Wafer tray and vapor deposition equipment

Abstract

The utility model provides a wafer tray and vapor deposition equipment. The wafer tray is arranged on a rotating cylinder in a reaction cavity of vapor deposition equipment, the wafer tray is of an integrated structure, an annular boss is arranged on the lower surface of the wafer tray, the outer diameter of the annular boss is matched with the inner diameter of an opening in the top of the rotating cylinder, and the annular boss is used for limiting the wafer tray; the upper surface of the wafer tray comprises a central area and a peripheral area surrounding the central area, the central area is provided with a concave pit, and a first step used for bearing a wafer is arranged along the side wall of the concave pit; the lower surface of the wafer and the bottom surface of the pit are spaced, and the lower surface of the wafer, the side wall of the first step and the bottom surface of the pit define a uniform heat space; a deflation structure is arranged at the first step so as to communicate the uniform heat space with the reaction cavity. The split type tray assembly is used for solving the problems that a tray in an existing split type tray assembly is prone to deformation, and the cavity opening maintenance frequency is too high.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor equipment, and particularly relates to a wafer tray and a chemical vapor deposition (CVD) equipment. Background Art

[0002] The CVD process is a very important process method in the semiconductor field, which is mainly used for depositing a thin film on the surface of a substrate. The process flow is as follows: the substrate is heated to a certain temperature in the reaction chamber of the CVD equipment, and then a process gas is introduced into the reaction chamber, so that a chemical reaction occurs on the surface of the substrate, thereby generating the required thin film.

[0003] A rotating cylinder is arranged in the reaction chamber of the CVD equipment. The rotating cylinder is used to support a tray assembly, and the tray assembly includes a tray, an outer heat equalizing plate, and an inner heat equalizing plate. The tray assembly with wafers is placed on the top of the rotating cylinder through a manipulator, and the rotating cylinder is driven to rotate around its own central axis, so as to drive the tray assembly and the wafers to rotate. During the process, the wafers are driven to rotate by the rotating cylinder, and the process gas undergoes a chemical reaction on the surface of the wafers to complete the thin film growth process.

[0004] During the process, the process gas will also form deposits on the upper surface of the tray. Excessive deposits will affect the process results, and the tray assembly needs to be replaced or maintained regularly. In addition, due to the thin thickness of the tray, the tray is prone to deformation under the stress of the deposits, affecting the uniformity of thin film deposition. Summary of the Utility Model

[0005] The purpose of the utility model is to provide a wafer tray and a CVD equipment, which are used to solve the problems that the tray in the existing split tray assembly is prone to deformation and the cavity opening maintenance frequency is too high.

[0006] In order to achieve the above purpose, the utility model is realized through the following technical solutions:

[0007] A wafer tray is arranged on a rotating cylinder in the reaction chamber of a CVD equipment. The wafer tray is of an integral structure, and an annular boss is arranged on its lower surface. The outer diameter of the annular boss is adapted to the diameter of the top opening of the rotating cylinder, and is used for limiting the wafer tray. The upper surface of the wafer tray includes a central area and a peripheral area surrounding the central area. The central area has an inwardly recessed pit, and a first step for carrying wafers is arranged along the side wall of the pit. The lower surface of the wafer is spaced from the bottom surface of the pit, and a heat equalizing space is formed by the lower surface of the wafer, the side wall of the first step, and the bottom surface of the pit. A gas release structure is arranged at the first step to communicate the heat equalizing space with the reaction chamber.

[0008] Optionally, the gas release structure includes a through hole communicating the heat equalizing space with the inner cavity of the rotating cylinder.

[0009] Optionally, the through-hole is an inclined hole, one end of the through-hole is formed on the side wall of the first step, and the other end is formed at the connection between the lower surface of the wafer tray and the outer side surface of the annular boss.

[0010] Optionally, the air release structure includes a plurality of supports provided on the step surface of the first step, and the supports are used to support the wafer so that there is a gap between the wafer and the step surface.

[0011] Optionally, the air release structure includes a groove provided on the step surface of the first step, and the groove communicates with the side wall of the first step and the side wall of the pit.

[0012] Optionally, a plurality of wafer limiters are provided along the circumferential direction in the peripheral area.

[0013] Optionally, the wafer limiter is a cylinder with a rounded corner at the top.

[0014] Optionally, the top of the side wall of the pit has a rounded corner transition.

[0015] Optionally, the wafer has a flat-edge notch, the pit has a flat-edge side wall matching the flat-edge notch, and the top of the flat-edge side wall has a rounded corner transition.

[0016] Optionally, the peripheral area includes an annular plane.

[0017] Optionally, the peripheral area includes an annular inclined surface, and the annular inclined surface extends downward along the direction radially inward of the wafer tray to the side wall of the pit.

[0018] Optionally, an annular covering portion extends outward from the outer side wall of the wafer tray, and the annular covering portion is used to cover the upper surface of the rotating cylinder.

[0019] Optionally, a connecting portion is formed outward from the outer side wall of the wafer tray, and the connecting portion is used to lap an annular covering member, and the annular covering member is used to cover the upper surface of the rotating cylinder.

[0020] Optionally, a central opening is provided in the middle of the pit, and a second step is provided along the side wall of the central opening, and the second step is used to carry a heat equalizing plate.

[0021] Optionally, the material of the wafer tray is graphite, or the wafer tray includes a graphite substrate and a silicon carbide coating, or the wafer tray includes a graphite substrate and a tantalum carbide coating.

[0022] A vapor deposition device, comprising: a reaction chamber; a rotating cylinder located at the bottom of the reaction chamber, and a plurality of through pressure relief holes are provided on the annular side wall of the rotating cylinder to release the pressure inside the rotating cylinder; the wafer tray as described in any one of the above is arranged on the top of the rotating cylinder.

[0023] Compared with the prior art, the present utility model has the following advantages:

[0024] The wafer tray provided by the present utility model is of an integral structure, with enhanced anti-deformation ability, overcoming the problem that the tray in the existing split tray assembly is prone to deformation, affecting the uniformity of thin film deposition. At the same time, the frequency of cavity opening maintenance can be reduced, and the equipment operation cost can be reduced. A first step is provided in the pit in the central area of the wafer tray, so as to form a uniform heat space below the wafer, and even if the wafer is deformed during the process, it can be uniformly heated. By providing a gas release structure in the wafer bearing pit, the uniform heat space below the wafer is communicated with the reaction chamber, avoiding the oscillation of the wafer during the process. A wafer limiting member is arranged in the edge area of the wafer tray to prevent the wafer from flying out of the pit after deforming at high temperature. The wafer limiting member and the top of the pit side wall are treated with rounded corners to prevent the accumulation of deposits, affecting the process results and wafer picking and placing. Description of the Drawings

[0025] In order to more clearly illustrate the technical solutions of the present utility model, the drawings required to be used in the description will be briefly introduced below. Obviously, the drawings in the following description are an embodiment of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts:

[0026] Figure 1 It is a schematic diagram of an existing vapor deposition device;

[0027] Figure 2 is Figure 1 The partial enlarged view of the dashed box in;

[0028] Figure 3 It is a schematic diagram of the wafer tray provided by an embodiment of the present utility model placed on the rotating cylinder;

[0029] Figure 4 It is a structural diagram of the wafer tray provided by an embodiment of the present utility model;

[0030] Figure 5 、 Figure 6 is the partial enlarged view of the wafer tray;

[0031] Figure 7 、 Figure 8 It is a schematic diagram of the gas release structure in other embodiments;

[0032] Figure 9 isFigure 3 Partial enlarged view at the dashed box in the middle;

[0033] Figure 10 It is a partial enlarged view of the wafer tray in another embodiment. Detailed implementation manners

[0034] The solution proposed by the present utility model will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners. According to the following description, the advantages and features of the present utility model will be clearer. It should be noted that the accompanying drawings are in a very simplified form and all use non-precise scales, only for the purpose of conveniently and clearly assisting in explaining the implementation manners of the present utility model. In order to make the purpose, features and advantages of the present utility model more obvious and understandable, please refer to the accompanying drawings. It should be noted that the structures, scales, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those skilled in this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present utility model. Therefore, they do not have technical essence. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effects that the present utility model can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed by the present utility model.

[0035] As Figure 1 shown, the existing chemical vapor deposition equipment includes a reaction chamber 100, at the bottom of which there is a rotatable rotating cylinder 10. The top of the rotating cylinder 10 is used to support a tray assembly 20. An intake device 30 is provided at the top of the reaction chamber 100 for introducing process gas into the reaction chamber. The top of the rotating cylinder 10 has an opening 11. When the tray assembly 20 is placed on the top of the rotating cylinder 10, this opening 11 can limit the tray assembly 20.

[0036] Combined with Figure 2 shown, the tray assembly 20 is a split tray, including an annular tray 21, an outer heat uniforming plate 22, and an inner heat uniforming plate 23. The annular tray 21 is used to carry a wafer W. The annular tray 21 is placed on the outer heat uniforming plate 22. The middle of the outer heat uniforming plate 22 has a central opening, and the inner heat uniforming plate 23 is located at this central opening.

[0037] The rotating cylinder 10 has a hollow inner cavity 12, in which a heater (not shown) is provided. The heat of the heater is transferred to the wafer W through the outer heat - equalizing plate 22 and the inner heat - equalizing plate 21 to uniformly heat the wafer W. A plurality of through pressure - relief holes 13 are formed in the annular side wall of the rotating cylinder 10 to communicate the inner cavity 12 of the rotating cylinder 10 with the reaction chamber, thereby releasing the pressure inside the rotating cylinder 10. An annular covering member 24 is further provided outside the outer heat - equalizing plate 22 to cover the upper surface of the rotating cylinder 10 to prevent the formation of deposits P on the upper surface of the rotating cylinder 10 during the process.

[0038] As Figure 2 shown, during the process, process gases will form deposits P on the annular tray 21 and the annular covering member 24. Since the thickness of the annular tray 21 is relatively thin, it is easily deformed under the stress of the deposits P, affecting the uniformity of the thin - film deposition on the wafer surface. In addition, after deposits P are formed on components such as the annular tray 21 and the annular covering member 24, the cavity needs to be opened regularly to polish or scrap the tray components. Once the cavity is maintained, the vapor deposition equipment also needs to be baked, so a large amount of time cost will be consumed. Since the maintenance cycles of components such as the annular tray 21, the outer heat - equalizing plate 22, the inner heat - equalizing plate 23, and the annular covering member 24 are different, in order to reduce costs, the cavity is usually opened for maintenance separately according to the maintenance cycles of each component, which will lead to too high a frequency of cavity opening for maintenance.

[0039] Based on this, the present utility model provides a wafer tray. Combining Figures 3 to 10 shown, the wafer tray is of an integral structure, which enhances the strength of the entire tray, increases the anti - deformation ability, is not easily deformed during the process, thereby improving the uniformity of wafer thin - film deposition and reducing the maintenance frequency.

[0040] In this embodiment, the material of the wafer tray is usually graphite, which has good thermal conductivity and can improve the heating effect on the wafer. In other embodiments, the wafer tray includes a graphite substrate and a silicon carbide coating, or the wafer tray includes a graphite substrate and a tantalum carbide coating.

[0041] The lower surface of the wafer tray 200 is provided with an annular boss 210, and the outer diameter of the annular boss 210 is adapted to the diameter of the top opening 11 of the rotating cylinder 10 for limiting the wafer tray 200.

[0042] The upper surface of the wafer tray 200 includes a central region a and a peripheral region b surrounding the central region a. The central region a has a recessed pit 220, and a first step 230 for carrying the wafer W is provided on the inner side of the side wall of the pit 220. When the wafer W is accommodated in the pit 220, the first step 230 spaces the lower surface of the wafer W from the bottom surface of the pit 220, and a heat - uniform space A is formed by the lower surface of the wafer W, the side wall of the first step 230, and the bottom surface of the pit 220. During the process, the wafer W will warp upward or downward at high temperature. Since the wafer W is not in contact with the bottom surface of the pit 220, the wafer W is in a suspended state, so that the wafer W can be uniformly heated even if it is deformed.

[0043] During the process, the heat - uniform space A is in a sealed state. The gas in this space expands at high temperature and may lift the wafer W. Therefore, a gas - releasing structure 231 is provided at the first step 230 to connect the heat - uniform space A with the reaction chamber, thereby preventing the wafer W from oscillating.

[0044] In one embodiment, the gas - releasing structure 231 includes a through - hole connecting the heat - uniform space A with the inner cavity 12 of the rotating cylinder 10. As described above, the inner cavity 12 of the rotating cylinder 10 is connected with the reaction chamber through a pressure - releasing hole 13. Therefore, the gas - releasing structure 231 indirectly connects the heat - uniform space A with the reaction chamber. As Figure 5 、 Figure 6 、 Figure 9 、 Figure 10 shown, the through - hole is an inclined hole. One end of the through - hole is formed on the side wall of the first step 230, and the other end is formed at the connection between the lower surface of the wafer tray 200 and the outer side surface of the annular boss 210. Setting the through - hole at the edge can prevent the heater below from directly heating the wafer W, making the temperature of the wafer W uneven and affecting the uniformity of thin - film deposition.

[0045] In another embodiment, as Figure 7 shown, the gas - releasing structure 231 includes a plurality of supports provided on the step surface of the first step 230. The supports are used to support the wafer W, so that there is a gap between the wafer W and the step surface of the first step 230. Thus, the heat - uniform space A is connected with the reaction chamber through this gap. The supports are evenly distributed on the step surface of the first step 230 to keep the height of the wafer W consistent.

[0046] In other embodiments, as Figure 8As shown, the deflation structure 231 includes a groove provided on the stepped surface of the first step 230. The groove communicates with the side wall of the first step 230 and the side wall of the pit 220, so that the heat - uniform space A is communicated with the reaction chamber through this groove.

[0047] In this embodiment, a plurality of wafer limiters 240 are provided along the circumferential direction of the edge region b to prevent the wafer W from flying out of the pit 220 after being deformed at high temperature. As Figure 6 shown, the wafer limiter 240 is a cylinder with a rounded - corner transition at the top. Rounding the top of the wafer limiter 240 can prevent the formation of mushroom - shaped deposits at the top of the wafer limiter 240, which affects the disassembly and assembly of the wafer W.

[0048] As Figure 6 shown, the top of the side wall of the pit 220 adopts a rounded - corner transition to prevent deposits from accumulating on the top of the side wall of the pit 220, which affects the height of the pit 220 and the picking and placing of the wafer W. Further, when the wafer W has a flat - edge notch, the pit 220 has a flat - edge side wall matching the flat - edge notch to achieve the positioning of the wafer W. The top of the flat - edge side wall adopts a rounded - corner transition to avoid the accumulation of deposits on the top of the flat - edge side wall, which affects the picking and placing of the wafer.

[0049] In one embodiment, as Figure 9 shown, the peripheral region b includes an annular plane b1 to make the flow field at the edge of the wafer W smooth. In another embodiment, as Figure 10 shown, the peripheral region b includes an annular inclined plane b2. The annular inclined plane b2 extends downward along the direction radially inward of the wafer tray 200 to the side wall of the pit 220.

[0050] To facilitate the picking and placing of the wafer W, a central opening is provided in the middle of the pit 220, and a second step 250 is provided along the side wall of the central opening. The second step 250 is used to carry a heat - uniform disk 260. The heat - uniform disk 260 is similar to the inner heat - uniform disk 23 in Figure 1 and will not be elaborated here.

[0051] In this embodiment, an annular covering portion 270 extends outward from the outer sidewall of the wafer tray 200, and the annular covering portion 270 is used to cover the upper surface of the rotating cylinder 10. In this embodiment, the annular tray 21, the outer heat - equalizing plate 22, and the annular covering member 24 are designed as an integral wafer tray 200, and the thicknesses of all three are increased, thereby enhancing the anti - deformation ability of the wafer tray 200. In addition, when too much sediment is deposited in the edge region b, the cavity can be opened once to process all three at the same time, thereby reducing the frequency of cavity - opening maintenance; and the cost of the integral wafer tray 200 is lower than that of the split - type tray. Therefore, the cost can be reduced while reducing the frequency of cavity - opening maintenance.

[0052] In other embodiments, the annular covering member 24 can also be independent of the wafer tray 200. As Figure 10 shown, a connecting portion 280 is formed outward from the outer sidewall of the wafer tray 200, and the connecting portion 280 is used to lap the annular covering member 24, and the annular covering member 24 is used to cover the upper surface of the rotating cylinder 10. In this embodiment, the annular tray 21 and the outer heat - equalizing plate 22 are designed as an integral wafer tray 200, and the thicknesses of both are increased, thereby enhancing the anti - deformation ability of the wafer tray 200. In addition, when too much sediment is deposited in the edge region b, the cavity can be opened once to process both at the same time, thereby reducing the frequency of cavity - opening maintenance; and the cost of the integral wafer tray 200 is lower than that of the split - type tray. Therefore, the cost can be reduced while reducing the frequency of cavity - opening maintenance.

[0053] In summary, the wafer tray provided by the present utility model is of an integral structure, with enhanced anti - deformation ability, overcoming the problem that the tray in the existing split - type tray assembly is prone to deformation, which affects the uniformity of film deposition. At the same time, the frequency of cavity - opening maintenance can be reduced, and the equipment operation cost can be reduced. A first step is provided in the pit in the central region of the wafer tray, so as to form a heat - equalizing space below the wafer, and the wafer can be evenly heated even if it is deformed during the process. By providing a gas - releasing structure in the wafer - carrying pit, the heat - equalizing space below the wafer is connected to the reaction chamber, avoiding the oscillation of the wafer during the process. A wafer limiting member is provided in the edge region of the wafer tray to prevent the wafer from flying out of the pit after being deformed at high temperature. The wafer limiting member and the top of the pit sidewall are treated with rounded corners to prevent sediment accumulation, which affects the process result and wafer picking and placing.

[0054] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0055] Although the content of the present utility model has been described in detail through the above preferred embodiments, it should be recognized that the above description should not be considered as a limitation of the present utility model. After those skilled in the art have read the above content, various modifications and alternatives to the present utility model will be obvious. Therefore, the protection scope of the present utility model should be defined by the appended claims.

Claims

1. A wafer tray is arranged on a rotating cylinder in a reaction chamber of a chemical vapor deposition device, characterized in that The wafer tray is of an integral structure, and an annular boss is provided on its lower surface. The outer diameter of the annular boss is adapted to the diameter of the top opening of the rotating cylinder for limiting the wafer tray. The upper surface of the wafer tray includes a central region and a peripheral region surrounding the central region. The central region has an indented pit, and a first step for carrying the wafer is provided along the side wall of the pit. The lower surface of the wafer is spaced from the bottom surface of the pit, and a heat uniforming space is formed by the lower surface of the wafer, the side wall of the first step, and the bottom surface of the pit. A gas releasing structure is provided at the first step to communicate the heat uniforming space with the reaction chamber.

2. The wafer tray according to claim 1, characterized in that, The gas releasing structure includes a through hole communicating the heat uniforming space with the inner cavity of the rotating cylinder.

3. The wafer tray according to claim 2, wherein The through hole is an inclined hole. One end of the through hole is formed on the side wall of the first step, and the other end is formed at the connection between the lower surface of the wafer tray and the outer side surface of the annular boss.

4. The wafer tray according to claim 1, wherein, The gas releasing structure includes a plurality of supports provided on the step surface of the first step. The supports are used to support the wafer so that there is a gap between the wafer and the step surface.

5. The wafer tray according to claim 1, wherein, The gas releasing structure includes a groove provided on the step surface of the first step. The groove communicates the side wall of the first step and the side wall of the pit.

6. The wafer tray according to claim 1, characterized in that, A plurality of wafer limiters are provided in the peripheral region along the circumferential direction.

7. The wafer tray according to claim 6, characterized in that, The wafer limiter is a cylinder with a rounded corner at the top.

8. The wafer tray according to claim 1, wherein, The top of the side wall of the pit has a rounded corner transition.

9. The wafer tray as claimed in claim 8, wherein, The wafer has a flat-edge notch, and the pit has a flat-edge side wall matching the flat-edge notch. The top of the flat-edge side wall has a rounded corner transition.

10. The wafer tray according to claim 1, characterized in that, The peripheral region includes an annular plane.

11. The wafer tray according to claim 1, wherein, The peripheral region includes an annular inclined surface, and the annular inclined surface extends downward along the direction radially inward of the wafer tray to the side wall of the pit.

12. The wafer tray according to claim 1, wherein, The outer side wall of the wafer tray extends outward to form an annular covering portion for covering the upper surface of the rotating cylinder.

13. The wafer tray according to claim 1, wherein The outer side wall of the wafer tray forms a connecting portion outward for lapping an annular covering member for covering the upper surface of the rotating cylinder.

14. The wafer tray according to claim 1, wherein, A central opening is provided in the middle of the pit, and a second step is provided along the side wall of the central opening for carrying a heat uniforming plate.

15. The wafer tray according to claim 1, wherein The material of the wafer tray is graphite, or the wafer tray includes a graphite substrate and a silicon carbide coating, or the wafer tray includes a graphite substrate and a tantalum carbide coating.

16. A vapor deposition device, characterized in that, Comprising: Reaction chamber; Rotating cylinder, located at the bottom of the reaction chamber. A plurality of through pressure relief holes are opened on the annular side wall of the rotating cylinder to release the pressure inside the rotating cylinder. The wafer tray according to any one of claims 1 to 15, provided on the top of the rotating cylinder.

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