Magnetron sputtering device

Abstract

The invention provides a magnetron sputtering device capable of forming a predetermined thin film with good in-plane uniformity of the film. This magnetron sputtering device (SM1) has a vacuum chamber (1) in which a target (2) and a substrate (Sg) are disposed facing each other, and is provided with: a shield plate (4) which is disposed so as to surround the periphery of the target and which functions as an anode when sputtering the target; and a magnet unit (3) that causes a leakage magnetic field to act in a film formation space between the target and the substrate. A lower surface of the shield plate, which is a direction from the target toward the substrate, is provided with a cylindrical wall portion (40) extending downward from a position near the target end by a predetermined length.

Description

TECHNICAL FIELD

[0001] The present application relates to a magnetron sputtering apparatus having a vacuum chamber in which a target and a substrate are arranged opposite to each other, and a shield plate arranged so as to surround the periphery of the target and functioning as an anode during sputtering of the target, and a magnet unit that causes a magnetic field to act on a film formation space between the target and the substrate. BACKGROUND

[0002] In a manufacturing process of a flat panel display, there is a film formation process in which various thin films are formed on the surface of a glass substrate (hereinafter referred to as "substrate") having a rectangular profile. In the film formation process, the substrate is sometimes heated to a predetermined temperature. The size of the substrate as a film formation target is becoming larger with the progress of generations (for example, 2300 mm x 2700 mm for G8.7 generation), and the thickness of the substrate is becoming thinner (for example, 0.5 mm). A magnetron sputtering apparatus for forming a film on such a substrate is known, for example, from Patent Document 1. The apparatus has a vacuum chamber in which a substrate and a single target having an area larger than the substrate by one turn are arranged opposite to each other. On the side of the target opposite to the sputtering surface, a plurality of magnet units are arranged in parallel at intervals in one direction, and each magnet unit reciprocates at a predetermined speed in the direction in which the magnet units are arranged in parallel during film formation. Further, a shield plate in the form of a frame is arranged so as to surround the periphery of the target and functions as an anode during sputtering. Generally, the shield plate is arranged such that the surface of one side thereof is at the same height position as the sputtering surface when the target is not used.

[0003] As the magnet unit, a product generally used has a central magnet arranged linearly on the surface of one side of a rectangular support plate (magnet yoke) arranged parallel to the target, and a peripheral magnet surrounding the periphery of the central magnet, the peripheral magnet having linear portions extending in parallel at equal intervals on both sides of the central magnet, and bridge portions respectively bridging both free ends of the linear portions, the central magnet and the peripheral magnet having opposite polarities on the side of the target. Thus, the magnetic field leaking from the sputtering surface toward the film formation space is caused to act in such a manner that a line passing through a position at which the vertical component of the magnetic field is zero extends in the X-axis direction and closes in a racetrack shape. Then, a sputtering gas such as argon gas is introduced into the vacuum chamber in a vacuum atmosphere, and when direct current power having a negative potential, for example, is applied to the target, a racetrack-shaped plasma is formed in the film formation space, and the target is sputtered with ions of the sputtering gas in the plasma, and the sputtered particles flying from the target in accordance with a predetermined cosine law are attached and accumulated on the surface of the substrate, thereby forming a predetermined thin film.

[0004] Here, when a target made of molybdenum with a specified composition is used, and a molybdenum film with a crystalline structure that is easily affected by the substrate temperature during film formation is formed on the substrate surface using the aforementioned magnetron sputtering device, there are regions with high thin-film resistivity at the outer periphery of the substrate (especially at both ends of the reciprocating motion direction of the magnet unit), which fails to improve the in-plane uniformity of the film, such as the thin-film resistivity. Therefore, after repeated and in-depth research, the inventors finally discovered the following: In the aforementioned conventional example, when simulating the orbit or density of electrons or secondary electrons (hereinafter referred to as "orbiting electrons") in a plasma orbiting along a track, it was found that in the magnet units located at both ends of the parallel arrangement direction, at both ends of their length direction, a large number of orbiting electrons diverge towards the substrate side. This is thought to be because when plasma is formed in the film formation space, the entire surface of the shielding plate that can be directly viewed in the film formation space acts as an anode, but in reality, only a portion of the surface of the shielding plate near the target acts as an anode, which is caused by the uneven density distribution of the plasma.

[0005] Existing technical documents Patent documents [Patent Document 1] Japanese Patent Publication No. 2021-1376 Summary of the Invention The technical problem that the invention aims to solve The present invention is based on the above understanding, and its technical problem is to provide a magnetron sputtering apparatus capable of forming a specified thin film with good in-plane uniformity.

[0006] means of solving technical problems To solve the above-mentioned technical problems, the magnetron sputtering apparatus of the present invention is characterized by having a vacuum chamber in which the target and the substrate are arranged opposite to each other, and comprising: a shielding plate arranged to surround the target and functioning as an anode when sputtering the target; and a magnet unit that causes the leakage magnetic field to act in the film-forming space between the target and the substrate; and a cylindrical wall portion extending downward from a position near the target end for a predetermined length on the lower surface of the shielding plate in the direction from the target toward the substrate.

[0007] Here, when a cylindrical wall extending downwards from near the target end for a predetermined length is provided on the lower surface of the shielding plate, and an attempt is made to simulate the orbit and density of orbiting electrons, the divergence of orbiting electrons towards the substrate at both ends of the magnet units located at opposite ends in the parallel arrangement direction is significantly suppressed compared to the prior art described above. It has been confirmed that, in this state, for example, when forming a molybdenum film, the in-plane uniformity of the film, such as the thin-film resistivity, can be improved. This can be attributed to the fact that when plasma is formed in the film-forming space, in addition to the shielding plate, the inner surface portion of the cylindrical wall near the target and locally surrounding the film-forming space also functions as an anode (in other words, the area functioning as an anode increases compared to the prior art described above), thereby improving the plasma density distribution.

[0008] Furthermore, when the cylindrical wall portion is provided as described above, sputtered particles scattered from the target are directly attached to the inner surface of the cylindrical wall portion that partially surrounds the film-forming space, thus also serving as an anti-attachment plate to prevent sputtered particles from escaping into the space behind it. In this invention, a structure can also be adopted in which another shielding plate is provided around the substrate disposed in the vacuum chamber, the cylindrical wall portion is used as the upper cylindrical wall portion, and a lower cylindrical wall portion is provided on the upper surface of the other shielding plate, the lower cylindrical wall portion having a length in which its upper end overlaps with the lower end of the upper cylindrical wall portion with a gap.

[0009] By employing the above method, an anti-adhesion plate is formed within the vacuum chamber by two shielding plates and two cylindrical walls, surrounding the entire film-forming space, thus suppressing sputtered particles from escaping into their back space. Since the upper cylindrical wall is located near the target end (in other words, the anti-adhesion plate can be positioned at a location that moves towards the inside of the vacuum chamber), miniaturization of the vacuum chamber is possible. During film formation, vacuum venting is also required from the film-forming space at a certain venting rate; therefore, the lengths of the upper and lower cylindrical walls, their overlap, and the size of their gap are appropriately set considering factors such as venting flow direction. As another shielding plate, for example, if a substrate platform is provided within the vacuum chamber, and the substrate platform is equipped with a substrate, a shielding plate can be used to prevent sputtered particles from escaping into the upper surface of the substrate platform or the back space of the substrate platform, which is disposed around the substrate platform and exposed from the substrate. On the other hand, if a mask body is provided within the vacuum chamber to limit the film-forming range for the substrate, this mask body can also serve as another shielding plate.

[0010] In this invention, the following structure can also be adopted: the upper cylindrical wall portion is the first wall portion, and the second wall portion is located around the first wall portion and disposed on the lower surface of the shielding plate. The upper end of the lower cylindrical wall portion penetrates the gap between the first wall portion and the second wall portion, thereby forming a labyrinthine gap around the film-forming space where the lower cylindrical wall portion engages with the first and second wall portions without contact. This is advantageous because it can further suppress the detachment of sputtered particles during film formation. In addition, it is generally known that sputtered particles flying from the target lose their kinetic energy and remain there after bouncing three times. Therefore, in addition to serving as the anode mechanism, it is preferable to set the length of the first wall portion such that the sputtered particles to be detached bounce as many times as possible on the opposing surfaces of the first wall portion and the lower cylindrical wall portion. Attached Figure Description

[0011] Figure 1 This is a cross-sectional schematic diagram of the magnetron sputtering apparatus according to the first embodiment.

[0012] Figure 2 It is a graph showing the changes in discharge current and discharge voltage during film formation using the magnetron sputtering apparatus of the first embodiment.

[0013] Figure 3 This is a cross-sectional schematic diagram of the magnetron sputtering apparatus according to the second embodiment.

[0014] Figure 4 (a) is Figure 3 (a) is an enlarged cross-sectional view of the main part of the magnetron 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.

[0015] Figure 5 yes Figure 3 Enlarged cross-sectional view of other major parts of the magnetron sputtering apparatus shown. Detailed Implementation

[0016] Hereinafter, with reference to the accompanying drawings, an embodiment of the present invention will be described using an example of a magnetron sputtering apparatus 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 platform body mentioned later will be defined as the X-axis direction and the Y-axis direction, and the direction orthogonal to the X-axis direction and the Y-axis direction will be defined as the Z-axis direction. The terminology indicating direction is shown in the mounting posture employing the magnetron sputtering apparatus. Figure 1 Based on.

[0017] Reference Figure 1The magnetron sputtering apparatus SM1 of the first 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 inside 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.

[0018] The cathode unit Uc includes: a single target 2 whose outline corresponds to the substrate Sg and whose area is larger than that of the substrate Sg; and a plurality of magnet units 3 arranged at equal intervals (six in this embodiment) above the target 2 in the Z-axis direction (on the side of the target 2 facing away from the sputtering surface 21 and outside the vacuum chamber 1) in the X-axis direction. 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 SM1 of the first embodiment, it is particularly effective for forming molybdenum or tungsten films whose crystalline structure is easily affected by the substrate temperature during film formation. 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. Furthermore, the target 2 is disposed in 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, separated by an insulating plate 23. The output 24a from the sputtering power supply 24 is connected to the target 2 via the backplate 22, and can apply a negative DC power or a pulsed DC power to the target 2.

[0019] Inside the vacuum chamber 1, a frame-shaped ground potential shielding plate 4 is provided primarily to prevent coating of the portion of the backplate 22 extending outward from the outer periphery of the target 2, and the wall portion (including components located in the back space) of the vacuum chamber 1 located in the back space of the backplate 22. The shielding plate 4 functions as an anode during sputtering. The shielding plate 4, designed with a specified width, is supported by the vacuum chamber 1 such that its lower surface is at the same height as the sputtering surface of the target 2 when it is not in use. On the lower surface of the shielding plate 4, a cylindrical wall portion (hereinafter referred to as "upper cylindrical wall portion 40") extending downward in the Z-axis direction from a position near the end of the target 2 is provided. The distance D1 between the end of the target 2 and the inner surface of the upper cylindrical wall portion 40 is set within the range where the inner surface of the upper cylindrical wall portion 40 functions as an anode when the target 2 is sputtered, for example, within the range of 5 mm to 20 mm. Furthermore, it has been confirmed that even when the distance D1 is set to 5 mm, abnormal discharge (arc discharge) is not induced, and the discharge voltage and discharge current remain stable. On the other hand, it was confirmed that when the distance D1 is set to be longer than 20 mm, the in-plane uniformity of the thin film resistivity cannot be improved, similar to the existing examples described above. A longer extension of the upper cylindrical wall portion 40 from the shielding plate 4 is advantageous, but it needs to be appropriately set considering the vacuum exhaust from the film-forming space 1a.

[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 sputtering surface 21 when the target 2 is not used, with its long side in the Y-axis direction. On the lower surface of the support plate 31, a central magnet 32 ​​is arranged in a straight line at its center with opposite polarities on its upper side; and peripheral magnets 33 are arranged along the outer periphery of the support plate 31, surrounding the central magnet 32 ​​at intervals. Moreover, 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 a consistent posture in the Y-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 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, 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. Known magnet units can be used as each magnet unit 3, so further explanation is omitted. 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 together with a predetermined stroke value. Furthermore, a substrate platform St is arranged inside the vacuum chamber 1, facing the target 2.

[0021] The substrate stage St includes a metal stage body St1 with spacer insulators Is disposed on the lower inner wall of the vacuum chamber. The substrates Sg are disposed on the upper surface of the stage body St1 with their opposing edges aligned with the X-axis and Y-axis directions, respectively. Although not specifically illustrated, a chuck with a corresponding profile can be assembled on the stage body St1 to electrostatically attract the substrates Sg during film deposition. Alternatively, a refrigerant circulation passage or heater can be assembled within the stage body St1 to heat or cool the substrates Sg to a specified temperature during film deposition via a sputtering target. Since known components can be used as these components, further detailed descriptions are omitted. Furthermore, a frame-like shielding plate Sd with a ground potential is disposed around the stage body St1 as another shielding plate to prevent film deposition onto the wall portions (including components within the back space) of the vacuum chamber 1 located around and behind the stage body St1.

[0022] A lower cylindrical wall portion Sd1 is provided on the upper surface of the shielding plate Sd, having a length that overlaps the upper end of the lower end of the upper cylindrical wall portion with a gap Gp (in the X-axis direction). In the first embodiment, the shielding plate Sd constitutes another shielding plate. The length of the lower cylindrical wall portion Sd1 extending from the upper surface of the shielding plate Sd is set within a range that will not unnecessarily block the scattering path of sputtered particles flying from the target 2. Furthermore, the size of the gap Gp and the overlap length are appropriately set considering the exhaust flow from the film deposition space 1a. In the first embodiment, the lower cylindrical wall portion Sd1 is located further inside the vacuum chamber 1 than the upper cylindrical wall portion 40 to suppress the coating onto the upper surface of the shielding plate Sd as much as possible. However, it is not limited to this, and the upper cylindrical wall portion 40 may also be located further inside the vacuum chamber 1 than the lower cylindrical wall portion Sd1.

[0023] Using the above method, after a substrate Sg is placed on the upper surface of the main body St1 of the test stand, 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. As a result, (multiple) racetrack-shaped plasmas are formed in the film deposition space 1a. The target 2 is sputtered by ions of the sputtering gas in the plasma. Sputtered particles, which disperse from the target 2 according to a predetermined cosine law, adhere and accumulate on the upper surface of the substrate Sg, forming a predetermined thin film. Furthermore, it has been confirmed that when a molybdenum film, for example, is formed on the upper surface of the substrate Sg, the in-plane uniformity of the film, such as the thin-film resistivity, can be improved. Furthermore, since the upper cylindrical wall portion 40 also serves as an anti-adhesion plate, and the lower cylindrical wall portion Sd1 is provided on another shielding plate Sd, an anti-adhesion plate is formed in the vacuum chamber 1 to cover the entire film-forming space 1a between the target 2 and the substrate Sg. The upper cylindrical wall portion 40 is located near the end of the target 2 (in other words, the anti-adhesion plate can be provided while moving towards the inside of the vacuum chamber 1), thus enabling miniaturization of the vacuum chamber 1.

[0024] Here, as in the first embodiment, when a cylindrical wall portion 40 extending downward from near the target 2 end is provided on the lower surface of the shielding plate 4, and an attempt is made to simulate the orbit and density of orbiting electrons, although not specifically illustrated, it is confirmed that the divergence of orbiting electrons from both ends of the magnet units 3 located at both ends in the X-axis direction (parallel arrangement direction) towards the substrate Sg side is significantly suppressed compared to the prior art described above. Therefore, it can be considered that when plasma is formed within the film-forming space 1a, in addition to the lower surface of the shielding plate 4, the inner surface portion of the upper cylindrical wall portion 40 near the target 2 and partially surrounding the film-forming space also functions as an anode (in other words, the area functioning as an anode is increased compared to the area in the prior art described above), thereby improving the plasma density distribution and enhancing the in-plane uniformity of the film.

[0025] To confirm the effectiveness of the present invention, the following experiment was conducted using the sputtering apparatus SM1 of the first embodiment. Specifically, a G8.7 generation glass substrate was used as the substrate Sg, positioned on the upper surface of the stage body St1, and a molybdenum film with a thickness of 250 nm was formed. The in-plane distribution of the thin-film resistivity (Ω / □) of the substrate was measured. As sputtering conditions, a target of molybdenum material of a specified purity was used, and the TS distance between the target 2 and the substrate Sg was set to 135 mm. The distance D1 between the end of the target 2 and the inner surface of the upper cylindrical wall 40, and the length of the upper cylindrical wall 40 extending from the shielding plate 4 were set to 5 mm and 115 mm, respectively. Furthermore, during sputtering, Ar gas was introduced at 120 sccm to maintain the pressure in the vacuum chamber 1 at 0.2 Pa, and a DC power of 200 kW was applied to the target 2 from the sputtering power supply 24 to sputter the target 2. During film formation, each magnet unit 3 was reciprocated at a specified speed with a specified stroke value in the X-axis direction. Before film formation, the glass substrate placed on the main body St1 of the stage is preheated to 150°C. As a comparative experiment, a shielding plate without the upper cylindrical wall portion 40 on its lower surface (however, an anti-adhesion plate is set in front of the chamber wall 20 mm from the end of the target 2 in a manner surrounding the film formation space 1a: equivalent to the existing example) is used as shielding plate 4, and all other conditions are the same, and a molybdenum film with a film thickness of 250 nm is formed.

[0026] Using the above method, in the comparative experiment, regions with increased resistivity were observed at both ends of the substrate Sg along the X-axis, with an in-plane distribution of the thin film resistance of approximately ±9%. In contrast, in the inventive experiment, the in-plane distribution of the thin film resistance was confirmed to be improved to approximately ±7%. Furthermore, the changes in the discharge current and discharge voltage of the sputtering power supply were measured in both the inventive and comparative experiments, and the results are as follows... Figure 2 ( Figure 2 (a) is a comparative experiment. Figure 2 (b) shows the inventive experiment. Thus, it was confirmed that even with the cylindrical wall portion 40 extending downwards from a position near the target 2 end for a specified length, as in the prior art, abnormal discharge (arc discharge) was not induced, and the discharge voltage and discharge current remained stable. Furthermore, regarding the in-plane distribution of the film thickness, it was the same in the inventive experiment as in the comparative experiment (approximately ±9%).

[0027] The first embodiment of the present invention has been described above, but various modifications can be made without departing from the technical concept of the present invention. In the first embodiment described above, a magnetron sputtering apparatus SM1 for film deposition in a downward deposition manner has been described, but it is not limited thereto. For example, the present invention can also be applied to sputtering apparatuses for film deposition in an upward deposition manner. Furthermore, in the first embodiment described above, an example was given where a substrate stage St is fixedly disposed within a vacuum chamber 1 and a lower cylindrical wall portion is disposed on another shielding plate Sd, but it is not limited thereto. The magnetron sputtering apparatus SM2 can also be configured as follows.

[0028] Reference Figures 3 to 5 The magnetron sputtering apparatus SM2 of the second embodiment includes a vacuum chamber 1. In the figures, the same components and parts as in the first embodiment are labeled with the same reference numerals as described above, and specific descriptions are omitted. Furthermore, the substrate stage St is movably disposed within the vacuum chamber 1 in the vertical direction. The substrate stage St has a metal stage body 6, which, as described above, is disposed on the upper surface of the stage body 6 in an orientation such that the opposite edges of the substrates Sg are aligned with the X-axis and Y-axis directions, respectively. A known mechanism for heating or cooling the substrates Sg disposed on its upper surface can also be assembled on the stage body 6, allowing the substrates to be controlled at a predetermined temperature during film deposition. A drive shaft 61, which is airtightly maintained and protrudes into the vacuum chamber 1, is connected to the lower surface of the stage body 6. Furthermore, the stage body 6 is movably disposed vertically via the drive shaft 61 using a drive source 62 such as a cylinder or a direct-drive motor disposed outside the vacuum chamber 1. Thus, the stage body 6 is positioned at the substrate junction point (where the substrate Sg is transferred from the target 2) when it leaves the target 2. Figure 4 (b) shows the location) and the substrate processing location near the target 2 where film formation is performed ( Figure 3 and Figure 4 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. The diameter of each through hole 63 and the distance between each through hole 63 are appropriately set considering the substrate size and the temperature distribution of the substrate Sg during film formation.

[0029] 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 gapped within 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. 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 into the other small-diameter portions formed at the upper end of each support rod 64 from above. On the stand body 6, a guide member 65 is vertically provided to surround the lower edge of each through hole 63.

[0030] The guide member 65 has a cylindrical member 65b of a predetermined length, which is made of a metal material with relatively 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. Furthermore, 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 platform body 6 at the substrate junction position and the thickness of the platform body 6. Also, 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 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 up-down direction.

[0031] 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 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. 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, when a substrate Sg is disposed on the upper surface of the main body 6 for film deposition at the substrate processing position, a mask unit Um is disposed within the vacuum chamber 1 to cover the outer periphery of the substrate Sg and limit the film deposition range toward the substrate Sg.

[0032] Mask unit Um such Figure 4 As shown in magnified views in (a) and (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 portion. 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 as a spacer. The first mask 71 is electrically levitated. 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 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, 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, there is a receiving recess that is recessed upward and downward (hereinafter referred to as "first receiving recess 72").

[0033] 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 outside the substrate Sg. Furthermore, when the stage body 6 is moved upward to the substrate processing position, the first protruding wall 69 is received with a gap in the first receiving recess 72 of the first mask body 71, forming a labyrinth structure gap Gp1 around the outer periphery of 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 body 71 and the second mask body 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.

[0034] When the first protruding wall 69 of the stage body 6 is formed, sputtering particles reflected by the first protruding wall 69 may sometimes get caught around the outer periphery of the substrate Sg during film formation. 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 fixed by the caught sputtering particles, posing a risk of substrate breakage during transport. Therefore, a frame-shaped support plate 6a of a predetermined thickness is provided on the upper surface of the stage body 6, abutting against a portion of the substrate Sg that is further inward than the outer periphery, thereby supporting the substrate Sg. This allows the substrate Sg (especially the 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 may also be used.

[0035] On the upper surface of the rear end portion of the first mask 71, a second protruding wall 73 is provided, which stands upright upwards. 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 gap Gp2 is formed on the outer periphery of the substrate Sg, in which the second protruding wall 73 and the receiving recess 74 engage in a labyrinth structure 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 except for 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. 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 72, a cylindrical wall portion (hereinafter referred to as "lower cylindrical wall portion 76") extending upwards and reaching the vicinity of the shielding plate 4 is provided, surrounding the film-forming space 1a. In the second embodiment, the second mask 72 constitutes another shielding plate.

[0036] like Figure 5As shown in the enlarged view, by changing the distance from the center of the target 2, two upper cylindrical wall portions extending downwards by a predetermined length (hereinafter, the upper cylindrical wall portion located inside the vacuum chamber is referred to as "first wall portion 41", and the other cylindrical wall portion is referred to as "second wall portion 42") are respectively provided on the lower surface of the shielding plate 4. In the second embodiment, the first wall portion 41 constitutes a cylindrical wall portion extending downwards by a predetermined length from a position near the end of the target 2. 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 invades the gap between the first wall portion 41 and the second wall portion 42, forming a gap Gp3 in a labyrinth structure around the outer side of the film-forming space 1a, where 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, 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.

[0037] 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 5 As illustrated in the enlarged description, examples include surface treatments that increase surface area by creating 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. Furthermore, this 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. Moreover, for example, considering cost, in order to effectively suppress film peeling, spray plating can be performed on the portion with the largest film amount in addition to AET treatment, then only spray plating can be performed on the portion with a relatively large film amount, and only sandblasting can be performed on the other portions. The film formation on the substrate Sg will be specifically described below.

[0038] When depositing a film on the substrate Sg, firstly, the main body 6 of the substrate stage St is moved to the substrate junction position (also refer to...). Figure 4(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 on the side wall of the vacuum chamber 1... Figure 3 The 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 moves back and the substrate delivery outlet 18 is closed, when the vacuum in the vacuum chamber 1 is exhausted to the specified pressure, the main body 6 of the platform moves upward relative to each support rod 64.

[0039] 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 3 At this point, the substrate Sg is positioned in contact with the upper surface of the stage body 6. Furthermore, the first protruding wall 69 is embedded in the first receiving recess 72 of the first mask body 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 non-contactly. 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 body 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.

[0040] In the second embodiment described above, similar to the first embodiment, the inner surface of the first wall portion 41 functions as an anode during sputtering. This improves the in-plane uniformity of the film, such as the resistivity, when forming a molybdenum film on the upper surface of the substrate Sg. Furthermore, miniaturization of the sputtering apparatus is possible. During the sputtering of the target 2, sputtered particles may scatter into various parts of the vacuum chamber outside the substrate Sg, or bounce off and scatter further. However, since the target 2 or the film-forming space 1a is surrounded by the upper cylindrical wall portion 76 and the lower cylindrical wall portions 41, 42 of the gap Gp3 forming a labyrinth structure, the detachment of sputtered particles from the target 2 or bounced sputtered particles can be effectively suppressed. Furthermore, since the area of ​​the first wall portion 41 opposite to the lower cylindrical wall portion 76 is set to be larger than the area of ​​the second wall portion 42 opposite to the lower cylindrical wall portion 76, the sputtered particles to be evaded can bounce as many times as possible on the surfaces of the first wall portion 41 and the lower cylindrical wall portion 76, thus more effectively suppressing the evasion of sputtered particles.

[0041] Explanation of reference numerals in the attached figures SM1, SM2. Magnetron sputtering apparatus, 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, 3. Magnet unit, 4. Shielding plate, 40. Upper cylindrical wall (cylindrical wall part), 41. First wall part (component of upper cylindrical wall part), 42. Second wall part (component of upper cylindrical wall part), St1, 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, D1. Distance between the target tip and the cylindrical wall, Gp, Gp1, Gp2, Gp3. Gap in the labyrinth structure, Sp. Peeling inhibition treatment.

Claims

1. A magnetron sputtering apparatus characterized by: a vacuum chamber having a target and a substrate disposed opposite each other, and provided with: a shield plate disposed in a manner of surrounding a periphery of the target, which functions as an anode when sputtering the target; and a magnet unit that causes a leakage magnetic field to act within a film formation space between the target and the substrate; and a cylindrical wall portion extending downward from a position near a target end in a direction from the target toward the substrate, i.e., a lower surface of the shield plate.

2. A magnetron sputtering apparatus characterized by: a further shield plate disposed around the substrate within the vacuum chamber, the cylindrical wall portion serving as an upper cylindrical wall portion, and a lower cylindrical wall portion provided on an upper surface of the further shield plate, the lower cylindrical wall portion having a length in which an upper end portion thereof overlaps a lower end portion of the upper cylindrical wall portion with a gap.

3. The magnetron sputtering apparatus according to claim 2, characterized in that: the upper cylindrical wall portion serves as a first wall portion, a second wall portion is located around the first wall portion, and the lower end portion of the lower cylindrical wall portion intrudes into a gap between the first wall portion and the second wall portion, which are provided on the lower surface of the shield plate, whereby a gap of a labyrinth structure in which the lower cylindrical wall portion and the first wall portion and the second wall portion are engaged non-contactingly is formed on an outside of the periphery of the film formation space. ​ ​ ​ ​

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