Sputtering device

Abstract

The invention provides a sputtering device (SM) capable of realizing miniaturization of the device and effectively suppressing detour falling of sputtering particles. The device comprises a target (2) and a vacuum chamber (1) with a substrate stage (St). The substrate stage (St) is provided with: a stage main body (6) on which a substrate is provided; and a moving device (62) that moves the rack body up and down. The apparatus includes a mask body (71) that restricts a film formation range with respect to the substrate when the stage main body is moved upward to the substrate processing position. A ground potential shield plate (4) is disposed around the target, and two upper cylindrical wall portions (41, 42) having different distances from the center of the target are provided on the lower surface of the shield plate. The upper surface of the mask body is provided with a lower cylindrical wall part (76), the upper end part of which is inserted into the gap between the two upper cylindrical walls, and the upper cylindrical wall part and the lower cylindrical wall part form a gap (Gp2) of a labyrinth structure on the outer side of the periphery of the target and the film forming space between the target and the substrate.

Description

TECHNICAL FIELD

[0001] The present application relates to a sputtering device having a vacuum chamber provided with a target, and a substrate stage provided in the vacuum chamber, the substrate stage having a stage main body on which a substrate is set in a posture opposite to the target, and a moving device that relatively moves the stage main body in the vertical direction. BACKGROUND

[0002] In a manufacturing process of a flat panel display, there is a film forming process of forming various thin films on the surface of a glass substrate (hereinafter referred to as "substrate") of a rectangular outline. In the film forming process, a sputtering device is widely used in consideration of productivity and the like. The size of the substrate as a film forming object is large-sized with the progress of generations (for example, 2300 mm x 2700 mm for G8.7 generation), and the thickness of the substrate is thin (for example, 0.5 mm). It is known that in the case of film forming on such a substrate in a single piece, a sputtering device of a so-called side deposition method is used (for example, refer to Patent Literature 1).

[0003] In the above-described sputtering device, a space is required in the vacuum chamber to swing the substrate stage on which the substrate is set between a horizontal posture in which the film forming surface of the substrate faces upward in the vertical direction and a standing posture in which the film forming surface faces in the horizontal direction, and therefore the device (vacuum chamber) inevitably becomes large-sized. Further, in the vacuum chamber, a shield plate (anti-adhesion plate) for preventing sputtering particles from adhering to the inner wall surface of the vacuum chamber or various components present in the vacuum chamber is provided not only in the film forming space between the target and the stage but also around the target or the stage, but there are limitations in suppressing the sputtering particles from circumferentially falling off to the back side of the anti-adhesion plate due to the presence of a mechanism for swinging the substrate and the like. That is, actually, unlike a sputtering device for film forming on a semiconductor wafer, in a sputtering device for film forming on a large-area glass substrate, the circumferential falling off of the sputtering particles to the back side of the anti-adhesion plate cannot be effectively suppressed.

[0004] PRIOR ART DOCUMENTS PATENT LITERATURE Patent Literature SUMMARY PROBLEMS TO BE SOLVED BY THE INVENTION In view of the above-described circumstances, the present application aims to provide a sputtering device capable of achieving a small-sized device and having a structure in which the circumferential falling off of sputtering particles can be effectively suppressed.

[0005] MEANS FOR SOLVING THE PROBLEMS To solve the above-mentioned technical problems, the sputtering apparatus of the present invention has a vacuum chamber in which a target is disposed, and a substrate stage is disposed in the vacuum chamber. The substrate stage has: a stage body on which a substrate is disposed in an orientation opposite to the target on its upper surface; and a moving device that moves the stage body relative to the target in the vertical direction; and a mask body that restricts the film deposition range of the substrate when the stage body is moved upward to a substrate processing position where film deposition is performed on the substrate by sputtering through the target. A frame-shaped shielding plate is disposed around the target at ground potential. Two upper cylindrical wall portions extending downward at different distances from the center of the target are respectively disposed on the lower surface of the shielding plate. A lower cylindrical wall portion extending upward and whose upper end penetrates the gap between the two upper cylindrical walls is disposed on the upper surface of the mask body. A labyrinth structure gap is formed around the target and the film deposition space between the target and the substrate, in which the two upper cylindrical wall portions and the lower cylindrical wall portions engage non-contactly.

[0006] According to the present invention, after the substrate, transported by a transport robot, is placed on the substrate body at the substrate junction position away from the target, the substrate body is moved upward, and the substrate is moved to a substrate processing position relative to the target at a predetermined TS interval distance. At this time, since there is no need to provide space within the vacuum chamber for target oscillation, miniaturization of the sputtering apparatus (vacuum chamber) is possible. When the substrate body moves to the substrate processing position, sputtering gases such as argon (sometimes containing reactive gases such as oxygen or nitrogen) are introduced into the vacuum chamber with a vacuum atmosphere, and a DC power with a negative potential is applied to the target. Plasma is then formed between the substrate and the target, and the target is sputtered by ions of the sputtering gas in the plasma. Sputtered particles that fly off from the target according to a predetermined cosine law adhere to and accumulate on the substrate surface, forming a predetermined thin film. During the sputtering process of the target, sputtered particles are scattered or recoiled into various parts of the vacuum chamber outside the substrate and further scattered. However, since the target or the film-forming space is surrounded by a shielding plate and the upper and lower cylindrical walls that form the gap of the labyrinth structure, it is possible to effectively suppress, for example, sputtered particles (including recoiled sputtered particles) from circling and falling into the space behind the target.

[0007] Here, it is known that sputtered particles ejected from the target lose their kinetic energy and remain stationary after three recoils. In this invention, a structure is adopted in which the portion of the upper cylindrical wall closest to the target center is designated as the first wall, and the remaining portion as the second wall. The area of ​​the first wall facing the lower cylindrical wall is larger than the area of ​​the second wall facing the lower cylindrical wall. This allows the sputtered particles to recoil as many times as possible on the opposing surfaces of the first and lower cylindrical walls, thus more effectively suppressing the detachment of sputtered particles. Since the gaps in this labyrinth structure function as venting pathways from the film-forming space, the size of the gap between the lower cylindrical wall and the first or second wall, as well as the lengths of the lower cylindrical wall, the first wall, and the second wall, are appropriately set to ensure adequate venting flow.

[0008] 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 coating amount is relatively large. 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 target center to suppress the peeling of the coating. This reduces the frequency of replacement of the first wall and lower cylindrical wall. Examples of peel-suppression treatments include surface treatments that increase the surface area by forming fine irregularities (so-called AET treatment), known sputtering treatments, or sandblasting treatments.

[0009] Furthermore, in this invention, when exhaust ports are provided on the side wall or bottom wall of the vacuum chamber located below the substrate stage to reduce the size of the device, it is preferable to also include a support portion supporting the mask body within the vacuum chamber, and an exhaust path connected to a vacuum pump for venting vacuum from the vacuum chamber is formed on the support portion. Thus, during the film deposition process, vacuum venting of the film deposition space is always performed at a certain exhaust rate, enabling efficient film deposition on the substrate.

[0010] In this invention, a sputtering apparatus for downward deposition can be realized by adopting the following structure: a plurality of through holes extending in the vertical direction are formed on the main body of the platform, and a support rod is inserted into each through hole. When the main body of the platform is moved upward by the moving device, it moves relative to the substrate junction position from the substrate junction position to the substrate processing position. The substrate junction position is the position where the upper end of each support rod protrudes from the main body of the platform and the substrate is joined to the main body of the platform. The substrate processing position is the position where the upper end of each support rod is inserted into the through hole and the substrate is processed for film deposition.

[0011] Furthermore, in this invention, it is preferable to provide a foreign object falling prevention disc around the main body of the stage located at the substrate junction. This prevents bolts and other components from falling to the bottom surface when they fall under the stage body in the miniaturized vacuum chamber. In this case, if a cylindrical guide plate is suspended from the lower surface of the mask support, and an annular falling prevention disc is provided in the space between the guide plate and the substrate stage located at the substrate junction, the undesirable situation of blocking the exhaust path from the film-forming space to the vacuum pump and reducing the exhaust speed can be avoided. Attached Figure Description

[0012] Figure 1 This is a cross-sectional schematic diagram of the sputtering apparatus of this embodiment at the substrate processing location.

[0013] Figure 2 (a) is Figure 1 (a) is an enlarged cross-sectional view of the main part of the sputtering apparatus shown, and (b) is an enlarged cross-sectional view of the main part when the main body of the stage is moved to the substrate junction position.

[0014] Figure 3 yes Figure 1 Enlarged cross-sectional view of the other main parts of the sputtering apparatus shown.

[0015] Figure 4 This is a cross-sectional schematic diagram of a sputtering apparatus involving a modified example.

[0016] Figure 5 Figures (a) and (b) illustrate the installation of a second mask on the support within the vacuum chamber. Detailed Implementation

[0017] Hereinafter, with reference to the accompanying drawings, an embodiment of the sputtering apparatus of the present invention will be described using an example of a magnetron sputtering apparatus SM suitable for depositing a film on one surface of a glass substrate (hereinafter referred to as "substrate Sg") of a specified size having a rectangular profile by sputtering in a downward deposition manner. Hereinafter, the directions orthogonal to each other on the upper surface of the stage body mentioned later will be defined as the X-axis direction and the Y-axis direction, and the stage body will move vertically in the Z-axis direction, which is orthogonal to the X-axis and Y-axis directions. The terms indicating direction are shown in the mounting posture of the magnetron sputtering apparatus SM. Figure 1 Based on.

[0018] Reference Figure 1 and Figure 2The 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, enabling the vacuum in the vacuum chamber 1 to be exhausted to a specified pressure. A gas inlet 14 is also provided on the side wall of the vacuum chamber 1 for introducing sputtering gas composed of rare gases such as argon (and sometimes reactive gases such as oxygen). The gas inlet 14 is connected to a gas source (not shown) via a gas inlet pipe 16 with an intervening mass flow controller 15, enabling the flow-controlled sputtering gas to be introduced into the vacuum chamber 1 (i.e., the film formation space 1a between the target 2 and the substrate Sg). Furthermore, a cathode unit Uc is detachably mounted on the upper wall of the vacuum chamber 1.

[0019] The cathode unit Uc includes: a single target 2 whose outline corresponds to the substrate Sg and whose area is slightly larger than the substrate Sg; and multiple (six in this embodiment) magnet units 3 arranged at equal intervals in the X-axis direction above the target 2 (on the side of the target 2 facing away from the sputtering surface 21 and outside the vacuum chamber 1). The target 2 is selected according to the composition of the thin film to be formed on the surface of the substrate Sg and is manufactured into a generally rectangular cuboid shape when viewed from above using known methods. In the magnetron sputtering apparatus SM of this embodiment, thin films such as aluminum (Al), titanium (Ti), tungsten (W), or molybdenum (Mo) films can be formed simply by changing the target 2. A back plate 22 is bonded to the upper surface of the target 2, and during sputtering of the target 2, a coolant can be circulated in the back plate 22 to cool the target 2. The target 2 is positioned at the upper part of the vacuum chamber 1 with its sputtering surface 21 facing the inside of the vacuum chamber 1 and opposite to the substrate Sg, spaced apart from the insulating plate 23. The output 24a from the sputtering power supply 24 is connected to the target 2 via the backplate 22, enabling the application of a negatively charged DC power or a pulsed DC power to the target 2. Furthermore, within the vacuum chamber 1, a frame-shaped ground potential shielding plate 4 is provided, primarily to prevent coating on the portion of the backplate 22 extending outward from the outer periphery of the target 2 or on the wall portion of the vacuum chamber 1 located on the back side of the backplate 22. In this embodiment, the shielding plate 4 functions as an anode during sputtering.

[0020] Each magnet unit 3 has the same shape and has a support plate (yoke) 31 made of magnetic material, which is arranged approximately parallel to the unused sputtering surface 21 of the target 2 and whose long side is in the Y-axis direction. On the lower surface of the support plate 31, the upper side is provided with alternating polarities: a central magnet 32 ​​arranged in a straight line at its center; and peripheral magnets 33 arranged along the outer periphery of the support plate 31, leaving gaps around the central magnet 32. Moreover, each magnet unit 3 is arranged side by side with the central magnet 32 ​​aligned with the Y-axis direction, leaving gaps in the X-axis direction, and the distance between the sputtering surface 21 and each magnet unit 3 is at 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, so that a closed-loop leakage magnetic field (not shown) in balance acts in the film formation space 1a, so that the line passing through the position where the vertical component of the magnetic field is zero extends along the extension direction of the central magnet 32 ​​and closes into a racetrack shape. Each magnet unit 3 is connected to the drive shaft 51 of the drive device 5, such as an electric motor or cylinder, and reciprocates in one piece with a specified stroke value. In addition, a substrate platform St is arranged in the vacuum chamber 1 opposite to the target 2.

[0021] The substrate stand St has a metal stand body 6, and substrates Sg are arranged on the upper surface of the stand body 6 with their opposite edges aligned with the X-axis and Y-axis directions, respectively. A known mechanism for heating or cooling the substrates Sg on its upper surface can be assembled on the stand body 6, allowing the substrates to be controlled at a specified temperature during film deposition. A drive shaft 61, which is airtight, penetrates the lower wall of the vacuum chamber 1 and protrudes into the vacuum chamber 1, is connected to the lower surface of the stand body 6. Furthermore, the stand body 6 can move freely up and down via the drive shaft 61 using a drive source 62 such as a cylinder or a direct-drive motor located outside the vacuum chamber 1. Thus, at the substrate junction position where the stand body 6 leaves the target 2 and the substrate Sg is transferred (… Figure 2 (b) shows the location) and the substrate processing location near the target 2 where film formation is performed ( Figure 1 and Figure 2 The position shown in (a) can be moved up and down. Multiple through holes 63 are formed on the main body 6 of the platform in the vertical direction. Taking into account the substrate size and the temperature distribution of the substrate Sg during film formation, the diameter of each through hole 63 and the distance between each through hole 63 are appropriately set.

[0022] Support rods 64 are inserted into each through hole 63 with gaps. Each support rod 64 is made of a metal rod with relatively high mechanical strength and has a large-diameter portion 64a that is stored in the through hole 63 with gaps at the substrate processing position; and a small-diameter portion 64b that extends continuously downward from the large-diameter portion 64a. Furthermore, a cover 64c made of a different type of material is installed at the upper end of each support rod 64. The cover 64c is, for example, made of a molded resin material such as polyimide. Although not specifically illustrated, an upwardly extending mounting hole is formed on the lower surface of the cover 64c, and the cover 64c is installed by inserting it from above into the other small-diameter portions formed at the upper end of each support rod 64. On the stand body 6, a guide member 65 is vertically provided to surround the lower edge of each through hole 63.

[0023] The guide member 65 has a cylindrical member 65b of a predetermined length, which is made of a metal with high mechanical strength and has through holes 65a through which the small-diameter portions 64b of each support rod 64 pass. A cylindrical protrusion 65c is provided on the upper surface of the cylindrical member 65b, extending upwards to surround the upper edge of the through hole 65a. The protrusion 65c is fitted into the through hole 63 from its lower side. Thus, when the platform body 6 moves upwards 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 locking each support rod 64 (restricting downward movement of each support rod 64) and preventing each support rod 64 from falling out of the 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 main body 6 at the substrate junction and the thickness of the main body 6. Furthermore, the diameters of the large-diameter portion 64a and the small-diameter portion 64b are set considering the diameters of the through hole 63 and the through hole 65a. Moreover, a pair of upper and lower guide rollers 66 are provided on the cylindrical member 65b to guide the relative movement of each support rod 64 (the small-diameter portion 64b) in the vertical direction.

[0024] 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 to restrict the downward movement of each support rod 64, and also acts 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. Furthermore, spacer members (not shown) may be detachably disposed on the upper or lower surface of the limiting stage 68 to appropriately change the amount of protrusion of each support rod 64 from the main body 6 at the substrate junction position. Moreover, in the substrate processing position, when a substrate Sg is disposed on the upper surface of the main body 6 for film deposition, in order to cover the outer periphery of the substrate Sg and limit the film deposition range towards the substrate Sg, the mask unit Um is disposed inside the vacuum chamber 1.

[0025] Mask unit Um such Figure 2 As shown in (a) and 2(b), a first mask 71 and a second mask 72 are respectively made of a metal material that is frame-shaped and not easily deformed by heat. The second mask 72 is mounted on a support frame 17, which serves as a support. The support frame 17 is disposed on the inner side wall of the vacuum chamber 1, corresponding to the substrate processing position. Furthermore, the first mask 71 is disposed on the flange portion 17a of the support frame 17 extending toward the inside of the vacuum chamber 1, with an insulator 17b spaced between them. The first mask 71 is electrically levitated. In this embodiment, the first mask 71 constitutes a mask body. The front end portion 71 of the first mask 71 located inside the vacuum chamber 1 is formed as an inclined surface whose upper surface is continuously inclined downward toward the inside of the vacuum chamber 1, so as to suppress so-called mask blurring of the substrate Sg at the outer periphery. At the substrate processing position, the front end portion 71 is located directly above the outer periphery of the substrate Sg with a gap in the vertical direction. Furthermore, a receiving recess (hereinafter referred to as "first receiving recess 72") is formed on the lower surface of the first mask body 71, which is located further outside the vacuum chamber 1 than the front end portion 71.

[0026] When a substrate Sg is placed 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 around the substrate Sg. Furthermore, when the stage body 6 is moved upward to the substrate processing position, the first protruding wall 69 penetrates the first receiving recess 72 of the first mask 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. The size of the gap Gp1 is appropriately set according to the sputtering conditions (target type, applied power, or sputtering time) and the thermal deformation (thermal expansion) of the first mask 71 and the second mask 72 during the film formation process. At this time, the size of the gap Gp1 can be changed by changing the stopping position of the stage body 6 at the substrate processing position.

[0027] Here, when the first protruding wall 69 of the stage body 6 is formed, during film formation, sputtering particles that bounce off the first protruding wall 69 may sometimes get caught around the outer periphery of the substrate Sg. At this time, since the amount of warpage of the substrate during film formation varies depending on the sputtering conditions, the outer periphery of the substrate Sg and the upper surface of the stage body 6 may sometimes be partially fixed by the caught sputtering particles, thus posing a risk of substrate breakage during substrate Sg transport. Therefore, a frame-shaped support plate 6a of a predetermined thickness is provided on the upper surface of the stage body 6, which abuts against and supports the substrate Sg at a portion further inward than its outer periphery. This allows the substrate Sg (especially its outer periphery) to float off the upper surface of the stage body 6, minimizing the fixation of the outer periphery of the substrate Sg to the upper surface of the stage body 6. Furthermore, while the support plate 6a has been described as an example of a support body, multiple support pins could also be used.

[0028] On the upper surface of the rear end portion of the first mask 71 located outside the vacuum chamber 1, a second protruding wall 73 is provided, which stands upright. Correspondingly, on the lower surface of the second mask 72, a second receiving recess 74 is provided to receive the second protruding wall 73 with a gap. In the assembled state of the first mask 71 and the second mask 72, a labyrinth structure gap Gp2 is formed around the outer side of the substrate Sg, in which the second protruding wall 73 and the receiving recess 74 engage in a non-contact manner. The front end portion of the second mask 72 located inside the vacuum chamber 1 is formed as an inclined surface whose upper surface is inclined at the same angle as described above, covering the upper surface portion of the first mask 71 other than the front end portion 71, which can suppress the formation of the coating as much as possible. Furthermore, through holes 17c and 75 extending in the vertical direction are provided on the support frame 17 and the second mask 72 provided on the support frame 17, and the through holes 17c and 75 constitute part of the exhaust path from the film formation space 1a to the vacuum pump 13. Furthermore, at a predetermined position on the upper surface of the second mask body 72, a cylindrical wall portion (hereinafter referred to as "lower cylindrical wall portion 76") extending upward and reaching the vicinity of the shielding plate 4 is provided, surrounding the film-forming space 1a.

[0029] like Figure 3As shown in the enlarged view, two upper cylindrical wall portions (hereinafter, the one located inside the vacuum chamber 1 will be referred to as "first wall portion 41", and the other cylindrical wall portion as "second wall portion 42") extending downwards at a predetermined length are respectively disposed on the lower surface of the shielding plate 4 with varying distances from the center of the target 2. In the assembled state of the shielding plate 4 and the second mask 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, forming a labyrinthine structure gap Gp3 around the outer periphery of the film-forming space 1a, where the first and second wall portions 41, 42 and the lower cylindrical wall portion 76 engage non-contactly. The gap Gp3 also serves as an exhaust path from the film-forming space 1a to the vacuum pump 13. Therefore, in order to ensure a certain exhaust flow, 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, but it is preferable to set the area opposite to the lower cylindrical wall portion 76 such that the first wall portion 41 is larger than the second wall portion 42.

[0030] 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 deposited film is relatively large. Therefore, it is preferable to perform a peeling suppression treatment Sp to inhibit film peeling on at least the entire surface of the first wall 41 and the surface of the lower cylindrical wall 76 located inside the vacuum chamber 1. As the peeling suppression treatment Sp, such as... Figure 3 As illustrated in the enlarged description, examples include surface treatments that increase surface area by forming fine irregularities on the surface (so-called AET treatment), known spray plating, or sandblasting. This reduces the frequency of replacement between the first wall portion 41 and the lower cylindrical wall portion 76. Such peeling suppression treatment can also be applied to the surface portion of the second mask 72 that is closer to the inner side of the vacuum chamber 1 than the lower cylindrical wall portion 76, or to the second wall portion 42. Furthermore, for example, considering cost, in order to effectively suppress peeling of the coating in the portion with the largest coating amount, spray plating can be performed on top of AET treatment; then, only spray plating can be performed in the portion with a large coating amount, and only sandblasting can be performed in the other portions. The film formation on the substrate Sg will be specifically described below.

[0031] When depositing a film on substrate Sg, firstly, the main body 6 of the substrate stage St is moved to the substrate junction position (also refer to...). Figure 2 (b) Although not specifically illustrated, at the substrate junction, 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 the substrate Sg, the amount by which each support rod 64 protrudes from the outer periphery of the stage body 6 of the substrate Sg can be increased. Then, through the substrate delivery outlet 18 (see reference) opened in the side wall of the vacuum chamber 1... Figure 1The substrate Sg is transported into the vacuum chamber 1 by a transport robot, and is temporarily received with the substrate supported by the upper surfaces of each support rod 64. After the transport robot retracts and the substrate delivery outlet 18 is closed, the vacuum chamber 1 is evacuated to a specified pressure, and the stage body 6 is moved upward relative to each support rod 64. At this time, unlike the so-called side deposition method, it is not necessary to set up a space in the vacuum chamber 1 for the target 2 to swing, thus enabling miniaturization of the sputtering apparatus SM (vacuum chamber 1).

[0032] When the platform body 6 moves upward, the small-diameter portion 64b of each support rod 64 is guided by a pair of upper and lower guide rollers 66 and moves downward relative to the platform body 6. When the lower surface of its large-diameter portion 64a abuts against the upper surface of the protrusion portion 65c, thereby locking each support rod 64, 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 platform 68. Furthermore, the large-diameter portion 64a of each support rod 64, including the cover 64c, reaches the substrate processing position where it is completely submerged in the through hole 63 (see reference). Figure 1 At this point, the substrate Sg is positioned with its upper surface in contact with the upper surface of the stage body 6. Furthermore, the first protruding wall 69 penetrates the first receiving recess 72 of the first mask 71, forming a labyrinthine gap Gp1 around the outer periphery of the substrate Sg where the first protruding wall 69 and the first receiving recess 72 engage without contact. Then, sputtering gases such as argon (sometimes containing reactive gases such as oxygen or nitrogen) are introduced into the vacuum chamber 1 under a vacuum atmosphere. A DC power with a negative potential is applied to the target 2 via the sputtering power supply 24. This forms a plasma in the film-forming space 1a, and ions from the sputtering gas in the plasma sputter the sputtering surface 21 of the target 2. Sputtered particles, scattering from the target 2 according to a predetermined cosine law, pass over the first mask 71 and accumulate on the lower surface of the substrate Sg, forming a predetermined thin film. After film formation, the stage body 6 moves downward from the substrate processing position to the substrate junction position.

[0033] By adopting the above-described embodiments, miniaturization of the sputtering apparatus can be achieved. Furthermore, during the sputtering process of the target 2, sputtered particles scatter to various locations within the vacuum chamber outside the substrate Sg, or recoil and further scatter. However, since the target 2 or the film-forming space 1a is 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 scattering and shedding of sputtered particles from the target 2 or recoiled sputtered particles can be effectively suppressed. Moreover, since the area of ​​the first wall portion 41 opposite the lower cylindrical wall portion 76 is set to be larger than that of the second wall portion 42, sputtered particles that are to scatter and detach can be recoiled as many times as possible on the surfaces of the first wall portion 41 and the lower cylindrical wall portion 76, further effectively suppressing the scattering and shedding of sputtered particles.

[0034] During the film deposition process, since the first mask 71 is maintained in an electrically floating state, it is possible to avoid the undesirable situation of plasma expanding to the vicinity of the first mask 71 and locally heating the outer periphery of the substrate Sg. Furthermore, since the upper surface of the first mask 71 is covered by the second mask 72 with a gap Gp2 in the labyrinth structure, even during long-term film deposition processing, it is possible to avoid coating on most of the surface of the first mask 71, and depending on the situation, to avoid the undesirable situation of conduction to the vacuum chamber (support) at ground potential, thus ensuring stable film deposition. Moreover, by utilizing the gap Gp2 in the labyrinth structure between the first mask 71 and the second mask 72, an exhaust path is ensured, while further suppressing sputtered particles from escaping and falling off below 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 target type, undesirable situations such as particle generation due to thermal expansion, for example, when the stage body 6 comes into contact with the first mask 71, can be avoided. Thus, a structure for forming various thin films (Al films, Ti films, Mo films, or W films) using a single sputtering device SM can be realized without any modifications.

[0035] The embodiments of the present invention have been described above, but various modifications can be made without departing from the technical concept of the present invention. In the above embodiments, a magnetron sputtering apparatus SM for film formation by downward deposition has been described, but it is not limited thereto. For example, the present invention can also be applied to sputtering apparatuses for film formation by upward deposition. Furthermore, in the above embodiments, an example was described where a first wall portion 41 and a second wall portion 42 are provided on the lower surface of a shielding plate 4, and in the assembled state of the shielding plate 4 and the second mask 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 mask body 72, the upper end portion of the lower cylindrical wall portion 76 penetrates the aforementioned recess to form a labyrinth structure gap. In this case, the size of the gap is set considering the thermal deformation of the shielding plate 4 or the lower cylindrical wall portion 76 during film formation.

[0036] However, in the aforementioned magnetron sputtering apparatus SM, maintenance such as periodic replacement or cleaning of components (e.g., substrate stage St or mask unit Um) within the vacuum chamber 1 is typically performed. At this time, if an operator accidentally drops bolts or similar items onto the bottom surface of the stage body 6 within the vacuum chamber 1, it is difficult to retrieve them without disassembling the components within the vacuum chamber 1. Therefore, as...Figure 4 As shown, a cylindrical guide plate 81 is preferably suspended on the lower surface of the support frame 17, and an annular anti-drop disc 82 with an open upper surface is provided in the space between the guide plate 81 and the stage body 6 located at the junction with the substrate. This prevents bolts and the like from falling to the bottom surface and avoids adverse situations such as blockage of the exhaust path from the film-forming space 1a to the vacuum pump 13, which would reduce the exhaust speed.

[0037] Furthermore, in the aforementioned magnetron sputtering apparatus SM, when the substrate Sg to which the film is to be deposited is a large-area substrate (e.g., G8.7 generation), the metal mask unit Um is relatively heavy. In this case, for example, a crane from a factory equipment is used to install and remove the mask unit Um from the support frame 17. Here, one of the main purposes of the second mask 72 is to prevent coating onto the first mask 71 (i.e., to prevent the ground potential from being connected to the vacuum chamber (support part) (grounding fault)). The second mask 72 is heated by radiation from the plasma and expands thermally, but even if its relative position to the first mask 71 is slightly offset, it can effectively prevent coating onto the first mask 71. Therefore, it is sufficient to maintain the gap Gp2 between the first mask 71 and the second mask 72 within an appropriate range.

[0038] In the aforementioned sputtering apparatus SM, such as Figure 5 As shown, multiple positioning pins 83 are vertically arranged at predetermined positions on the upper surface of the support frame 17, and positioning holes 84 through which the positioning pins 83 pass are formed on the upper surface of the second mask body 72. If the second mask body 72 is installed on the support frame 17 with each positioning pin 83 passing through each positioning hole 84, the second mask body 72 will be roughly positioned relative to the support frame 17. After the second mask body 72 is installed on the support frame 17, the support frame 17 and the second mask body 72 are fixed by installing fixing pins 86 in the mounting holes 85 formed on the support frame 17. At this time, the upper end of the fixing pin 86 reaches the receiving hole 87 provided on the second mask body 72. The storage hole 87 consists of a circular main storage hole 87a and an oblong secondary storage hole 87b. The main storage hole 87a is fitted into the upper part of the fixing pin 86, and the long side of the secondary storage hole 87b is in the X-axis direction or the Y-axis direction to allow the second mask body 72 to expand thermally in the X-axis direction or the Y-axis direction.

[0039] Explanation of reference numerals in the attached figures SM. Magnetron sputtering apparatus (sputtering device), St. Substrate stand, Sg. Substrate, Um. Mask unit (mask body), 1. Vacuum chamber, 13. Vacuum pump, 17. Support frame (support part), 17c. Exhaust path, 2. Target, 4. Shielding plate, 41. First wall (component of upper cylindrical wall), 42. Second wall (component of upper cylindrical wall), 6. Stand body, 6a. Support body, 62. Drive device, 63. Through hole, 64. Support rod, 69. First protruding wall, 71. First mask body, 72. Second mask body, 72. First receiving recess, 73. Second protruding wall, 74. Second receiving recess, Gp1, Gp2, Gp3. Gap of labyrinth structure, Sp. Peeling suppression treatment.

Claims

1. A sputtering apparatus characterized by comprising: a vacuum chamber provided with a target; a substrate stage provided in the vacuum chamber, the substrate stage having a stage main body on an upper surface of which a substrate is disposed in a posture opposite to the target, and a moving device that relatively moves the stage main body in a vertical direction; a mask body that limits a range of film formation on the substrate when the stage main body is moved upward to a substrate processing position at which film formation on the substrate is performed by sputtering from the target; a shield plate in the shape of a frame provided at a ground potential around the target, two upper cylindrical wall portions extending downward from a lower surface of the shield plate being provided at different distances from a center of the target; and a lower cylindrical wall portion extending upward from an upper surface of the mask body, an upper end portion of the lower cylindrical wall portion intruding into a gap between the two upper cylindrical wall portions by a length of the gap, a gap of a labyrinth structure in which the two upper cylindrical wall portions and the lower cylindrical wall portion are engaged without contact being formed outside a periphery of the target and a film formation space between the target and the substrate.

2. The sputtering apparatus according to claim 1, characterized in that: a portion of the upper cylindrical wall portion near the center of the target is a first wall portion, and other portions are second wall portions, an area of the first wall portion opposite to the lower cylindrical wall portion being larger than areas of the second wall portions opposite to the lower cylindrical wall portion.

3. The sputtering apparatus according to claim 2, characterized in that: a peeling suppression process that suppresses peeling of a film is performed on the first wall portion and a portion of the lower cylindrical wall portion facing the center of the target.

4. The sputtering apparatus according to any one of claims 1 to 3, characterized by further comprising a support portion that supports the mask body in the vacuum chamber, an exhaust path that communicates with a vacuum pump that performs vacuum exhaust in the vacuum chamber being formed in the support portion.

5. The sputtering apparatus according to any one of claims 1 to 3, characterized in that: a plurality of through holes extending in the vertical direction are formed in the stage main body, and a support rod is inserted in each of the through holes, the stage main body being relatively moved upward from a substrate handover position at which an upper end portion of each support rod protrudes from the stage main body to perform handover of the substrate to the stage main body to a substrate processing position at which the upper end portion of each support rod is immersed in the through hole to perform film formation processing on the substrate when the stage main body is moved upward by the moving device.

6. The sputtering apparatus according to claim 5, characterized by comprising a foreign matter drop prevention disk provided around the stage main body at the substrate handover position. ​ ​ ​ ​ ​ ​ ​ ​ ​

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