Sputtering device

Abstract

The present invention provides a sputtering apparatus that can suppress localized temperature rises on a substrate when depositing a film onto the substrate through a mask. [Solution] The vacuum chamber 1 comprises a target 2 and a substrate stage St. The substrate stage St has a stage body 6 on which the substrate is placed and a moving means 62 for moving it up and down, and includes a mask unit that restricts the film deposition area on the substrate when the stage body is moved upward to the substrate processing position. The mask unit comprises a first mask body 71 that is electrically floating and a second mask body 72 that covers the upper surface portion of the first mask body with a gap in the vertical direction. A first protruding wall 69 is provided on the upper surface of the stage body, positioned outside the periphery of the substrate and standing upright above it, and a first receiving recess is provided on the lower surface of the first mask body to receive the first protruding wall, forming a labyrinth structure gap where the first protruding wall and the first receiving recess interlock non-contact outside the periphery of the substrate at the substrate processing position.

Description

Technical Field

[0001] The present invention relates to a sputtering apparatus provided with a substrate stage having a vacuum chamber in which a target is disposed, and in the vacuum chamber, a stage body on which a substrate is placed on the upper surface in a posture facing the target, and moving means for relatively moving the stage body in the vertical direction. More specifically, the present invention relates to a film forming apparatus that forms a film on a large-area substrate by a so-called deposition-down method.

Background Art

[0002] In the manufacturing process of flat panel displays, there is a film forming process in which various thin films such as aluminum (Al) film, titanium (Ti) film, molybdenum (Mo) film, or tungsten (W) film are formed on the surface of a glass substrate (hereinafter referred to as "substrate") having a rectangular contour. In the film forming process, sputtering apparatuses are widely used in consideration of productivity and the like. The size of the substrate to be formed with a film 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). When forming a film on such a substrate in a single-piece manner, it is known to use a so-called side deposition type sputtering apparatus (see, for example, Patent Document 1). In such a sputtering apparatus, a space is required in the vacuum chamber to swing the substrate stage on which the substrate is placed between a horizontal posture in which the film forming surface of the substrate faces vertically upward and a standing posture in which the film forming surface faces horizontally. Therefore, the size of the apparatus (vacuum chamber) cannot be avoided from increasing. Moreover, in the vacuum chamber, not only the film forming space between the target and the substrate stage, but also a shield plate (anti-deposition plate) for preventing the adhesion of sputtering particles to the inner wall surface of the vacuum chamber and various components existing in the vacuum chamber around the target and the substrate stage is installed. However, due to the presence of a mechanism for swinging the substrate, there is a limit to suppressing the bypass of sputtering particles to the back side of the anti-deposition plate. That is, unlike a sputtering apparatus for film formation on a semiconductor wafer, in a sputtering apparatus for film formation on a large-area glass substrate, it has been a fact that the bypass of sputtering particles to the back side of the anti-deposition plate cannot be effectively suppressed.

[0003] Even for large-area substrates, a so-called deposit-down sputtering system can be used, and by adopting a configuration in which the stage on which the substrate is placed moves only vertically, the system can be miniaturized. Furthermore, when depositing a film through a mask that covers the outer edge of the substrate and restricts the deposition area, this mask can be pre-installed in the vacuum chamber corresponding to the upper position of the substrate stage (substrate processing position). However, if the mask is at the same potential as the vacuum chamber (ground potential), when plasma is formed in the deposition space, the plasma will spread to the vicinity of the mask plate, causing a problem where the outer edge of the substrate is locally heated due to heat input from the plasma. As a result, the film quality may change locally depending on the thin film being deposited. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2024-24746 [Overview of the project] [Problems that the invention aims to solve]

[0005] In view of the above, the object of the present invention is to provide a sputtering apparatus having a configuration that suppresses local temperature rise of the substrate when depositing a film on the substrate through a mask. [Means for solving the problem]

[0006] To solve the above problems, the present invention provides a sputtering apparatus having a vacuum chamber in which a target is placed, and a substrate stage device having a stage body on which a substrate is placed on its upper surface in a position facing the target, and a moving means for relatively moving the stage body in the vertical direction, wherein when the stage body is moved upward to a substrate processing position in which film deposition on the substrate is carried out by sputtering of the target, a mask unit is provided to restrict the film deposition area on the substrate, the mask unit comprises a first mask body that is electrically floating on a support part in the vacuum chamber and covers at least the outer peripheral edge of the substrate, and a second mask body that covers the upper surface portion of the first mask body with a gap in the vertical direction, the upper surface of the stage body is provided with a first protruding wall that is positioned outside the periphery of the substrate placed thereon and stands upright above, and the lower surface of the first mask body is provided with a gap to receive the first protruding wall, and when the stage body is moved upward, a labyrinth structure gap is formed outside the periphery of the substrate with non-contact interlocking.

[0007] According to the present invention, after the substrate transported by a transport robot is placed on the stage body at a substrate transfer position separated from the target, the stage body is moved upward to a substrate processing position where the substrate faces the target at a predetermined TS distance. At this time, the first protruding wall of the stage body penetrates into the first receiving recess of the first mask body, forming a labyrinth-like gap around the periphery of the substrate. This effectively suppresses the leakage of sputtered particles to the lower part of the stage body while ensuring an exhaust path from the film deposition space. At this time, if a configuration is adopted in which a second protruding wall rising upward is provided on the upper surface of the first mask body, and a second receiving recess that receives the second protruding wall with a gap is provided on the lower surface of the second mask body, it is advantageous that the leakage of sputtered particles to the lower part of the stage body can be suppressed while ensuring an exhaust path even between the first mask body and the second mask body which are pre-installed in the vacuum chamber. At the substrate processing position, at least the outer peripheral edge of the substrate is covered by the first mask body, and the film deposition area on the substrate is restricted.

[0008] When the stage unit moves to the substrate processing position, a sputtering gas such as argon gas (which may contain reaction gases such as oxygen gas or nitrogen gas) is introduced into the vacuum chamber, and a DC power with a negative potential, for example, is applied to the target. As a result, plasma is formed in the deposition space between the substrate and the target, and the target is sputtered by ions of the sputtering gas in the plasma. Sputtered particles that scatter from the target according to a predetermined cosine law adhere to and deposit on the substrate surface, forming a predetermined thin film. During film deposition by sputtering of the target, the first mask is electrically floating, thus avoiding problems such as the plasma spreading to the vicinity of the first mask and locally heating the outer edge of the substrate. In addition, the upper part of the first mask is covered by the second mask with a labyrinth structure gap. Therefore, even when film deposition is performed over a long period of time, film is deposited on most of the surface of the first mask, and problems such as electrical contact with the vacuum chamber (support part) at ground potential are avoided, allowing for stable film deposition at all times.

[0009] Here, the target species is selected according to the composition of the thin film to be deposited on the substrate, and the deposition conditions (power input and sputtering time) do not necessarily coincide. During deposition, the first and second masks expand (deform) due to heat input from the plasma, and the amount of thermal expansion also changes depending on the deposition conditions. In this invention, the size of the gap in the labyrinth structure can be changed simply by changing the vertical stopping position of the stage body at the substrate processing position. Therefore, by managing the size of the gap according to the target species, problems such as contact between the stage body and the first mask body due to thermal expansion and generation of particles can be avoided. As a result, a configuration can be realized in which a single sputtering apparatus can handle the deposition of multiple types of thin films (Al films, Ti films, Mo films, and W films) without changing the apparatus configuration in any way.

[0010] Incidentally, when the first protruding wall of the stage body is formed as described above, sputtered particles that bounce off the first protruding wall may wrap around to the outer edge of the substrate during film formation. At this time, because the amount of warping of the substrate during film formation differs depending on the sputtering conditions, the outer edge of the substrate and the upper surface of the stage body may locally adhere to each other via the wraparound sputtered particles, which may cause damage to the substrate during transport. In the present invention, it is preferable to provide a support on the upper surface of the stage body that abuts against the portion of the substrate inside the outer edge and supports the substrate. This is advantageous because it can suppress adhesion between the outer edge of the substrate and the upper surface of the stage body as much as possible.

[0011] In the present invention, if a configuration is adopted in which 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, and when the stage body is moved upward by the moving means, the upper ends of each support rod protrude from the stage body and move relative to a substrate transfer position in which the substrate is transferred to the stage body, and the upper ends of each support rod retract into the through holes and film deposition is performed on the substrate, then a deposit-down sputtering apparatus can be realized. [Brief explanation of the drawing]

[0012] [Figure 1] A schematic cross-sectional view showing the sputtering apparatus of this embodiment at the substrate processing position. [Figure 2] (a) is an enlarged cross-sectional view of the main part of the sputtering apparatus shown in Figure 1, and (b) is an enlarged cross-sectional view of the main part when the stage body is moved to the substrate transfer position. [Figure 3] An enlarged cross-sectional view of another key part of the sputtering apparatus shown in Figure 1. [Figure 4] A schematic cross-sectional view of a sputtering apparatus according to a modified example. [Figure 5] (a) and (b) are diagrams illustrating the attachment of the second mask body to the support within the vacuum chamber. [Modes for carrying out the invention]

[0013] Hereinafter, with reference to the drawings, an embodiment of the sputtering apparatus of the present invention will be described using as an example an application to a magnetron sputtering apparatus SM 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 SM.

[0014] 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 in the side wall (or bottom 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 vacuum chamber 1 (i.e., the film deposition space 1a between the target 2 and the substrate Sg). A cathode unit Uc is detachably attached to the top wall of the vacuum chamber 1.

[0015] 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 (outside the vacuum chamber 1 on the side facing away from the sputtering surface 21 of the target 2) and arranged in parallel 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 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 Al films, Ti films, W films, and Mo 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 during sputtering of the target 2, a coolant can be circulated through the backing plate 22 to cool the target 2. 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, and on the wall portion of the vacuum chamber 1 located behind the backing plate 22. In this embodiment, the shield plate 4 functions as an anode during sputtering.

[0016] 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. A substrate stage St is positioned inside the vacuum chamber 1, facing the target 2.

[0017] The substrate stage St comprises a metal stage body 6, on which a substrate Sg is placed with its opposing edges aligned in the X-axis and Y-axis directions, respectively. Known means for heating or cooling the substrate Sg placed on its upper surface may be incorporated into the stage body 6 to control the substrate temperature during film deposition. A drive shaft 61 is connected to the lower surface of the stage body 6, penetrating the lower wall of the vacuum chamber 1 while maintaining an airtight seal and protruding into the vacuum chamber 1. The stage body 6 is then capable of vertical movement via the drive shaft 61 by a drive source 62, such as an air seal or linear motor, installed outside the vacuum chamber 1. This allows the stage body 6 to move vertically between a substrate transfer position (shown in Figure 2(b)) where the substrate Sg is transferred at a distance from the target 2, and a substrate processing position (shown in Figures 1 and 2(a)) where film deposition is performed in close proximity to the target 2. Multiple through holes 63 are formed in the stage body 6, penetrating in the vertical direction. The diameter of each through-hole 63 and the distance between each through-hole 63 are set appropriately, taking into consideration the substrate size and the temperature distribution of the substrate Sg during film deposition.

[0018] Support rods 64 are inserted into each through-hole 63 with a gap between them. Each support rod 64 is made of a metal rod with relatively high mechanical strength and has a large-diameter portion 64a that is housed in the through-hole 63 with a gap between it and the substrate processing position, and a small-diameter portion 64b that extends downward from the large-diameter portion 64a. A cap body 64c made of a different material is attached to the upper end of each support rod 64. The cap body 64c is made of a molded resin such as polyimide. Although not specifically illustrated and explained, an upward-extending mounting hole is formed on the lower surface of the cap body 64c, and the cap body 64c is attached by fitting it from above into the other small-diameter portion formed at the upper end of each support rod 64. Guide members 65 are vertically attached to the stage body 6 so as to surround the lower edge of each through-hole 63.

[0019] The guide member 65 has a cylindrical member 65b made of metal with relatively high mechanical strength and a predetermined length, in which an insertion hole 65a through which the small-diameter portion 64b of each support rod 64 is inserted is formed. On the upper surface of the cylindrical member 65b, a cylindrical protruding piece 65c that extends upward so as to surround the upper end edge of the insertion hole 65a is provided, and the protruding piece 65c is fitted into the through hole 63 from below. Thus, when the stage body 6 moves relative to the upper side with respect 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 protruding piece 65c, whereby each support rod 64 is locked (the downward movement of each support rod 64 is restricted), and the dropout of each support rod 64 from each through hole 63 is prevented. Incidentally, the length of the large-diameter portion 64a of each support rod 64 is appropriately set in consideration of the amount of protrusion of each support rod 64 from the stage body 6 at the substrate delivery position, the thickness of the stage body 6, etc., and the diameters of the large-diameter portion 64a and the small-diameter portion 64b are set in consideration of the hole diameters of the through hole 63 and the insertion hole 65a. Further, 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 thereof) in the vertical direction.

[0020] A support plate 67 is disposed on the inner surface of the lower wall of the vacuum chamber 1. On the upper surface of the support plate 67, a regulating base 68 is disposed such that the lower end surface of each support rod 64 abuts thereon to restrict the downward movement of each support rod 64, and the regulating base 68 also serves as a stopper member. Incidentally, the regulating base 68 can be directly disposed on the inner surface of the lower wall of the vacuum chamber 1 without installing the support plate 67. Further, a spacer member (not shown) may be detachably installed on the upper surface or the lower surface of the regulating base 68 so that the amount of protrusion of each support rod 64 from the stage body 6 at the substrate delivery position can be appropriately changed. When forming a film by placing a substrate Sg on the upper surface of the stage body 6 at the substrate processing position, a mask unit Um is disposed in the vacuum chamber 1 to cover the outer peripheral edge portion of the substrate Sg and regulate the film-forming range on the substrate Sg.

[0021] As shown enlarged in Figs. 2(a) and 2(b), the mask unit Um has a first mask body 71 and a second mask body 72, each of which is in the shape of a frame plate and made of a metal material that is difficult to thermally deform. The second mask body 72 is attached to a support frame 17 as a support portion provided on the inner surface of the side wall of the vacuum chamber 1 corresponding to the substrate processing position. The first mask body 71 is installed on the flange portion 17a of the support frame 17 extending inwardly of the vacuum chamber 1 with an insulator 17b interposed therebetween, and the first mask body 71 is in an electrically floating state. The tip portion 71 of the first mask body 71 located on the inner side of the vacuum chamber 1 is formed as an inclined surface whose upper surface continuously slopes downward toward the inside of the vacuum chamber 1 so as to suppress so-called mask blur at the outer peripheral edge of the substrate Sg. At the substrate processing position, the tip portion 71 is located directly above the outer peripheral edge of the substrate Sg with a vertical gap. Further, a receiving recess (hereinafter referred to as the "first receiving recess 72") that recesses vertically is formed on the lower surface of the first mask body 71 located outside the vacuum chamber 1 from the tip portion 71.

[0022] When the substrate Sg is placed on the upper surface of the stage body 6, a first ridge wall 69 that stands upward is provided on the outer peripheral edge portion of the upper surface of the stage body 6 located outside the periphery of the substrate Sg. Then, when the stage body 6 moves upward to the substrate processing position, the first ridge wall 69 enters the first receiving recess 72 of the first mask body 71 with a gap, and a gap Gp1 having a labyrinth structure in which the first ridge wall 69 and the first receiving recess 72 mesh with each other without contact is formed outside the periphery of the substrate Sg. The size of the gap Gp1 is appropriately set according to the sputtering conditions (target species, input power, sputtering time) and the thermal deformation (thermal expansion amount) between the first mask body 71 and the second mask body 72 during film formation. At this time, if the stop position of the stage body 6 at the substrate processing position is changed, the size of the gap Gp1 changes.

[0023] Here, when the first protruding wall 69 of the stage body 6 is formed, sputtered particles that bounce off the first protruding wall 69 during film formation may wrap around to the outer edge of the substrate Sg. At this time, because the amount of warping of the substrate Sg during film formation differs depending on the sputtering conditions, the outer edge of the substrate Sg and the upper surface of the stage body 6 may locally adhere to each other via the wraparound sputtered particles, which could damage the substrate during transport. Therefore, an annular support plate 6a of a predetermined thickness is provided on the upper surface of the stage body 6 to support the substrate Sg by contacting the portion of the substrate Sg inside the outer edge. This lifts the substrate Sg (especially the outer edge of the substrate) away from the upper surface of the stage body 6, thereby suppressing adhesion between the outer edge of the substrate Sg and the upper surface of the stage body 6 as much as possible. Although the support plate 6a is used as an example of a support, it is also possible to configure it by providing multiple support pins (not shown), for example.

[0024] A second protruding wall 73 is provided on the upper surface of the rear end portion of the first mask body 71, rising upward. Correspondingly, a second receiving recess 74 is provided on the lower surface of the second mask body 72, which receives the second protruding wall 73 with a gap between them. When the first mask body 71 and the second mask body 72 are assembled, a labyrinth-like gap Gp2 is formed around the outer periphery of the substrate Sg, where the second protruding wall 73 and the second receiving recess 74 interlock non-contact. The tip portion of the second mask body 72, located on the inside side of the vacuum chamber 1, has its upper surface formed as an inclined surface with the same inclination angle as described above, covering the upper surface portion of the first mask body 71 other than the tip portion 71, thereby suppressing film formation as much as possible. Furthermore, the support frame 17 and the second mask body 72 installed thereon are provided with through holes 17c and 75 that penetrate vertically, and these through holes 17c and 75 constitute part of the exhaust path leading from the film deposition space 1a to the vacuum pump 13. In addition, a cylindrical wall portion (hereinafter referred to as the "lower cylindrical wall portion 76") is provided at a predetermined position on the upper surface of the second mask body 72, extending upward and with its upper end portion reaching near the shield plate 4, so as to surround the film deposition space 1a.

[0025] On the lower surface of the shield plate 4, as shown in an enlarged view in Figure 3, two upper cylindrical wall sections (hereinafter, one upper cylindrical wall section located on the inner side of the vacuum chamber 1 will be referred to as the "first wall section 41," and the other cylindrical wall section as the "second wall section 42") are provided at different distances from the center of the target 2, extending downward for a predetermined length. When the shield plate 4 and the second mask body 72 are assembled, the upper end portion of the lower cylindrical wall section 76 penetrates the gap between the first wall section 41 and the second wall section 42, forming a labyrinth-like gap Gp3 outside the periphery of the film deposition space 1a, in which the first and second wall sections 41, 42 and the lower cylindrical wall section 76 interlock without contact. The gap Gp3 also serves as an exhaust path leading from the film deposition 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 set appropriately in order to ensure a certain exhaust conductance, but it is preferable to set the area facing the lower cylindrical wall portion 76 to be larger for the first wall portion 41 than for the second wall portion 42.

[0026] Here, during film formation, sputtered particles directly adhere to the first wall portion 41 and the lower cylindrical wall portion 76, which allow direct viewing of the target 2, resulting in a relatively large amount of film deposition. Therefore, it is preferable that a peeling suppression treatment Sp is applied to at least the entire surface of the first wall portion 41 and the surface of the lower cylindrical wall portion 76 located on the inner side of the vacuum chamber 1 to suppress film peeling. Examples of peeling suppression treatment Sp include surface treatments that increase the surface area by forming fine irregularities on the surface (so-called AET treatment), as shown in the enlarged explanation in Figure 3, as well as known thermal spraying and blasting treatments. This reduces the frequency of replacement between the first wall portion 41 and the lower cylindrical wall portion 76. Such peeling suppression treatment may also be applied to the surface portion of the second mask body 72, which is located on the inner side of the vacuum chamber 1 than the lower cylindrical wall portion 76, and to the second wall portion 42. Furthermore, for example, considering cost considerations, the areas with the largest film deposition may be treated with thermal spraying in addition to AET treatment to effectively suppress film peeling, while the areas with the next largest film deposition may be treated only with thermal spraying, and the remaining areas may be treated only with blasting. The film deposition on the substrate Sg will be described in detail below.

[0027] When depositing a film onto the substrate Sg, first, the stage body 6 of the substrate stage St is moved to the substrate transfer position (see also Figure 2(b)). 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 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 discharge port 18 (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 discharge port 18 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. Unlike the so-called side-deposit method, this method does not require a space within the vacuum chamber 1 for oscillating the target 2, thus enabling miniaturization of the sputtering apparatus SM (vacuum chamber 1).

[0028] 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, and the lower surface of its large-diameter portion 64a comes into contact with the upper surface of its projection 65c, thereby locking each support rod 64 in place. This restricts the downward movement of each support rod 64 and prevents 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 placed in surface contact with the upper surface of the stage body 6, and the first protruding wall 69 penetrates the first receiving recess 72 of the first mask body 71, forming a labyrinth-like gap Gp1 around the outer periphery of the substrate Sg where the first protruding wall 69 and the first receiving recess 72 interlock in a non-contact manner. When the vacuum chamber is evacuated to a predetermined pressure, sputtering gas such as argon gas (which may contain reaction gases such as oxygen gas or nitrogen gas) is introduced into the vacuum chamber 1, and DC power with a negative potential, for example, is applied to the target 2 by the sputtering power supply 24. Then, plasma is formed in the deposition space 1a, and the sputtering surface 21 of the target 2 is sputtered by ions of the sputtering gas in the plasma, and sputtered particles scattered from the target 2 according to a predetermined cosine law adhere to and deposit on the lower surface of the substrate Sg through the first mask body 71, thereby forming a predetermined thin film. After film formation, the stage body 6 is moved down from the substrate processing position to the substrate transfer position.

[0029] According to the above embodiment, since the first mask body 71 is maintained in an electrically floating state during film deposition, problems such as the plasma spreading to the vicinity of the first mask body 71 and locally heating the outer edge of the substrate Sg can be avoided. Furthermore, since the upper portion of the first mask body 71 is covered by the second mask 72 with a labyrinth structure gap Gp2, even when the film deposition process is carried out over a long period of time, the film adheres to most of the surface of the first mask body 71, and problems such as electrical contact with the vacuum chamber (support part) at ground potential can be avoided, and film deposition can be performed stably at all times. Moreover, the labyrinth structure gap Gp2 between the first mask body 71 and the second mask body 72 secures an exhaust path, while further suppressing the leakage of sputtered particles downwards to the stage body 6. Furthermore, by simply changing the vertical stopping position of the stage body 6 at the substrate processing position, the size of the gap Gp1 in the labyrinth structure can be changed. Therefore, by managing the size of the gap according to the target type, problems such as the stage body 6 and the first mask body 71 coming into contact due to thermal expansion and generating particles can be avoided. As a result, a configuration can be realized in which a single sputtering apparatus SM can handle the deposition of multiple types of thin films (Al films, Ti films, Mo films, and W films) without changing the apparatus configuration in any way.

[0030] During sputtering of target 2, sputtered particles scatter to various locations within the vacuum chamber other than the substrate Sg, or bounce and scatter further. However, since the area around the target and the deposition space 1a are surrounded by the upper cylindrical wall portions 41, 42 and the lower cylindrical wall portion 76, which form the gaps Gp3 of the labyrinth structure, the circling and passing of sputtered particles from target 2 and bounced sputtered particles can be effectively suppressed. It is generally known that sputtered particles scattered from target 2 lose their kinetic energy and remain there after bouncing at most three times. However, as in the above embodiment, if the area of ​​the first wall portion 41 facing the lower cylindrical wall portion 76 is larger than that of the second wall portion 42, sputtered particles attempting to circling and passing through can be made to bounce as many times as possible between the opposing surfaces of the first wall portion 41 and the lower cylindrical wall portion 76, thereby more effectively suppressing the circling and passing of sputtered particles.

[0031] 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, a magnetron sputtering apparatus SM that deposits films using a deposit-down method has been described, but the present invention is not limited thereto, and can also be applied to a sputtering apparatus that deposits films using a deposit-up method, for example. Furthermore, in the above embodiments, a first wall portion 41 and a second wall portion 42 are provided on the lower surface of the shield plate 4, and in the assembled state of the shield 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 the present invention is not limited thereto. Although not specifically illustrated and described, for example, a recess that is recessed upward is formed on the lower surface of the shield plate 4, and in the assembled state of the shield plate 4 and the second mask body 72, the upper end portion of the lower cylindrical wall portion 76 penetrates the recess and forms a labyrinth structure gap. At this time, the size of the gap is set taking into consideration the thermal deformation of the shield plate 4 and the lower cylindrical wall portion 76 during film formation.

[0032] Incidentally, in the magnetron sputtering apparatus SM described above, maintenance such as replacing and cleaning components located inside the vacuum chamber 1 (for example, the substrate stage St and the mask unit Um) is normally performed periodically. At this time, if an operator accidentally drops a bottle or the like into the vacuum chamber 1 located below the stage body 6, it is difficult to retrieve it without removing components located inside or outside the vacuum chamber 1. For this reason, as shown in Figure 4, it is preferable to suspend a cylindrical guide plate 81 from the lower surface of the support frame 17, and to provide an annular drop prevention pan 82 with an open top in the space between the guide plate 81 and the stage body 6 located at the substrate transfer position. This prevents bottles and the like from falling to the bottom, and also avoids problems such as blocking the exhaust path from the film deposition space 1a to the vacuum pump 13 and reducing the exhaust speed.

[0033] Furthermore, in the magnetron sputtering apparatus SM described above, if the substrate Sg to be deposited is a large-area substrate (for example, G8.7 generation), the metal mask unit Um becomes heavy. In such cases, for example, a hoist crane of factory equipment is used to attach and detach the mask unit Um to the support frame 17. Here, one of the main purposes of the second mask body 72 is to prevent film deposition on the first mask body 71 (i.e., to prevent conduction (ground fault) with the vacuum chamber (support part) at ground potential). The second mask body 72 is heated and thermally expands due to radiation from the plasma, but even if its relative position to the first mask body 71 is slightly shifted, film deposition on the first mask body 71 can be effectively prevented, so it is sufficient that the gap Gp2 between the first mask body 71 and the second mask body 72 is maintained within an appropriate range.

[0034] In the sputtering apparatus SM described above, as shown in Figure 5, a plurality of positioning pins 83 are erected at predetermined positions on the upper surface of the support frame 17, and positioning holes 84 are formed in the upper surface portion of the second mask body 72 through which the positioning pins 83 are inserted. When the second mask body 72 is placed on the support frame 17 with each positioning pin 83 inserted through each positioning hole 84, the second mask body 72 is positioned approximately on the support frame 17. After the second mask body 72 is attached to the support frame 17, the support frame 17 and the second mask body 72 are fixed together by attaching fixing pins 86 to mounting holes 85 formed in the support frame 17. At this time, the upper end portion of the fixing pin 86 is made to reach the housing hole 87 provided in the second mask body 72. The housing hole 87 consists of a circular main housing hole 87a into which the upper end portion of the fixing pin 86 fits, and an oval-shaped secondary housing hole 87b that is elongated in the X-axis or Y-axis direction to allow thermal expansion of the second mask body 72 in the X-axis or Y-axis direction. [Explanation of Symbols]

[0035] SM...Magnetron sputtering apparatus (sputtering apparatus), St...Substrate stage, Sg...Substrate, Um...Mask unit (mask body), 1...Vacuum chamber, 13...Vacuum pump, 17...Support frame (support part), 17c...Exhaust path, 2...Target, 4...Shield plate, 41...First wall section (component of upper cylindrical wall section), 42...Second wall section (component of upper cylindrical wall section), 6...Stage body, 6a...Support, 62...Driving means, 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, 76...Lower cylindrical wall section, Gp1, Gp2, Gp3...Labyrinth structure gap, Sp...Peeling suppression treatment.

Claims

1. A sputtering apparatus having a vacuum chamber in which a target is placed, and a substrate stage having a stage body on which a substrate is placed on its upper surface in a position facing the target, and a moving means for moving the stage body relative to it in the vertical direction, In a system where a mask unit is provided to restrict the film deposition area on the substrate when the stage body is moved upward to a substrate processing position where film deposition on the substrate is carried out by target sputtering, The sputtering apparatus is characterized in that the mask unit comprises a first mask body that is electrically floating in a support part within a vacuum chamber and covers at least the outer edge of the substrate, and a second mask body that covers the upper surface portion of the first mask body with a gap in the vertical direction, and the upper surface of the stage body is provided with a first protruding wall that is positioned outside the periphery of the substrate on which it is installed and stands upright above, and the lower surface of the first mask body is provided with a first receiving recess that receives the first protruding wall with a gap, and when the stage body is moved upward, a labyrinth structure gap is formed outside the periphery of the substrate in which the first protruding wall and the first receiving recess interlock in a non-contact manner.

2. The sputtering apparatus according to claim 1, characterized in that a second protruding wall is provided on the upper surface of the first mask body, and a second receiving recess is provided on the lower surface of the second mask body to receive the second protruding wall with a gap between them.

3. The sputtering apparatus according to claim 1, characterized in that a support is provided on the upper surface of the stage body that contacts the portion of the substrate that is inward from the outer edge of the substrate and supports the substrate.

4. 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 body, and a support rod is inserted into each through hole, and when the stage body is moved upward by the moving means, the upper ends of each support rod move relative to a substrate transfer position where the upper ends of each support rod protrude from the stage body and the substrate is transferred to the stage body, and to a substrate processing position where the upper ends of each support rod retract into the through holes and the film deposition process is performed on the substrate.

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