metal film is deposited on a substrate while it is heated uniformly across its entire surface, and at this time, the film quality degradation region that occurs on the peripheral edge of the substrate is identified. Accordingly, the areas of the first peripheral region and the second peripheral region (distances in the X-axis direction and Y-axis direction from the outer edge of the stage body) should be set, and the area inside these two regions should be designated as the central region.

[0011] Thus, in this invention, the central region is divided into a first peripheral region and a second peripheral region surrounding this central region, and a configuration is adopted in which the amount of heat generated in each of these regions is varied. Therefore, depending on the target type, it is possible to achieve both the function of heating a large-area substrate with a rectangular outline to a predetermined temperature with good in-plane uniformity and the function of creating a predetermined temperature gradient between the central part and the outer edge of the substrate. Furthermore, multiple types of thin films can be deposited with good uniformity of film thickness and film quality (i.e., even when depositing tungsten films or molybdenum films, good in-plane uniformity of film quality) using a single magnetron sputtering apparatus. In other words, the temperature distribution within the substrate surface can be adjusted according to the amount of heat input to the substrate due to the plasma during film deposition.

[0012] In this invention, the central region may further have subdivided regions on both sides of its X-axis direction, and when other heaters provided in each subdivided region are also operated to heat the substrate, a configuration may be adopted in which the amount of heat generated in the subdivided regions is lower than the amount of heat generated in the central region. By changing the amount of heat generated by the stage body between the main region of the central region and the second peripheral region other than the subdivided regions in this way, the film quality can be further adjusted according to the amount of heat input to the substrate due to plasma during film formation, and in-plane uniformity can be further improved. The area of ​​the subdivided regions can also be determined experimentally in advance. [Brief explanation of the drawing]

[0013] [Figure 1] A schematic cross-sectional view of a magnetron sputtering apparatus equipped with the substrate stage of this embodiment. [Figure 2] A cross-sectional view along the line II-II in Figure 1. [Figure 3] A diagram illustrating the state of a circuit board when it is heated. [Modes for carrying out the invention]

[0014] Hereinafter, with reference to the drawings, embodiments of the substrate stage ST and the magnetron sputtering apparatus SM equipped with the substrate stage ST of the present invention will be described as an example of application to a magnetron sputtering apparatus that deposits a film on one side of a predetermined-size glass substrate with a rectangular outline (hereinafter referred to as "substrate Sg") using a deposit-down method. In the following, the directions that are mutually orthogonal within the upper surface of the stage body described later will be referred to as the X-axis direction and the Y-axis direction, and the stage body will be assumed to move up and down in the Z-axis direction which is orthogonal to the X-axis direction and the Y-axis direction. The terms indicating direction will be based on Figure 1, which shows the installation position of the magnetron sputtering apparatus.

[0015] Referring to Figure 1, the magnetron sputtering apparatus SM of this embodiment includes a vacuum chamber 1. An exhaust port 11 is provided in the side wall of the vacuum chamber 1. The exhaust port 11 is connected to a vacuum pump 13, such as a rotary pump or cryopump, via an exhaust pipe 12, and the inside of the vacuum chamber 1 can be evacuated to a predetermined pressure. A gas inlet 14 is also provided in the side wall of the vacuum chamber 1 for introducing sputtering gas consisting of a noble gas such as argon (which may also contain reaction gases such as oxygen). The gas inlet 14 is connected to a gas source (not shown) via a gas introduction pipe 16 with a mass flow controller 15 interposed therebetween, and the flow-controlled sputtering gas can be introduced into the film deposition space 1a between the target and the substrate. A cathode unit Uc is detachably attached to the upper wall of the vacuum chamber 1.

[0016] The cathode unit Uc comprises a single target 2 having a contour corresponding to the substrate Sg and an area slightly larger than the substrate Sg, and a plurality of magnet units 3 (six in this embodiment) arranged above the target 2 (on the side facing away from the sputtering surface 21 of the target 2 and outside the vacuum chamber 1) and spaced equally apart in the X-axis direction. The target 2 is selected according to the composition of the thin film to be deposited on the substrate Sg surface and is manufactured in a substantially rectangular parallelepiped shape in plan view using known methods. In the magnetron sputtering apparatus SM of this embodiment, thin films such as aluminum films, titanium films, tungsten films, and molybdenum films can be deposited simply by changing the target 2. A backing plate 22 is bonded to the upper surface of the target 2, and a coolant is circulated through the backing plate 22 to cool the target 2 during sputtering. The target 2 is provided on the upper part of the vacuum chamber 1 via an insulating plate 23, with its sputtering surface 21 facing the substrate Sg with the inside of the vacuum chamber 1 facing it. The output 24a from the sputtering power supply 24 is connected to the target 2 via the backing plate 22, allowing for the application of DC power with a negative potential or pulsed DC power to the target 2. Furthermore, a frame-shaped shield plate 4 at ground potential is provided inside the vacuum chamber 1 to prevent film deposition on the portion of the backing plate 22 extending outward from the outer edge of the target 2. During sputtering, the shield plate 4 functions as an anode.

[0017] Each magnet unit 3 has the same shape and is provided with a magnetic material support plate (yoke) 31 that is longitudinal in the Y-axis direction and is positioned substantially parallel to the unused sputtering surface 21 of the target 2. On the lower surface of the support plate 31, a central magnet 32 ​​is provided linearly in the center, and peripheral magnets 33 are provided along the outer edge of the support plate 31 so as to surround the central magnet 32 ​​at predetermined intervals, with their upper polarities reversed. The magnet units 3 are arranged side by side such that the central magnets 32 of each magnet unit 3 are aligned in the Y-axis direction, with spacing in the X-axis direction, and the distance between the sputtering surface 21 and each magnet unit 3 is predetermined. The volume of the central magnet 32 ​​when converted to the same magnetization is designed to be equivalent to the sum of the volumes of each peripheral magnet 33 when converted to the same magnetization, and a closed-loop leakage magnetic field (not shown) that balances the deposition space 1a acts so that a line passing through the position where the vertical component of the magnetic field is zero extends along the direction of extension of the central magnet 32 ​​and closes in a racetrack-like manner. Each magnet unit 3 is connected to a drive shaft 51 of a drive means 5 such as a motor or air cylinder, and is moved back and forth as a single unit with a predetermined stroke value. The substrate stage ST of this embodiment is positioned inside the vacuum chamber 1, facing the target 2.

[0018] The substrate stage ST includes a stage body 6 made of metal. The substrate Sg is placed on the upper surface of the stage body 6 in a posture where the sides facing each other are aligned in the X-axis direction and the Y-axis direction, respectively. A drive shaft 61 that penetrates the lower wall portion of the vacuum chamber 1 while maintaining airtightness and protrudes into the vacuum chamber 1 is connected to the lower surface of the stage body 6. Then, the stage body 6 can move up and down via the drive shaft 61 by a drive source 62 such as an air cylinder or a linear motor installed outside the vacuum chamber 1. Thereby, the stage body 6 moves up and down between a substrate delivery position where the substrate Sg is delivered while being separated from the target 2 and a substrate processing position (the position shown in FIG. 1) where film formation is performed close to the target 2. A plurality of through holes 63 penetrating in the vertical direction are formed in the stage body 6. The aperture diameter of each through hole 63 and the distance between each pair of through holes 63 are appropriately set in consideration of the substrate size and the arrangement of a heater 7 described later. Support rods 64 are inserted into each through hole 63 with a gap therebetween. Each support rod 64 is composed of a metal rod having relatively high mechanical strength, and has a large-diameter portion 64a stored in the through hole 63 with a gap at the substrate processing position and a small-diameter portion 64b extending downward continuously from the large-diameter portion 64a. A cap body 64c made of a material different from that of the support rod 64 is attached to the upper end of each support rod 64. The cap body 64c is composed of a molded body made of a resin such as polyimide. Although not particularly illustrated and described, an attachment hole extending upward is formed on the lower surface of the cap body 64c, and the cap body 64c is attached by being inserted from above into another small-diameter portion formed at the upper end of each support rod 64.

[0019] Guide members 65 are vertically installed on the stage body 6 so as to surround the lower edge of each through hole 63. The guide member 65 has a cylindrical member 65b of a predetermined length made of metal with relatively high mechanical strength, through holes 65a through which the small diameter portion 64b of each support rod 64 is inserted. A cylindrical projection 65c is provided on the upper surface of the cylindrical member 65b, extending upward so as to surround the upper edge of the through hole 65a, and the projection 65c is fitted into the through hole 63 from below. As a result, when the stage body 6 moves upward relative to each support rod 64, the lower surface of the large diameter portion 64a of each support rod 64 comes into contact with the upper surface of the projection 65c, locking each support rod 64 in place (restricting the downward movement of each support rod 64) and preventing each support rod 64 from falling out of each through hole 63. The length of the large-diameter portion 64a of each support rod 64 is appropriately set considering the amount of protrusion of each support rod 64 from the stage body 6 at the substrate transfer position and the thickness of the stage body 6. The diameters of the large-diameter portion 64a and the small-diameter portion 64b are set considering the diameters of the through-holes 63 and insertion holes 65a. Furthermore, a pair of upper and lower guide rollers 66, 66 are provided on the cylindrical member 65b to guide the relative vertical movement of each support rod 64 (specifically the small-diameter portion 64b).

[0020] A support plate 67 is positioned on the inner surface of the lower wall of the vacuum chamber 1. A regulating base 68 is positioned on the upper surface of the support plate 67, which contacts the lower end surfaces of each support rod 64 to restrict the downward movement of each support rod 64. The regulating base 68 also acts as a stopper. Alternatively, the regulating base 68 can be directly positioned on the inner surface of the lower wall of the vacuum chamber 1 without installing the support plate 67. Furthermore, a spacer member (not shown) may be detachably installed on the upper or lower surface of the regulating base 68 to allow for appropriate adjustment of the amount each support rod 64 protrudes from the stage body 6 at the substrate transfer position. The stage body 6 is equipped with a heater 7 to control the substrate Sg to a predetermined temperature during film deposition by the sputtering method. The heater 7, although not specifically illustrated and described in detail, is a known sheath heater in which a heating element such as a nichrome wire that generates heat when energized is assembled inside a metal pipe, and is energized by a known power supply.

[0021] Referring also to FIG. 2, the upper surface of the stage body 6 is partitioned into a central region Cz (rectangular in length in the X-axis direction with its center inward) and a peripheral region Sz surrounding the central region Cz. The central region Cz is further partitioned into a main region Cz1 and sub-regions Cz2, Cz2 which are positioned on both sides of the main region Cz1 in the X-axis direction and have a smaller area than the main region Cz1. On the other hand, the peripheral region Sz has a first peripheral region Sz1 (rectangular in length in the X-axis direction) positioned on both sides of the central region Cz in the Y-axis direction and a second peripheral region Sz2 (rectangular in length in the Y-axis direction) positioned on both sides of the central region Cz in the X-axis direction. In the present embodiment, the second peripheral region Sz2 extends to both ends of the stage body 6 in the Y-axis direction, and the first peripheral region Sz1 is positioned between both ends of the second peripheral region Sz2 in the Y-axis direction, making the four corners of the stage body 6 substantially part of the second peripheral region Sz2, but it is not limited thereto. Also, the length of the first peripheral region Sz1 in the Y-axis direction is set so as to have a width straddling each of two sides of the substrate Sg extending in the X-axis direction in a state where the substrate Sg is positioned and installed on the stage body 6, and the length of the second peripheral region Sz2 in the X-axis direction is set so as to have a width straddling each of two sides of the substrate Sg extending in the Y-axis direction. Note that the areas of the central region Cz and the peripheral region Sz (width from the outer edge of the substrate Sg) are experimentally determined in advance according to the size of the substrate Sg, the temperature range when heating the substrate Sg, and the temperature gradient to be applied. Usually, the main region Cz1, which is a region less likely to be affected by plasma during film formation, has a large area, and the areas of the first peripheral region Sz1 and the second peripheral region Sz2, which are more likely to be affected by thermal shrinkage and plasma during film formation, are smaller than the main region Cz1, and the areas of the sub-regions Cz2 are also smaller than the main region Cz1.

[0022] A first heater 7a is incorporated as a sheath heater 7 to heat the main region Cz1 of the central region Cz, a second heater 7b is incorporated as a sheath heater 7 to heat the first peripheral region Sz1, a third heater 7c is incorporated as a sheath heater 7 to heat the second peripheral region Sz2, and a fourth heater 7d is incorporated as a sheath heater 7 to heat the sub-region Cz2 of the central region Cz. In this case, the type (material, etc.) and length of the first to fourth heaters 7a to 7d are appropriately set according to the area of ​​the central region Cz and the peripheral region Sz, the heating temperature range (for example, 50°C to 200°C), and the temperature gradient to be applied (for example, 50°C to 100°C), and they are provided in a predetermined wiring pattern. At this time, the sheath heaters may be arranged relatively densely at both ends in the Y-axis direction of the second peripheral region Sz2 so that the four corners of the stage body 6 can be heated efficiently. When heating the substrate Sg, the power density (W / cm²) of the first heater 7a to the fourth heater 7d is set such that the heat generated in the first peripheral region Sz1 is lower than that of the main region Cz1 of the central region Cz, and the heat generated in the second peripheral region Sz2 is lower than that of the first peripheral region Sz1, and the heat generated in the sub-region Cz2 of the central region Cz is lower than that of the main region Cz1. 2 ) will be adjusted.

[0023] As an example, the power density (W / cm²) of the first heater 7a depends on the temperature at which the substrate Sg is to be heated (e.g., 150°C). 2 Based on this, the power density of the second heater 7b is set to 1.1 to 1.75 times that of the first heater 7b, and the power density of the third heater 7c (W / cm²) is set. 2 The power density of the fourth heater 7d (W / cm²) is set to be 1.1 to 2.0 times that of the first heater 7a. 2 ) is set to 1.1 to 1.5 times that of the first heater 7a. On the other hand, when a predetermined temperature gradient is applied, the power density of the second heater 7b (W / cm²) is set to at least the power density of the second heater 7b (W / cm²) based on the power density of the first heater 7a. 2 The power density of the third heater (W / cm²) is set to 1.5 to 2.5 times that of the first heater 7a. 2 The power density of the fourth heater 7d (W / cm²) is set appropriately according to the area of ​​the second peripheral region, and in some cases the power density is set to zero. 2The setting for the first heater 7a is set to 2.0 to 4.5 times. The deposition of the film onto the substrate Sg is described in detail below.

[0024] When depositing a film onto the substrate Sg, the first heater 7a to the fourth heater 7d are powered from the power supply while the stage body 6 of the substrate stage ST is in the substrate transfer position. Although not specifically illustrated and explained, at the substrate transfer position, the lower surface of the small diameter portion 64b of each support rod 64 abuts against the upper surface of the regulating base 68, and each support rod 64 protrudes from the stage body 6 by a predetermined amount. Taking into account the deflection due to the weight of the substrate Sg, the amount of protrusion of the large diameter portion 64a of each support rod 64 from the stage body 6 on the outer edge side of the substrate Sg may be increased. Then, the substrate Sg is transported into the vacuum chamber 1 by a transport robot through the substrate outlet 17 (see Figure 1) opened in the side wall of the vacuum chamber 1, and the substrate is temporarily received so that it is supported by the upper end surfaces of each support rod 64. After the transport robot is moved away and the substrate outlet 17 is closed, the inside of the vacuum chamber 1 is evacuated to a predetermined pressure, and the stage body 6 is moved upward relative to each support rod 64.

[0025] As the stage body 6 moves upward, the small-diameter portion 64b of each support rod 64 moves downward relative to the stage body 6, guided by a pair of upper and lower guide rollers 66, 66. When the lower surface of the large-diameter portion 64a of the support rod 64 contacts the upper surface of the projection portion 65c, each support rod 64 is locked in place, restricting the downward movement of each support rod 64 and preventing them from falling out of the through holes 63. In this state, the lower surface of the small-diameter portion 64b of each support rod 64 is separated from the upper surface of the regulating base 68, and the large-diameter portion 64a, including the cap body 64c of each support rod 64, reaches a substrate processing position where it is completely immersed in the through hole 63 (see Figure 1). At this time, the substrate Sg is positioned in surface contact with the upper surface of the stage body 6. In this state, the substrate Sg is heated to a predetermined temperature by contact heat conduction from the stage body 6.

[0026] When heating a substrate Sg to a predetermined temperature (e.g., 150°C) with uniform in-plane heating across its entire surface, for example, the heat generation of the first peripheral region Sz1 is set to be in the range of 30% to 50% of the heat generation of the main region Cz1 of the central region Cz, the heat generation of the second peripheral region Sz2 is set to be in the range of 80% to 99% of the heat generation of the first peripheral region Sz1, and in addition, the heat generation of the sub-region Cz2 of the central region Cz is set to be in the range of 10% to 30% of the heat generation of the main region Cz1. As a result, it has been confirmed that even if the substrate Sg is a large-area substrate of the G8.7 generation, the substrate Sg can be heated with uniform in-plane heating (e.g., 150°C ± 5°C). Consequently, this method can be used to preheat the substrate Sg to a predetermined temperature when depositing, for example, an aluminum film or a titanium film on the surface of the substrate Sg.

[0027] On the other hand, when heating the substrate Sg while applying a predetermined temperature gradient between the central part and the outer edge (especially the ends in the X-axis direction), the amount of heat generated in the first peripheral region Sz1 is set to 30% to 50% of the heat generated in the main region Cz1 of the central region Cz, depending on the heating temperature of the main region Cz1 of the central region Cz, and the amount of heat generated in the second peripheral region Sz2 is set to 10% or less (or even zero in some cases) of the heat generated in the first peripheral region Sz1. In addition, the amount of heat generated in the sub-region Cz2 of the central region Cz is set to 60% to 80% of the heat generated in the main region Cz1 of the central region Cz. As a result, a temperature difference region is formed in the outer edge of the substrate Sg, especially on the ends in the X-axis direction, where the temperature decreases as you move towards the substrate edge, and it has been confirmed that the substrate Sg can be heated while applying a predetermined temperature gradient (for example, the temperature of the central part of the substrate Sg is 200°C and the temperature difference between the central part and the ends in the X-axis direction is, for example, 100°C). As a result, it can be used to heat the substrate Sg while applying a predetermined temperature gradient, taking into account localized heat input caused by plasma, such as when depositing a tungsten film or a molybdenum film (i.e., a film whose crystal structure is easily changed by the substrate temperature during deposition) on the surface of the substrate Sg. When the substrate Sg is heated to the predetermined temperature, the film is deposited on the upper surface of the substrate Sg by sputtering each target 2 in a vacuum chamber 1 with a vacuum atmosphere, and after deposition, the stage body 6 is moved down from the substrate processing position to the substrate handover position.

[0028] According to the above embodiment, it is possible to achieve both the function of heating a large-area substrate Sg with a rectangular contour to a predetermined temperature with good in-plane uniformity, and the function of creating a predetermined temperature gradient between the central region and the outer edge of the substrate Sg, depending on the target type. As a result, multiple types of thin films can be deposited with good uniformity of film quality (i.e., even when depositing tungsten films or molybdenum films, good in-plane uniformity of film quality) using a single magnetron sputtering apparatus SM.

[0029] To confirm the effects of the present invention, the following experiment was conducted using the magnetron sputtering apparatus SM described above. A G8.7 generation glass substrate was used as the substrate Sg, positioned and placed on the upper surface of the stage body 6, and the glass substrate was heated in a vacuum chamber 1 under a vacuum atmosphere. In the first experiment, the heat generation of the first peripheral region Sz1 was set to 40% of that of the main region Cz1, the heat generation of the second peripheral region Sz2 to 80% of that of the first peripheral region Sz1, and the heat generation of the sub-region Cz2 of the central region Cz to 20% of that of the main region Cz1, based on the heat generation of the main region Cz1 of the central region Cz, and the substrate was heated so that the center temperature of the substrate was 150°C. As a result, although not specifically illustrated and explained, it was confirmed that although the temperature was relatively low at both ends of the substrate Sg in the X-axis direction, the substrate surface was heated substantially uniformly within a range of ±5°C.

[0030] In the second experiment, using the heat generation of the main region Cz1 of the central region Cz as a reference, the heat generation of the first peripheral region Sz1 was set to 40% of that of the main region Cz1, the heat generation of the second peripheral region Sz2 was set to 0% of that of the first peripheral region Sz1, and the heat generation of the sub-region Cz2 of the central region Cz was set to 70% of that of the main region Cz1. The substrate was heated so that the central part reached 200°C, and the results are shown in Figure 3. According to this, the central part Sg1 of the substrate Sg corresponding to the central region Cz of the stage body 6 was heated to approximately 200°C throughout, and the parts Sg2 on both ends in the Y-axis direction of the substrate Sg corresponding to the first peripheral region Sz1 were heated to approximately 180°C. Furthermore, in the parts Sg3 to Sg5 on both sides in the X-axis direction of the substrate Sg corresponding to the second peripheral region Sz2, the temperature decreased towards the substrate edge in the X-axis direction, and part Sg5 was heated to 100°C higher than the central region Sg1. This confirmed that the regions Sg3 to Sg5 on both sides in the X-axis direction become temperature difference regions, allowing for the application of a predetermined temperature gradient.

[0031] In the third experiment, a molybdenum film with a thickness of 250 nm was deposited on a glass substrate that had been heated in the second experiment, and the in-plane distribution of the sheet resistance (Ω / □) within the substrate surface was measured. For the sputtering conditions, a molybdenum target of a predetermined purity was used, the TS distance between target 2 and substrate Sg was set to 110 mm, and Ar gas was introduced at 120 sccm to maintain the pressure in vacuum chamber 1 at 0.2 Pa. In addition, 200 kW of DC power was supplied to target 2 from the sputtering power supply 24 to sputter target 2. As a comparative experiment, the substrate was heated uniformly to 200°C across its entire surface, and then a molybdenum film with a thickness of 250 nm was deposited under the same conditions as above. According to this, in the comparative experiment, the in-plane distribution of film thickness was approximately ±9%, and the in-plane distribution of sheet resistance was approximately ±17%. At this time, it was found that the resistivity was highest in the center of the substrate, and the sheet resistance was lower at both ends of the substrate in the X-axis direction. In contrast, the molybdenum film in the third experiment showed an in-plane distribution of film thickness of approximately ±9%, similar to that in the comparative experiment. Furthermore, the difference in sheet resistance between the center of the substrate and both ends of the substrate in the X-axis direction was reduced, and it was confirmed that the in-plane distribution of sheet resistance was approximately ±10%.

[0032] Although embodiments of the present invention have been described above, various modifications are possible as long as they do not deviate from the technical concept of the present invention. In the above embodiments, the substrate stage ST and the magnetron sputtering apparatus SM equipped with the substrate stage ST of the present invention were described using the deposit-down method as an example, but the invention is not limited thereto and can be broadly applied to methods such as the so-called deposit-up method and the side-deposit method for film formation. Furthermore, in the above embodiments, the sheet resistance value was described as an example of the film quality, but by using the substrate stage of the present invention and applying a predetermined temperature gradient to the substrate, it is also possible to control the stress of the thin film, for example. Moreover, in the above embodiments, the use of a sheath heater as the heater 7 was described as an example, but the invention is not limited thereto and other known heating means can be used as long as they can set the amount of heat generated in the central region Cz and the peripheral region Sz to predetermined values. [Explanation of Symbols]

[0033] SM...Magnetron sputtering apparatus, ST...Substrate stage, Sg...Substrate (glass substrate), 1...Vacuum chamber, 2...Target, 3...Magnet unit, 4...Shield plate (anode plate), 5...Drive means, 6...Stage body, 7...Heater, 7a...First heater (heater component), 7b...Second heater (heater component), 7c...Third heater (heater component), 7d...Fourth heater (other heater component), Cz...Central region, Sz1...First peripheral region (peripheral region), Sz2...Second peripheral region (peripheral region).

Claims

1. A substrate stage comprising a stage body on which a substrate having a rectangular outline is placed on its upper surface, and a heater provided on the stage body for heating the substrate by heat conduction, The directions perpendicular to each other within the upper surface of the stage body are defined as the X-axis and Y-axis directions, and the upper surface of the stage body is divided into a central region with its center inward and a peripheral region surrounding this central region. The peripheral region has a first peripheral region located on both sides of the central region in the Y-axis direction and having a width that spans two sides extending in the X-axis direction of the substrate installed on the upper surface of the stage body, and a second peripheral region located on both sides of the central region in the X-axis direction and having a width that spans two sides extending in the Y-axis direction of the substrate installed on the upper surface of the stage body. A substrate stage characterized by having a heater provided for each of the partitioned central region, first peripheral region, and second peripheral region, and being configured such that when each heater is operated to heat the substrate, the amount of heat generated in the first peripheral region is lower than the amount of heat generated in the central region, and the amount of heat generated in the second peripheral region is lower than the amount of heat generated in the first peripheral region.

2. The substrate stage according to claim 1, characterized in that the central region further has subdivided regions on both sides of its X-axis direction, and when the substrate is heated by operating other heaters provided in each subdivided region, the amount of heat generated in the subdivided region is lower than the amount of heat generated in the central region.

3. A magnetron sputtering apparatus comprising a substrate stage according to claim 1 or claim 2 in a vacuum chamber, The stage body is equipped with a target positioned opposite to the substrate, and a ground potential anode plate positioned around the target, wherein the target is a single unit larger than the contour of the substrate, and multiple magnet units are arranged side by side at intervals in the X-axis direction on the side facing away from the sputtering surface of the target, and the stage further comprises a driving means that synchronizes the reciprocating motion of each magnet unit in the X-axis direction. A sputtering apparatus characterized in that the amount of heat generated in the first peripheral region, the second peripheral region, and the subdivided region is adjusted based on the amount of heat input to the substrate due to plasma during film formation, with the amount of heat generated in the central region as a reference.

Images