Edge ring for supporting wafer

Abstract

Disclosed is an edge ring for supporting a wafer, the edge ring comprising a first edge ring positioned outside a wafer to support the outer circumferential portion of the wafer, wherein the first edge ring comprises: a first main body ring formed in a ring shape having a predetermined width and thickness; a first seating ring formed in a stepped shape stepped downward from the upper surface of the first main body ring and having a first seating area on which the outer circumferential portion of the wafer is seated; a separation protrusion formed in a protrusion shape positioned outside the wafer in the first seating area; and a first support ring having a predetermined thickness, having the upper end coupled to the outer circumferential end of the first main body ring, and extending downward to a predetermined height.

Description

Wafer support edge ring

[0001] The present invention relates to an edge ring for supporting a wafer in a process chamber for semiconductor manufacturing.

[0002] A process chamber for semiconductor manufacturing can perform semiconductor processes, such as heat treatment or deposition processes, while supporting a wafer using edge rings in its internal space. Additionally, the heat treatment process may include processes such as heat treatment of various thin films deposited on the semiconductor wafer, ion implantation, and activation. The heat treatment process may be performed using a VCSEL device or a halogen lamp. At this time, the heat treatment process may be performed using a Rapid Thermal Process (RTP) at 1,000 to 1,200°C for several seconds. Furthermore, to reduce the heat treatment time to the range of msec to usec, the heat treatment process may utilize a Xe-flash lamp, and methods such as Flash Lamp Annealing (FLA) irradiating in the range of μsec to msec and Laser Spike Annealing (LSA) irradiating with a laser may be used.

[0003] The above heat treatment process requires small temperature deviations and high temperature uniformity across the entire area of ​​the wafer due to the miniaturization of semiconductor technology. The wafer can generally be heat-treated while its outer periphery is supported by an edge ring. As the outer periphery of the wafer's bottom surface comes into contact with the edge ring, heat is conducted and released, causing the temperature of the outer periphery to become relatively lower, which may result in a temperature difference between the center and the outer periphery. Furthermore, if the wafer is positioned eccentrically within the edge ring, the outer surface may come into partial contact with the inner surface of the edge ring, causing additional temperature deviations along the circumferential direction at the outer periphery. Moreover, when the wafer and the edge ring rotate, the likelihood of the outer surface of the wafer coming into physical contact with the inner surface of the edge ring increases during the rotation process. In such cases, the temperature deviation along the circumferential and diametric directions at the outer periphery in contact with the edge ring may become larger.

[0004] The present invention aims to provide an edge ring for wafer support that can reduce the temperature variation of the wafer.

[0005] In addition, the present invention aims to provide an edge ring for supporting a wafer that can reduce thermal shock damage caused by temperature variations of the wafer.

[0006] The wafer support edge ring of the present invention includes a first edge ring located on the outer side of the wafer to support the outer periphery of the wafer, and the first edge ring is characterized by supporting the outer periphery of the wafer while making line contact or point contact with the outer surface of the wafer.

[0007] Additionally, the wafer support edge ring comprises a first edge ring located on the outer side of the wafer to support the outer periphery of the wafer, wherein the first edge ring comprises a first main body ring formed in a ring shape having a predetermined width and thickness, a first seating ring formed in a stepped shape extending downward from the upper surface of the first main body ring to have a first seating area on which the outer periphery of the wafer is seated, a spaced projection formed in a projection shape located on the outer side of the wafer in the first seating area, and a first support ring having a predetermined thickness, wherein the upper end is coupled to the outer periphery of the first main body ring and extends to a predetermined height in a downward direction.

[0008] The first seating ring comprises a first seating vertical ring, the upper end of which is coupled to the inner circumferential end of the first main body ring and extends to a predetermined height in a downward direction, and a first seating horizontal ring, the outer end of which is coupled to the lower end of the first seating inclined ring and extends inwardly in a horizontal direction to form the first seating area, and the spacing projection may be formed by extending from the inner circumferential surface of the first seating vertical ring to the upper surface of the first seating horizontal ring.

[0009] In addition, the above-mentioned spacing protrusion may have a planar shape that is triangular, and may be formed such that one vertex faces the inside of the first main body ring.

[0010] In addition, the above-mentioned spacing protrusion may have a planar shape that is arc-shaped, and the curved portion may be formed to face the inner side of the first main body ring.

[0011] In addition, the corners of the upper surface of the above-mentioned spacing protrusions may be rounded.

[0012] In addition, the above-mentioned spacing projection can be formed integrally with the first seating ring.

[0013] In addition, the above-mentioned spacing projection is in the shape of a column and is formed separately from the first seating ring and can be coupled to the first seating receiving portion of the first seating ring.

[0014] In addition, at least four of the above-mentioned spacing protrusions may be positioned spaced apart in the circumferential direction of the first main body ring, and the diameter of the virtual circle connecting the inner ends may be formed to be larger than the outer diameter of the wafer.

[0015] In addition, the above-mentioned spacing protrusions may be formed such that their thickness is smaller than the thickness of the wafer and greater than half the thickness of the wafer.

[0016] In addition, it may include a second edge ring located on the outer side of the first edge ring and supporting the outer periphery of the first edge ring.

[0017] In addition, the first edge ring may be formed of a material having lower thermal conductivity than the second edge ring.

[0018] In addition, the first edge ring may be formed of sintered SiC, and the second edge ring may be formed of CVD-SiC.

[0019] Additionally, the first edge ring may include a first main body ring formed in a ring shape having a predetermined width and thickness, a first seating ring having a first seating area formed in a stepped shape extending downward from the upper surface of the first main body ring to be seated on the outer periphery of the wafer, and a first support ring having a predetermined thickness, with its upper end coupled to the outer periphery of the first main body ring and extending to a predetermined height in the downward direction; and the second edge ring may include a second main body ring formed in a ring shape having a predetermined width and thickness, a second seating ring having a second seating area formed in a stepped shape extending downward from the upper surface of the second main body ring to be seated on the first support ring of the first edge ring, and a second support ring having a predetermined thickness, with its upper end coupled to the outer periphery of the second main body ring and extending to a predetermined height in the downward direction.

[0020] Additionally, the first seating ring may include a first seating inclined ring, the upper end of which is coupled to the inner end of the first main body ring and extends to a predetermined height in a downward direction, and a first seating horizontal ring, the outer end of which is coupled to the lower end of the first seating inclined ring and extends horizontally inward to form the first seating area, and the second seating ring may include a second seating inclined ring, the upper end of which is coupled to the inner end of the second main body ring and extends to a predetermined height in a downward direction, and a second seating horizontal ring, the outer end of which is coupled to the lower end of the second seating inclined ring and extends horizontally inward to form the second seating area.

[0021] In addition, the thickness of the second seating area may be formed to be thinner than the thickness of the second main body ring.

[0022] In addition, the second main body ring may further include a second blocking groove in the shape of a groove that extends from the lower surface to the upper surface and forms a ring shape.

[0023] The wafer support edge ring of the present invention is provided with a plurality of spaced protrusions that protrude inward from the inner surface of the edge ring that directly supports the wafer, thereby reducing the contact area between the outer surface of the wafer and the inner surface of the edge ring, and thus reducing the temperature variation of the wafer in contact with the edge ring.

[0024] In addition, the wafer support edge ring of the present invention can reduce temperature deviations in the circumferential direction and the center direction at the outer periphery of the wafer in contact with the edge ring.

[0025] In addition, the wafer support edge ring of the present invention can reduce the temperature difference between the outer periphery and the inner periphery of the wafer.

[0026] In addition, the wafer support edge ring of the present invention can prevent thermal shock damage to the wafer by reducing the temperature variation at the outer periphery of the wafer.

[0027] FIG. 1 is a vertical cross-sectional view of a substrate heat treatment device equipped with an edge ring for wafer support according to one embodiment of the present invention.

[0028] FIG. 2 is a vertical cross-sectional view of an edge ring for wafer support according to one embodiment of the present invention.

[0029] Figure 3 is a plan view of the area including the wafer and the inner circumference of the edge ring in Figure 2.

[0030] FIG. 4 is a plan view of an area including a spaced projection according to another embodiment of the present invention.

[0031] FIG. 5 is a plan view corresponding to FIG. 3 of an edge ring for wafer support according to another embodiment of the present invention.

[0032] Figure 6 is a vertical cross-sectional view of AA in Figure 5.

[0033] Figure 7 is a graph of the analysis results according to the configuration of the edge ring.

[0034] The wafer support edge ring according to an embodiment of the present invention will be described in more detail below through the examples and the attached drawings.

[0035]

[0036] First, the structure of an edge ring for wafer support according to one embodiment of the present invention will be described.

[0037] FIG. 1 is a vertical cross-sectional view of a substrate heat treatment apparatus equipped with a wafer support edge ring according to one embodiment of the present invention. FIG. 2 is a vertical cross-sectional view of a wafer support edge ring according to one embodiment of the present invention. FIG. 3 is a plan view of an area including the wafer and the inner circumference of the edge ring in FIG. 2. FIG. 4 is a plan view of an area including a spacing projection according to another embodiment of the present invention. FIG. 5 is a plan view of a wafer support edge ring according to another embodiment of the present invention corresponding to FIG. 3. FIG. 6 is a vertical cross-sectional view of AA in FIG. 5.

[0038]

[0039] A wafer support edge ring (100) according to one embodiment of the present invention may include a first edge ring (110) as shown in FIGS. 1 to 6. Additionally, the wafer support edge ring (100) may further include a second edge ring (120). The first edge ring (110) directly supports the wafer (a) from the outside of the wafer (a), and the second edge ring (120) may directly support the first edge ring (110) from the outside of the first edge ring (110). Additionally, the wafer support edge ring (100) may further include at least one edge ring having a structure similar to the first edge ring (110) or the second edge ring (120) between the first edge ring (110) and the second edge ring (120). The wafer support edge ring (100) may additionally include at least one edge ring having a structure similar to the second edge ring (120) on the outer side of the second edge ring (120). Accordingly, the wafer support edge ring (100) may be formed with a plurality of edge rings including the first edge ring (110) and the second edge ring (120). The wafer support edge ring (100) may be mounted inside a substrate heat treatment device in which a heat treatment process of the wafer (a) is performed to support the wafer (a).

[0040] The wafer support edge ring (100) is provided with a plurality of spaced protrusions protruding inward from the inner surface of a first edge ring (110), which is an edge ring that directly supports the wafer (a), thereby reducing the contact area between the outer surface of the wafer (a) and the inner surface of the edge ring, and thus reducing the temperature difference in the circumferential direction from the outer surface of the wafer (a). In addition, the wafer support edge ring (100) can reduce the temperature difference in the circumferential direction and the center direction of the wafer (a) from the outer surface of the wafer (a) that contacts the edge ring. In addition, the wafer support edge ring (100) can reduce the temperature difference between the outer surface and the inner surface of the wafer (a). In addition, the wafer support edge ring (100) can prevent thermal shock damage to the wafer (a) by reducing the temperature difference from the outer surface of the wafer (a).

[0041] Additionally, the wafer support edge ring (100) is formed to accommodate variations caused by thermal expansion or thermal contraction at the surfaces where the first edge ring (110) and the second edge ring (120) come into contact with each other, thereby preventing the first edge ring (110) and the second edge ring (120) from being damaged by thermal shock. That is, the wafer support edge ring (100) may include a tolerance for thermal expansion or thermal contraction between the first edge ring (110) and the second edge ring (120).

[0042] The above substrate heat treatment device (10) may be a general heat treatment device used in the heat treatment process of a wafer (a) in a semiconductor manufacturing process. For example, the above substrate heat treatment device (10) may be equipped with a process chamber (20), a beam irradiation module (30), and a substrate rotation module (40), as shown in FIG. 1. Additionally, the above substrate heat treatment device (10) may further include a gas injection module for injecting process gas, although not specifically illustrated.

[0043] The above substrate heat treatment device (10) can perform heat treatment processes such as an epitaxial process, a crystallization process, an ion implantation process, a deposition process, or an activation process on a wafer (a). The above substrate heat treatment device (10) can perform heat treatment processes while rotating the wafer (a) and the wafer support edge ring (100) using a substrate rotation module. The above substrate heat treatment device (10) can heat the wafer (a) by irradiating it with a laser beam generated from a beam irradiation module (30).

[0044] The process chamber (20) may provide an internal space in which a wafer (a) is received and heat-treated. The process chamber (20) may include an outer housing (21), an inner housing (22), a beam irradiation plate (23), and a rotating support (24). The outer housing (21), the inner housing (22), and the beam irradiation plate (23) may form an internal space in which the wafer (a) is located. Additionally, the beam irradiation plate (23) may be located below the wafer (a) and allow a laser beam irradiated from the beam irradiation module (30) to be transmitted and irradiated to the bottom of the wafer (a). Meanwhile, the beam irradiation plate (23) may be located above the wafer (a) depending on the position of the beam irradiation module (30). The beam irradiation plate (23) may be formed of a transparent plate through which the laser beam is transmitted, such as quartz or glass. The above-mentioned rotating support (24) can support the wafer support edge ring (100) and the wafer (a) on the inside. Additionally, the wafer (a) and the wafer support edge ring (100) can be rotated by the above-mentioned substrate rotation module (40). Meanwhile, when the above-mentioned beam irradiation module (30) rotates, the rotating support (24) and the wafer (a) may not rotate.

[0045] The beam irradiation module (30) may be located at the bottom of the beam irradiation plate (23) inside the inner housing (22). The beam irradiation module (30) may irradiate a laser beam onto the lower surface of the wafer (a) through the beam irradiation plate (23) from outside the process chamber (20). The beam irradiation module (30) may include a VCSEL element that generates a laser beam. Additionally, the beam irradiation module (30) may include a halogen lamp instead of the VCSEL element. Additionally, the beam irradiation module may include a Xe-flash lamp. Furthermore, the beam irradiation module may include various means for irradiating a laser.

[0046] Meanwhile, the beam irradiation module (30) may be located on the upper part of the wafer (a) outside the process chamber (20). In this case, the beam irradiation plate (23) may be coupled to an external housing (21) on the upper part of the wafer (a).

[0047] The substrate rotation module (40) may include an inner rotation means (41) and an outer rotation means (42). The substrate rotation module (40) can rotate the rotation support (24) in a non-contact manner in a horizontal direction. More specifically, the inner rotation means (41) may be coupled to the lower part of the rotation support (24) in the chamber lower space of the process chamber (20). The inner rotation means (41) may be formed with a structure similar to a motor rotor. Additionally, the outer rotation means (42) may be located on the outside of the process chamber (20) opposite the inner rotation means (41). The outer rotation means (42) may rotate the inner rotation means (41) non-contact using magnetic force. The outer rotation means (42) may be formed with a structure similar to a motor stator.

[0048] The wafer support edge ring (100) is positioned between the rotating support (24) and the wafer (a), with its outer side supported by the rotating support (24), and can support the outer side of the wafer (a) located on the inner side. More specifically, the wafer support edge ring (100) may be formed to include a first edge ring (110) that directly supports the outer periphery of the wafer (a) and a second edge ring (120) that supports the outer periphery of the first edge ring (110). Additionally, the outer periphery of the second edge ring (120) may be supported by the rotating support (24). The rotating support (24) is formed in an overall ring shape, and a rotating mounting ring on which the wafer support edge ring (100) is seated may be formed on the inner side. Additionally, a rotating protrusion ring may be formed on the upper surface of the rotating mounting ring of the rotating support (24). The above-mentioned rotating protrusion ring is formed in a ring shape along the inner circumference on the upper surface of the rotating seating ring, and can prevent the wafer support edge ring (100) from coming off.

[0049] The wafer support edge ring (100) of the present invention is formed by dividing it into an edge ring including a first edge ring (110) and a second edge ring (120), so thermal shock damage caused by a difference in internal temperature distribution compared to an edge ring formed as a whole can be prevented.

[0050] In addition, the wafer support edge ring (100) of the present invention is formed by dividing it into a first edge ring (110) that directly supports the wafer (a) from the outside of the wafer (a) and a second edge ring (120) that supports the first edge ring (110) from the outside of the first edge ring (110), so that the heat of the wafer (a) is reduced from being transferred to the rotating support and the temperature difference with respect to the outer periphery of the wafer (a) can be reduced.

[0051] The first edge ring (110) and the second edge ring (120) may be formed from any one of silicon carbide (SiC), quartz, and graphite. The first edge ring (110) and the second edge ring (120) may be formed from the same material or a different material selected from silicon carbide (SiC), quartz, and graphite.

[0052] Additionally, the first edge ring (110) and the second edge ring (120) may preferably be formed of materials having different heat transfer characteristics to reduce the temperature variation with respect to the outer periphery of the wafer (a). The first edge ring (110) may be formed of a material having a lower thermal conductivity than the second edge ring (120). Additionally, the first edge ring (110) may be formed of a material having a higher specific heat than the second edge ring (120). For example, the first edge ring (110) may be formed of sintered SiC, and the second edge ring (120) may be formed of CVD-SiC. Here, the sintered CVD may refer to SiC manufactured by sintering a powder containing SiC powder with a particle size at the micro level. The above CVD-SiC may refer to high-purity SiC obtained by depositing SiC onto graphite using CVD (chemical vapor deposition) and then removing the graphite.

[0053] Additionally, in the following description, the inner side, inner end, inner surface, or inner circumference refers to the direction, direction, end, or end surface facing the center of the wafer (a) for each component, and the outer side, outer end, inner surface, or outer circumference may refer to the direction, direction, end, or end surface opposite to the center direction of the wafer (a).

[0054]

[0055] The first edge ring (110) may include a first main body ring (111), a first seating ring (112), a spacing projection (113), and a first support ring (114). The first edge ring (110) may be formed in a ring shape overall. The first edge ring (110) may be located on the outside of the wafer (a) to support the outer periphery of the lower surface of the wafer (a).

[0056] The first edge ring (110) can support the wafer (a) by having its inner surface make line contact or point contact with the outer surface of the wafer (a) through the spacing protrusion (113). Accordingly, the first edge ring (110) can reduce the contact area with the wafer (a) and reduce the temperature variation at the outer periphery of the wafer (a).

[0057] As described above, the first edge ring (110) may be formed of a material having a lower thermal conductivity than the second edge ring (120). The first edge ring (110) may be formed of sintered SiC. The first edge ring (110) may have a thermal conductivity of 120 to 240 W / mK. The first edge ring (110) may have a specific heat of 750 to 810 J / kgK.

[0058] The first edge ring (110) may be formed with a thickness of 0.3 to 0.6 mm overall. The first edge ring (110) may be formed with a thickness smaller than that of the second edge ring (120).

[0059] The first main body ring (111) may be formed in a ring shape having a predetermined width and thickness. The first main body ring (111) may be formed with an appropriate width and outer diameter to have the strength required to support the wafer (a) located inside. The first main body ring (111) may be formed in a ring shape where the width is greater than the thickness. The first main body ring (111) may be formed with a thickness of 0.3 to 0.6 mm. The inner diameter of the first main body ring (111) may be formed to be larger than the outer diameter of the wafer (a).

[0060] The first mounting ring (112) may be formed in a stepped shape extending downward from the upper surface of the first main body ring (111) to provide a first mounting area (112a) on which the lower outer periphery of the wafer (a) is mounted. More specifically, the first mounting ring (112) may have a vertical cross-section formed in an "L" shape. Additionally, the first mounting ring (112) may include a first mounting vertical ring (112b) and a first mounting horizontal ring (112c).

[0061] The first mounting ring (112) is coupled to the inner surface or inner side of the first main body ring (111) and can support a wafer (a) located on the inner side. More specifically, the first mounting ring (112) can support the outer periphery of the lower surface of the wafer (a). The upper end of the first mounting ring (112) is coupled to the inner end of the first main body ring (111) and can be located lower than the first main body ring (111). That is, the upper end of the first mounting vertical ring (112a) of the first mounting ring (112) is coupled to the inner end of the first main body ring (111), and the outer end of the first mounting horizontal ring (112c) is coupled to the lower part of the first mounting vertical ring (112b). The first seating ring (112) can be formed with the same thickness as the first main body ring (111).

[0062] The first mounting vertical ring (112b) has a predetermined thickness, and its upper end is coupled to the inner circumference of the first main body ring (111) and can be extended downward to a predetermined height. The first mounting vertical ring (112b) can be extended downward from the inner circumference of the first main body ring (111) in a vertical direction or in an inwardly inclined direction. The concept of vertical may include an inclined direction along with a vertical direction. The first mounting vertical ring (112b) can be formed with a height that corresponds approximately to the thickness of the wafer (a). The first mounting vertical ring (112b) can be formed with the same thickness as the first main body ring (111). Additionally, the first mounting vertical ring (112b) can be formed with a thickness greater than that of the first main body ring (111) to stably support the wafer (a).

[0063] The first horizontal mounting ring (112c) has a predetermined thickness and can be formed so that its outer edge is joined to the lower end of the first vertical mounting ring (112b) and extends horizontally inward. The first horizontal mounting ring (112c) may have a first mounting area (112a) on which the lower outer edge of the wafer (a) is mounted. The first horizontal mounting ring (112c) can be formed with a width necessary to stably support the wafer (a). The first horizontal mounting ring (112c) can be formed with the same thickness as the first vertical mounting ring (112b). Additionally, the first horizontal mounting ring (112c) can be formed with a thicker thickness than the first vertical mounting ring (112b) to stably support the wafer (a).

[0064] The above-mentioned spacing projection (113) may be formed in a projection shape in the first seating area (112a). Additionally, the spacing projection (113) may be located on the outer side of the wafer (a) in the first seating area (112a). Furthermore, the above-mentioned spacing projection (113) may be formed by extending from the first seating vertical ring (112b) toward the outer surface of the wafer (a). More specifically, the above-mentioned spacing projection (113) may be formed by extending from the inner surface of the first seating vertical ring (112b) toward the upper surface of the first seating horizontal ring (112c).

[0065] The above-mentioned spacing projection (113) can support the outer surface of the wafer (a) while making line contact or point contact with the outer surface of the wafer (a). The above-mentioned spacing projection (113) can reduce the contact area between the outer surface of the wafer (a) and the inner surface of the first main body ring (111) or the inner surface of the first mounting vertical ring (112b). Accordingly, the above-mentioned spacing projection (113) can improve the circumferential direction or the temperature difference between the outer and center directions at the outer periphery of the wafer (a) that occurs due to contact between the first edge ring (110) and the wafer (a).

[0066] The above-mentioned spacing projection (113) may have a planar shape that is triangular, and may be formed such that one vertex faces the inside of the first main body ring (111). Accordingly, the side of the vertex of the spacing projection (113) may make line contact or point contact with the outer surface of the wafer (a). Additionally, the above-mentioned spacing projection (113) may have a planar shape that is arc-shaped, and may be formed such that the curved portion faces the inside of the first main body ring (111). In this case, the side of the spacing projection (113) and the outer surface of the wafer (a) may be formed in an arc shape having a radius of curvature in opposite directions. Accordingly, the side of the vertex of the spacing projection (113) may make line contact or point contact with the outer surface of the wafer (a). The corners of the upper surface of the spacing projection (113) may be rounded between the upper surface and the side surfaces. That is, the above-mentioned spacing projection (113) may have a curved surface or an inclined surface formed between the upper surface and the side surfaces. The above-mentioned spacing projection (113) may be formed integrally with the first main body ring (111) and the first seating ring (112). That is, the above-mentioned spacing projection (113) may be formed by processing together with the first main body ring (111) and the first seating ring (112). When the above-mentioned spacing projection (113) contacts the outer surface of the wafer (a), the contact area is further reduced and heat transfer can be reduced.

[0067] Additionally, the thickness of the spacing projection (113) may be smaller than the thickness of the wafer (a). Additionally, the thickness of the spacing projection (113) may be thicker than half the thickness of the wafer (a). Accordingly, the spacing projection (113) can stably separate the wafer (a) from the inner surface of the first main body ring (111) or the inner surface of the first mounting vertical ring (112b) while reducing the contact area with the wafer (a).

[0068] A plurality of the above-mentioned spacing protrusions (113) may be spaced apart along the circumferential direction of the first main body ring (111). At least three of the above-mentioned spacing protrusions (113) may be spaced apart along the circumferential direction of the first main body ring (111). For example, when three of the above-mentioned spacing protrusions (113) are formed, they may be spaced apart at 120° intervals, or four may be spaced apart at 90° intervals. Additionally, the above-mentioned spacing protrusions (113) may preferably be spaced apart at 60° intervals, with six of them.

[0069] The above-mentioned spacing projection (113) may be formed such that the diameter of the virtual circle connecting the inner ends is larger than the outer diameter of the wafer (a). Additionally, the length of the spacing projection (113) protruding from the inner surface of the first main body ring (111) or the inner surface of the first mounting vertical ring (112b) may be at least 1 mm. Accordingly, the wafer (a) is located inside the spacing projections (113), and its outer surface may be spaced apart from the spacing projections (113). Additionally, at least one of the spacing projections (113) may be spaced apart from the outer surface of the wafer (a).

[0070] Additionally, as shown in FIGS. 5 and 6, the above-mentioned spacing projection (113) may be manufactured separately and coupled to the first main body ring (111) or the first seating ring (112). The above-mentioned spacing projection (113) may be formed in a column shape having a predetermined height. The above-mentioned spacing projection (113) may be formed in a cylindrical shape. Additionally, the above-mentioned spacing projection (113) may be formed in a polygonal shape such as a square, a pentagon, or a hexagonal prism shape.

[0071] At this time, the first seating horizontal ring (112c) may further include a first seating receiving portion (112d) on the upper surface, as shown in FIG. 6. The first seating receiving portion may be formed in a groove or hole shape formed from the upper surface toward the lower surface. The first seating receiving portion may be formed in a planar shape corresponding to the planar shape of the spacing projection (113). When the spacing projection (113) is formed in a cylindrical shape, the first seating receiving portion may be formed in a circular groove or hole shape. Additionally, when the spacing projection (113) is formed in a polygonal shape, the first seating receiving portion may be formed in a polygonal groove or hole shape.

[0072] The first support ring (114) has a predetermined thickness and can be formed so that its upper end is connected to the outer circumference of the first main body ring (111) and extends downward to a predetermined height. The first support ring (114) can extend downward in a vertical direction or in an inwardly inclined direction from the outer circumference of the first main body ring (111). The first support ring (114) can be formed to a height greater than the height of the first seating ring (112). The first support ring (114) can be formed with the same thickness as the first main body ring (111). Additionally, the first support ring (114) can be formed with a thicker thickness than the first main body ring (111) to stably support the first main body ring (111).

[0073] The second edge ring (120) may include a second body ring (121), a second seating ring (122), and a second support ring (123). The second edge ring (120) may further include a second stop ring (124) and a second blocking groove (125).

[0074] The second edge ring (120) may be formed in an overall ring shape. The second edge ring (120) may be positioned at the first edge ring (110) to support the outer side of the first edge ring (110). Additionally, the outer side of the second edge ring (120) may be supported on the inner side of the rotational support (24). The second edge ring (120) may be formed integrally with the second main body ring (121), the second seating ring (122), and the second support ring (123). That is, the second edge ring (120) may be formed by processing a ring having a predetermined thickness and width to include the second main body ring (121), the second seating ring (122), and the second support ring (123).

[0075] As described above, the second edge ring (120) may be formed of a material having a higher thermal conductivity than the first edge ring (110). The second edge ring (120) may be formed of CVD-SiC. The second edge ring (120) may have a thermal conductivity of 320 to 3800 W / mK. The first edge ring (110) may have a specific heat of 640 to 700 J / kgK.

[0076] The second edge ring (120) may be formed with a thickness of 1.0 to 1.5 mm overall. The second edge ring (120) may be formed with a thickness greater than that of the first edge ring (110).

[0077] The second main body ring (121) may be formed in a ring shape having a predetermined width and thickness. The second main body ring (121) may be formed with an appropriate width and outer diameter to have the strength required to support the first edge ring (110) located on the inside and the wafer (a)(a). The second main body ring (121) may be formed in a ring shape where the width is greater than the thickness. The second main body ring (121) may be formed with a thickness of 1.0 to 1.5 mm. The inner diameter of the second main body ring (121) may be formed to be larger than the outer diameter of the first edge ring (110).

[0078] The second mounting ring (122) may be formed in an "L" shape. More specifically, the second mounting ring (122) may include a second mounting inclined ring (122a) and a second mounting horizontal ring (122b). The second mounting ring (122) may be formed in a stepped shape extending downward from the upper surface of the second main body ring (121) to provide a second mounting area (122c) on which the outer circumference of the first edge ring (110) is mounted. The second mounting ring (122) is coupled to the inner side of the second main body ring (121) and can support the first edge ring (110) located on the inner side. The second mounting ring (122) may be formed such that the thickness of the second mounting area (122c) on which the first edge ring (110) is mounted is the same as or thicker than other parts of the second mounting ring (122). For example, the thickness of the second mounting area (122c) may be formed such that it is the same as or thicker than the thickness of the second main body ring (121).

[0079] The second mounting ring (122) can support the first support ring (114) of the first edge ring (110) which is mounted in the second mounting area (122c). More specifically, the second mounting ring (122) can support the lower end of the first support ring (114). The upper end of the second mounting ring (122) may be coupled to the inner end of the second main body ring (121) and may be located lower than the second main body ring (121). That is, the upper end of the second mounting inclined ring (122a) may be coupled to the inner end of the second main body ring (121), and the outer end may be coupled to the lower end of the second mounting inclined ring (122a). The second seating ring (122) may be formed with the same thickness as the second main body ring (121). Additionally, the second seating ring (122) may be formed with a thicker thickness than the second main body ring (121) to stably support the first edge ring (110).

[0080] The second seating inclined ring (122a) has a predetermined thickness and can be formed so that its upper end is coupled to the inner end of the second main body ring (121) and extends downward to a predetermined height. The second seating inclined ring (122a) can extend downward in a vertical direction or in an inwardly inclined direction from the inner end of the second main body ring (121). The second seating inclined ring (122a) can be formed to a height that corresponds approximately to the height of the first support ring (114). The second seating inclined ring (122a) can be formed to have the same thickness as the second main body ring (121). The second seating ring (122) can be formed to have a thickness of 1.0 to 1.5 mm overall. Additionally, the second mounting inclined ring (122a) may be formed with a thicker thickness than the second main body ring (121) to stably support the first edge ring (110).

[0081] The second horizontal mounting ring (122b) has a predetermined thickness and can be formed so that its outer edge is joined to the lower end of the second inclined mounting ring (122a) and extends horizontally inward. The second horizontal mounting ring (122b) may have a second mounting area (122c) on which the first support ring (114) of the first edge ring (110) is mounted. The second horizontal mounting ring (122b) can be formed with a width necessary to stably support the first support ring (114) of the first edge ring (110). The second horizontal mounting ring (122b) can be formed with the same thickness as the second vertical mounting ring. The second horizontal mounting ring (122b) can be formed with a thickness of 1.0 to 1.5 mm. Additionally, the second mounting horizontal ring (122b) may be formed with a thicker thickness than the first mounting vertical ring (112b) to stably support the first edge ring (110).

[0082] The second support ring (123) may have a predetermined thickness and be formed so that its upper end is connected to the outer end of the second main body ring (121) and extends downward to a predetermined height. The second support ring (123) may extend downward in a vertical direction or in an inwardly inclined direction from the outer periphery of the first main body ring (111). The second support ring (123) may be formed with a height smaller than that of the second seating ring (122). The second support ring (123) may be formed with the same thickness as the second main body ring (121). Additionally, the second support ring (123) may be formed with a thicker thickness than the second main body ring (121) to stably support the second main body ring (121).

[0083] The second stop ring (124) is ring-shaped and may be formed to protrude along the inner circumference of the second seating area (122c) from the upper surface of the second seating ring (122). The second stop ring (124) may be formed in a semicircular shape with a vertical cross-section convex upward or in a square shape with rounded corners. The second stop ring (124) may prevent the first support ring (114) seated in the second seating area (122c) from detaching from the second seating area (122c). The second stop ring (124) may be formed at a height such that its upper end is spaced apart from the lower surface of the first main body ring (111) when the first support ring (114) is seated in the second seating area (122c). The second support ring (123) can be formed integrally with the second seating ring (122).

[0084] The second blocking groove (125) may be formed as a ring-shaped groove extending from the lower surface of the second main body ring (121) upward. The second blocking groove (125) may reduce the vertical cross-sectional area of ​​the second main body ring (121), thereby reducing the transfer of heat to the outside through the second main body ring (121). The second blocking groove (125) may be formed with a predetermined depth and width on the lower surface of the second main body ring (121). The second blocking groove (125) may be formed with a predetermined depth to maintain the strength required for the second main body ring (121) to support the first edge ring (110). For example, the second blocking groove (125) may be formed with a depth of 0.4 to 0.7 times the total thickness of the second main body ring (121). Additionally, the second blocking groove (125) may be formed with a predetermined width to maintain the strength required for the second main body ring (121) to support the first edge ring (110). The second blocking groove (125) may be formed on the inner lower surface of the second main body ring (121). Additionally, the second blocking groove (125) may be located in the middle or on the outer side of the second main body ring (121).

[0085]

[0086] The following describes the analysis results of an edge ring for wafer support according to one embodiment of the present invention.

[0087] Figure 7 is a graph of the analysis results according to the configuration of the edge ring.

[0088] In this analysis, a wafer support edge ring was configured under the following conditions.

[0089] - Ref: The edge ring structure of FIG. 2, provided that no spacing protrusion is formed on the first edge ring and the wafer does not come into contact with the first edge ring.

[0090] - Case 1: The edge ring structure of FIG. 2, wherein there is no spacing protrusion on the first edge ring and the wafer is in contact with the first edge ring (first main body ring or first mounting vertical ring).

[0091] - Case 2: An edge ring structure of FIG. 2, wherein the first edge ring has a spacing projection and a wafer contacts the spacing projection, and is an edge ring according to an embodiment of the present invention.

[0092]

[0093] For this analysis, COMSOL Multi Physics was used as the analysis tool, and Heat Transfer in Solid and Surface to Surface Radiation were used as geometry conditions, and Heat Source (Ray Optics Result), Rotated 50 [RPM], Ambient radiation @ 473K, and Thermal Resistance: Air Layer 10μm were used as boundary conditions.

[0094] In addition, known density, specific heat, thermal conductivity, and emissivity were used for the materials constituting the wafer (silicon), the first edge ring (sintered SiC), and the second edge ring (CVD SiC) as analysis conditions.

[0095] In this analysis, the temperature difference between the contact area that contacts the first edge ring at the outer edge of the wafer and the non-contact area that does not contact was evaluated.

[0096] As shown in Figure 7, it can be confirmed that Case 2 has a temperature difference of approximately 4.8°C smaller than Case 1 at the outer edge of the wafer. More specifically, Ref has a temperature difference of 0.01°C depending on the location, Case 1 has a temperature difference of 6.14°C between the contact and non-contact parts, and Case 2 has a temperature difference of 1.31°C between the contact and non-contact parts.

[0097] Therefore, it is determined that Case 2 reduces the temperature variation on the outer periphery of the wafer as the contact area decreases due to the contact between the spacing protrusion and the wafer.

[0098]

[0099] The embodiments disclosed in this specification are merely the most preferred embodiments selected and presented to aid the understanding of those skilled in the art among various possible embodiments, and the technical concept of this invention is not necessarily limited or restricted only by these embodiments. Various changes, additions, and modifications are possible within the scope of the technical concept of this invention, and equivalent other embodiments can be implemented.

Claims

1. Includes a first edge ring located on the outer side of the wafer and supporting the outer periphery of the wafer, and A wafer support edge ring characterized by the first edge ring supporting the outer surface of the wafer while making line contact or point contact with the outer surface of the wafer.

2. Includes a first edge ring located on the outer side of the wafer to support the outer periphery of the wafer, and The above-mentioned first edge ring is A first main body ring formed in a ring shape having a predetermined width and thickness, and A first mounting ring having a first mounting area formed in a stepped shape extending downward from the upper surface of the first main body ring, on which the outer periphery of the wafer is mounted, and A spaced projection formed in a projection shape located on the outer side of the wafer in the first seating area, and An edge ring for supporting a wafer, characterized by having a predetermined thickness and including a first support ring having an upper end coupled to the outer circumference of the first main body ring and extending to a predetermined height in a downward direction.

3. In Paragraph 2, The above-mentioned first seating ring is A first mounting vertical ring, the upper end of which is coupled to the inner end of the first main body ring and extends downward to a predetermined height, and It includes a first horizontal mounting ring, the outer end of which is coupled to the lower end of the first mounting inclined ring and extends horizontally inward to form the first mounting area, A wafer support edge ring characterized by the above-mentioned spacing projection being formed by extending from the inner circumferential surface of the first mounting vertical ring to the upper surface of the first mounting horizontal ring.

4. In Paragraph 2, A wafer support edge ring characterized in that the above-mentioned spacing projection has a planar shape of a triangle and is formed such that one vertex faces the inner side of the first main body ring.

5. In Paragraph 2, A wafer support edge ring characterized in that the above-mentioned spacing projection has a planar shape that is arc-shaped and a curved portion is formed to face the inner side of the first main body ring.

6. In Paragraph 2, A wafer support edge ring characterized by the above-mentioned spacing protrusions having rounded edges on the upper surface.

7. In Paragraph 2, A wafer support edge ring characterized in that the above-mentioned spacing projection is formed integrally with the first seating ring.

8. In Paragraph 2, A wafer support edge ring characterized in that the above-mentioned spacing projection is column-shaped and is formed separately from the first seating ring and coupled to the first seating receiving portion of the first seating ring.

9. In Paragraph 2, A wafer support edge ring characterized in that at least four of the above-mentioned spacing protrusions are positioned spaced apart in the circumferential direction of the first main body ring, and the diameter of a virtual circle connecting the inner ends is formed to be larger than the outer diameter of the wafer.

10. In Paragraph 2, A wafer support edge ring characterized in that the above-mentioned spacing protrusion is formed such that its thickness is smaller than the thickness of the wafer and greater than 1 / 2 the thickness of the wafer.

11. In Paragraph 2, A wafer support edge ring characterized by including a second edge ring located on the outer side of the first edge ring and supporting the outer periphery of the first edge ring.

12. In Paragraph 1, A wafer support edge ring characterized in that the first edge ring is formed of a material having lower thermal conductivity than the second edge ring.

13. In Paragraph 1, The first edge ring is formed of sintered SiC, and A wafer support edge ring characterized in that the second edge ring is formed of CVD-SiC.

14. In Paragraph 11, The above-mentioned first edge ring is A first main body ring formed in a ring shape having a predetermined width and thickness, and A first mounting ring having a first mounting area formed in a stepped shape extending downward from the upper surface of the first main body ring, on which the outer periphery of the wafer is mounted, and It includes a first support ring having a predetermined thickness, wherein the upper end is coupled to the outer circumference of the first main body ring and extends to a predetermined height in a downward direction, The above second edge ring is A second main body ring formed in a ring shape having a predetermined width and thickness, and A second seating ring having a second seating area formed in a stepped shape extending downward from the upper surface of the second main body ring, on which the first support ring of the first edge ring is seated, and A wafer support edge ring characterized by having a predetermined thickness and including a second support ring, the upper end of which is coupled to the outer circumference of the second main body ring and extends to a predetermined height in the downward direction.

15. In Paragraph 14, The above-mentioned first seating ring is A first seating inclined ring, the upper end of which is coupled to the inner circumference of the first main body ring and extends downward to a predetermined height, and It includes a first horizontal mounting ring, the outer end of which is coupled to the lower end of the first mounting inclined ring and extends horizontally inward to form the first mounting area, The above second seating ring is A second seating inclined ring, the upper end of which is coupled to the inner circumference of the second main body ring and extends downward to a predetermined height, and An edge ring for supporting a wafer, characterized by including a second horizontal mounting ring in which the outer end is coupled to the lower end of the second inclined mounting ring and extends horizontally inward to form a second mounting area.

16. In Paragraph 15, A wafer support edge ring characterized in that the thickness of the second seating area is thinner than the thickness of the second main body ring.

17. In Paragraph 14, A wafer support edge ring characterized by the above-mentioned second main body ring further including a second blocking groove in the shape of a groove that extends from the lower surface to the upper surface and forms a ring shape.

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