Bearing device and semiconductor processing equipment

Abstract

The utility model provides a bearing device and semiconductor processing equipment, the bearing device comprises a base body, the plane of the base body bearing a wafer is a reference plane, the base body is provided with a first surface and a second surface which are lower than the reference plane, the first surface is close to the edge of the base body, and the second surface is located in the central area of the base body. The base body is further provided with a third surface which is located between the first surface and the second surface and is recessed in the direction away from the reference surface. And the first surface, the second surface and the third surface are all provided with air channel structures which are communicated with one another. According to the scheme, the pressure distribution uniformity between the wafer and the base can be improved, so that the process uniformity can be improved.

Description

Technical Field

[0001] The utility model relates to the field of semiconductor manufacturing, and in particular to a carrier device and semiconductor processing equipment. Background Art

[0002] In the wafer preparation process, especially in the key stages such as deposition, lithography and etching, the wafer must be stably fixed and heated (or cooled) to ensure that the relevant process operations can be carried out smoothly on the wafer. Therefore, the performance requirements of the equipment for wafer fixing and heating (or cooling) are extremely high. At present, the vacuum adsorption heater (Vacuum Chuck heater) is a commonly used wafer fixing and heating (or cooling) equipment. The base is to absorb and fix the wafer by using the air pressure difference between the upper and lower surfaces of the wafer by evacuating the space between the wafer and the base. In addition, the gas between the wafer and the base can play a role in heat conduction, and the effect of uniform gas can be achieved by designing different gas path shapes on the top surface of the base.

[0003] The prior art has the problem of uneven pressure distribution in the gas space between the wafer and the susceptor, which leads to uneven temperature distribution of the wafer, thereby causing poor process uniformity (such as uniformity of coating thickness). Utility Model Content

[0004] The utility model aims to solve at least one of the technical problems existing in the prior art, and proposes a carrier device and a semiconductor processing equipment, which can solve the problem of uneven pressure distribution in the gas space between the wafer and the base body in the prior art, thereby improving process uniformity.

[0005] In order to achieve the purpose of the utility model, a carrying device is provided, comprising a base body, wherein the plane where the base body carries the wafer is a reference plane, the base body has a first surface and a second surface lower than the reference plane, the first surface is close to the edge of the base body, the second surface is located in the central area of ​​the base body, and the base body further has a third surface located between the first surface and the second surface and concave in a direction away from the reference plane;

[0006] The first surface, the second surface and the third surface are all distributed with interconnected airway structures.

[0007] In some embodiments, the third surface is a first annular surface surrounding the second surface; or, the third surface is a plurality of surfaces surrounding the second surface;

[0008] The first surface is a second annular surface surrounding the first annular surface.

[0009] In some embodiments, the third surface is a curved surface or a stepped surface.

[0010] In some embodiments, the first annular surface and the second annular surface are both annular surfaces; the second surface is a circular surface;

[0011] The inner diameter of the second annular surface is equal to the outer diameter of the first annular surface; the inner diameter of the first annular surface is equal to the outer diameter of the second surface.

[0012] In some embodiments, the air channel structures distributed on the second annular surface include annular air channels extending along the circumference of the second annular surface.

[0013] In some embodiments, a plurality of adsorption air holes connected to the air channel structure are formed on the second surface, and the centers of the plurality of adsorption air holes are distributed on a circle with the center of the second surface as the center.

[0014] In some embodiments, the ratio of the outer diameter of the second surface to the diameter of the circle where the center of the adsorption pore is located is greater than or equal to 1.2 and less than or equal to 1.8.

[0015] In some embodiments, the ratio of the outer diameter of the second annular surface to the outer diameter of the second surface is greater than or equal to 2.35 and less than or equal to 3.73; the ratio of the inner diameter of the second annular surface to the outer diameter of the second surface is greater than or equal to 2.16 and less than or equal to 3.48.

[0016] In some embodiments, the outer diameter of the second annular surface is greater than or equal to 282 mm and less than or equal to 298 mm; the inner diameter of the second annular surface is greater than or equal to 259 mm and less than or equal to 279 mm.

[0017] In some embodiments, the outer diameter of the second surface is greater than or equal to 80 mm and less than or equal to 120 mm.

[0018] In some embodiments, the distance between the third surface and the reference plane is 4.5 to 15 times the distance between the second surface and the reference plane; and / or,

[0019] The distance between the third surface and the reference plane is 4.5 to 15 times the distance between the first surface and the reference plane.

[0020] In some embodiments, the distance between the second surface and the reference plane is less than or equal to the distance between the first surface and the reference plane.

[0021] In some embodiments, the distance between the second surface and the reference plane is greater than 0 μm and less than or equal to 50 μm; and / or,

[0022] The distance between the first surface and the reference plane is greater than 0 μm and less than or equal to 50 μm.

[0023] In some embodiments, the difference between the distance between the third surface and the reference plane and the distance between the second surface and the reference plane is greater than or equal to 60 μm and less than or equal to 140 μm; and / or,

[0024] A difference between a distance between the third surface and the reference plane and a distance between the first surface and the reference plane is greater than or equal to 60 μm and less than or equal to 140 μm.

[0025] In some embodiments, the airway structures distributed on the first surface, the second surface, and the third surface have the same depth.

[0026] In some embodiments, the depth of the airway structures distributed on the first surface, the second surface, and the third surface is greater than or equal to 60 μm and less than or equal to 140 μm.

[0027] In some embodiments, a plurality of protrusions are distributed on both the second surface and the third surface, and the top surface of each protrusion is flush with the reference surface, for supporting the wafer;

[0028] The percentage of the total horizontal cross-sectional area of ​​the plurality of protrusions on the second surface to the area of ​​the second surface is greater than the percentage of the total horizontal cross-sectional area of ​​the plurality of protrusions on the third surface to the area of ​​the second surface.

[0029] In some embodiments, the percentage of the sum of the horizontal cross-sectional areas of the plurality of protrusions on the third surface to the area of ​​the second surface is greater than or equal to 0.8% and less than or equal to 2%;

[0030] The percentage of the total horizontal cross-sectional area of ​​the plurality of protrusions on the second surface to the area of ​​the second surface is greater than or equal to 1% and less than or equal to 2.2%.

[0031] In some embodiments, a plurality of protrusions are distributed on both the second surface and the third surface, and the top surface of each protrusion is flush with the reference surface, for supporting the wafer;

[0032] The plurality of protrusions on the second surface and the third surface are distributed along the circumference of the base body for at least one circle;

[0033] The distance between adjacent protrusions in the same circle on the second surface is smaller than the distance between adjacent protrusions in the same circle on the third surface; and / or, the radial distance between the circumferences of two adjacent circles of protrusions on the second surface is smaller than the radial distance between the circumferences of two adjacent circles of protrusions on the third surface.

[0034] In some embodiments, a plurality of adsorption air holes connected to the air channel structure are formed on the second surface, the supporting device further comprises a base shaft disposed at the bottom of the base body, a gas channel is disposed in the base shaft, one end of the gas channel is connected to the adsorption air holes, and the other end of the gas channel is used to communicate with the gas extraction device;

[0035] The gas channel is provided with a reduced diameter portion, and the reduced diameter portion is used to reduce the ventilation cross-sectional area of ​​the gas channel at the location of the reduced diameter portion.

[0036] In some embodiments, the reduced diameter portion is located at an end of the gas channel away from the base body.

[0037] In some embodiments, the diameter of the reduced diameter portion is three-eighths to five-eighths of the diameter of the gas channel.

[0038] As another technical solution, the utility model further provides a semiconductor processing equipment, including a process chamber and a carrying device arranged in the process chamber, and the carrying device adopts the above-mentioned carrying device provided by the utility model.

[0039] The utility model has the following beneficial effects:

[0040] The utility model provides a carrying device, wherein the base body has a first surface and a second surface which are lower than the reference plane where the carrying wafer is located, the first surface is close to the edge of the base body, the second surface is located in the central area of ​​the base body, and the base body also has a third surface which is located between the first surface and the second surface and is recessed in the direction away from the reference plane. The third surface is located in the area between the edge area and the central area of ​​the gas space formed between the base body and the wafer (referred to as the inner ring area), and by recessing the third surface in the direction away from the reference plane, the volume of the inner ring area of ​​the gas space can be increased, and the increase in the volume helps to make the pressure of the inner ring area more uniform in the radial direction, and can increase the pressure of the central area, thereby not only improving the uniformity of the pressure distribution of the inner ring area, but also compensating for the pressure difference between the central area and the inner ring area of ​​the gas space, thereby improving the uniformity of the pressure distribution. On this basis, the distances between the first surface, the second surface and the third surface and the reference plane can be adjusted according to the pressure distribution of different areas of the gas space, so as to change the volumes of the edge area, the central area and the inner ring area of ​​the gas space, thereby further compensating for the pressure difference between the edge area, the central area and the inner ring area of ​​the gas space. At the same time, by distributing interconnected airway structures on the first surface, the second surface and the third surface, not only can the volumes of the edge area, the central area and the inner circle area of ​​the gas space be further increased, but also a method for adjusting the volume of the gas space is added, so that the pressure distribution of gas spaces with different diameters can be more flexibly adjusted, thereby further improving the uniformity of the pressure distribution, thereby improving the uniformity of the wafer temperature distribution, and improving the process uniformity (such as the uniformity of the coating thickness).

[0041] The semiconductor processing equipment provided by the utility model can improve the uniformity of pressure distribution by adopting the supporting device provided by the utility model, thereby improving the uniformity of wafer temperature distribution, thereby improving process uniformity (such as uniformity of coating thickness). BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a cross-sectional schematic diagram of a load-bearing device in the prior art;

[0043] Figure 2 A curve comparison diagram of different diameters and pressures of the base body in the prior art and the embodiment of the utility model;

[0044] Figure 3 It is a simulation diagram of the pressure of the base body with different diameters in the prior art;

[0045] Figure 4 A top view of the base body used in the embodiment of the utility model;

[0046] Figure 5The base body used in the embodiment of the utility model is along Figure 4 A partial enlarged view of the middle AA line;

[0047] Figure 6 A three-dimensional diagram of the base body used in the embodiment of the utility model;

[0048] Figure 7 for Figure 6 Enlarged view of the middle I area;

[0049] Figure 8 for Figure 6 Enlarged view of the middle II region;

[0050] Fig. 9 for Figure 6 A simulation diagram of the pressure distribution of the gas space of the base body used;

[0051] Fig.10 A structural top view of the airway structure distributed on the first surface and the second surface of the base body above the height of the airway bottom surface;

[0052] Fig.11 A top view of the structure of the base body below the height of the third surface;

[0053] Fig.12 A simulation diagram of the pressure distribution of the gas space when the airway structure is distributed on the first surface and the second surface, and the third surface is concave in a direction away from the reference surface but is not distributed with the airway structure;

[0054] Fig.13 A simulation diagram of the pressure distribution of the gas space when the distance between the third surface and the reference plane is reduced to the same as the distance between the first surface and the second surface and the reference plane, and the first surface, the second surface and the third surface are all provided with airway structures, and the depth of the airway structure distributed on the third surface is greater than the depth of the airway structure distributed on the first surface and the second surface;

[0055] Fig.14 for Fig.12 , Fig.13 and Fig. 9 Comparison of the pressure distribution curves of the gas space;

[0056] Fig.15 A cross-sectional schematic diagram of a base body and a base shaft used in an embodiment of the utility model;

[0057] Fig.16 A schematic diagram of the structure of a process chamber of a semiconductor processing device used in an embodiment of the present utility model;

[0058] Fig.17 It is a comparison diagram of the pressure distribution curve of the gas space without the reduced diameter part and with the reduced diameter part in the embodiment of the utility model;

[0059] Fig.18 It is a comparison diagram of the film thickness distribution curve of the prior art and the embodiment of the utility model. DETAILED DESCRIPTION

[0060] In order to enable those skilled in the art to better understand the technical solution of the present invention, the carrier device and semiconductor processing equipment provided by the present invention are described in detail below in conjunction with the accompanying drawings.

[0061] The present invention provides a carrier device, which is applied to semiconductor processing equipment, for example. The carrier device is used to be arranged in a process chamber of the semiconductor processing equipment to carry a wafer. In some embodiments, the carrier device is, for example, a vacuum chuck heater, which can not only fix the wafer, but also control the temperature of the wafer by heating (or cooling). Furthermore, the carrier device fixes the wafer by, for example, vacuum chuck (i.e., the wafer is fixed by using the pressure difference between the upper and lower surfaces of the wafer).

[0062] like Figure 1 As shown, the supporting device in the prior art includes a base body 01, and an annular boss 011 is provided at the top edge of the base body 01. The top surface 012 of the annular boss 011 is used to support the edge area of ​​the bottom of the wafer 02, and a gas space 04 is formed between the top surface of the base body 01 and the wafer 02 on the inner side of the annular boss 011. In addition, a plurality of adsorption holes 03 connected to the gas space 04 are also provided on the top surface of the base body 01. The plurality of adsorption holes 03 are used to connect to an external exhaust device through a gas channel. When the exhaust device is working, the gas in the gas space 04 flows toward the adsorption holes 03 close to the center of the base body 01, and is extracted through the adsorption holes 03, thereby forming a pressure difference between the upper and lower surfaces of the wafer 02, so as to fix the wafer 02 to the base body 01.

[0063] Moreover, if Figure 2 and Figure 3 As shown, in the prior art, the pressure distribution in the gas space 04 is as follows: the pressure in the central area of ​​the base body 01 located inside the circumference of the multiple adsorption holes 03 (the diameter of the circle is, for example, 80 mm) is lower than that in other areas outside the central area, and the pressure in the inner circle area of ​​the gas space 04 located between its edge area and the above-mentioned central area (the outer diameter is, for example, 250 mm) decreases sharply along the radial direction from the outer circumference to the inner circumference, which leads to uneven pressure distribution in the inner circle area and also leads to uneven pressure distribution between different areas of the gas space 04.

[0064] The inventor has found through research that the reason for the above-mentioned uneven pressure distribution is that during the process, the edge of the wafer is prone to warping under high temperature conditions, causing external gas to directly enter the inner circle area of ​​the gas space 04 from the gap between the wafer 02 and the top surface 012 of the annular boss 011. Since the distance between the top surface of the base body 01 in the gas space 04 and the wafer 02 in the prior art is very small, the volume of the gas space 04 is limited, so the gas flowing into the inner circle area will cause the pressure of the inner circle area to be higher as it approaches the outer periphery, and lower as it approaches the inner periphery (affected by the suction of the adsorption holes 03), that is, the pressure decreases sharply from the outer periphery to the inner periphery in the radial direction, resulting in uneven pressure distribution in the inner circle area, and uneven pressure distribution between different areas of the gas space 04, which in turn leads to poor process uniformity (such as uniformity of coating thickness). Figure 2 Curve 1 in FIG. 1 is a curve of the prior art regarding different diameters and pressures of the base body. According to the curve 1, the uniformity of the pressure distribution of the gas space 04 in the prior art can be calculated to be 20.17. Figure 3 As shown in FIG. 1 , it is a simulation diagram of the pressure distribution of the gas space 04 in the prior art. Figure 2 Curve 1 and Figure 3 It can be seen that the pressure distribution uniformity of the base body with different diameters in the prior art is poor.

[0065] In order to solve the above problems, an embodiment of the utility model provides a carrying device, which can solve the problem of uneven pressure distribution between the wafer and the base body in the prior art, thereby improving process uniformity.

[0066] For details, please refer to Figures 4 to 8 The carrying device provided in the embodiment of the utility model comprises a base body 1, wherein the plane where the base body 1 carries the wafer 2 is a reference plane H0. Figure 5As shown. When the wafer 2 is placed on the base body 1, the bottom surface of the wafer 2 is flush with the reference plane H0. In some embodiments, the base body 1 has an annular protrusion 14, the top surface of which is flush with the reference plane H0, which can be used as a sealing surface to support and seal the edge area of ​​the wafer 2, and a gas space is formed inside the annular protrusion 14, located between the wafer 2 and the base body 1, and the gas in the gas space can be heat exchanged between the wafer 2 and the base body 1 to achieve temperature control of the wafer. Moreover, by extracting a portion of the gas in the gas space, a pressure difference can be generated between the upper and lower surfaces of the wafer to achieve vacuum adsorption and fixation of the wafer. For example, an adsorption air hole 5 is set in the central area of ​​the base body 1, and the adsorption air hole 5 is used to connect to an external exhaust device through a gas channel. When the exhaust device is working, the gas in the gas space flows to the adsorption air hole 5 and is extracted through each adsorption air hole 5, thereby forming a pressure difference between the upper and lower surfaces of the wafer 2.

[0067] On this basis, in response to the problem of uneven pressure distribution in the gas space between the wafer and the base body in the prior art, the embodiments of the utility model increase the volume of different areas in the gas space accordingly according to the pressure distribution in the gas space, so as to improve the uniformity of the pressure distribution in the gas space, thereby improving the uniformity of the wafer temperature distribution and improving the process uniformity (for example, the uniformity of the coating thickness).

[0068] Specifically, the base body 1 has a first surface 11 and a second surface 12 that are lower than the reference plane H0, and the first surface 11 is close to the edge of the base body 1, for example, located on the inner side of the annular protrusion 14, that is, located in the edge area of ​​the above-mentioned gas space. The second surface 12 is located in the central area of ​​the base body 1, that is, located in the central area of ​​the above-mentioned gas space. The base body 1 also has a third surface 13 that is located between the first surface 11 and the second surface 12 and is recessed in a direction away from the reference plane H0. That is, the third surface 13 is located in the area between the edge area and the central area of ​​the above-mentioned gas space (hereinafter referred to as the inner circle area).

[0069] Since the third surface 13 is recessed in a direction away from the reference plane H0, each position of the third surface 13 is lower than the first surface 11 and / or the second surface 12. It is easy to understand that if the first surface 11 and the second surface 12 are flush, each position of the third surface 13 (excluding the boundary position between the third surface 13, the first surface 11 and the second surface 12) is lower than the first surface 11 and the second surface 12; if the first surface 11 is higher than the second surface 12, each position of the third surface 13 is lower than the first surface 11, and a part of each position of the third surface 13 is lower than the second surface 12, while another part is higher than the second surface 12. Conversely, if the second surface 12 is higher than the first surface 11, each position of the third surface 13 is lower than the second surface 12, and a part of each position of the third surface 13 is lower than the first surface 11, while another part is higher than the first surface 11.

[0070] The third surface 13 can increase the volume of the inner circle area of ​​the gas space by making the third surface 13 concave in the direction away from the reference plane H0. The increase in volume can make the inner circle area accommodate more gas when external gas flows in, so that more gas in the inner circle area flows to the central area with the gas flow, which helps to make the pressure distribution of the inner circle area more uniform in the radial direction, and can increase the pressure in the central area, thereby not only improving the uniformity of the pressure distribution in the inner circle area, but also compensating for the pressure difference between the central area and the inner circle area of ​​the gas space, thereby improving the uniformity of the pressure distribution. On this basis, the distance between the first surface, the second surface and the third surface and the reference plane can be adjusted according to the pressure distribution of different areas of the gas space to change the volume of the edge area, the central area and the inner circle area of ​​the gas space, thereby further compensating for the pressure difference between the central area, the inner circle area and the edge area of ​​the gas space, thereby improving the uniformity of the pressure distribution.

[0071] Moreover, the first surface 11, the second surface 12 and the third surface 13 are all distributed with interconnected airway structures. Specifically, the first surface 11, the second surface 12 and the third surface 13 are respectively distributed with the first airway structure 41, the second airway structure 42 and the third airway structure 43, which are interconnected. With the help of the above-mentioned airway structure, on the basis of achieving the transmission and uniform gas function, not only can the volumes of the edge area, the central area and the inner circle area of ​​the gas space be further increased, but also a way of adjusting the volume of the gas space is added, such as adjusting the shape, depth and width of the airway structure and other volume-related parameters to change the volume of the area where the airway structure is located, so that the pressure distribution of different diameters of the gas space can be adjusted more flexibly, and the uniformity of the pressure distribution can be further improved, thereby improving the uniformity of the temperature distribution of the wafer and improving the process uniformity (such as the uniformity of the coating thickness).

[0072] Through experiments, we know that Figure 2 Curve 2 in FIG. 1 is a pressure distribution curve in the gas space of the embodiment of the utility model. According to curve 2, the uniformity of pressure distribution of the gas space of the embodiment of the utility model can be calculated to be 6.12, which is significantly better than the uniformity of pressure distribution of the gas space 04 of the prior art (20.17). Fig. 9 This is a simulation diagram of the pressure distribution of the gas space of the embodiment of the utility model, compared with Figure 3 and Fig. 9 It can be seen that the pressure distribution uniformity of the gas space in the embodiment of the utility model is better.

[0073] In some embodiments, the air channel structure can be connected to the adsorption pores 5, so that when the air extraction device is working, a part of the gas in the gas space flows to the adsorption pores 5 along the first air channel structure 41, the third air channel structure 43 and the second air channel structure 42 in sequence. The shapes and arrangements of the first air channel structure 41, the second air channel structure 42 and the third air channel structure 43 can be set according to specific needs, and there is no particular limitation on this in the embodiment of the utility model.

[0074] It should be noted that the shapes and arrangements of the first airway structure 41, the second airway structure 42, and the third airway structure 43 can be set according to specific needs, and the embodiments of the present utility model have no particular restrictions on this. In some embodiments, the airway structure 41 distributed on the first surface 11 (i.e., the second annular surface) includes an annular airway extending circumferentially along the second annular surface. The annular airway can evenly guide the gas entering the gas space from the circumferential edge of the gas space to the airway structure 43 distributed on the third surface 13 (i.e., the first annular surface), thereby improving the uniformity of gas distribution in the circumferential direction of the gas space, and further improving the uniformity of pressure distribution in the circumferential direction of the gas space.

[0075] The second air duct structure 42 and the third air duct structure 43 are arranged between the above-mentioned annular air duct and each adsorption air hole 5. The second air duct structure 42 and the third air duct structure 43 are, for example, two parts in which multiple air ducts are respectively distributed on the second surface 12 and the third surface 13. The projections of the multiple air ducts on the top of the base 1 are, for example, axially symmetrically distributed. The multiple air ducts are configured to divert and converge the gas flowing through to improve the uniformity of gas distribution. The number and arrangement of the multiple air ducts for realizing the above-mentioned functions can be set according to specific needs, and there is no particular restriction on this in the embodiment of the utility model.

[0076] In some embodiments, in order to compensate for the pressure difference between the central area, the inner ring area and the edge area of ​​the gas space, thereby improving the uniformity of the pressure distribution of different diameters of the gas space, the third surface 13 is a first annular surface surrounding the second surface 12; the first surface 11 is a second annular surface surrounding the first annular surface. The first surface 11 and the third surface 13 adopt annular surfaces. In other embodiments, the third surface 13 can also be multiple and surround the second surface 12, which can also increase the spatial volume of the inner ring area to compensate for the pressure difference between the central area, the inner ring area and the edge area of ​​the gas space. In this case, each third surface 13 can be any shape such as a circle or a polygon, and the shapes of the multiple third surfaces 13 can be the same or different. In addition, when the first surface 11 and the second surface 12 are not flush, the area in the inner ring area of ​​the gas space other than the multiple third surfaces 13 can be flush with the first surface 11 or the second surface 12; when the first surface 11 and the second surface 12 are flush, the area in the inner ring area of ​​the gas space other than the multiple third surfaces 13 can be flush with the first surface 11 and the second surface 12.

[0077] In some embodiments, the third surface 13 (i.e., the first annular surface) can be an arcuate surface or a step surface. The depth of the depression of the arcuate surface decreases from the outer peripheral edge and the inner peripheral edge of the first annular surface to the middle direction. The depression depth is the distance of the depression in the direction away from the reference plane H0. The step surface is composed of multiple planes with height differences, and the distances between the multiple planes and the reference plane H0 increase one by one from the outer peripheral edge and the inner peripheral edge of the first annular surface to the middle direction, that is, for each adjacent two-level plane, the first-level plane close to the middle is lower than the other-level plane away from the middle. Of course, the distribution mode of the depression depth of the arcuate surface and the height distribution mode of the multi-level plane of the step surface are not limited to the distribution mode of the above-mentioned embodiment. In practical applications, the distribution mode can be set according to the pressure difference between the central area, the inner circle area and the edge area of ​​the gas space.

[0078] In some embodiments, in order to compensate for the pressure difference between the central area, inner circle area and edge area of ​​the gas space, thereby improving the uniformity of pressure distribution of different diameters of the gas space, the first surface 11 (i.e., the second annular surface) can be a plane, which can be parallel to the horizontal plane or inclined relative to the horizontal plane, for example, inclined downward from the outer peripheral edge of the second annular surface to the inner peripheral edge. In this case, the outer peripheral edge of the second annular surface can be flush with the reference plane H0, and the distance between the second annular surface and the reference plane H0 increases from the outer peripheral edge to the inner peripheral edge.

[0079] In some embodiments, in order to further increase the pressure in the central area of ​​the gas space, the second surface 12 may be a plane, and the plane may be parallel to the horizontal plane, that is, the distance between the second surface 12 and the reference plane H0 is equal everywhere.

[0080] In some embodiments, the third surface 13 (i.e., the first annular surface) and the first surface 11 (i.e., the second annular surface) are both annular surfaces; the second surface 12 is a circular surface. Moreover, the boundaries of the first surface 11, the third surface 13, and the second surface 12 coincide. Figure 5 As shown, the outer circumference of the first surface 11 is the circumference where the K1 line is located. Optionally, the inner circumference of the annular protrusion 14 coincides with the outer circumference of the first surface 11. The inner circumference of the first surface 11 coincides with the outer circumference of the third surface 13, which is the circumference where the K2 line is located. The inner circumference of the third surface 13 coincides with the outer circumference of the second surface 12, which is the circumference where the K3 line is located. In this case, the inner diameter of the first surface 11 (i.e., the second annular surface) is equal to the outer diameter of the third surface 13 (i.e., the first annular surface); the inner diameter of the third surface 13 (i.e., the first annular surface) is equal to the outer diameter of the second surface 12. By making the third surface 13 and the first surface 11 adopt annular surfaces and the second surface 12 adopt a circular surface, it can be ensured that the volume of the gas space is consistent on the circumference of the same diameter, thereby improving the uniformity of the pressure distribution in the circumferential direction of the gas space. Of course, in practical applications, the inner peripheral edge shape (i.e., the outer peripheral edge shape of the second surface 12) and the outer peripheral edge shape (i.e., the inner peripheral edge shape of the first surface 11) of the third surface 13 (i.e., the first annular surface) can also be designed according to the pressure distribution of the gas space in the circumferential direction, and the inner peripheral edge shape and the outer peripheral edge shape have different radial distances from the center of the gas space in the circumferential direction, i.e., non-circular edges, such as elliptical edges or special-shaped edges, etc.

[0081] In some embodiments, a plurality of adsorption air holes 5 connected to the air channel structure 42 are formed on the second surface 12 (i.e., a circular surface), and the centers of the plurality of adsorption air holes 5 are distributed on a circumference with the center of the second surface 12 as the center, and the diameter of the circumference of the plurality of adsorption air holes 5 is smaller than the outer diameter of the second surface 12. Preferably, the plurality of adsorption air holes 5 are evenly distributed along the circumference of the second surface 12 to improve the uniformity of gas distribution in the circumferential direction of the gas space, thereby improving the uniformity of pressure distribution in the circumferential direction of the gas space.

[0082] In some embodiments, in order to increase the pressure in the central area of ​​the gas space and reduce the pressure difference between the central area and the inner circle area of ​​the gas space, the outer diameter of the second surface 12 can be set according to the diameter of the circumference of the multiple adsorption holes 5. Specifically, the ratio of the outer diameter of the second surface 12 to the diameter of the circumference of the circle where the center of the adsorption hole 5 is located is greater than or equal to 1.2 and less than or equal to 1.8.

[0083] In some embodiments, taking the maximum outer diameter of the base body 1 as 300 mm (or 12 inches) as an example, the outer diameter of the second surface 12 is greater than or equal to 80 mm and less than or equal to 120 mm.

[0084] In some embodiments, in order to reduce the pressure difference between the edge area, the center area and the inner circle area of ​​the gas space, the outer diameter of the first surface 11 (i.e., the second annular surface) and / or the inner diameter of the first surface 11 (i.e., the second annular surface) can be determined according to the outer diameter of the second surface 12. Specifically, the ratio of the outer diameter of the first surface 11 (i.e., the second annular surface) to the outer diameter of the second surface 12 is greater than or equal to 2.35 and less than or equal to 3.73; the ratio of the inner diameter of the first surface 11 (i.e., the second annular surface) to the outer diameter of the second surface 12 is greater than or equal to 2.16 and less than or equal to 3.48. Of course, in practical applications, the outer diameter of the first surface 11 (i.e., the second annular surface) and / or the inner diameter of the first surface 11 (i.e., the second annular surface) can also be determined based on the ratio of the maximum outer diameter of the base body 1 to the outer diameter of the first surface 11 (i.e., the second annular surface), the ratio of the maximum outer diameter of the base body 1 to the inner diameter of the first surface 11 (i.e., the second annular surface), and the maximum outer diameter of the base body 1 currently used. In some embodiments, the ratio of the maximum outer diameter of the base body 1 to the outer diameter of the first surface 11 (i.e., the second annular surface) is, for example, greater than or equal to 1.01 and less than or equal to 1.06; the ratio of the maximum outer diameter of the base body 1 to the inner diameter of the first surface 11 (i.e., the second annular surface) is, for example, greater than or equal to 1.16 and less than or equal to 1.08. Taking the maximum outer diameter of the base body 1 as 300 mm (or 12 inches) as an example, the outer diameter of the first surface 11 (i.e., the second annular surface) is greater than or equal to 282 mm and less than or equal to 298 mm; the inner diameter of the first surface 11 (i.e., the second annular surface) is greater than or equal to 259 mm and less than or equal to 279 mm.

[0085] In some embodiments, in order to increase the volume of the inner circle area of ​​the gas space and improve the uniformity of the pressure distribution between the inner circle area and the central area of ​​the gas space, the distance between the third surface 13 and the reference plane H0 is 4.5 to 15 times the distance between the second surface 12 and the reference plane H0, for example, 4.5 times, 5.5 times, 6 times, 6.5 times, 7 times, 7.5 times, 8 times, 8.5 times, 9 times, 9.5 times, 10 times, 10.5 times, 11 times, 11.5 times, 12 times and 15 times, preferably 5 times.

[0086] In some embodiments, in order to increase the volume of the inner circle area of ​​the gas space and improve the uniformity of the pressure distribution between the inner circle area and the edge area of ​​the gas space, the distance between the third surface 13 and the reference plane H0 is 4.5 to 15 times the distance between the first surface 11 and the reference plane H0, for example, 4.5 times, 5.5 times, 6 times, 6.5 times, 7 times, 7.5 times, 8 times, 8.5 times, 9 times, 9.5 times, 10 times, 10.5 times, 11 times, 11.5 times, 12 times and 15 times, preferably 5 times.

[0087] In some embodiments, in order to further increase the pressure in the central area of ​​the gas space, the distance between the second surface 12 and the reference plane H0 is less than or equal to the distance between the first surface 11 and the reference plane H0. For example, when the distance between the second surface 12 and the reference plane H0 is equal to the distance between the first surface 11 and the reference plane H0, Fig.10 The structure of the base body 1 above the height of the airway bottom surface of the airway structure distributed on the first surface 11 and the second surface 12 is shown. Since the airway structure distributed on the third surface 13 is located below this height, Fig.10 The third surface 13 is not shown. Fig.10 It can be seen that the gas entering the gas space is first evenly guided to the inner circle area where the third surface 13 (i.e., the first annular surface) is located through the first air channel structure 41 (annular air channel) distributed on the first surface 11. Since the third surface 13 is concave in the direction away from the reference plane H0, the space volume between the third surface 13 and the wafer is larger, which helps to make the pressure in the inner circle area more evenly distributed in the radial direction and increase the pressure in the central area, thereby not only improving the uniformity of the pressure distribution in the inner circle area, but also compensating for the pressure difference between the central area and the inner circle area of ​​the gas space, thereby improving the uniformity of the pressure distribution. Fig.11 The structure of the base body 1 below the height of the third surface 13 is shown. Since the first surface 11 and the second surface 12 and the airway structure distributed thereon are located above this height, Fig.11 Not shown in .

[0088] Through simulation experiments, it is found that Figure 12 to Figure 14 As shown, Fig.12 It is a simulation diagram of the pressure distribution of the gas space when the airway structure is distributed on the first surface and the second surface, and the third surface is concave in the direction away from the reference plane but has no airway structure distributed. Fig.13 A simulation diagram of the pressure distribution in the gas space when the distance between the third surface and the reference plane is reduced to the same as the distance between the first surface and the second surface and the reference plane, and the first surface 11, the second surface 12 and the third surface 13 are all provided with airway structures, and the depth of the airway structure distributed on the third surface 13 is greater than the depth of the airway structure distributed on the first surface 11 and the second surface 12. Fig.14 Curve 1 in Fig.13 The pressure distribution curve of the gas space; Fig.14 Curve 2 in Fig.12 The pressure distribution curve of the gas space; Fig.14 Curve 3 in Figure 7 By comparing curve 1, curve 2 and curve 3, it can be seen that when the third surface is concave in the direction away from the reference surface and the first surface 11, the second surface 12 and the third surface 13 are all provided with airway structures, the uniformity of the pressure distribution of the gas space is optimal.

[0089] In some embodiments, the distance between the second surface 12 and the reference plane H0 is greater than 0 μm and less than or equal to 50 μm.

[0090] In some embodiments, the distance between the first surface 11 and the reference plane H0 is greater than 0 μm and less than or equal to 50 μm.

[0091] In some embodiments, the difference between the distance between the third surface 13 and the reference plane H0 and the distance between the second surface 12 and the reference plane H0 is greater than or equal to 60 μm and less than or equal to 140 μm.

[0092] In some embodiments, the difference between the distance between the third surface 13 and the reference plane H0 and the distance between the first surface 11 and the reference plane H0 is greater than or equal to 60 μm and less than or equal to 140 μm.

[0093] In some embodiments, the airway structures distributed on the first surface 11, the second surface 12, and the third surface 13 are respectively the first airway structure 41, the third airway structure 43, and the second airway structure 42, and the depths of the airway structures are the same. Of course, in practical applications, according to the specific needs of adjusting the volume of the gas space, at least two of the depths of the first airway structure 41, the third airway structure 43, and the second airway structure 42 can also be different.

[0094] In some embodiments, the depth of the air channel structures distributed on the first surface 11 , the second surface 12 , and the third surface 13 is greater than or equal to 60 μm and less than or equal to 140 μm.

[0095] In some embodiments, a plurality of protrusions 3 are distributed on both the second surface 12 and the third surface 13, and the top surface of each protrusion 3 is flush with the reference plane H0, for supporting the wafer 2. By using a plurality of protrusions 3 to support the wafer 2, the contact area between the base body 1 and the wafer 2 can be reduced, thereby reducing the metal ion contamination caused by the contact between the base body 1 and the wafer 2. Specifically, the protrusion 3 is, for example, columnar, and the bottom end of the protrusion 3 is connected to the second surface 12 or the third surface 13, for example, connected as one body, and the top surface of the protrusion 3 contacts the wafer 2 to support the wafer 2, and the top surfaces of all the protrusions 3 are flush with each other to ensure the horizontality of the wafer 2.

[0096] The protrusions distributed on the third surface 13 are first protrusions 3a, and the protrusions distributed on the second surface 12 are second protrusions 3b. The percentage of the sum of the horizontal cross-sectional areas of the plurality of second protrusions 3b to the area of ​​the second surface 12 is greater than the percentage of the sum of the horizontal cross-sectional areas of the plurality of first protrusions 3a to the area of ​​the second surface 12. That is, the distribution density of the plurality of second protrusions 3b is greater than the density of the plurality of first protrusions 3a, which can further increase the volume of the inner ring area of ​​the gas space and increase the pressure in the central area, thereby improving the uniformity of the pressure distribution between the inner ring area and the central area of ​​the gas space. In some preferred embodiments, the percentage of the sum of the horizontal cross-sectional areas of the plurality of protrusions (i.e., the first protrusions 3a) on the third surface 13 to the area of ​​the second surface 12 is greater than or equal to 0.8% and less than or equal to 2%; the percentage of the sum of the horizontal cross-sectional areas of the plurality of protrusions (i.e., the second protrusions 3b) on the second surface 12 to the area of ​​the second surface 12 is greater than or equal to 1% and less than or equal to 2.2%.

[0097] In some embodiments, the volume of the inner circle area of ​​the gas space is further increased, and the pressure in the central area can be increased at the same time, thereby improving the uniformity of the pressure distribution between the inner circle area and the central area of ​​the gas space. The multiple protrusions 3 on the second surface 12 (i.e., the circular surface) and the third surface 13 (i.e., the first annular surface) are distributed along the circumference of the base body 1 for at least one circle; and the distance between adjacent protrusions in the same circle on the second surface 12 (i.e., the second protrusions 3b) is smaller than the distance between adjacent protrusions in the same circle on the third surface 13 (i.e., the first protrusions 3a); and / or the radial distance between the circumferences of two adjacent circles of protrusions on the second surface 12 (i.e., the second protrusions 3b) is smaller than the radial distance between the circumferences of two adjacent circles of protrusions on the third surface 13 (i.e., the first protrusions 3a).

[0098] In some embodiments, Fig.15 and Fig.16As shown, the carrier device also includes a base shaft 7 arranged at the bottom of the base body 1, and the base shaft 7 is used to drive the base body 1 to rise and fall. A gas channel 51 is provided in the base shaft 7, one end of the gas channel 51 is connected to each adsorption hole 5, and the other end of the gas channel 51 is used to communicate with the exhaust device 61. The exhaust device is, for example, a molecular pump. When the exhaust device 61 is working, the gas in the gas space flows to the adsorption hole 5, and is successively extracted through each adsorption hole 5 and the gas channel 51, thereby forming a pressure difference between the upper and lower surfaces of the wafer 2. In a specific example, the other end of the gas channel 51 is connected to the exhaust device 61 through a gas pipeline, and a pressure controller 62 is also connected to the gas pipeline, which is used to control the pressure in the gas channel 51 so that it is less than the chamber pressure in the process chamber 100, so as to form a pressure difference between the upper and lower surfaces of the wafer 2, thereby realizing vacuum adsorption and fixation of the wafer. For example, if the chamber pressure is 3Torr, the pressure in the gas channel 51 is 2Torr.

[0099] Moreover, a reduced diameter portion 8 is provided in the gas channel 51, and the reduced diameter portion 8 is used to reduce the ventilation cross-sectional area of ​​the gas channel 51 at the location of the reduced diameter portion 8. In this way, air suffocation can be generated in the gas passage between the reduced diameter portion 8 and the air inlet end of the adsorption air hole 5. Compared with the gas channel without the reduced diameter portion 8, this can not only further increase the pressure in the central area of ​​the gas space, but also reduce the pressure fluctuation of the gas passage between the reduced diameter portion 8 and the air inlet end of the adsorption air hole 5 caused by the fluctuation of the chamber pressure and the pressure fluctuation generated by the pressure controller 62 during the pressure control process, that is, improve the pressure stability of the gas space, thereby avoiding the problem of wafer displacement caused by the instantaneous pressure in the gas space being greater than the chamber pressure due to pressure fluctuation. In other words, the presence of the reduced diameter portion 8 will reduce the pressure fluctuation in the gas passage between the reduced diameter portion 8 and the air inlet end of the adsorption air hole 5, and improve the pressure stability of the gas space.

[0100] like Fig.17 As shown, curve 1 is the gas space pressure distribution curve when the reduced diameter portion 8 is not provided in the embodiment of the utility model; curve 2 is the gas space pressure distribution curve when the reduced diameter portion 8 is provided in the embodiment of the utility model. By comparing curve 1 and curve 2, it can be seen that when the reduced diameter portion 8 is provided, the uniformity of the gas space pressure distribution is better. On this basis, Fig.18 As shown, curve 1 is the film thickness distribution curve of the prior art. According to curve 1, the uniformity of the film thickness distribution of the prior art can be calculated to be 1.19. Curve 2 is the film thickness distribution curve of the embodiment of the utility model. According to curve 2, the uniformity of the film thickness distribution of the embodiment of the utility model can be calculated to be 0.36. It can be seen that the film thickness uniformity of the embodiment of the utility model is significantly better than that of the prior art.

[0101] In some embodiments, the reduced diameter portion 8 is located at an end of the gas channel 51 away from the base body 1. In this way, the reduced diameter portion 8 can be away from the base body 1, so that the airflow near the gas space is relatively stable, thereby avoiding the interference of the local airflow field caused by airflow fluctuations at the location of the reduced diameter portion 8.

[0102] In some preferred embodiments, in order to effectively increase the pressure in the central area of ​​the gas space and the pressure stability of the gas space, the diameter of the reduced diameter portion 8 is three-eighths to five-eighths of the diameter of the gas channel 51 .

[0103] As another technical solution, an embodiment of the utility model further provides a semiconductor processing equipment, including a process chamber and a carrying device arranged in the process chamber, and the carrying device adopts the above-mentioned carrying device provided in the embodiment of the utility model.

[0104] The semiconductor processing equipment provided by the embodiment of the utility model can improve the uniformity of pressure distribution by adopting the supporting device provided by the embodiment of the utility model, and further improve the uniformity of wafer temperature distribution, thereby improving process uniformity (such as uniformity of coating thickness).

[0105] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A carrying device, characterized in that: The base body comprises a base body, wherein the plane where the wafer is carried by the base body is a reference plane, the base body has a first surface and a second surface which are lower than the reference plane, the first surface is close to the edge of the base body, the second surface is located in the central area of ​​the base body, and the base body further has a third surface which is located between the first surface and the second surface and is concave in a direction away from the reference plane; The first surface, the second surface and the third surface are all distributed with interconnected airway structures.

2. The carrying device according to claim 1, characterized in that: The third surface is a first annular surface surrounding the second surface; or, the third surface is a plurality of surfaces surrounding the second surface; The first surface is a second annular surface surrounding the first annular surface.

3. The carrying device according to claim 2, characterized in that: The third surface is a curved surface or a stepped surface.

4. The carrying device according to claim 2, characterized in that: The first annular surface and the second annular surface are both circular annular surfaces; the second surface is a circular surface; The inner diameter of the second annular surface is equal to the outer diameter of the first annular surface; the inner diameter of the first annular surface is equal to the outer diameter of the second surface.

5. The carrying device according to claim 2, characterized in that: The air channel structure distributed on the second annular surface includes annular air channels extending along the circumference of the second annular surface.

6. The carrying device according to claim 4, characterized in that: A plurality of adsorption air holes connected to the air channel structure are formed on the second surface, and the centers of the plurality of adsorption air holes are distributed on a circumference with the center of the second surface as the center.

7. The carrying device according to claim 6, characterized in that: The ratio of the outer diameter of the second surface to the diameter of the circle where the center of the adsorption pore is located is greater than or equal to 1.2 and less than or equal to 1.

8.

8. The carrying device according to claim 4, characterized in that: The ratio of the outer diameter of the second annular surface to the outer diameter of the second surface is greater than or equal to 2.35 and less than or equal to 3.73; the ratio of the inner diameter of the second annular surface to the outer diameter of the second surface is greater than or equal to 2.16 and less than or equal to 3.

48.

9. The carrying device according to claim 4, characterized in that: The outer diameter of the second annular surface is greater than or equal to 282 mm and less than or equal to 298 mm; the inner diameter of the second annular surface is greater than or equal to 259 mm and less than or equal to 279 mm.

10. The carrying device according to claim 4, characterized in that: The outer diameter of the second surface is greater than or equal to 80 mm and less than or equal to 120 mm.

11. The carrying device according to any one of claims 1 to 10, characterized in that: The distance between the third surface and the reference plane is 4.5 to 15 times the distance between the second surface and the reference plane; and / or, The distance between the third surface and the reference plane is 4.5 to 15 times the distance between the first surface and the reference plane.

12. The carrying device according to any one of claims 1 to 10, characterized in that: The distance between the second surface and the reference plane is less than or equal to the distance between the first surface and the reference plane.

13. The carrying device according to any one of claims 1 to 10, characterized in that: The distance between the second surface and the reference plane is greater than 0 μm and less than or equal to 50 μm; and / or, The distance between the first surface and the reference plane is greater than 0 μm and less than or equal to 50 μm.

14. The carrying device according to any one of claims 1 to 10, characterized in that: A difference between a distance between the third surface and the reference plane and a distance between the second surface and the reference plane is greater than or equal to 60 μm and less than or equal to 140 μm; and / or, A difference between a distance between the third surface and the reference plane and a distance between the first surface and the reference plane is greater than or equal to 60 μm and less than or equal to 140 μm.

15. The carrying device according to any one of claims 1 to 10, characterized in that: The airway structures distributed on the first surface, the second surface, and the third surface have the same depth.

16. The carrying device according to claim 15, characterized in that: The depth of the airway structures distributed on the first surface, the second surface, and the third surface is greater than or equal to 60 μm and less than or equal to 140 μm.

17. The carrying device according to any one of claims 1 to 10, characterized in that: A plurality of protrusions are distributed on the second surface and the third surface, and the top surface of each protrusion is flush with the reference surface, for supporting the wafer; The percentage of the total horizontal cross-sectional area of ​​the plurality of protrusions on the second surface to the area of ​​the second surface is greater than the percentage of the total horizontal cross-sectional area of ​​the plurality of protrusions on the third surface to the area of ​​the second surface.

18. The carrying device according to claim 17, characterized in that: The percentage of the total horizontal cross-sectional area of ​​the plurality of protrusions on the third surface to the area of ​​the second surface is greater than or equal to 0.8% and less than or equal to 2%; The percentage of the total horizontal cross-sectional area of ​​the plurality of protrusions on the second surface to the area of ​​the second surface is greater than or equal to 1% and less than or equal to 2.2%.

19. The carrying device according to claim 4, characterized in that: A plurality of protrusions are distributed on the second surface and the third surface, and the top surface of each protrusion is flush with the reference surface, for supporting the wafer; The plurality of protrusions on the second surface and the third surface are distributed along the circumference of the base body for at least one circle; The distance between adjacent protrusions in the same circle on the second surface is smaller than the distance between adjacent protrusions in the same circle on the third surface; and / or, the radial distance between the circumferences of two adjacent circles of protrusions on the second surface is smaller than the radial distance between the circumferences of two adjacent circles of protrusions on the third surface.

20. The carrying device according to any one of claims 1 to 10, characterized in that: A plurality of adsorption air holes connected to the air channel structure are formed on the second surface, the bearing device further comprises a base shaft arranged at the bottom of the base body, a gas channel is arranged in the base shaft, one end of the gas channel is connected to the adsorption air holes, and the other end of the gas channel is used to communicate with the exhaust device; The gas channel is provided with a reduced diameter portion, and the reduced diameter portion is used to reduce the ventilation cross-sectional area of ​​the gas channel at the location of the reduced diameter portion.

21. The carrying device according to claim 20, characterized in that: The reduced diameter portion is located at an end of the gas passage away from the base body.

22. The carrying device according to claim 20, characterized in that: The diameter of the reduced diameter portion is three-eighths to five-eighths of the diameter of the gas passage.

23. A semiconductor processing device, comprising a process chamber and a carrier arranged in the process chamber, characterized in that: The carrying device adopts the carrying device as described in any one of claims 1-22.

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