sputtering apparatus

Abstract

[The technical problem to be solved] A sputtering apparatus (SM) is provided that enables device miniaturization and effectively suppresses sputtering particles from bypassing. Technical means to solve the problem The system comprises a vacuum chamber (1) having a target (2) and a substrate stage (St). The substrate stage (St) has a stage body (6) for placing the substrate and a moving means (62) for moving it up and down. When the stage body moves upward to the substrate processing position, it has a shield (71) that limits the film formation area on the substrate. A shield plate (4) at a ground potential is arranged around the target. Two upper cylindrical wall portions (41, 42) are provided on the lower surface of the shield plate at different distances from the center of the target. A lower cylindrical wall portion (76) is provided on the upper surface of the shield, the upper end of which penetrates the gap between the two upper cylindrical walls. A labyrinthine gap (Gp2) is formed around the target and the film formation space between the target and the substrate through the upper and lower cylindrical wall portions.

Description

[Technical Field]

[0001] The present invention relates to a sputtering apparatus having a vacuum chamber for disposing of a target material and a substrate stage disposed therein. The substrate stage has: a stage body on which a substrate is disposed on an upper surface in an orientation facing the target material; and a moving means for moving the stage body relative to the target body in a vertical direction. [Previous Technology]

[0002] In the manufacturing process of flat panel displays, there is a film deposition process in which various thin films are deposited on the surface of a glass substrate (hereinafter referred to as "substrate") having a rectangular outline. In the film deposition process, sputtering equipment is widely used considering factors such as production efficiency. The size of the substrate to which the film is to be deposited has become larger with the advancement of generations (for example, 2300mm × 2700mm in the G8.7 generation), and its thickness is also very thin (for example, 0.5mm). When performing monolithic film deposition on such substrates, sputtering equipment of the so-called side deposition method is known to be used (for example, see Patent Document 1).

[0003] In the above-described sputtering apparatus, a space is required within the vacuum chamber to allow the substrate stage, on which the substrate is placed, to swing between a horizontal orientation with the substrate film-forming surface facing vertically upwards and an upright orientation with the film-forming surface facing horizontally. Therefore, the large size of the apparatus (vacuum chamber) is unavoidable. Furthermore, within the vacuum chamber, shielding plates (anti-adhesion plates) are provided not only in the film-forming space between the target and the substrate stage, but also around the target and substrate stage to prevent sputtering particles from adhering to the inner wall of the vacuum chamber and to shield various components present within the vacuum chamber. However, due to the presence of mechanisms that cause the substrate to swing, there are limitations in suppressing sputtering particles from bypassing the back side of the anti-adhesion plate. In other words, unlike sputtering apparatuses for semiconductor wafers, sputtering apparatuses for large-area glass substrates cannot effectively suppress sputtering particles from bypassing the back side of the anti-adhesion plate. [Prior Art Documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2024-24746 [Summary of the Invention]

[0005] [Problem to be Solved by the Invention] In view of the above points, the problem of the present invention is to provide a structure that enables device miniaturization and effectively suppresses sputtering particles from bypassing the device. [Means for Solving the Problem]

[0006] To solve the above-mentioned problems, the sputtering apparatus of the present invention includes a vacuum chamber for arranging a target material, and a substrate stage is provided in the vacuum chamber. The substrate stage has: a stage body facing the target material and having a substrate disposed on its upper surface; and a moving means for moving the stage body relative to the target material in the vertical direction. Its characteristic is that it is configured to include a shielding body for limiting the film deposition area on the substrate when the stage body moves upward to a substrate processing position, and film deposition is performed on the substrate through the sputtering target material at this substrate processing position. A shielding body is provided around the target material. A frame-shaped shielding plate at ground potential has two downward-extending upper cylindrical wall portions on its lower surface. These two upper cylindrical wall portions are configured with varying distances from the center of the target material. A lower cylindrical wall portion of a certain length is provided on the upper surface of the shielding body. This lower cylindrical wall portion of a certain length extends upward and its upper end penetrates the gap between the two upper cylindrical walls. A labyrinth structure gap is formed around the target material and the film-forming space between the target material and the substrate, in which the two upper cylindrical wall portions and the lower cylindrical wall portion engage in a non-contact manner.

[0007] According to the present invention, after a substrate transported by a transfer robot is placed on a stage body located at a substrate junction position, the stage body is separated from the target material at this junction position. The stage body moves upward, and the substrate moves to a substrate processing position facing the target material at a predetermined TS interval. At this time, since it is not necessary to provide space for swinging the target material in the vacuum chamber, miniaturization of the sputtering apparatus (vacuum chamber) can be achieved. When the stage body moves to the substrate processing position, a sputtering gas such as argon gas (possibly containing reactive gases such as oxygen gas and nitrogen gas) is introduced into the vacuum chamber in a vacuum atmosphere, and DC power with a negative potential is applied to the target material. In this way, a plasma is formed between the substrate and the target material, and the ions of the sputtering gas in the plasma sputter the target material. Sputtering particles scattered from the target material adhere to and deposit on the substrate surface according to a predetermined cosine law to form a predetermined thin film. During the sputtering process of the target material, sputtered particles are scattered to various places in the vacuum chamber outside the substrate, or bounce off and scatter further. However, since the target material and the film formation space are surrounded by a shielding plate and the upper and lower cylindrical walls that form the gap of the labyrinth structure, the sputtered particles (including bounced ones) can be effectively prevented from bypassing to, for example, the space on the back side of the target material.

[0008] Here, it is generally known that sputtered particles scattered from the target material bounce off a maximum of three times before losing their kinetic energy and remaining at that location. In this invention, the upper cylindrical wall portion closest to the center of the target material is referred to as the first wall portion, and the others as the second wall portions, and the area of ​​the first wall portion facing the lower cylindrical wall portion is larger than the area of ​​the second wall portion facing the lower cylindrical wall portion. Accordingly, sputtered particles attempting to bypass can bounce off as many times as possible within the facing surfaces of the first wall portion and the lower cylindrical wall portion, thus more effectively suppressing the bypassing of sputtered particles. The gaps in this labyrinth structure function as exhaust channels from the film-forming space; therefore, in order to ensure a certain exhaust conductivity, the size of the gap between the lower cylindrical wall portion and the first or second wall portion, as well as the lengths of the lower cylindrical wall portion, the first wall portion, and the second wall portion, are appropriately set.

[0009] Here, during film formation, since sputtered particles directly adhere to the portions of the first wall and lower cylindrical wall that are directly visible to the target, the amount of attached film is relatively large. Therefore, in this invention, it is preferable to perform a peel-suppression treatment on the portions of the first wall and the lower cylindrical wall facing the center of the target to suppress the peeling of the attached film. Accordingly, the replacement frequency of the first wall and the lower cylindrical wall can be reduced. Examples of peel-suppression treatments include surface treatments that form fine irregularities on the surface to increase the surface area (so-called AET treatment) and known thermal spraying or blasting processes.

[0010] Furthermore, in this invention, when an exhaust port is provided on the side wall or bottom wall of the vacuum chamber located below the substrate stage for the purpose of device miniaturization, it is preferable to further include a support portion that supports the aforementioned shield body within the vacuum chamber, and an exhaust path is formed in the support portion leading to a vacuum pump for vacuum exhaust within the vacuum chamber. Accordingly, during film deposition, the film deposition space is vacuumed at a consistently constant exhaust rate, enabling efficient film deposition on the substrate.

[0011] In this invention, a plurality of through holes extending in the vertical direction are formed in the stage body, and a support rod is inserted into each through hole. When the stage body is moved upward by the aforementioned moving means, the upper end of each support rod protrudes from the stage body and moves relative to the substrate transfer position where the substrate is transferred to the stage body, and the upper end of each support rod is inserted into the through hole and the substrate is processed to form a film on the substrate. If such a configuration is adopted, a sputtering apparatus for downward deposition can be realized.

[0012] Furthermore, in this invention, it is preferable to provide a foreign object falling prevention disc around the stage body located at the substrate junction. Accordingly, when components such as bolts fall below the stage body in a miniaturized vacuum chamber, bottles and the like can be prevented from falling to the bottom. At this time, if a cylindrical guide plate is suspended from the lower surface of the support portion of the shield, and an annular falling prevention disc is provided in the space between the guide plate and the substrate stage located at the substrate junction, problems such as blocking the exhaust path from the film-forming space to the vacuum pump and reducing the exhaust speed can be avoided.

Implementation Method

[0014] Hereinafter, referring to the drawings, an embodiment of the sputtering apparatus of the present invention will be described using a magnetron sputtering apparatus SM, which is suitable for depositing a film on one side of a glass substrate (hereinafter referred to as "substrate Sg") of a predetermined size with a rectangular outline by sputtering in a downward deposition manner. Hereinafter, the mutually orthogonal directions within the upper surface of the stage body described later will be defined as the X-axis direction and the Y-axis direction, and the stage body will move up and down in the Z-axis direction, which is orthogonal to the X-axis direction and the Y-axis direction. The terminology indicating direction is based on FIG1, which shows the setting posture of the magnetron sputtering apparatus SM.

[0015] Referring to Figures 1 and 2, the magnetron sputtering apparatus SM of this embodiment includes a vacuum chamber 1. An exhaust port 11 is provided on the side wall (or lower wall) of the vacuum chamber 1. The exhaust port 11 is connected to a vacuum pump 13, such as a rotary pump or a cryogenic pump, via an exhaust pipe 12, which can exhaust the vacuum in the vacuum chamber 1 to a predetermined pressure. A gas inlet 14 is also provided on the side wall of the vacuum chamber 1, through which a sputtering gas composed of rare gases such as argon (and possibly reactive gases such as oxygen) is introduced. The gas inlet 14 is connected to a gas source (not shown) via a gas inlet pipe 16, which is equipped with a mass flow controller 15, allowing the sputtering gas with controlled flow to be introduced into the vacuum chamber 1 (i.e., the film formation space 1a between the target 2 and the substrate Sg). A cathode unit Uc is detachably mounted on 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 one size larger than the substrate Sg; and multiple (six in this embodiment) magnet units 3 disposed 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 arranged side by side at equal intervals in the X-axis direction. The target 2 is selected according to the composition of the thin film to be deposited on the surface of the substrate Sg and is manufactured into a roughly rectangular cube shape by known methods. In the magnetron sputtering apparatus SM of this embodiment, thin films such as aluminum (Al), titanium (Ti), tungsten (W), and molybdenum (Mo) films can be deposited simply by changing the target 2. A back plate 22 is bonded to the upper surface of the target 2, and the target 2 can be cooled by circulating a coolant in the back plate 22 during sputtering. The target 2 is positioned with its sputtering surface 21 facing the vacuum chamber 1 and the substrate Sg, and is disposed on the upper part of the vacuum chamber 1 through the insulating plate 23. The target 2 is connected to the output 24a of the sputtering power supply 24 through the back plate 22, allowing the target 2 to be supplied with DC power having a negative potential or pulsed DC power. Additionally, a frame-shaped grounding shield 4 is provided inside the vacuum chamber 1, primarily to prevent the adhesion of thin films to the portion of the back plate 22 extending outward from the outer periphery of the target 2 and to the wall portion of the vacuum chamber 1 located on the back side of the back plate 22. In this embodiment, the shield 4 functions as an anode during sputtering.

[0017] Each magnet unit 3 has the same shape and has a support plate (yoke) 31 made of magnetic material with its long side along the Y-axis. The support plate 31 is set approximately parallel to the sputtering surface 21 of the target material 2 when it is not in use. On the lower surface of the support plate 31, a central magnet 32 ​​is arranged linearly in its center, and peripheral magnets 33 are arranged around the central magnet 32 ​​with gaps along the outer periphery of the support plate 31, with opposite polarities on the upper side. The magnet units 3 are arranged side by side such that the central magnets 32 of each magnet unit 3 are spaced apart in the X-axis direction with the Y-axis direction, and the distance between the sputtering surface 21 and each magnet unit 3 is a predetermined interval. The volume of the central magnet 32 ​​when converted to the same magnetization is designed to be equal to the sum of the volumes of each peripheral magnet 33 when converted to the same magnetization. A balanced closed-loop leakage magnetic field (not shown) acts on the film formation space 1a, such that a line passing through the position where the magnetic field perpendicular to the component is zero extends along the extension direction of the central magnet 32 ​​and closes in a racetrack shape. Each magnet unit 3 is connected to the drive shaft 51 of a drive means 5 such as a motor or cylinder, and reciprocates as a unit with a predetermined stroke value. In addition, a substrate stage St is arranged in front of the target material 2 in the vacuum chamber 1.

[0018] The substrate stage St includes a metal stage body 6, and the substrate Sg is disposed on the upper surface of the stage body 6 with its opposing edges aligned with the X-axis and Y-axis directions, respectively. A known method of assembling the stage body 6 to heat or cool the substrate Sg disposed on its upper surface allows the substrate to be controlled to a predetermined temperature during film deposition. A drive shaft 61, which penetrates and protrudes into the vacuum chamber 1 while maintaining the lower wall of the vacuum chamber 1 in an airtight state, is connected to the lower surface of the stage body 6. The stage body 6 can be moved up and down via the drive shaft 61 through a drive source 62 such as a cylinder or a direct-drive motor disposed outside the vacuum chamber 1. Thus, the stage body 6 moves up and down between a substrate junction position (shown in FIG. 2(b)) at a distance from the target 2 where the substrate Sg is joined, and a substrate processing position (shown in FIG. 1 and FIG. 2(a)) close to the target 2 where film deposition is performed. A plurality of through holes 63 extending in the vertical direction are formed on the stage body 6. The diameter of each through hole 63 and the distance between each through hole 63 can be appropriately set taking into account the substrate size or the temperature distribution of the substrate Sg during film formation.

[0019] Support rods 64 are inserted into each through hole 63 with a gap. Each support rod 64 is made of a metal rod with relatively high mechanical strength and has: a large-diameter portion 64a that is received with a gap in the through hole 63 at the substrate processing position; and a small-diameter portion 64b that extends continuously downward from the large-diameter portion 64a. In addition, a cap 64c made of a different material is installed at the upper end of each support rod 64. The cap 64c is made of a molded body of resin such as polyimide. Although not specifically illustrated, an upwardly extending mounting hole is formed on the lower surface of the cap 64c, and the cap 64c is installed by inserting it into the other small-diameter portion formed at the upper end of each support rod 64. A guide member 65 is vertically provided on the stage body 6 around the lower edge of each through hole 63.

[0020] The guide member 65 has a cylindrical member 65b of a predetermined length, which is made of a metal with relatively high mechanical strength and has through holes 65a through which the small-diameter portions 64b of each support rod 64 are inserted. On the upper surface of the cylindrical member 65b, there is a cylindrical protrusion 65c that extends upward around the upper edge of the through hole 65a and is inserted into the through hole 63 from the lower side. Thus, when the platform body 6 moves upward relative to each support rod 64, the lower surface of the large-diameter portion 64a of each support rod 64 abuts against the upper surface of the protrusion 65c, thereby engaging each support rod 64 (restricting the downward movement of each support rod 64) and preventing each support rod 64 from falling out of each through hole 63. Furthermore, the length of the large-diameter portion 64a of each support rod 64 can be appropriately set considering the amount of protrusion of each support rod 64 from the platform body 6 at the substrate junction position or the thickness of the platform body 6, etc. The diameter of the large-diameter portion 64a or the small-diameter portion 64b can be set considering the diameter of the through hole 63 or the insertion hole 65a. Further, a pair of guide rollers 66, 66 are provided on the cylindrical member 65b to guide the relative movement of each support rod 64 (small-diameter portion 64b) in the vertical direction.

[0021] A support plate 67 is disposed on the inner surface of the lower wall of the vacuum chamber 1, and a limiting stage 68 is disposed on the upper surface of the support plate 67. The limiting stage 68 abuts against the lower end face of each support rod 64 and restricts the downward movement of each support rod 64. The limiting stage 68 also functions as a stop member. Alternatively, the support plate 67 may be omitted, and the limiting stage 68 may be directly disposed on the inner surface of the lower wall of the vacuum chamber 1. In addition, a spacer member (not shown) may be detachably disposed on the upper or lower surface of the limiting stage 68 so that the amount of protrusion of each support rod 64 from the stage body 6 at the substrate junction position can be appropriately changed. When a substrate Sg is disposed on the upper surface of the stage body 6 at the substrate processing position for film deposition, a masking unit Um is disposed in the vacuum chamber 1 to cover the outer periphery of the substrate Sg and limit the film deposition range of the substrate Sg.

[0022] As shown in enlarged versions of Figures 2(a) and (b), the shielding unit Um has a first shielding body 7₁ and a second shielding body 7₂ made of a frame-like metal material that is not easily deformed by heat. The second shielding body 7₂ is mounted on a support frame 17, which is provided as a support portion on the inner side wall of the vacuum chamber 1, corresponding to the substrate processing position. The first shielding body 7₁ is provided on the flange portion 17a of the support frame 17 extending into the vacuum chamber 1 via an insulator 17b, and the first shielding body 7₁ is in an electro-floating state. In this embodiment, the first shielding body 7₁ constitutes a shielding body. The front end portion 71 of the first mask body 7₁ located inside the vacuum chamber 1 has an upper surface that is continuously inclined downward toward the inside of the vacuum chamber 1 in order to suppress so-called mask blur at the outer periphery of the substrate Sg. At the substrate processing position, the front end portion 71 is located directly above the outer periphery of the substrate Sg and has a gap in the vertical direction. In addition, a receiving recess (hereinafter referred to as "first receiving recess 72") is formed on the lower surface of the first mask body 7₁ located outside the vacuum chamber 1, which is located at the front end portion 71.

[0023] When a substrate Sg is disposed on the upper surface of the stage body 6, a first protruding wall 69 is provided on the outer periphery of the upper surface of the stage body 6 located outside the substrate Sg. Furthermore, when the stage body 6 moves upward to the substrate processing position, the first protruding wall 69 penetrates the first receiving recess 72 of the first shielding body 7₁, forming a labyrinth structure gap Gp1 around the substrate Sg where the first protruding wall 69 and the first receiving recess 72 engage in a non-contact manner. The size of the gap Gp1 can be appropriately set according to the sputtering conditions (target type, applied power, or sputtering time) and the thermal deformation (thermal expansion) of the first shielding body 7₁ and the second shielding body 7₂ during film formation. Therefore, if the stopping position of the stage body 6 at the substrate processing position is changed, the size of the gap Gp1 will change.

[0024] Here, when forming the first protruding wall 69 of the stage body 6, during film formation, sputtering particles rebounding from the first protruding wall 69 sometimes wrap around to the outer periphery of the substrate Sg. At this time, since the warpage of the substrate Sg during film formation varies depending on the sputtering conditions, the swirling sputtering particles may cause the outer periphery of the substrate Sg to locally adhere to the upper surface of the stage body 6. This poses a risk of substrate breakage during transport. Therefore, a frame-shaped support plate 6a of predetermined thickness is provided on the upper surface of the stage body 6 to abut against and support the inner portion of the outer periphery of the substrate Sg. Thus, by causing the substrate Sg (especially the outer periphery) to float from the upper surface of the stage body 6, adhesion between the outer periphery of the substrate Sg and the upper surface of the stage body 6 can be suppressed as much as possible. Although the support plate 6a is described as an example of the support body, multiple support pins may also be provided, for example.

[0025] A second protruding wall 73 is provided on the upper surface of the rear end portion of the first shield body 7₁ located outside the vacuum chamber 1. Correspondingly, a second receiving recess 74 with a gap and receiving the second protruding wall 73 is provided on the lower surface of the second shield body 7₂. In the assembled state of the first shield body 7₁ and the second shield body 7₂, a gap Gp2 is formed around the substrate Sg in a labyrinth structure where the second protruding wall 73 and the second receiving recess 74 engage in a non-contact manner. The upper surface of the front end portion of the second shield body 7₂ located inside the vacuum chamber 1 is formed as an inclined surface with the same inclination angle as described above, covering the upper surface portion of the first shield body 7₁ other than the front end portion 71, thereby suppressing the formation of the attached film as much as possible. Additionally, through holes 17c and 75 extending vertically are provided on the support frame 17 and the second shield body 7₂ disposed thereon. The through holes 17c and 75 form part of the exhaust path from the film-forming space 1a to the vacuum pump 13. Furthermore, at a predetermined position on the upper surface of the second shield body 7₂, a cylindrical wall portion (hereinafter referred to as "lower cylindrical wall portion 76") extending upward and reaching the vicinity of the shield plate 4 is provided to surround the periphery of the film-forming space 1a.

[0026] As shown in the enlarged version of Figure 3, two upper cylindrical wall portions are provided on the lower surface of the shielding plate 4 (hereinafter, the upper cylindrical wall portion located on the inner side of the vacuum chamber 1 is referred to as "first wall portion 41", and the other cylindrical wall portion is referred to as "second wall portion 42"). These two upper cylindrical wall portions extend downwards by a predetermined length, and their distance from the center of the target material 2 is set differently. In the assembled state of the shielding plate 4 and the second shielding body 7₂, the upper end portion of the lower cylindrical wall portion 76 invades the gap between the first wall portion 41 and the second wall portion 42, and a labyrinth structure gap Gp3 is formed around the film-forming space 1a, in which the first and second wall portions 41, 42 and the lower cylindrical wall portion 76 engage in a non-contact manner. The gap Gp3 also serves as an exhaust path from the film-forming space 1a to the vacuum pump 13. Therefore, the size of the gap Gp3 and the lengths of the lower cylindrical wall portion 76, the first wall portion 41 and the second wall portion 42 are appropriately set to ensure a certain exhaust conductance. However, it is preferable to set the area of ​​the first wall portion 41 and the lower cylindrical wall portion 76 facing each other to be greater than the area of ​​the second wall portion 42 and the lower cylindrical wall portion 76 facing each other.

[0027] Here, during film formation, since sputtered particles directly adhere to the portions of the first wall 41 and the lower cylindrical wall 76 that are directly visible to the target 2, the amount of attached film is relatively large. Therefore, it is preferable to perform a peeling suppression treatment Sp, which inhibits the peeling of the attached film, on at least the entire surface of the first wall 41 and the surface of the lower cylindrical wall 76 located on the inner side of the vacuum chamber 1. As illustrated in the enlarged view in FIG3, examples of peeling suppression treatment Sp include surface treatments that form fine irregularities on the surface to increase the surface area (so-called AET treatment) and known thermal spraying or blasting processes. This reduces the replacement frequency of the first wall 41 and the lower cylindrical wall 76. Such peeling suppression treatment can also be performed on the surface portion of the second shield 7₂ that is closer to the inner side of the vacuum container 1 than the lower cylindrical wall 76 and on the second wall 42. In addition, considering factors such as cost, for the area with the largest amount of attached film, in order to effectively suppress the peeling of the attached film, a melt spraying process is performed in addition to the AET process; for the area with the second largest amount of attached film, only a melt spraying process is performed; and for other areas, only a sandblasting process is performed. The following is a detailed explanation of the film formation on the substrate Sg.

[0028] When forming a film on substrate Sg, the stage body 6 of substrate stage St is first moved to the substrate junction position (see also Figure 2(b)). Although not specifically illustrated, at the substrate junction position, the lower surface of the small diameter portion 64b of each support rod 64 abuts against the upper surface of the limiting stage 68, and each support rod 64 protrudes from the stage body 6 by a predetermined amount. Considering the deflection caused by the weight of substrate Sg, the protrusion amount of each support rod 64 from the stage body 6 on the outer peripheral side of substrate Sg can also be set to be large. Then, through the substrate transfer outlet 18 (see Figure 1) opened on the side wall of vacuum chamber 1, a transfer robot is used to transfer substrate Sg into vacuum chamber 1. Once the substrate is received, it is supported by the upper end face of each support rod 64. After the transfer robot is moved back and the substrate transfer outlet 18 is closed, when the vacuum chamber 1 is evacuated to a predetermined pressure, the stage body 6 is moved upward relative to each support rod 64. At this point, unlike the so-called lateral deposition method, since there is no need to set up a space in the vacuum chamber 1 for the target 2 to swing, the miniaturization of the sputtering apparatus SM (vacuum chamber 1) becomes possible.

[0029] When the stage body 6 moves upward, the small-diameter portion 64b of each support rod 64 moves downward relative to the stage body 6 under the guidance of a pair of upper and lower guide rollers 66, 66. The lower surface of the large-diameter portion 64a abuts against the upper surface of the protrusion portion 65c, thereby engaging with each support rod 64. Thus, the downward movement of each support rod 64 is restricted, and each support rod 64 is prevented from falling out of each through hole 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 limiting stage 68. In addition, the large-diameter portion 64a of each support rod 64, including the cap 64c, is completely submerged in the through hole 63, reaching the substrate processing position (see Figure 1). At this time, the substrate Sg is placed on the upper surface of the stage body 6 in a surface-to-surface contact state. Furthermore, the first protruding wall 69 penetrates the first receiving recess 72 of the first shield 7₁, forming a labyrinthine gap Gp1 around the substrate Sg where the first protruding wall 69 and the first receiving recess 72 engage in a non-contact manner. Additionally, sputtering gases such as argon (possibly containing reactive gases such as oxygen or nitrogen) are introduced into the vacuum chamber 1 under a vacuum atmosphere. DC power with a negative potential is applied to the target 2 through the sputtering power supply 24. Thus, a plasma is formed in the film formation space 1a. The sputtering surface 21 of the target 2 is sputtered by ions from the sputtering gas in the plasma. Sputtering particles scattered from the target 2 adhere to and deposit on the lower surface of the substrate Sg through the first shield 7₁ according to a predetermined cosine law, forming a predetermined thin film. After film formation, the stage body 6 is moved from the substrate processing position to the substrate junction position.

[0030] According to the above embodiments, the sputtering apparatus can be miniaturized. Furthermore, during sputtering of the target 2, sputtering particles disperse into various parts of the vacuum chamber outside the substrate Sg, or bounce off and disperse further. However, since the target and the film-forming space 1a are surrounded by the lower cylindrical wall portion 76 and the upper cylindrical wall portions 41 and 42 of the gap Gp3 forming a labyrinth structure, the bypassing of sputtering particles from the target 2 or bounced sputtering particles can be effectively suppressed. Furthermore, by setting the area of ​​the first wall portion 41 facing the lower cylindrical wall portion 76 to be larger than the area of ​​the second wall portion 42 facing the lower cylindrical wall portion 76, sputtering particles attempting to bypass can bounce off as many times as possible within the planes where the first wall portion 41 and the lower cylindrical wall portion 76 face each other, thus more effectively suppressing the bypassing of sputtering particles.

[0031] During film deposition, the first masking body 7₁ remains in an electroflotated state, thus preventing the plasma from spreading to the vicinity of the first masking body 7₁ and locally heating the outer periphery of the substrate Sg. Furthermore, the upper surface of the first masking body 7₁ is partially covered by a second masking body 7₂ with a labyrinthine gap Gp2. Therefore, even with prolonged film deposition, the problem of most of the adhered film on the surface of the first masking body 7₁ sometimes communicating with the vacuum chamber (support) at ground potential can be avoided, ensuring stable film deposition. Moreover, through the labyrinthine gap Gp2 between the first masking body 7₁ and the second masking body 7₂, the exhaust path is ensured, further suppressing the problem of sputtering particles circling under the stage body 6. Furthermore, the size of the gap Gp1 in the labyrinth structure can be changed simply by altering the stopping position of the stage body 6 in the vertical direction at the substrate processing location. Therefore, by managing the gap size according to the type of target material, problems such as particle generation due to thermal expansion, for example, contact between the stage body 6 and the first shielding body 7₁, can be avoided. As a result, it is possible to form films of various types (Al, Ti, Mo, and W films) using a single sputtering apparatus SM without any modifications.

[0032] The embodiments of the present invention have been described above, but various modifications can be made without departing from the scope of the technical concept of the present invention. The above embodiments describe a magnetron sputtering apparatus SM for film formation using a downward deposition method, but it is not limited thereto. For example, the present invention can also be applied to sputtering apparatuses for film formation using an upward deposition method. Furthermore, the above embodiments are described using the example of a first wall portion 41 and a second wall portion 42 provided on the lower surface of a shielding plate 4, where, in the assembled state of the shielding plate 4 and the second shielding body 7₂, the upper end portion of the lower cylindrical wall portion 76 penetrates the gap between the first wall portion 41 and the second wall portion 42 to form a labyrinth structure gap Gp3, but it is not limited thereto. Although not specifically illustrated, for example, an upwardly recessed portion can be formed on the lower surface of the shielding plate 4, and in the assembled state of the shielding plate 4 and the second shielding body 7₂, the upper end portion of the lower cylindrical wall portion 76 penetrates the aforementioned recess to form a labyrinth structure gap. At this point, the size of the gap can be determined by taking into account the thermal deformation of the shielding plate 4 or the lower cylindrical wall 76 in the film formation.

[0033] Furthermore, in the aforementioned magnetron sputtering apparatus SM, maintenance such as replacement or cleaning of components (e.g., substrate stage St or masking unit Um) present in the vacuum chamber 1 is typically performed periodically. At this time, if an operator accidentally drops bottles or other objects onto the bottom surface of the vacuum chamber 1 located below the stage body 6, it is difficult to recover them without removing the components present in the vacuum chamber 1. Therefore, as shown in FIG4, it is preferable to suspend a cylindrical guide plate 81 on the lower surface of the support frame 17, and simultaneously provide an annular drop-prevention disc 82 with an open upper surface in the space between the guide plate 81 and the stage body 6 located at the substrate junction. This prevents bottles and other objects from falling to the bottom surface and avoids the problem of blocking the exhaust path from the film deposition space 1a to the vacuum pump 13, thus reducing the exhaust speed.

[0034] Furthermore, in the above-described magnetron sputtering apparatus SM, when the substrate Sg to which the film is to be formed is a large-area substrate (e.g., generation G8.7), the metal shielding unit Um becomes a heavy object. In this case, for example, a crane from a factory equipment is used to install and remove the shielding unit Um from the support frame 17. Here, one of the main purposes of the second shielding body 7₂ is to prevent the formation of an attached thin film on the first shielding body 7₁ (that is, to prevent conduction (grounding fault) between the vacuum chamber (support) with the ground potential). Although the second shielding body 7₂ is thermally expanded by radiation heating from the plasma, even if its relative position to the first shielding body 7₁ is slightly offset, it can effectively prevent the formation of an attached thin film on the first shielding body 7₁. Therefore, the gap Gp2 between the first shielding body 7₁ and the second shielding body 7₂ can be maintained within an appropriate range.

[0035] In the above-described sputtering apparatus SM, as shown in FIG5, multiple positioning pins 83 are erected at predetermined positions on the upper surface of the support frame 17, and positioning holes 84 for the positioning pins 83 to be inserted are formed on the upper surface of the second shield 7₂. When the second shield 7₂ is placed on the support frame 17 with each positioning pin 83 inserted into its respective positioning hole 84, the second shield 7₂ is in a generally positioned state relative to the support frame 17. After the second shield 7₂ is installed on the support frame 17, the support frame 17 and the second shield 7₂ are fixed by installing a fixing pin 86 into the mounting hole 85 formed on the support frame 17. At this time, the upper end of the fixing pin 86 reaches the receiving hole 87 provided in the second shield 7₂. The receiving hole 87 consists of: a circular main receiving hole 87a that fits into the upper part of the fixing pin 86; and an oblong secondary receiving hole 87b on the long side in the X-axis or Y-axis direction to allow thermal expansion of the second shield 7₂ in the X-axis or Y-axis direction. [Simplified Explanation of the Diagram]

[0013] [Fig. 1] A schematic cross-sectional view of the sputtering apparatus of this embodiment at the substrate processing position. [Fig. 2](a) is an enlarged cross-sectional view of an important part of the sputtering apparatus shown in Fig. 1, and (b) is an enlarged cross-sectional view of an important part when the stage body moves to the substrate junction position. [Fig. 3] An enlarged cross-sectional view of other important parts of the sputtering apparatus shown in Fig. 1. [Fig. 4] A schematic cross-sectional view of the sputtering apparatus of a modified example. [Fig. 5](a) and (b) are diagrams illustrating the support portion in which the second shield body is installed in the vacuum chamber.

Claims

1. A sputtering apparatus comprising a vacuum chamber for disposing of a target material, wherein a substrate stage is disposed within the vacuum chamber, the substrate stage comprising: a stage body facing the target material and having a substrate disposed on its upper surface; and a moving means for moving the stage body relative to the target body in a vertical direction; characterized in that: A shielding body is provided to limit the film deposition area on the substrate when the stage body moves upward to the substrate processing position. At this substrate processing position, film deposition is performed on the substrate using a sputtering target. A frame-shaped shielding plate at a ground potential is disposed around the target. Two downward-extending upper cylindrical wall portions are respectively provided on the lower surface of the shielding plate, and these two upper cylindrical wall portions are respectively disposed at varying distances from the center of the target. The shielding body comprises: a first shielding body, which is electrically floating and covers at least the outer periphery of the substrate; and a second shielding body, which covers the upper surface portion of the first shielding body with a gap in the vertical direction; and a support portion mounted within a vacuum chamber via the second shielding body, forming an exhaust path between the support portion and the second shielding body, thereby performing vacuum exhaust in the film deposition space between the target and the substrate. A lower cylindrical wall portion with a length is provided on the upper surface of the second shield body. The lower cylindrical wall portion with a length extends upward and its upper end penetrates the gap between the two upper cylindrical walls, forming a labyrinth structure gap in which the two upper cylindrical walls and the lower cylindrical wall portion engage in a non-contact manner around the target material and the film-forming space.

2. The sputtering apparatus as described in claim 1, wherein, The portion of the upper cylindrical wall closest to the center of the target material is referred to as the first wall portion, and the others are referred to as the second wall portions. The area of ​​the lower-facing cylindrical wall portion of the first wall portion is larger than the area of ​​the lower-facing cylindrical wall portion of the second wall portion.

3. The sputtering apparatus as described in claim 2, wherein, A peel suppression treatment is performed on the aforementioned first wall portion and the aforementioned lower cylindrical wall portion facing the center side of the target material to suppress the peeling of the attached film.

4. A sputtering apparatus as described in any of claims 1 to 3, wherein, It also includes: a support portion that supports the aforementioned shield body within the aforementioned vacuum chamber, and an exhaust path that leads to a vacuum pump for venting vacuum from the vacuum chamber is formed in the support portion.

5. A sputtering apparatus as described in any of claims 1 to 3, wherein, The configuration is as follows: multiple through holes extending in the vertical direction are formed on the aforementioned stage body, and support rods are inserted into each through hole. When the stage body is moved upward by the aforementioned moving means, the upper end of each support rod protrudes from the stage body and moves relative to the substrate handover position where the substrate is handed over to the stage body, and the upper end of each support rod is inserted into the through hole and the substrate processing position where the substrate is film-forming is performed.

6. The sputtering apparatus as claimed in claim 5, wherein, A foreign object falling prevention disc is provided around the aforementioned stage body located at the aforementioned substrate junction position.

Images