Substrate processing apparatus, bevel mask and substrate processing method

Abstract

An example of a substrate processing device comprises a chamber, a shielding component which is a susceptor or an upper cover provided within the chamber, and a bevel mask provided in the chamber, wherein the bevel mask has an inclined surface in which the vertical distance from the shielding component increases toward the center side of the shielding component.

Description

Technology Field

[0001] Examples regarding a substrate processing device, a bevel mask, and a substrate processing method are described. Background Technology

[0002] For example, forming a film on the front surface of a substrate may cause the substrate to warp. To suppress substrate warping, a high-stress film may be formed on the back side of the substrate. In this case, to perform processing on the back side while suppressing processing on the front surface, a bevel mask may be made close to the bevel of the substrate. According to one example, a bevel mask has been used to suppress film formation on the front surface of the substrate. If the bevel mask conceals or chucks the outer edges of the back side of the substrate, uniform processing of the back side of the substrate will not be possible. For example, when a film is formed on the back side of the substrate, the film thickness in the area of ​​several millimeters inside the bevel is smaller than the film thickness in the center of the substrate. If uniform processing cannot be performed on the back side of the substrate, it becomes impossible to completely chuck the substrate in subsequent steps, or pattern misalignment or film formation defects may occur. The problem to be solved

[0003] Some examples described in this specification may solve the aforementioned problems. Some examples described herein may provide a substrate processing apparatus, a bevel mask, and a substrate processing method that enable substantially uniform processing of the back surface of a substrate while suppressing processing of the front surface of the substrate in substrate processing using a bevel mask. means of solving the problem

[0004] In some examples, a substrate processing device comprises a chamber, a shielding component which is a susceptor or upper cover provided within the chamber, and a bevel mask provided in the chamber, wherein the bevel mask has a slanted surface in which the vertical distance from the shielding component increases toward the center side of the shielding component. Brief explanation of the drawing

[0005] Figure 1 is a cross-sectional view of a substrate processing device. Figure 2 is a bottom view of the bevel mask. Figure 3 is a cross-sectional view of a substrate processing device. Figure 4 is an enlarged view of the bevel mask and its vicinity. Figure 5 is a cross-sectional view showing a bevel mask according to another example. Figure 6 is a cross-sectional view showing a bevel mask according to another example. Figure 7 is a cross-sectional view showing a bevel mask according to another example. Figure 8 is a cross-sectional view showing a bevel mask according to another example. FIG. 9 is a cross-sectional view of a substrate processing device according to another example. Figure 10 is an enlarged view of the bevel mask and its vicinity. Specific details for implementing the invention

[0006] A substrate processing apparatus, a bevel mask, and a substrate processing method will be described with reference to the drawings. Identical or corresponding components are indicated by the same reference numerals, and redundant descriptions may be omitted.

[0007] FIG. 1 is a cross-sectional view illustrating an example configuration of a substrate processing device (10) according to one example. The substrate processing device (10) includes a susceptor (16) provided in a chamber (12). The susceptor (16) is fixed to a shaft (18). The shaft (18) is moved up and down by a lifting mechanism, which also enables the up and down movement of the susceptor (16). A susceptor pin (17) fixed to the chamber (12) protrudes above the upper surface of the susceptor (16) when the susceptor (16) is positioned on the lower side. Additionally, the susceptor pin (17) is positioned below the susceptor (16) when the susceptor (16) is positioned on the upper side, and thus does not protrude above the upper surface of the susceptor (16).

[0008] A shower plate (14) is placed on a susceptor (16). A plurality of slits (14a) are provided in the shower plate (14). A gas inlet tube (22) is secured to the shower plate (14) through an insulating component (20). Any gas supplied from a gas source passes through the gas inlet tube (22) and the slits (14a) and is supplied to the space above the susceptor (16). The direction of gas supply is indicated by an arrow.

[0009] A parallel plate structure is provided by the aforementioned susceptor (16) and shower plate (14). High-frequency power is applied to the shower plate (14) while supplying gas to the space between the susceptor (16) and the shower plate (14), thereby allowing plasma to be generated in this space.

[0010] A flow control ring (hereinafter 'FCR') (38) is placed on the chamber (12), for example, via an O-ring. An exhaust duct (30) is placed on the chamber (12), for example, via an O-ring (34). The exhaust duct (30) may be formed of an insulator such as ceramic. Additionally, a shower plate (14) is placed on the exhaust duct (30), for example, via an O-ring (32), thereby electrically insulating the chamber (12) and the shower plate (14) from each other. An annular exhaust passage (36) is provided in plan view by the exhaust duct (30) and the FCR (38). This exhaust passage (36) is connected to the exhaust duct (24). A vacuum pump, valve, etc., is provided at the middle of the exhaust duct (24) or at the end of the exhaust duct (24) to enable pressure adjustment within the chamber (12).

[0011] A bevel mask (39) is placed on an FCR (38) inside a chamber (12). The bevel mask (39) is a ring formed in an annular shape when viewed in a planar view. The material of the bevel mask (39) is, for example, AlN, but can be any insulator. The bevel mask (39) includes a flat surface (39a) and an inclined surface (39b) inside the flat surface (39a). In the example of FIG. 1, the bevel mask (39) is placed on the FCR (38) so that the flat surface (39a) contacts the upper surface of the FCR (38). The inclined surface (39b) is a surface where the vertical distance from the susceptor (16) increases toward the center of the susceptor (16). That is, the inclined surface (39b) is a surface that is not parallel to the horizontal direction and becomes higher toward the center of the part enclosed by the bevel mask (39).

[0012] FIG. 2 is a bottom view of a bevel mask (39). According to one example, the bevel mask (39) includes a flat surface (39a) and a slanted surface (39b) connected to the flat surface (29a) and located inside the flat surface (39a). The slanted surface (39b) may be formed in an annular shape when viewed from the flat and bottom views.

[0013] Next, a substrate processing method using a substrate processing device (10) will be described. First, as shown in FIG. 1, a substrate (40) is introduced into a chamber (12) and placed on a susceptor pin (17). For example, a wafer transfer arm holding the substrate (40) is introduced into the chamber (12), and the arm moves downward on the susceptor pin so that the substrate (40) is placed on the susceptor pin (17).

[0014] Next, the susceptor (16) and the shaft (18) are raised by a lifting mechanism provided outside the chamber (12). FIG. 3 is a cross-sectional view illustrating an example configuration of a substrate processing device with the susceptor (16) in a raised state. When the susceptor (16) is raised, the susceptor (16) and the substrate (40) come into contact with each other, and the substrate (40) is separated from the susceptor pin (17). While the susceptor (16) moves upward, the susceptor (16) and the bevel mask (39) come into contact with each other, and the bevel mask (39) is separated from the FCR (38). Subsequently, as shown in FIG. 3, the substrate (40) and the bevel mask (39) are supported by the susceptor (16).

[0015] FIG. 4 is an enlarged view of the bevel mask (39) of FIG. 3 and its vicinity. According to one example, the substrate (40) has a device surface (40a) which is the surface on which the device is formed, and a back surface (40b) which is the surface opposite to the device surface (40a). The bevel (40A) is the sloped portion of the outer edge of the substrate (40). The device surface (40a) forms a device through a well-known semiconductor process, and as a result, the substrate (40) can be bent to some extent.

[0016] In the example of FIG. 4, the susceptor (16) includes an upward convex portion (16A), a middle portion (16B), and a central portion (16C). Of the three portions, the upper surface of the upward convex portion (16A) is the highest. The middle portion (16B) is a slope in which the height decreases from the upward convex portion (16A) to the central portion (16C). The upper surface of the central portion (16C) is a flat surface.

[0017] In the example of FIG. 4, the bevel mask (39) includes a main body portion (39A) and a convex portion (39B) on the lower surface on the inner edge side of the main body portion (39A). In this example, the bevel mask (39) is placed on the susceptor (16) so that the flat surface (39a) contacts the upward convex portion (16A). Additionally, the inclined surface (39b) contacts the bevel (40A). In this example, the bevel mask (39) contacts only the bevel (40A) and does not contact the rear surface (40b) or the device surface (40a). For example, by bringing the inclined surface (39b) into contact with the bevel (40A), the twisted substrate (40) can be pressed against the susceptor (16). According to another example, the inclined surface (39b) is close to the bevel (40A) but does not contact the bevel (40A). In that case, the inclined surface is provided slightly above the inclined surface (39b) of FIG. 4. As a result, there is no contact between the bevel mask (39) and the substrate (40).

[0018] As described above, the substrate (40) is placed on the susceptor (16) such that the device surface (40a) and the susceptor (16) face each other. Next, after the susceptor is moved to a process position as needed, the back surface (40b) is plasma treated. Gas supply to the space between the susceptor (16) and the shower plate (14) and the application of high-frequency power to the shower plate (14) are performed alternately or simultaneously. By generating plasma in this space, film formation on the back surface (40b), etching treatment on the back surface (40b), and modification of the film on the back surface (40b) are performed. According to one example, this plasma treatment is applied to the entire back surface (40b). However, because the bevel mask (39) is in contact with or close to the bevel (40A), there is no significant plasma treatment on the bevel (40A). According to one example, it is possible to prevent any step difference on the back surface by forming a film over the entire back surface (40b) through plasma treatment.

[0019] In the above example, the plasma is generated by a parallel plate structure, but the plasma can be generated in other ways. In the example of FIG. 1, the shower plate (14) is adopted as the plasma unit provided in relation to the susceptor. However, as described above, a well-known microwave plasma generator or a well-known inductively coupled plasma device may be adopted as the plasma unit.

[0020] FIG. 5 is a cross-sectional view illustrating a bevel mask (39) according to another example. The inclined surface of the lower surface of the convex portion (39B) includes a flat inclined surface (39b) and a concave curved surface (39c). The curved surface (39c) is a surface that contacts or is close to the bevel (40A). According to one example, the curved surface (39c) enables surface contact between the convex portion (39B) and the bevel (40A) or inhibits gas intrusion through the gap between the convex portion (39B) and the bevel (40A).

[0021] FIG. 6 is a cross-sectional view illustrating a bevel mask (39) according to another example. A concave curved surface (39d) is provided as an inclined surface of the lower surface of the convex portion (39B). In this example, the entire lower surface of the convex portion (39B) becomes the curved surface (39d). Thus, even if the substrate (40) is misaligned, the curved surface (39d) and the bevel (40A) can come into contact with or be close to each other.

[0022] By making the curvature of the curved surface of FIGS. 5 and 6 match or close to the curvature of the bevel (40A), the intrusion of gas through the gap between the convex portion (39B) and the bevel (40A) can be further suppressed.

[0023] FIG. 7 is a cross-sectional view illustrating a bevel mask (39) according to another example. An inclined surface (39b) and a convex curved surface (39e) are provided as inclined surfaces of the lower surface of the convex portion (39B). The convex curved surface (39e) is a surface that contacts or is close to the bevel (40A).

[0024] FIG. 8 is a cross-sectional view illustrating a bevel mask (39) according to another example. A convex curved surface (39f) is provided as an inclined surface of the lower surface of the convex portion (39B). The entire lower surface of the convex portion (38B) becomes a convex curved surface (39f).

[0025] According to the examples in FIGS. 7 and 8, by providing a convex surface (39e) or a convex surface (39f), the bevel mask (39) and the bevel (40A) can be brought into secure contact or sufficiently close to each other.

[0026] FIG. 9 is a cross-sectional view of a substrate processing apparatus according to another example. This substrate processing apparatus is a parallel plate type plasma processing apparatus. A door (13) is attached to the chamber (12) to allow a substrate to be placed inside the chamber (12) or removed from the chamber (12). The chamber (12) may be provided as part of a dual chamber module (DCM) or a quad chamber module (QCM). An upper cover (80) is provided inside the chamber (10). According to one example, the upper cover (80) is provided as a ground electrode. The ground electrode is an electrode for grounding.

[0027] The upper cover (80) includes a shaft portion (80a) and a disc portion (80b) connected to the shaft portion (80a). The shaft portion (80a) is fixed to a first lifting mechanism (51) capable of moving in the z positive-negative direction. According to one example, the first lifting mechanism (51) is provided by a plate (51a) fixed to the top of the bellows (51b) and fixed to the shaft portion (80a), and a plate (51c) fixed to the bottom of the bellows (51b) and fixed to the chamber (12). As the first lifting mechanism (51), various configurations for moving the upper cover (80) up and down within the chamber (10) may be employed.

[0028] The disc portion (80b) is circular or substantially circular in shape when viewed in a plane. The lower surface of the disc portion (80b), which is the lower surface of the upper cover (80), has, for example, a first lower surface (80c) and a second lower surface (80d) located below the first lower surface (80c) and surrounding the first lower surface (80c). Thus, the lower surface of the disc portion (80b) has a shape having a dent in the center.

[0029] The upper cover (80), which is the ground electrode, functions as the upper electrode in a parallel plate structure. To enable plasma coupling and prevent or reduce electric discharge, the height difference between the first lower surface (80c) and the second lower surface (80d) can be made, for example, 1 mm or less.

[0030] A bevel mask (90) is provided inside the chamber (12). The bevel mask (90) includes a flat surface (90a) and an inclined surface (90b) surrounded by the flat surface (90a). The inclined surface (90b) is a surface in which the vertical distance from the upper cover (80) increases toward the center of the upper cover (80). That is, the inclined surface (90b) is a surface in which the height decreases toward the center of the portion surrounded by the bevel mask (90) and is not parallel to the horizontal direction.

[0031] According to one example, the bevel mask (90) is supported or suspended by a support bar (91). The support bar (91) is fixed to a second lifting mechanism (53) driven by a motor (52). The second lifting mechanism (53) is configured to move the support bar (91) and the bevel mask (90) up and down within the chamber (10). That is, the support bar (91) and the bevel mask (90) can be moved up and down by the motor (52) and the lifting mechanism (53). According to one example, the second lifting mechanism (53) is provided by a plate (53a) fixed to the support bar (91) which is fixed to the top of the bellows (53b), and a plate (53c) fixed to the chamber (12) which is fixed to the bottom of the bellows (53b). As a second lifting mechanism (53), various configurations for moving the bevel mask (90) up and down within the chamber (12) may be employed.

[0032] The support bar (91) and the bevel mask (90) may be formed integrally with the dielectric, for example. The bevel mask (90) has an annular shape when viewed in a plane. The bevel mask (90) includes an annular flat surface (90a) and an inclined surface (90b) located immediately below the upper cover (80). In some examples, as shown in FIG. 9, the height of the flat surface (90a) is greater than the height of the inclined surface (90b). The height difference between the flat surface (90a) and the inclined surface (90b) is, for example, greater than the thickness of the substrate to be processed (40). According to other examples, as shown in FIG. 10, the height of the flat surface (90a) may be lower than the height of the inclined surface (90b).

[0033] FIG. 10 is an enlarged view of the bevel mask (90) and its vicinity. The bevel mask (90) includes a main body portion (90A) and a convex portion (90B) on the upper surface on the inner edge side of the main body portion (90A). The main body portion (90A) has a flat surface (90a), and the convex portion (90B) has an inclined surface (90b). The inclined surface (90b) is an inclined surface in which the vertical distance from the main body portion (90A) decreases toward the center side of the bevel mask (90). In some examples, an oblique third lower surface (80e) contacts the bevel (40A). According to other examples, the third lower surface (80e) is omitted so that the upper cover (80) does not contact the substrate (40).

[0034] The inclined surface (90b) contacts the bevel (40A), thereby supporting the substrate (40) by the bevel mask (90). According to one example, the bevel mask (90) contacts only the bevel (40A) of the substrate (40) and does not contact any part of the substrate (40) other than the bevel (40A). Thus, the rear surface (40b) of the substrate (40) is exposed, and plasma treatment can be performed on the entire rear surface (40b). An inclined surface having various shapes as described above may be adopted as the inclined surface (90b).

[0035] FIG. 9 illustrates a rotating arm (92) located near the inner wall of the chamber (12). The rotating arm (92) is provided to transport a substrate into, for example, the four chambers constituting the QCM. The substrate processing device includes a plasma unit configured to generate plasma in the area below the upper cover (80) and the bevel mask (90). In the example of FIG. 9, the plasma unit includes a shower plate (93), gas sources (94, 95), and an RF power source (96). The shower plate (93) is provided below the upper cover (80) so as to face the upper cover (80). The shower plate (93) includes plates (93a, 93c) having slits for supplying gas from the gas sources (94, 95) in the z-positive direction, and a spacer (93b) provided between the plates (93a, 93b). The entire shower plate (93) may be formed of metal. According to another example, at least the plate (93c) is formed of metal. Gas sources (94, 95) provide the gas required for plasma processing. An RF power source (96) provides high-frequency power to the shower plate (93) to make the gas into a plasma state. In this way, the substrate processing device can perform plasma processing with a parallel plate structure including an upper cover (80) and a shower plate (93).

[0036] In some examples, the upper cover (80) is evacuated upward by a motor (50) that moves, for example, the first lifting mechanism (51). Additionally, the bevel mask (90) is evacuated upward by a motor (52) that moves, for example, the second lifting mechanism (53). Then, a support pin, which is part of the rotating arm (92), is provided to a substrate receiving position inside the chamber (12) by the rotation of the rotating arm (92). The support pin for supporting the substrate is provided to one of the four chambers by the rotation of the rotating arm (92). The support pin can be positioned in a location surrounded by the bevel mask (90). Then, after the bevel mask (90) moves downward below the top of the support pin, the substrate is placed on the support pin provided just below the upper cover (80). Then, as the bevel mask (90) moves upward, the inclined surface (90b) comes into contact with the bevel (40A). As a result of this contact, the support pin is separated from the substrate (40) and evacuated from a position just below the upper cover (80) by rotating the rotating arm (92).

[0037] Subsequently, the flat surface (90a) comes into close contact with the upper cover (80) while avoiding contact between the upper cover (80) and the substrate (40). In this example, the flat surface (90a) comes into close contact with the second lower surface (80d) as the upper cover (80) moves downward. According to one example, contact between the upper cover (80) and the substrate (40) can be prevented by providing a first lower surface (80c) positioned on the second lower surface (80d).

[0038] The flat surface (90a) is located directly below the second lower surface (80d), and when the second lower surface (80d) comes into contact with the flat surface (90a), the flow of gas through the space between the upper cover (80) and the bevel mask (90) is suppressed. In another example, when the lower surface of the disc portion (80b) of the upper cover (80) is flat, the flow of gas through the space between the lower surface of the upper cover (80) and the flat surface (90a) is suppressed as a result of the lower surface of the upper cover coming into contact with the flat surface (90a).

[0039] In some examples, the space enclosed by the substrate (40), the bevel mask (90), and the top cover (80) becomes a sealed space. In this case, the gas supplied from the gas source (94, 95) and the plasma provided between the parallel plates are hardly provided to the sealed space.

[0040] Next, plasma treatment is performed on the rear surface (40b) of the substrate (40). In some examples, it is possible to protect the device surface (40a) by avoiding contact between the substrate (40) and the upper cover (80). This avoidance of contact can be ensured by providing a concave portion on the lower surface of the upper cover (80). According to one example, the film formed on the rear surface (40b) of the substrate (40) through plasma treatment alleviates the warping of the substrate (40).

[0041] In some of the examples described above, the shielding component, which is a susceptor or an upper cover, faces the device surface of the substrate. If the shielding component is a susceptor, the susceptor (16) and the substrate (40) are in contact with each other, and contact between the bevel (40A) of the substrate (40) and the bevel mask (39) may not be essential. On the other hand, if the shielding component is an upper cover (80), the bevel (40A) of the substrate (40) and the bevel mask (90) are in contact with each other, and contact between the substrate (40) and the upper cover (80) may not be essential.

[0042] In each of the examples described above, at least partially inclined surfaces of the bevel mask may be circular when viewed from the bottom, or may have a shape that takes into account a notch or an orientation flat. Specifically, the inclined surface of the bevel mask may be adjusted so that the notch or orientation flat and the inclined surface of the bevel mask may come into contact or be close to each other.

Claims

Claim 1 A substrate processing device comprising: a chamber; a shielding component provided within the chamber and being a susceptor or an upper cover; a bevel mask provided within the chamber and having an inclined surface such that a vertical distance from the shielding component increases toward the center side of the shielding component, wherein the bevel mask has a convex portion extending in the direction of the vertical distance to form the inclined surface. Claim 2 A substrate processing apparatus according to claim 1, wherein the inclined surface is formed in an annular shape when viewed from a planar view. Claim 3 A substrate processing apparatus according to claim 1, wherein the inclined surface has a flat surface. Claim 4 A substrate processing apparatus according to claim 1, wherein the inclined surface has a concave curved surface. Claim 5 A substrate processing apparatus according to claim 1, wherein the inclined surface has a convex curved surface. Claim 6 A substrate processing apparatus according to any one of claims 1 to 5, further comprising a flow control ring in contact with the lower surface of the bevel mask. Claim 7 A substrate processing apparatus according to any one of claims 1 to 5, further comprising a lifting mechanism for moving the bevel mask up and down. Claim 8 A substrate processing apparatus according to any one of claims 1 to 5, further comprising a plasma unit provided in relation to the shielding component. Claim 9 A substrate processing apparatus according to any one of claims 1 to 5, wherein the shielding component is a susceptor, and the bevel mask has a flat surface configured to contact the upper surface of the susceptor outside the inclined surface. Claim 10 A bevel mask comprising: a body portion having an annular shape; and a convex portion on a lower surface or an upper surface on the inner edge side of the body portion, wherein the convex portion has an inclined surface in which the distance from the body portion decreases toward the center side of the bevel mask, and the convex portion extends in the direction of the distance to form the inclined surface. Claim 11 A bevel mask according to claim 10, wherein the inclined surface is formed in an annular shape when viewed in a plane. Claim 12 In claim 10, the inclined surface is a bevel mask having a flat surface. Claim 13 In claim 10, the inclined surface is a bevel mask having a concave curved surface. Claim 14 In claim 10, the inclined surface is a bevel mask having a convex curved surface. Claim 15 A substrate processing method for a substrate having a device surface on which a device is formed and a back surface opposite to the device surface, the method comprising: a step of orienting the device surface toward a shielding component which is a susceptor or an upper cover; a step of bringing an inclined surface of a bevel mask into contact with or close to the bevel of the substrate — the bevel mask having a convex portion that extends in a direction of a vertical distance from the shielding component to form the inclined surface — and a step of plasma processing the back surface. Claim 16 A substrate treatment method according to claim 15, wherein the plasma treatment is performed over the entire rear surface.

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