Wafer pedestal and semiconductor device

Abstract

The utility model discloses a wafer pedestal and a semiconductor device. The wafer pedestal comprises an inner tray used for bearing a wafer, an outer ring arranged around the inner tray, and a sleeve supporting the outer ring. The outer ring comprises a first structural part which is placed on the top of the side wall of the sleeve; the inner edge of the first structural part extends inwards and exceeds the inner side wall of the sleeve, and the outer edge of the first structural part extends outwards and exceeds the outer side wall of the sleeve; the lower surface of the inner edge of the first structural part is connected with a second structural part which extends downwards; the inner tray comprises an inner tray main body and an extension part extending downwards from the bottom surface of the inner tray main body; the inner tray main body is placed on the first structural member; the outer side of the extension part can abut against the outer ring; the outer diameter of the inner tray is smaller than that of the outer ring; and the upper surface of the inner tray is higher than the upper surface of the outer ring.

Description

Technical Field

[0001] The utility model relates to the field of semiconductors, and in particular to a wafer base and semiconductor equipment. Background Art

[0002] like Figure 1 As shown, a cylindrical sleeve A is provided in the reaction chamber of an MOCVD (Metal-organic Chemical Vapor Deposition) reactor, and the top of the sleeve A supports a tray, which is used to carry a wafer W. A heating device B is provided inside the sleeve A, and the heat generated is radiated upward evenly and transferred from the bottom of the tray to the wafer W. The tray includes two parts, one of which is a center tray C located in the central area of ​​the sleeve, and the upper surface of the center tray C is recessed downward for the wafer to be placed. The other part is an edge ring D located in the peripheral area, and the outer end of the edge ring D includes an outer extension portion, which extends beyond the outer wall of the sleeve A, so that the robot arm can extend into the bottom surface of the outer extension portion to lift and move the tray. The outer side of the edge ring D is closer to the outer cold zone, and the inner side is in contact with the center tray C with a higher temperature. Therefore, the coating on the surface of the edge ring D is at risk of cracking and damage due to uneven temperature.

[0003] Moreover, the edge ring D is closer to the cold source in the side wall of the reaction chamber, and the temperature of the edge ring D gradually decreases from the inside to the outside. When the edge area of ​​the center tray C is closer to the edge ring D, the wafer on the center tray C will produce a monotonically changing temperature gradient along the radial direction, affecting the temperature uniformity of the wafer. Utility Model Content

[0004] The utility model aims to provide a wafer base which can improve the temperature uniformity of the wafer.

[0005] In order to achieve the above-mentioned object, the utility model provides a wafer base, comprising an inner tray for carrying a wafer, an outer ring arranged around the inner tray, and a sleeve supporting the outer ring;

[0006] The outer ring includes a first structural member, which is placed on the top of the sleeve side wall; the inner edge of the first structural member extends inwardly and exceeds the inner side wall of the sleeve, and the outer edge of the first structural member extends outwardly and exceeds the outer side wall of the sleeve;

[0007] The lower surface of the inner edge of the first structural member is connected to a second structural member extending downward;

[0008] The inner tray comprises an inner tray body and an extension portion extending downward from the bottom surface of the inner tray body; the inner tray body is placed on the first structural member; the outer side of the extension portion can abut against the outer ring;

[0009] The outer diameter of the inner tray is smaller than the outer diameter of the outer ring;

[0010] The upper surface of the inner tray is higher than the upper surface of the outer ring.

[0011] Optionally, the height of the bottom surface of the second structural member is smaller than the height of the bottom surface of the inner tray.

[0012] Optionally, a chamfer is provided between the outer side surface of the second structural member and the bottom surface of the second structural member.

[0013] Optionally, the bottom surface of the second structural member is inclined upward from inside to outside along the radial direction.

[0014] Optionally, the second structural member has a thickness of 2 mm-100 mm.

[0015] Optionally, a height difference between an upper surface of the first structural member and a bottom surface of the second structural member is 3 mm-110 mm.

[0016] Optionally, at least a portion of the upper surface of the inner tray body is recessed toward the interior of the sleeve to form a wafer groove for carrying wafers.

[0017] Optionally, the horizontal distance from the edge of the wafer slot to the outer edge of the inner tray is 5mm-80mm.

[0018] Optionally, the distance from the edge of the wafer groove to the outer side of the extension portion is 5 mm-80 mm.

[0019] Optionally, the outer diameter of the inner tray is smaller than the outer diameter of the sleeve.

[0020] Optionally, the outer diameter of the inner tray is smaller than the inner diameter of the sleeve.

[0021] Optionally, the thickness of the edge of the inner tray body gradually decreases from the inside to the outside in the radial direction.

[0022] Optionally, the extension portion is formed by extending downward from a central area of ​​the bottom surface of the inner tray body.

[0023] Optionally, an edge of the bottom surface of the extension portion extends downward to form an extension ring.

[0024] Optionally, a height difference between a bottom surface of the extension portion and a bottom surface of the second structural member is 1 mm-100 mm.

[0025] Optionally, there is a first gap between the extension portion and the second structural member, and the first gap is 0mm-5mm; there is a second gap between the second structural member and the sleeve, and the second gap is 0mm-5mm.

[0026] Optionally, a height of a lower surface of the extension portion is not less than a height of a lower surface of the second structural member.

[0027] Optionally, the inner tray is integrally formed, and the outer ring is integrally formed.

[0028] The present invention also provides a semiconductor device, comprising:

[0029] Reaction chamber;

[0030] The wafer base mentioned above is arranged in the reaction chamber;

[0031] A gas supply device, located above the reaction chamber and arranged opposite to the wafer base, for delivering reaction gas into the reaction chamber;

[0032] A sleeve, which can drive the wafer base to rotate;

[0033] The heater is arranged in the sleeve.

[0034] Optionally, the lower surface of the second structural member is above the heater and the height from the heater is 0mm-95mm; or the lower surface of the second structural member is below the heater and the height from the heater is 0mm-10mm.

[0035] The beneficial effects of the utility model are:

[0036] (1) The utility model provides a wafer base, the tray of which is a two-piece structure, including an outer ring placed on the top of a sleeve, and an inner tray placed on the outer ring. The upper surface of the inner tray is recessed inward to form a wafer slot for carrying wafers, and the upper surface of the inner tray is higher than the upper surface of the outer ring. When the wafer is placed in the wafer slot, the position of the wafer is still higher than the upper surface of the outer ring, so that the wafer is away from the outer ring in the vertical direction, which can reduce the influence of heat loss at the edge of the inner tray on the temperature uniformity of the wafer surface.

[0037] (2) The outer ring of the utility model includes a first structural member and a second structural member, wherein the lower part of the second structural member is chamfered, or the bottom surface of the second structural member is an inclined surface, so that the side of the lower part of the second structural member close to the sleeve is away from the inner wall of the sleeve, which can reduce the collision between the outer ring and the sleeve when the outer ring is lifted in the vertical direction.

[0038] (3) The outer diameter of the inner tray is smaller than the outer diameter of the sleeve, and further, can be smaller than the inner diameter of the sleeve. The area of ​​the inner tray's downward projection on the sleeve is as small as possible, so as to control the degree of heat dissipation from the edge area of ​​the inner tray. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1Schematic diagram of a MOVCD reactor in the prior art.

[0040] Figure 2 This is a structural schematic diagram of the wafer base provided by the utility model.

[0041] Figure 3 for Figure 2 A partial schematic diagram of a wafer base.

[0042] Figure 4 It is a structural schematic diagram of a wafer base according to another embodiment of the utility model.

[0043] Figure 5 It is a structural schematic diagram of a wafer base according to another embodiment of the utility model.

[0044] Figure 6 It is a structural schematic diagram of the semiconductor device of the present utility model.

[0045] Description of reference numerals:

[0046] In the prior art:

[0047] Bushing A

[0048] Heating device B

[0049] Center Tray C

[0050] Edge Ring D

[0051] Wafer W

[0052] In the utility model:

[0053] Inner tray 1

[0054] Inner tray body 11

[0055] Wafer slot 110 inner tray body bottom surface 111 inner tray upper surface 112 extension portion 12

[0056] Extension ring 120 Extension portion outer side 121 Extension portion bottom surface 122 Outer ring 2

[0057] The inner edge 211 of the first structural member 21

[0058] Outer edge 212 Outer ring upper surface 213

[0059] Part 2214

[0060] Part III 215

[0061] The second structural member 22

[0062] The second structural member outer side surface 221 The second structural member bottom surface 222 Chamfer 223

[0063] Sleeve 3

[0064] Sleeve inner wall surface 31 Sleeve outer wall surface 32

[0065] First gap 41

[0066] Second gap 42

[0067] Semiconductor equipment 5

[0068] Reaction chamber 51

[0069] Gas supply device 52

[0070] Heater 53 DETAILED DESCRIPTION

[0071] The technical solution of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0072] In the description of the present invention, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0073] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0074] like Figure 2 As shown, this embodiment provides a side cross-sectional view of a wafer base. The wafer base includes an inner tray 1 for carrying wafers, an outer ring 2 arranged around the inner tray 1, and a sleeve 3 supporting the outer ring 2. The outer ring 2 is placed on the top of the side wall of the sleeve 3. Figure 3As shown, the outer ring 2 includes a first structural member 21 and a second structural member 22. The first structural member 21 is a transverse portion in the outer ring 2, and the second structural member 22 is a longitudinal portion connected to the lower surface of the transverse first structural member 21. Among them, the first structural member 21 is a circular ring-shaped member, and is placed horizontally in the wafer base. The inner edge 211 of the first structural member 21 extends inward and exceeds the inner wall surface 31 of the sleeve, and the outer edge 212 of the first structural member 21 extends outward and exceeds the outer wall surface 32 of the sleeve. Therefore, the lower surface of the first structural member 21 includes a first portion located inside the sleeve 3 and a second portion 214 placed on the top of the side wall of the sleeve 3 and overlapping with the top of the side wall of the sleeve 3, and a third portion 215 located outside the sleeve 3. Among them, the first portion is used to connect the second structural member 22 extending downward and arranged longitudinally. Since the third part 215 exceeds the outer wall surface 32 of the sleeve, the third part 215 serves as the area where the robot arm acts. The robot arm extends below the third part 215, and lifts the outer ring 2 on the outside of the sleeve 3 by lifting the third part 215 of the first structural member 21, thereby lifting and moving the outer ring 2 and the inner tray 1 as a whole. The second structural member 22 is a vertically arranged annular member. The second structural member 22 is arranged below the first part of the first structural member 21 and extends downward from the first part of the first structural member 21, that is, the second structural member 22 is arranged vertically with respect to the first structural member 21. Figure 2 As shown, the inner tray 1 includes an inner tray main body 11 and an extension portion 12 extending downward from the bottom surface of the inner tray main body 11. The inner tray 1 is arranged on the outer ring 2. Specifically, the inner tray main body 11 is placed on the first structural member 21; the extension portion 12 of the inner tray 1 is embedded in the interior of the first structural member 21, and the outer side 121 of the extension portion can abut against the inner edge 211 of the first structural member 21 of the outer ring 2 when the sleeve 3 rotates; thereby, the outer ring 2 limits the extension portion 12 of the inner tray 1 through the first structural member 21 to radially position the inner tray 1, ensuring that the inner tray 1 can be accurately positioned in the radial direction when rotating during the process, thereby avoiding excessive radial displacement of the inner tray 1 relative to the outer ring 2 during the process. Furthermore, the outer diameter of the inner tray 1 is smaller than the outer diameter of the outer ring 2. During the process, Figure 6As shown, the wall of the reaction chamber 51 is provided on the outside of the outer ring 2, and a cooling pipe is provided inside the wall. A coolant is provided inside the cooling pipe to cool the wall of the reaction chamber 51, and the reaction gas will be drawn from the top of the inner tray 1 through the outside of the sleeve 3 to the bottom of the reaction chamber. Therefore, along the radial direction of the outer ring 2, the temperature of the side closer to the wall of the reaction chamber 51 is lower. The outer diameter of the inner tray 1 is set to be smaller than the outer diameter of the outer ring 2, so that the inner tray 1 is as far away as possible from the cooling pipe in the wall of the reaction chamber 51 outside the outer ring 2, reducing the heat exchange intensity between the inner tray 1 and the cooling pipe of the wall of the reaction chamber 51, reducing the temperature difference at different positions of the inner tray 1, improving the temperature uniformity of various places on the inner tray 1, and avoiding the inner tray 1 from being broken due to excessive temperature difference at various places during the process, thereby generating particles that affect the film quality of the wafer.

[0075] In addition, the upper surface 112 of the inner tray is higher than the upper surface 213 of the outer ring. By setting the upper surface 112 of the inner tray to be higher than the upper surface 213 of the outer ring, the inner tray 1 can dissipate heat directly radially outward. If the upper surface of the inner tray 1 is not higher than the upper surface of the outer ring 2, the main heat at the edge of the inner tray 1 will be lost radially through the outer ring 2, that is, the inner tray 1 needs to transfer most of the heat to the outer ring 2, and dissipate the heat through the cooling pipe of the outer ring 2 to the wall of the reaction chamber 51. As a result, the temperature difference of the outer ring 2 at various locations along the radial direction increases, so that the deformation difference between the inner and outer edges of the outer ring 2 is large during operation, and the risk of rupture and particle generation is increased. In this embodiment, by setting the upper surface 112 of the inner tray to be higher than the upper surface 213 of the outer ring, the area where the inner tray 1 contacts the outer ring 2, in addition to the thermal contact and heat transfer with the outer ring 2, also increases the heat radiated outward from the area, reduces the heat transferred from the inner tray 1 to the outer ring 2, reduces the temperature difference at various locations on the outer ring 2 along the radial direction, improves the temperature uniformity of the outer ring 2, and reduces the risk of the outer ring 2 breaking and generating particles due to excessive temperature difference at various locations. In addition, the increase in the amount of heat radiated outward by the raised upper surface portion of the inner tray 1 is controllable, so that a slight increase will not significantly reduce the heat loss at the edge of the substrate and significantly reduce the uneven temperature of the substrate.

[0076] In the radial direction, the sleeve 3 is positioned and connected with the second structural member 22 of the outer ring 2 to realize radial positioning of the sleeve 3 on the outer ring 2 through the second structural member 22. The inner wall surface 31 of the sleeve can be against the outer side surface 221 of the second structural member during the process. At the same time, the second structural member 22 is positioned and connected with the inner tray 1 to realize radial positioning of the outer ring 2 on the inner tray 1. Due to the positioning connection between the second structural member 22 and the inner tray 1, the inner tray 1 will inevitably transfer heat to the outer ring 2 through the second structural member 22, resulting in an increase in the temperature difference of the outer ring 2 in the radial direction. By designing the height of the bottom surface 222 of the second structural member from the bottom of the reaction chamber 51 to be lower than the bottom surface height of the extension portion 12 of the inner tray 1, the radial positioning of the sleeve 3, the outer ring 2 and the inner tray 1 can be achieved, and at the same time, the thermal resistance between the inner tray 1 and the outer ring 2 is improved, and the heat transfer from the inner tray 1 to the outer ring 2 is reduced, thereby reducing the temperature difference at various locations on the outer ring 2 along the radial direction, improving the temperature uniformity of the outer ring 2, and reducing the risk of the outer ring 2 breaking and generating particles due to excessive temperature differences at various locations. In addition, the height difference between the upper surface of the first structural member 21 and the bottom surface 222 of the second structural member is 3mm-110mm, so as to ensure that the second structural member 22 has sufficient thickness in the height direction to reliably position the inner tray 1. In addition, in this embodiment, the thickness of the second structural member 22 is 2mm-100mm, so as to ensure the reliable positioning of the sleeve 3, the second structural member 22 and the inner tray 1.

[0077] In another embodiment, Figure 4 As shown, a chamfer 223 is provided between the outer side surface 221 of the second structural member and the bottom surface 222 of the second structural member. With such a configuration, when the outer ring 2 is installed into the sleeve 3 from top to bottom, the chamfer 223 between the outer side surface 221 of the second structural member and the bottom surface 222 of the second structural member gradually reduces the bottom width of the second structural member 22, which facilitates the guiding and positioning installation between the second structural member 22 and the sleeve 3. In addition, a chamfer 223 is provided between the outer side surface 221 of the second structural member and the bottom surface 222 of the second structural member, and the distance between the connection between the outer side surface 221 of the second structural member and the bottom surface 222 of the second structural member and the inner wall surface 31 of the sleeve is farther than the distance between the outer side surface 221 of the second structural member and the inner wall surface 31 of the sleeve. When the robot arm lifts the outer ring 22 in the vertical direction, the chamfer 223 makes it difficult for the connection between the outer side surface 221 of the second structural member and the bottom surface 222 of the second structural member to collide with the sleeve 33, thereby reducing the generation of particulate matter.

[0078] In another embodiment, Figure 5As shown, the bottom surface 222 of the second structural member is inclined upward from the inside to the outside along the radial direction. By setting the bottom surface of the second structural member 22 to be inclined upward from the inside to the outside along the radial direction, the width of the bottom of the second structural member 22 is gradually reduced, and when the outer ring 2 is installed into the sleeve 3 from top to bottom, it is convenient for the second structural member 22 to be guided and positioned for installation with the sleeve 3, thereby facilitating the guiding and positioning installation between the outer ring 2 and the sleeve 3. In addition, the bottom surface 222 of the second structural member is set to be inclined upward from the inside to the outside along the radial direction. When the robot arm lifts the outer ring 2 in the vertical direction, the second structural member bottom surface 222 of the second structural member 22 is inclined, so that the connection between the outer side surface of the second structural member 22 and the bottom surface 222 of the second structural member is not easy to collide with the sleeve 3, thereby reducing the generation of particulate matter.

[0079] like Figure 2-5 As shown, at least part of the upper surface of the inner tray body 11 is recessed downward to form a wafer slot 110 for carrying wafers. The wafer slot 110 is a horizontal slot to ensure that the wafer can be placed horizontally on the inner tray 1 when the inner tray 1 is carrying the wafer, to ensure that the wafer is placed horizontally during processing, and to avoid the wafer tilting and affecting the processing quality of the wafer surface. In addition, the wafer slot 110 above the inner tray 1 can play a radial positioning effect on the wafer, to avoid the situation in which the inner tray 1 rotates during the process and the wafer lacks radial positioning, resulting in relative displacement or even separation between the wafer and the inner tray 1. By arranging the wafer slot 110 on the top of the inner tray 1, the wafer and the inner tray 1 can reliably position the wafer. In order to avoid the edge of the wafer slot 110 being too close to the outer edge of the inner tray 1, causing the wafer to be affected by the cooling pipe in the wall of the reaction chamber 51, thereby causing excessive temperature drop on the wafer surface, the horizontal distance L1 from the edge of the wafer slot 110 to the outer edge of the inner tray 1 is 5mm-80mm. And as Figure 2 As shown, the distance L2 from the edge of the wafer slot 110 to the outer edge of the extension portion 12 is 5mm-80mm. By setting this distance, the edge of the substrate can be in a suitable position with the inner tray 1 and the outer ring contact area where heat loss is greater, which will not increase the size of the overall wafer base and avoid a large temperature difference between the center and edge of the wafer.

[0080] Continuing with the embodiment shown in Figures 2-5, the outer diameter of the inner tray 1 is smaller than the outer diameter of the sleeve 3. During the heating process of the wafer, the heater for generating heat is arranged inside the sleeve 3, and the heat generated by the heater is transferred upward to the wafer through the inner tray 1, that is, the heater first heats the inner tray 1, and the heat is transferred to the wafer through the inner tray 1. Since the heater is arranged inside the sleeve 3, and a cooling pipe is arranged on the cavity wall of the reaction chamber 51 outside the sleeve 3, a temperature gradient will be generated on the inner tray 1 along the radial direction of the inner tray 1, and the temperature at various locations on the inner tray 1 gradually decreases radially outward from the center of the inner tray 1. The outer diameter of the inner tray 1 is smaller than the inner diameter of the sleeve 3, which can reduce the temperature difference at different locations on the inner tray 1, and reduce the risk of the inner tray 1 breaking due to excessive temperature differences at different locations. As a more preferred embodiment, the outer diameter of the inner tray 1 is smaller than the inner diameter of the sleeve 3, thereby further reducing the outer diameter of the inner tray 1, further reducing the temperature gradient of the inner tray 1 along the radial direction, reducing the temperature difference at various locations on the inner tray 1, and reducing the risk of the inner tray 1 breaking and generating particles during processing due to excessive temperature differences at various locations.

[0081] The thickness of the edge area of ​​the inner tray body 11 gradually decreases from the inside to the outside in the radial direction. The edge area of ​​the inner tray body 11 refers to the area on the inner tray body 11 surrounding the wafer slot 110, and the edge area of ​​the inner tray body 11 is not used to carry wafers. Along the thickness direction of the inner tray 1, the diameter of the inner tray body 11 increases monotonically from the inner tray upper surface 112 to the inner tray body bottom surface 111. And in the cross section in the thickness direction of the inner tray 1, there is an upwardly convex arc between the bottom surface 111 of the inner tray body and the outer edge of the inner tray upper surface 112. By setting the side of the inner tray body 11 as an outwardly convex arc, it is beneficial for heat to flow inside the inner tray 1, avoiding the formation of a temperature mutation area on the inner tray 1, and reducing the risk of excessive concentration of temperature stress on the inner tray 1, which may easily cause the inner tray 1 to break and produce particles. In addition, during actual use, a cooling pipe is arranged in the cavity wall of the reaction chamber 51 along the radial direction of the inner tray 1. By setting the side of the inner tray 1 as an arc surface convex outward, the distance between the inner tray 1 and the cooling pipe is increased, the cooling effect of the cooling pipe on the inner tray 1 is reduced, and the temperature difference at different positions on the inner tray 1 is reduced.

[0082] The extension portion 12 is formed by extending downward from the central area of ​​the bottom surface of the inner tray body 11. Figure 4 and Figure 5In the embodiment shown, the edge of the bottom surface 122 of the extension portion continues to extend downward to form an extension ring 120. The extension ring 120 increases the contact area between the extension portion 12 and the outer ring 2, and improves the positioning accuracy between the inner tray 1 and the outer ring 2. At the same time, the extension ring 120 is further close to the heater arranged below the inner tray 1, shortening the distance between the inner tray 1 and the heater. Even if the contact area between the extension portion 12 and the outer ring 2 is increased, the heating effect of the heater on the extension ring 120 is still greater than the increased heat loss of the inner tray 1 due to the increase in the contact area, and can compensate for the original heat loss at the edge of the inner tray 1, thereby improving the heating uniformity of the inner tray 1. In this embodiment, only the edge of the bottom surface 122 of the extension portion extends downward, and the central area of ​​the bottom surface 122 of the extension portion does not extend downward, thereby reducing the overall weight of the inner tray 1. In this embodiment, the height difference between the bottom surface of the extension portion 12 and the bottom surface of the second structural member 22 is 1mm-100mm. If the height difference is too large, the heat of the heater will be more easily lost through the outer ring 2, and if it is too small, the influence of the processing error on the temperature uniformity cannot be controlled.

[0083] The eccentricity of the inner tray 1 caused by rotation may always deflect to the fixed side. In some embodiments, the wafer base is an asymmetric structure, that is, different areas of the circular tray are designed with different structures or sizes. Taking the extension ring 120 as an example, the inner tray 1 is close to the side of the outer ring 2, and its extension ring 120 is longer and closer to the heater, so as to compensate as much as possible for the heat loss caused by the close contact with the outer ring 2; the inner tray 1 is far away from the outer ring 2. The side of the extension ring 120 is shorter and farther away from the heater, so as to adjust the temperature uniformity of the entire inner tray 1.

[0084] To ensure reliable positioning between the extension portion 12 and the outer ring 2 and to ensure that the extension portion 12 can be detachably connected to the outer ring 2 and to accommodate thermal expansion during the heating process, as shown in FIG. Figure 3-5 As shown in the embodiment, there is a first gap 41 between the extension part 12 and the second structural member 22, and the width of the first gap 41 is 0mm-5mm. In order to ensure reliable positioning between the outer ring 2 and the sleeve 3 and to ensure that the extension part 12 can be detachably connected and thermally expanded with the outer ring 2, there is a second gap 42 between the second structural member 22 and the inner wall surface 31 of the sleeve, and the width of the second gap 42 is 0mm-5mm.

[0085] The inner tray 1 is integrally formed, and the inner tray body 11 and the extension portion 12 are integrally formed, which reduces the manufacturing process of the inner tray 1, improves the manufacturing efficiency of the inner tray 1, and reduces the manufacturing cost of the inner tray 1. The first structural member 21 and the second structural member 22 of the outer ring 2 are integrally formed, which reduces the manufacturing process of the outer ring 2, improves the manufacturing efficiency of the outer ring 2, and reduces the manufacturing cost of the outer ring 2.

[0086] In summary, the utility model provides a wafer base, the tray of which is a two-piece structure, including an outer ring 2 placed on the top of the sleeve 3, and an inner tray 1 placed on the outer ring 2. The upper surface 112 of the inner tray is recessed downward to form a wafer slot 110 for carrying wafers. The upper surface 112 of the inner tray is higher than the upper surface 213 of the outer ring. When the wafer is placed in the wafer slot 110, the position of the wafer is still higher than the upper surface 213 of the outer ring, so that the wafer is away from the outer ring 2 in the vertical direction, which can reduce the degree of heat loss along the radial direction of the inner tray 1 and reduce the influence of the outer ring 2 with a larger outer diameter on the temperature uniformity of the inner tray 1. By changing the shape of the contact area between the inner tray 1 and the outer ring, the requirements of wafer transmission and wafer temperature uniformity are met, and the damage caused by the temperature difference at the two ends of the tray edge area or the outer ring due to the breakage is avoided.

[0087] like Figure 6 As shown, the present embodiment further provides a semiconductor device 5, which includes a reaction chamber 51, the above-mentioned wafer base, a gas supply device 52, a sleeve 3 and a heater 53. The wafer base is arranged in the reaction chamber 51. The gas supply device 52 is located above the reaction chamber 51 and is arranged opposite to the wafer base, and is used to transport reaction gas into the reaction chamber 51. The sleeve 3 can drive the wafer base to rotate. The heater 53 is arranged in the sleeve 3 to heat the wafer on the wafer base.

[0088] In addition, the lower surface of the second structural member 22 can be located above or below the plane where the heater 53 is located. When located above, the height from the heater 53 is 0 mm-95 mm; when located below, the height from the heater 53 is 0 mm-10 mm. The distribution of heat in the inner tray 1 and the outer ring 2 is adjusted by the position of the second structural member 22 and the heater 53.

[0089] Although the content of the utility model has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the utility model. After reading the above content, various modifications and substitutions of the utility model will be obvious to those skilled in the art. Therefore, the protection scope of the utility model should be limited by the attached claims.

Claims

1. A wafer base, characterized in that: It comprises an inner tray for carrying wafers, an outer ring arranged around the inner tray, and a sleeve supporting the outer ring; The outer ring includes a first structural member, which is placed on the top of the side wall of the sleeve; the inner edge of the first structural member extends inwardly and exceeds the inner wall surface of the sleeve, and the outer edge of the first structural member extends outwardly and exceeds the outer wall surface of the sleeve; The lower surface of the inner edge region of the first structural member is connected to a second structural member extending downward; The inner tray comprises an inner tray body and an extension portion extending downward from the bottom surface of the inner tray body; the inner tray body is placed on the first structural member; the outer side of the extension portion can abut against the outer ring; The outer diameter of the inner tray is smaller than the outer diameter of the outer ring; The upper surface of the inner tray is higher than the upper surface of the outer ring.

2. The wafer pedestal according to claim 1, wherein: The height of the bottom surface of the second structural member is smaller than the height of the bottom surface of the inner tray.

3. The wafer pedestal according to claim 1, wherein: A chamfer is arranged between the outer side surface of the second structural member and the bottom surface of the second structural member.

4. The wafer pedestal according to claim 1, wherein: The bottom surface of the second structure member is inclined upward from inside to outside along the radial direction.

5. The wafer pedestal according to claim 1, wherein: The thickness of the second structural member is 2 mm-100 mm.

6. The wafer pedestal according to claim 1, wherein: The height difference between the upper surface of the first structural member and the bottom surface of the second structural member is 3 mm-110 mm.

7. The wafer pedestal according to claim 1, wherein: At least a portion of the upper surface of the inner tray body is recessed toward the inside of the sleeve to form a wafer groove for carrying wafers.

8. The wafer pedestal according to claim 7, wherein: The horizontal distance from the edge of the wafer slot to the outer edge of the inner tray is 5mm-80mm.

9. The wafer pedestal according to claim 7, wherein: The distance from the edge of the wafer groove to the outer edge of the extension portion is 5 mm-80 mm.

10. The wafer pedestal according to claim 1, wherein: The outer diameter of the inner tray is smaller than the outer diameter of the sleeve.

11. The wafer pedestal according to claim 1, wherein: The outer diameter of the inner tray is smaller than the inner diameter of the sleeve.

12. The wafer pedestal according to claim 1, wherein: The thickness of the edge area of ​​the inner tray body gradually decreases from the inside to the outside in the radial direction.

13. The wafer pedestal according to claim 1, wherein: The extension portion is formed by extending downward from a central area of ​​the bottom surface of the inner tray body.

14. The wafer pedestal according to claim 13, wherein: The edge of the bottom surface of the extending portion extends downward to form an extending ring.

15. The wafer pedestal according to claim 1, wherein: A height difference between a bottom surface of the extension portion and a bottom surface of the second structural member is 1 mm-100 mm.

16. The wafer pedestal according to claim 1, wherein: There is a first gap between the extension portion and the second structural member, and the width of the first gap is 0mm-5mm; there is a second gap between the second structural member and the sleeve, and the width of the second gap is 0mm-5mm.

17. The wafer pedestal according to claim 1, wherein: The height of the lower surface of the extending portion is not less than the height of the lower surface of the second structural member.

18. The wafer pedestal according to claim 1, wherein: The inner tray is integrally formed, and the outer ring is integrally formed.

19. A semiconductor device, characterized in that: The semiconductor device comprises: Reaction chamber; The wafer base according to any one of claims 1 to 18, wherein the wafer base is disposed in the reaction chamber; A gas supply device, located above the reaction chamber and arranged opposite to the wafer base, for delivering reaction gas into the reaction chamber; The sleeve can drive the wafer base to rotate; The heater is arranged in the sleeve.

20. The semiconductor device according to claim 19, wherein The lower surface of the second structural member is above the heater and at a height of 0mm-95mm from the heater; or the lower surface of the second structural member is below the heater and at a height of 0mm-10mm from the heater.

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