Base assembly and semiconductor process chamber

Abstract

The invention discloses a base assembly and a semiconductor process chamber, and belongs to the technical field of semiconductor processing. The base assembly comprises a base and an edge protection part, the edge protection part is located above the base, a through channel is formed between the base and the edge protection part, the through channel is provided with a first opening and a second opening which are communicated, the first opening can face the edge part of a wafer, and the second opening can face the edge part of the wafer. The second opening is located on an outer surface of at least one of the base and the edge protector. According to the scheme, the problem that the production yield of wafers is reduced due to the fact that polymers are stacked on the edges of the wafers can be solved.

Description

Technical Field

[0001] The present application belongs to the field of semiconductor processing technology, and specifically relates to a base assembly and a semiconductor process chamber. Background Art

[0002] At present, the application scope of semiconductor devices is becoming wider and wider, and improving the production yield of semiconductor devices has become one of the important production goals of semiconductor devices. This puts higher requirements on the processing technology of semiconductor devices and the semiconductor process equipment used to process semiconductor devices.

[0003] Taking the etching process as an example, the wafer can be placed in a semiconductor process chamber to perform the etching process. During the deep silicon etching process, the photoresist on the edge of the wafer will be removed, commonly known as "edge washing". At this time, there is no photoresist on the edge of the wafer. In order to avoid the edge of the wafer being etched and damaged due to the lack of photoresist, thereby affecting the subsequent processing of the wafer, an edge protection member can be added to the semiconductor process chamber. The edge protection member can block the edge position of the wafer, thereby preventing the edge of the wafer from being etched and damaged due to the lack of photoresist.

[0004] However, during the execution of the process, a relatively closed and narrow space is formed between the edge protection piece and the wafer. At the same time, polymers are generated during the processing of the wafer. These polymers will gather in the narrow space under the action of the flow field and then accumulate on the edge of the wafer. As the wafer flows on the production line, these polymers will adhere to the equipment in contact with it, causing these equipment to be contaminated, and ultimately resulting in a decrease in the production yield of the wafers processed by these equipment. Summary of the Invention

[0005] The present application discloses a base assembly and a semiconductor process chamber to solve the problem of reduced wafer production yield due to polymer accumulation at the wafer edge.

[0006] In order to solve the above technical problems, this application adopts the following technical solutions:

[0007] In a first aspect, an embodiment of the present application discloses a base assembly for a semiconductor process chamber, comprising a base and an edge protection member, wherein the edge protection member is located above the base, and a through channel is formed between the base and the edge protection member, wherein the through channel has a first opening and a second opening that are connected to each other, wherein the first opening can face the edge portion of the wafer, and the second opening is located on the outer surface of at least one of the base and the edge protection member.

[0008] In a second aspect, an embodiment of the present application discloses a semiconductor process chamber, comprising a chamber body and the above-mentioned base assembly, wherein the base assembly is disposed in the chamber body.

[0009] The technical scheme adopted in the application can achieve the following beneficial effects:

[0010] In the application, a through channel is formed between the base and the edge protection member, the through channel has a first opening and a second opening connected in communication, the first opening can be directed to the edge portion of the wafer, and the second opening is located on the outer surface of at least one of the base and the edge protection member, that is, the through channel penetrates from one side of the edge protection member directed to the wafer to the other side of the edge protection member away from the wafer. During processing of the wafer, if the polymer is accumulated in the space between the edge protection member and the wafer under the action of the flow field, the polymer can be further discharged through the through channel, and therefore the through channel can prevent the polymer from accumulating at the edge of the wafer. Therefore, the technical scheme disclosed in the application can solve the problem of reduced yield of the wafer caused by accumulation of the polymer at the edge of the wafer. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 Partial structural schematic diagram of the base assembly disclosed in the embodiments of the application;

[0012] Figure 2 Partial sectional view of the base assembly disclosed in the embodiments of the application;

[0013] Figure 3 Size schematic diagram of the through channel disclosed in the embodiments of the application;

[0014] Figures 4 to 6 Respective top view, bottom view and partial sectional view of the edge protection member disclosed in the embodiments of the application;

[0015] Figures 7 to 9 Respective top view, bottom view and partial sectional view of the base ring disclosed in the embodiments of the application;

[0016] Figure 10 Flow field simulation comparison diagram of the edge of the wafer before and after the base assembly disclosed in the embodiments of the application is adopted.

[0017] BRIEF DESCRIPTION OF DRAWINGS

[0018] 100-base, 110-base body, 120-base ring, 121-groove, 121a-groove bottom wall, 121b-groove side wall, 130-first through groove, 140-wafer bearing surface, 200-edge protection member, 210-protruding portion, 220-second through groove, 300-through channel, 310-first opening, 320-second opening, 330-first side edge, 340-second side edge, 350-third side edge, 360-fourth side edge, 370-arc-shaped transition surface, 500-wafer, 600-polymer. DETAILED DESCRIPTION

[0019] In order to make the objects, technical solutions and advantages of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0020] The base assembly and the semiconductor process chamber disclosed in the embodiments of the present application will be described in detail below with reference to the drawings and specific embodiments and application scenarios thereof.

[0021] At present, when a wafer is processed, an edge protection piece can be used to shield the edge portion of the wafer, so as to prevent the edge portion of the wafer from being damaged by etching due to the absence of photoresist. For example, in a deep silicon etching process, the photoresist on the edge of the wafer is removed. In order to prevent the edge of the wafer from being damaged by etching due to the absence of photoresist, the edge protection piece can be used to shield the edge portion of the wafer. At the same time, since the temperature of the edge protection piece is higher than the denaturation temperature of the photoresist, although the edge portion of the wafer is free of photoresist, the other areas of the wafer have photoresist. Therefore, once the edge protection piece is too close to the wafer, the photoresist will be affected by the temperature of the edge protection piece and problems such as paste will occur. Therefore, during the processing of the wafer, a certain gap needs to be maintained between the edge protection piece and the wafer. In this way, a relatively closed narrow space will be formed between the edge protection piece and the wafer. The polymer generated during the processing of the wafer will accumulate in the narrow space, and then accumulate on the edge of the wafer, finally resulting in a decrease in the production yield of the wafer.

[0022] In order to solve the above problems, the embodiments of the present application disclose a base assembly for a semiconductor process chamber, please refer to Figures 1-9 The base assembly includes a base 100 and an edge protection piece 200. The edge protection piece 200 is located above the base 100. The base 100 is used to support a wafer 500. Specifically, the base 100 has a wafer bearing surface 140, and the wafer 500 can be placed on the wafer bearing surface 140. Optionally, the base 100 can be an electrostatic chuck, or a mechanical chuck, or other structures capable of supporting and positioning the wafer 500, and the embodiments of the present application do not limit this. The edge protection piece 200 can be provided in a ring structure, which can be lifted relative to the base 100, so as to facilitate the placement and removal of the wafer 500. The edge of the edge protection piece 200 can be provided with a plurality of protruding portions 210 at intervals. The protruding portions 210 can be connected to a lifting device. The lifting device can drive the edge protection piece 200 to lift through the protruding portions 210, so as to change the distance between the edge protection piece 200 and the base 100, thereby facilitating the placement and removal of the wafer 500.

[0023] The through channel 300 is formed between the base 100 and the edge protector 200, and has a first opening 310 and a second opening 320 which are in communication. When the wafer 500 is placed on the base 100, the first opening 310 can be directed towards the edge portion of the wafer 500, and the second opening 320 is located on the outer surface of at least one of the base 100 and the edge protector 200, so that the spaces on the two sides of the edge protector 200 are in communication through the through channel 300. Specifically, the through channel 300 can be formed only on the base 100, and in this case, the second opening 320 of the through channel 300 is located on the outer surface of the base 100; or the through channel 300 can be formed only on the edge protector 200, and in this case, the second opening 320 of the through channel 300 is located on the outer surface of the edge protector 200; or a part of the through channel 300 is formed on the base 100, and the other part is formed on the edge protector 200, and in this case, a part of the second opening 320 of the through channel 300 is located on the outer surface of the base 100, and the other part is located on the outer surface of the edge protector 200. It should be noted that the outer surface of the base 100 can be the bottom surface of the base 100 or the outer circumferential surface of the base 100, the outer surface of the edge protector 200 can be the top surface of the edge protector 200 or the outer circumferential surface of the edge protector 200, and the outer circumferential surface of the part of the edge protector 200 other than the protruding portion 210 can be aligned with the outer circumferential surface of the base 100.

[0024] In the embodiments of the present application, the through channel 300 penetrates from one side of the edge protector 200 facing the wafer 500 to the other side of the edge protector 200 away from the wafer 500. During the processing of the wafer 500, if the polymer 600 is accumulated in the space between the edge protector 200 and the wafer 500 under the action of the flow field direction shown by the arrow in the figure, it can be further discharged through the through channel 300, so that the through channel 300 can prevent the polymer 600 from accumulating on the edge of the wafer 500. Therefore, the technical solution disclosed in the present application can solve the problem of the decrease of the production yield of the wafer 500 caused by the accumulation of the polymer 600 on the edge of the wafer 500. Figure 2

[0025] ​In the direction in which the first opening 310 extends to the second opening 320, the through channel 300 can have a converging structure, or the opposite inner walls of the through channel 300 are parallel to each other. In another embodiment, in the direction in which the first opening 310 extends to the second opening 320, the through channel 300 has a diverging structure, that is, at least one pair of opposite inner walls of the through channel 300 gradually move away in the direction in which the first opening 310 extends to the second opening 320. Since the gap between the edge protection member 200 and the wafer 500 needs to be as small as possible so that the edge protection member 200 can fully protect the edge portion of the wafer 500, the space in which the first opening 310 is formed is not large, that is, the opening area of the first opening 310 is not large. When the through channel 300 has a diverging structure, the internal space of the through channel 300 gradually increases in the direction in which the first opening 310 extends to the second opening 320, thereby increasing the size of the through channel 300 to facilitate the discharge of the polymer 600 from the through channel 300.

[0026] As described above, the base 100 has a wafer bearing surface 140, and in the cross section parallel to the wafer bearing surface 140 and in the cross section perpendicular to the wafer bearing surface 140 and parallel to the radial direction of the base 100, the through channel 300 has a diverging structure. Compared with the embodiment in which the through channel 300 has a diverging structure only in a single cross section, this embodiment can make the degree of divergence of the through channel 300 larger, thereby forming a larger through channel 300 under the condition that the size of the first opening 310 is limited, thereby more facilitating the discharge of the polymer 600 from the through channel 300 and the polymer 600 being less likely to accumulate at the edge of the wafer 500.

[0027] Optionally, the through channel 300 can be an annular channel, that is, the through channel 300 is a continuous channel arranged around the wafer 500. For example, the lifting device can control the lifting amplitude of the edge protection member 200, so that the edge protection member 200 is kept at a position spaced apart from the base 100 by a certain distance to form the through channel 300. At this time, the space formed between the base 100 and the edge protection member 200 is large, which is easy to affect the flow direction of the process gas. Once the process gas enters the through channel 300, the protective effect of the edge protection member 200 on the edge portion of the wafer 500 will be weakened, resulting in a decrease in the processing quality of the wafer 500.

[0028] In view of this, the through channels 300 can be arranged as discrete structures, specifically, the number of the through channels 300 is at least two, and each through channel 300 is arranged at intervals along the circumference of the susceptor 100. In this embodiment, the through channels 300 are formed between the partial edge protection member 200 and the partial susceptor 100, and no through channels 300 are formed in other regions, for example, the other regions of the edge protection member 200 and the other regions of the susceptor 100 can be in contact, so that the susceptor 100 can support the edge protection member 200, thereby improving the stability of the edge protection member 200. Moreover, the space of the through channels 300 formed in this embodiment is not too large, thereby not affecting the flow direction of the process gas, and preventing the process gas from entering the through channels 300 and affecting the protection effect of the edge of the wafer 500.

[0029] It should be noted that the specific number, size, and distance between adjacent through channels 300, and other structural parameters of the through channels 300 can be flexibly selected on the basis of meeting the protection effect of the edge of the wafer 500, so as to improve the drainage effect of the polymer 600, and the embodiments of the present application do not limit this. Alternatively, each through channel 300 is uniformly arranged at intervals along the circumference of the susceptor 100, thereby uniformly draining the polymer 600 at each position around the wafer 500, and forming a more uniform flow field at the edge of the wafer 500.

[0030] The through channels 300 can be fan-shaped channels, strip-shaped channels, etc. When the through channels 300 are strip-shaped channels, the cross-sectional size of the through channels 300 is small, thereby reliably preventing the process gas from entering the space between the edge protection member 200 and the wafer 500. Further, the strip-shaped through channels 300 can extend along the radial direction of the susceptor 100, or the extension direction of the through channels 300 has a certain angle with the radial direction of the susceptor 100. Relatively speaking, the former embodiment is more conducive to the structural design of the plurality of through channels 300, and the processing of the susceptor 100 and the edge protection member 200, and is also conducive to forming a more uniform flow field.

[0031] In an alternative embodiment, the through passage 300 is generally a quadrangular prism-shaped passage, and the through passage 300 has a first side edge 330, a second side edge 340, a third side edge 350 and a fourth side edge 360 arranged in sequence in the circumferential direction of the through passage 300. The first side edge 330 and the second side edge 340 are opposite in the circumferential direction of the base 100, and the third side edge 350 and the fourth side edge 360 are opposite in the circumferential direction of the base 100. Specifically, when the wafer bearing surface 140 is a horizontal plane, the first side edge 330 and the second side edge 340 are opposite in the horizontal direction, and the third side edge 350 and the fourth side edge 360 are opposite in the horizontal direction. At this time, the side wall of the through passage 300 includes four trapezoidal planes connected in sequence, and the distance between any pair of opposite trapezoidal planes gradually increases in the direction in which the first opening 310 extends to the second opening 320. Alternatively, an included angle β is formed between the first side edge 330 and the second side edge 340, and an included angle β is formed between the third side edge 350 and the fourth side edge 360. The included angle β between the first side edge 330 and the second side edge 340 is equal to the included angle β between the third side edge 350 and the fourth side edge 360, and both are 2° to 5°. An included angle α between the first side edge 330 and the wafer bearing surface 140, an included angle α between the second side edge 340 and the wafer bearing surface 140, an included angle α between the third side edge 350 and the wafer bearing surface 140, and an included angle α between the fourth side edge 360 and the wafer bearing surface 140 are equal, and all are 10° to 15°. The range of the included angles can make the size of the through passage 300 moderate, prevent the through passage 300 from being too large to cause the process gas to enter the space between the edge protection member 200 and the wafer 500, and prevent the through passage 300 from being too small to affect the discharge effect of the polymer 600.

[0032] Of course, the through passage 300 can also be a conical passage. In addition, the included angle β between the first side edge 330 and the second side edge 340 and the included angle β between the third side edge 350 and the fourth side edge 360 can both be less than 2° or greater than 5°. The included angle α between the first side edge 330 and the wafer bearing surface 140, the included angle α between the second side edge 340 and the wafer bearing surface 140, the included angle α between the third side edge 350 and the wafer bearing surface 140, and the included angle α between the fourth side edge 360 and the wafer bearing surface 140 can all be less than 10° or greater than 15°.

[0033] The first opening 310 can be a rectangular opening, which has a first dimension h2 in a direction perpendicular to the wafer bearing surface 140 and a second dimension W2 in a direction parallel to the wafer bearing surface 140. The first dimension h2 can be twice the distance h between the top surface of the susceptor 100 and the wafer bearing surface 140, and the second dimension W2 can be 3-5 mm. The first dimension h2 and the second dimension W2 are thus set to moderate the size of the first opening 310, preventing the first opening 310 from being too large to allow process gas to enter the space between the edge protection member 200 and the wafer 500, while preventing the first opening 310 from being too small to affect the discharge of the polymer 600. In addition, since the edge protection member 200 has a limited thickness, the selection of the first dimension h2 will affect the structural strength of the edge protection member 200 when the edge protection member 200 is provided with at least a portion of the through passage 300. When the first dimension h2 is twice the distance h between the top surface of the susceptor 100 and the wafer bearing surface 140, it is beneficial for the polymer 600 to enter the through passage 300 and for the structural strength of the edge protection member 200 to be improved.

[0034] Of course, the ratio between the first dimension h2 and the distance h can also be 1.5, 3, etc., and the second dimension W2 can be less than 3 mm or greater than 5 mm.

[0035] The second opening 320 can also be a rectangular opening, which has a third dimension h1 in a direction perpendicular to the wafer bearing surface 140 and a fourth dimension W1 in a direction parallel to the wafer bearing surface 140. Since the first side edge 330, the second side edge 340, the third side edge 350, and the fourth side edge 360 form four trapezoidal planes, and the trapezoidal planes are isosceles trapezoidal planes, h1 = 2*L*tanα + h2 and W1 = 2*L*tan(β / 2) + W2, where L is the length of the through passage 300, which can be selected to allow the first opening 310 to face the edge portion of the wafer 500 while extending the through passage 300 to the outer surface of the susceptor 100 or the edge protection member 200, for example, L can be slightly smaller than the width of the edge protection member 200. As can be seen, after the length L of the through passage 300, the angle α, the angle β, the first dimension h2, and the second dimension W2 are determined, the third dimension h1 and the fourth dimension W1 can be determined.

[0036] As mentioned above, the through channel 300 can be formed only on the base 100, or the through channel 300 can be formed only on the edge protector 200, or a part of the through channel 300 is formed on the base 100 and the other part of the through channel 300 is formed on the edge protector 200, in which case, the base 100 can be provided with a first through groove 130 and the edge protector 200 can be provided with a second through groove 220, the first through groove 130 faces the second through groove 220, and the two together enclose the through channel 300. When the edge protector 200 is close to the base 100 and reaches the target position, the first through groove 130 and the second through groove 220 are docked to together enclose the through channel 300. In this embodiment, the first through groove 130 and the second through groove 220 are both open structures, and the machining of the two is relatively easy to achieve, so it is more convenient to process the base assembly. Moreover, the depth of the first through groove 130 and the second through groove 220 can be set to be smaller, which is more convenient for the formation of the two.

[0037] As mentioned above, the base 100 can be in contact with the edge protector 200, and the first through groove 130 and the second through groove 220 are symmetrically arranged about the contact surface of the base 100 and the edge protector 200, that is, the first through groove 130 and the second through groove 220 are the same shape and size, and when the base 100 and the edge protector 200 are in contact, the first through groove 130 and the second through groove 220 are completely engaged to form a through channel 300 with a smoother inner wall. In this embodiment, the through channel 300 is not prone to protruding at the position of the contact surface of the base 100 and the edge protector 200, so the polymer 600 can flow more smoothly in the through channel 300 and is not prone to being stuck in the through channel 300.

[0038] Of course, the first through groove 130 and the second through groove 220 can also be different in shape and size, which is not limited in the embodiments of the application.

[0039] In an optional embodiment, the base 100 can include a base body 110 and a base ring 120, the base ring 120 is arranged around the base body 110, the top surface of the base ring 120 is provided with a groove 121, the groove bottom wall 121a of the groove 121 is used to support the edge portion of the wafer 500, and the groove side wall 121b of the groove 121 is used to fit the side surface of the wafer 500, that is, the wafer bearing surface 140 includes the top surface of the base body 110 and the groove bottom wall 121a of the groove 121, and the groove side wall 121b of the groove 121 can be limitedly matched with the side surface of the wafer 500. On the one hand, the groove 121 can assist in positioning the wafer 500 to prevent the wafer 500 from moving in the plane in which it is located; on the other hand, the edge portion of the wafer 500 completely covers the groove bottom wall 121a of the groove 121, and there is basically no gap between the wafer 500 and the groove side wall 121b of the groove 121, so the polymer 600 is not easy to accumulate in the groove 121, but directly enters the through channel 300, so that most or even all of the polymer 600 enters the through channel 300 in this embodiment. Of course, the top surface of the base ring 120 can also not be provided with the groove 121, at this time, a avoiding groove can be opened on the edge protector 200 to avoid the wafer 500.

[0040] The length L of the through channel 300 can be slightly smaller than the width of the base ring 120, and optionally, for an 8-inch wafer 500, L=(D-200) / 2, and for a 12-inch wafer 500, L=(D-300) / 2, where D is the outer diameter of the base ring 120, and the units of L and D are both mm. Of course, the length L of the through channel 300 can also be set to be smaller, and the embodiments of the present application do not limit this.

[0041] In an optional embodiment, the inner wall of the through channel 300 can be provided with a bending surface with a relatively large change in curvature at a position close to the first opening 310, or the inner wall of the through channel 300 includes an arc-shaped transition surface 370, which is arranged close to the first opening 310. The arc-shaped transition surface 370 here extends in the arc direction in the flow direction of the polymer 600. The latter embodiment makes the curvature change of the inner wall of the through channel 300 at the position close to the first opening 310 smaller, thereby preventing the inner wall of the through channel 300 from having a dead angle due to a too large change in curvature, and further preventing the polymer 600 from accumulating at the dead angle after entering the through channel 300 through the first opening 310 and being unable to be discharged. Therefore, the arc-shaped transition surface 370 here can make the polymer 600 more smoothly discharged from the through channel 300. Of course, the arc-shaped transition surface 370 can also be arranged at other positions of the through channel 300, thereby further improving the flow smoothness of the polymer 600.

[0042] Specifically, when the base 100 is provided with the first through groove 130 and the edge protector 200 is provided with the second through groove 220, the part with relatively large curvature change in the inner wall of at least one of the first through groove 130 and the second through groove 220 can be chamfered to form the arc transition surface 370. In addition, it should be noted that when the inner wall of the through channel 300 includes the arc transition surface 370, the process for forming the arc transition surface 370 will not change the overall shape and structural size of the through channel 300, the first opening 310 and the second opening 320, for example, the through channel 300 is still generally a quadrangular prism channel, and the first opening 310 and the second opening 320 can both be rectangular openings.

[0043] Reference Figure 10 The left side is a flow field simulation diagram of the wafer 500 when the base assembly of the prior art is used, and the right side is a flow field simulation diagram of the wafer 500 when the base assembly disclosed in the embodiment of the present application is used. According to the simulation results, after the base assembly disclosed in the embodiment of the present application is used, not only the flow rate of the edge flow field of the wafer 500 is improved, but also the flow field distribution of the edge of the wafer 500 is more uniform, so as to ensure that the polymer 600 generated in the process is smoothly discharged from the edge of the wafer 500, and further improve the process uniformity.

[0044] The embodiment of the present application also discloses a semiconductor process chamber, which comprises a chamber body and the base assembly described in any of the above embodiments, and the base assembly is arranged in the chamber body.

[0045] In the above embodiments, the differences between the various embodiments are mainly described, and the optimization features different between the various embodiments can be combined to form a better embodiment as long as they are not contradictory. Considering the brevity of the text, it will not be repeated here.

[0046] The above only describes the embodiments of the present application and is not used to limit the present application. The present application can have various changes and modifications for those skilled in the art. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the scope of the claims of the present application.

Claims

1. A base assembly for a semiconductor process chamber, characterized in that: The invention comprises a base (100) and an edge protection member (200), wherein the edge protection member (200) is located above the base (100), and a through channel (300) is formed between the base (100) and the edge protection member (200), wherein the through channel (300) has a first opening (310) and a second opening (320) that are connected to each other, wherein the first opening (310) can face the edge portion of the wafer (500), and the second opening (320) is located on the outer surface of at least one of the base (100) and the edge protection member (200).

2. The base assembly according to claim 1, wherein: In the direction in which the first opening (310) extends toward the second opening (320), the through channel (300) presents a flared structure.

3. The base assembly according to claim 2, wherein: The base (100) has a wafer carrying surface (140), and the through channel (300) is a flared structure in a cross section parallel to the wafer carrying surface (140) and in a cross section perpendicular to the wafer carrying surface (140) and parallel to the radial direction of the base (100).

4. The base assembly according to claim 1, wherein: The number of the through channels (300) is at least two, and the through channels (300) are arranged at intervals along the circumference of the base (100).

5. The base assembly according to claim 4, wherein: The through channel (300) is a strip-shaped channel, and the through channel (300) extends along the radial direction of the base (100).

6. The base assembly according to claim 5, wherein: The through channel (300) is a quadrangular prism-shaped channel. The through channel (300) has a first side edge (330), a second side edge (340), a third side edge (350), and a fourth side edge (360) arranged in sequence in its circumferential direction. The first side edge (330) and the second side edge (340) are opposite to each other in the circumferential direction of the base (100), and the third side edge (350) and the fourth side edge (360) are opposite to each other in the circumferential direction of the base (100). The first opening (310) is a rectangular opening.

7. The base assembly according to claim 6, wherein: The base (100) has a wafer carrying surface (140), the first opening (310) has a first size in a direction perpendicular to the wafer carrying surface (140), and has a second size in a direction parallel to the wafer carrying surface (140), The angle between the first side edge (330) and the second side edge (340) is equal to the angle between the third side edge (350) and the fourth side edge (360), and both are 2° to 5°. The angle between the first side edge (330) and the wafer bearing surface (140), the angle between the second side edge (340) and the wafer bearing surface (140), the angle between the third side edge (350) and the wafer bearing surface (140), and the angle between the fourth side edge (360) and the wafer bearing surface (140) are equal, and both are 10° to 15°. The first dimension is twice the distance between the top surface of the base (100) and the wafer bearing surface (140), and the second dimension is 3 mm to 5 mm.

8. The base assembly according to claim 1, wherein: The base (100) is provided with a first through-groove (130), and the edge protection member (200) is provided with a second through-groove (220), the first through-groove (130) faces the second through-groove (220), and the two together form the through-channel (300).

9. The base assembly according to claim 8, wherein: The base (100) can contact the edge protection member (200), and the first through-groove (130) and the second through-groove (220) are symmetrically arranged with respect to a contact surface between the base (100) and the edge protection member (200).

10. The base assembly according to claim 1, wherein: The base (100) comprises a base body (110) and a base ring (120), wherein the base ring (120) is arranged around the base body (110), and a groove (121) is provided on the top surface of the base ring (120), wherein the bottom wall (121a) of the groove (121) is used to support the edge portion of the wafer (500), and the side wall (121b) of the groove (121) is used to fit with the side surface of the wafer (500); And / or, the inner wall of the through channel (300) includes a curved transition surface (370), and the curved transition surface (370) is arranged close to the first opening (310).

11. A semiconductor process chamber, characterized in that: The invention comprises a chamber body and a base assembly according to any one of claims 1 to 10, wherein the base assembly is arranged in the chamber body.

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