Base for epitaxial reaction and wafer bearing and limiting assembly

Abstract

The invention discloses a base for epitaxial reaction and a wafer bearing and limiting assembly, the base is used for bearing a tray, the center of the bottom of the tray sinks inwards to form a concave hole, the middle of the body of the base protrudes upwards to form a tray bearing part, and the top of the tray bearing part sinks towards the bottom of the tray bearing part. A containing cavity and a limiting part surrounding the containing cavity are formed, and the containing cavity is matched with the tray in shape so that the tray can be embedded into the containing cavity; the center of the containing cavity protrudes upwards to form a clamping part, and the clamping part corresponds to the concave hole in position. Based on the base, the tray placed on the base is fixed and limited, slippage and edge landing between the tray and the base are avoided, and the situation that the concentration or thickness uniformity is abnormal due to relative displacement of the tray for bearing wafers on the base is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of wafer epitaxial reaction devices, and in particular to a base for epitaxial reaction and a wafer bearing and limiting component. Background Art

[0002] Epitaxial growth is the process of growing a new single-crystal layer on a single-crystal substrate, along its original crystallographic axis. This new single-crystal layer, called an epitaxial layer, has a lattice structure identical or similar to that of the substrate. Epitaxial layer growth methods are similar to those used for crystal growth, including chemical vapor deposition, molecular beam epitaxy, and liquid phase epitaxy. Currently, chemical vapor deposition is the mainstream method.

[0003] Chemical vapor deposition is a process in which gaseous or vaporous substances react in the gas phase or at the gas-solid interface to generate solid deposits. Chemical vapor deposition designs the flow field and the content of the reactive gas to ensure that the thickness and composition of the deposited film on each part of the wafer are uniform.

[0004] During the epitaxial reaction, whether it is a mechanical rotating base or an air-suspended rotating base, it is necessary to ensure that the base carrying the tray with the wafers placed on it remains on the center line of the airflow field. However, when the base starts to rotate, the tray is prone to slippage between the base and the tray, causing the tray to rotate in an elliptical trajectory, which can easily have an adverse effect on the concentration or thickness of the epitaxial deposition. During the production process, the base is limited by a circle of protrusions on the outer edge. After a period of use, the outer edge protrusions of the base will be etched in a high temperature and hydrogen environment. The edges gradually become shorter and lose their limiting effect on the tray, which is more likely to cause the tray to rest on the edge of the base and rotate abnormally. It is difficult to ensure that the base and tray remain stable during the reaction process by relying solely on the function of the limiting part.

[0005] In addition, given that the diameter of a general base is larger than the diameter of the bottom of the pallet, in order to ensure that the pallet does not overlap when placed on the base, it is necessary to improve the accuracy of the robot in placing the pallet on the base, thereby increasing the design, manufacturing and integration costs of the robot. Summary of the Invention

[0006] The object of the present invention is to provide a base for epitaxial reaction and a wafer carrying and limiting assembly that can fix and limit a tray to prevent slippage and overlap between the tray and the base.

[0007] To achieve the above objectives, the present invention discloses a susceptor for epitaxial reactions, the susceptor being used to receive a tray, the bottom center of the tray being recessed inward to form a recessed hole. The center portion of the susceptor's body protrudes upward to form a tray-receiving portion, the top of which is recessed toward the bottom of the tray-receiving portion to form a receiving cavity and a retaining portion surrounding the receiving cavity. The receiving cavity is shaped like the tray, allowing the tray to fit within the cavity. The center of the receiving cavity protrudes upward to form a latching portion, which corresponds to the position of the recessed hole.

[0008] Optionally, the recessed hole and the engaging portion are in mutually matching truncated cone shapes.

[0009] Optionally, the center of the bottom of the base is recessed toward the top of the base to form a fixing groove for engaging and fixing the base body.

[0010] Optionally, a guide groove for maintaining stable rotation of the base is provided at the bottom of the base, and the guide groove is spirally symmetrical with the fixing groove as the axis.

[0011] The present invention also discloses a wafer carrying and limiting assembly for epitaxial reaction, the carrying and limiting assembly comprising: A tray, wherein the center of the bottom of the tray is recessed inward to form a concave hole; A base for carrying the tray, wherein the middle portion of the base body protrudes upward to form a tray receiving portion, and the top of the tray receiving portion is recessed toward the bottom of the tray receiving portion to form a receiving cavity and a limiting portion surrounding the receiving cavity; The accommodating cavity is adapted to the shape of the tray so that the tray fits into the accommodating cavity; The center of the accommodating cavity protrudes upward to form a clamping portion, and the position of the clamping portion corresponds to the position of the concave hole, so that when the tray is engaged with the accommodating cavity, the clamping portion is inserted into the concave hole.

[0012] Optionally, the recessed hole and the engaging portion are in mutually matching truncated cone shapes.

[0013] Optionally, the tray includes an abutting portion and a carrying platform for carrying wafers, and the abutting portion is adapted to the shape of the accommodating cavity so as to be embedded in the accommodating cavity.

[0014] Optionally, the roughness of the abutting portion and the accommodating cavity is less than RA 3.2.

[0015] Optionally, the center of the bottom of the base is recessed toward the top of the base to form a fixing groove for engaging and fixing the base body.

[0016] Optionally, a guide groove for maintaining stable rotation of the base is provided at the bottom of the base, and the guide groove is spirally symmetrical with the fixing groove as the axis.

[0017] Compared with the prior art, the base for epitaxial reaction proposed in the present invention improves the stability and positioning accuracy of the tray placement in the epitaxial reaction through a unique structural combination. The tray receiving portion in the middle of the base protrudes upward to form a receiving cavity and a limiting portion, forming a nested fit with the tray, which can effectively prevent the tray from horizontally displacing during rotation. The precise alignment design of the clamping portion in the center of the base and the recessed hole of the tray further eliminates the risk of vertical shaking, ensuring that the tray and the base always remain stably aligned during the epitaxial reaction. This double limiting structure reduces the possibility of slippage and overlap between the tray and the base, ensuring the uniformity of epitaxial layer growth. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the three-dimensional structure of the base in an embodiment of the present invention.

[0019] Figure 2 2 is a side view of the base in an embodiment of the present invention.

[0020] Figure 3 It is a bottom view of the base in the embodiment of the present invention.

[0021] Figure 4 It is a side view of a wafer supporting and limiting assembly for epitaxial reaction in an embodiment of the present invention.

[0022] Figure 5 2 is a top view of a tray in an embodiment of the present invention.

[0023] Figure 6 It is an enlarged schematic diagram of the accommodating cavity and the limiting portion on the right side of the base in an embodiment of the present invention.

[0024] Figure 7 It is an enlarged schematic diagram of the abutting portion, the first sub-carrying platform, and the second sub-carrying platform on the right side of the tray in an embodiment of the present invention. DETAILED DESCRIPTION

[0025] In order to explain the technical content, structural features, achieved objectives and effects of the present invention in detail, the following is a detailed description in conjunction with the embodiments and the accompanying drawings.

[0026] Embodiments of the present invention disclose a susceptor for epitaxial growth reactions, which secures and limits the position of a tray placed on the susceptor, preventing slippage and overlap between the tray and the susceptor, and improving the situation in which the wafer-carrying tray experiences relative displacement on the susceptor, resulting in abnormal concentration or thickness uniformity. The susceptor is used to receive the tray, and the center of the tray's bottom is recessed inward to form a recessed hole, which is used to support the wafer. During the vapor deposition process, the susceptor is rotated by a rotating device, thereby driving the tray to perform the epitaxial growth reaction.

[0027] See Figure 1 、 Figure 2 as well as Figure 6 As shown, the base 1 for epitaxial reaction in this embodiment mainly includes the following specific structures: The center of the base 1's body protrudes upward to form a tray receiving portion 11. The top of the tray receiving portion 11 is recessed toward the bottom of the tray receiving portion 11 to form a receiving cavity 111 and a stopper 112 surrounding the receiving cavity 111. The receiving cavity 111 is shaped to match the shape of the tray 2, allowing the tray 2 to fit into the receiving cavity 111. A snap-fitting portion 113 protrudes upward from the center of the receiving cavity 111, corresponding to the position of the recessed hole 211.

[0028] Compared with the prior art, the base 1 proposed in the present invention improves the stability and positioning accuracy of the tray 2 during the epitaxial reaction through a unique structural combination. The tray receiving portion 11 in the middle of the base 1 protrudes upward to form a receiving cavity 111 and a limiting portion 112, forming a nested fit with the tray 2, which can effectively prevent the tray 2 from horizontally displacing during rotation. The precise alignment design of the clamping portion 113 in the center of the base 1 and the recessed hole 211 of the tray 2 further eliminates the risk of vertical shaking, ensuring that the tray 2 and the base 1 always remain stably aligned during the epitaxial reaction. This double limiting structure reduces the possibility of slippage and overlap between the tray 2 and the base 1, greatly ensuring the uniformity of epitaxial layer growth (i.e., avoiding uneven concentration and thickness distribution of various parts of the epitaxial layer due to the offset of the tray 2 and the base 1).

[0029] In summary, the base 1 for epitaxial reaction provided by the present invention achieves stability of the tray 2 and the base 1 during the epitaxial reaction through the nested interlocking structure of the accommodating cavity 111 and the limiting portion 112 and the precise alignment of the clamping portion 113 and the recessed hole 211 of the tray 2, effectively preventing displacement and shaking, thereby improving the uniformity of the growth of the epitaxial layer of the wafer and the process stability.

[0030] Optionally, the roughness of the contact surface between the accommodating cavity 111 and the tray 2 is less than RA 3.2. Roughness, to a certain extent, affects whether the base 1 can smoothly drive the tray 2 for stable rotation and whether it will deviate. In this embodiment, the roughness of the contact surface is preferably less than RA 3.2. In addition to the contact surface, the surfaces of the tray 2 and the base 1 are also coated with silicon carbide to improve corrosion resistance.

[0031] Optionally, see Figure 2 、 Figure 4 as well as Figures 6 and 7 As shown, in this embodiment, the cross-section of the limiting portion 112 of the base 1 is a trapezoid that matches the shape of the contact surface of the tray 2. In this embodiment, the height of the limiting portion 112 can be optionally increased to improve the reliability of the limitation and reduce the risk of failure to limit the tray 2 after the base 1 is corroded.

[0032] Optionally, see Figure 1 、 Figure 2 as well as Figure 4 As shown, the concave hole 211 and the clamping portion 113 are in the shape of a truncated cone that fits each other. Compared with the cylindrical clamping portion 113 and the concave hole 211, the truncated cone-shaped clamping portion 113 increases the tolerance space for positioning when the robot places the tray 2 on the base 1. Assuming that the robot has a small deviation when placing the tray 2 on the base 1, the tray 2 can slide down along the oblique edge of the clamping portion 113 at this time, so that the clamping portion 113 of the base 1 completely falls into the concave hole 211 at the bottom of the tray 2. This design reduces the requirements for the accuracy of the robot, indirectly reducing costs, while increasing the probability of successful overlap between the tray 2 and the base 1, improving the overlap efficiency, and reducing the preparation time before the epitaxial reaction.

[0033] It is worth mentioning that the top diameter, height, and bottom angle of the engaging portion 113 are not specifically limited and can be selected based on the effect that the tray 2 can slide along the engaging portion 113 so that the engaging portion 113 completely falls into the recessed hole 211. In this embodiment, the bottom angle of the engaging portion 113 is preferably 80°±2°.

[0034] Optionally, see Figure 3 As shown, the base 1 is further provided with a guide groove 12 at the bottom thereof for maintaining stable rotation of the base 1. The guide groove 12 is helically symmetrical about the fixed groove 13. The base 1 used in this embodiment is an air-suspended rotating base 1. After the base 1 is blown to the top, it rotates. During this process, the helically symmetrical guide groove 12 guides the gas flow, allowing the base 1 to maintain stable rotation.

[0035] Optionally, see Figures 2 to 3As shown, the center of the bottom of base 1 is recessed toward the top to form a securing groove 13 for securing the base 1. The design of securing groove 13 further ensures the stability of base 1 during rotation. The fixed shaft of the air suspension drive that drives base 1 is inserted into securing groove 13 at the bottom of base 1, ensuring that base 1 does not experience significant drift that could affect the stability of the epitaxial reaction and the concentration or thickness uniformity of the epitaxial layer. The interior of securing groove 13 is not coated with silicon carbide.

[0036] The present invention also discloses a wafer support and limiting assembly for epitaxial reaction, see Figure 2 、 Figure 4 As shown, the load-bearing and limiting components include: The tray 2 has a bottom center that is recessed inward to form a recessed hole 211 .

[0037] A base 1 for carrying a tray 2, wherein the middle portion of the base 1 protrudes upward to form a tray receiving portion 11, and the top of the tray receiving portion 11 is recessed toward the bottom of the tray receiving portion 11 to form an accommodating cavity 111 and a limiting portion 112 surrounding the accommodating cavity 111; The shape of the accommodating cavity 111 matches that of the tray 2 so that the tray 2 fits into the accommodating cavity 111 ; The center of the accommodating cavity 111 protrudes upward to form a clamping portion 113 , which corresponds to the position of the recessed hole 211 , so that when the tray 2 is engaged with the accommodating cavity 111 , the clamping portion 113 is inserted into the recessed hole 211 .

[0038] Optionally, see Figure 1 、 Figure 2 as well as Figure 4 As shown, the concave hole 211 and the clamping portion 113 are in mutually adapted truncated cone shapes. The concave hole 211 and the clamping portion 113 are consistent with the configuration and function of the susceptor 1 for epitaxial reaction described in the above embodiment, and will not be described in detail here.

[0039] Optionally, see Figures 3 to 5 as well as Figure 7 As shown, the tray 2 includes an abutment portion 21 and a carrying platform 22 for carrying wafers. The abutment portion 21 is shaped to fit within the accommodating cavity 111. In this embodiment, the upper and lower portions of the carrying platform 22 are respectively composed of a first sub-carrying platform 221 and a second sub-carrying platform 222 of different diameters. The first sub-carrying platform 221 is used to carry the wafers. The second sub-carrying platform 222 has a larger diameter than the first sub-carrying platform 221 and is disposed between the first sub-carrying platform 221 and the abutment portion 21, allowing the robot to better place and remove the tray 2. The abutment portion 21, the first sub-carrying platform 221, and the second sub-carrying platform 222 are integrally formed.

[0040] Optionally, the roughness of the abutment portion 21 and the accommodating cavity 111 is less than RA 3.2. Roughness, to a certain extent, affects whether the base 1 can smoothly drive the tray 2 for stable rotation and whether it will deviate. In this embodiment, the roughness of the contact surface between the abutment portion 21 and the accommodating cavity 111 is preferably less than RA 3.2. In addition to the contact surface, the surfaces of the tray 2 and the base 1 are also coated with silicon carbide to improve corrosion resistance.

[0041] Optionally, see Figures 2 to 3 As shown, the center of the bottom of the base 1 is recessed toward the top of the base 1 to form a fixing groove 13 for engaging and fixing the base 1 body. The configuration and function of the fixing groove 13 are consistent with those of the base 1 used for epitaxial reaction described in the above embodiment and will not be repeated here. The interior of the fixing groove 13 is not coated with silicon carbide coating.

[0042] Optionally, see Figure 3 As shown, the base 1 is provided with a guide groove 12 at the bottom for maintaining the stable rotation of the base 1. The guide groove 12 is spirally symmetrical with the fixed groove 13 as the axis. The guide groove 12 is consistent with the configuration and function of the base 1 for epitaxial reaction described in the above embodiment and will not be repeated here.

[0043] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

[0044] At the same time, the above disclosure is only a preferred embodiment of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention are still within the scope covered by the present invention.

Claims

1. A susceptor for epitaxial reaction, wherein the susceptor is used to receive a tray, and the center of the bottom of the tray is recessed inward to form a concave hole, characterized in that: The middle part of the body of the base protrudes upward to form a tray receiving part, and the top of the tray receiving part is recessed toward the bottom of the tray receiving part to form a accommodating cavity and a limiting part surrounding the accommodating cavity. The accommodating cavity is adapted to the shape of the tray so that the tray and the accommodating cavity are embedded; the center of the accommodating cavity protrudes upward to form a clamping part, and the clamping part corresponds to the position of the concave hole.

2. The susceptor for epitaxial reaction according to claim 1, characterized in that: The concave hole and the clamping portion are in mutually adapted truncated cone shapes.

3. The susceptor for epitaxial reaction according to claim 1, characterized in that: The center of the bottom of the base is recessed toward the top of the base to form a fixing groove for clamping and fixing the base body.

4. The susceptor for epitaxial reaction according to claim 3, characterized in that: The bottom of the base is provided with a guide groove for maintaining the stable rotation of the base, and the guide groove is spirally symmetrical with the fixing groove as the axis.

5. A wafer carrying and limiting assembly for epitaxial reaction, characterized in that: The load-bearing and limiting assembly includes: A tray, wherein the center of the bottom of the tray is recessed inward to form a concave hole; A base for carrying the tray, wherein the middle portion of the base body protrudes upward to form a tray receiving portion, and the top of the tray receiving portion is recessed toward the bottom of the tray receiving portion to form a receiving cavity and a limiting portion surrounding the receiving cavity; The accommodating cavity is adapted to the shape of the tray so that the tray fits into the accommodating cavity; The center of the accommodating cavity protrudes upward to form a clamping portion, and the position of the clamping portion corresponds to the position of the concave hole, so that when the tray is engaged with the accommodating cavity, the clamping portion is inserted into the concave hole.

6. The wafer supporting and limiting assembly for epitaxial reaction according to claim 5, characterized in that: The concave hole and the clamping portion are in mutually adapted truncated cone shapes.

7. The wafer supporting and limiting assembly for epitaxial reaction according to claim 5, characterized in that: The tray includes an abutting portion and a carrying platform for carrying wafers, and the abutting portion is adapted to the shape of the accommodating cavity so as to be embedded in the accommodating cavity.

8. The wafer supporting and limiting assembly for epitaxial reaction according to claim 7, characterized in that: The roughness of the abutting portion and the accommodating cavity is less than RA 3.

2.

9. The wafer supporting and limiting assembly for epitaxial reaction according to claim 5, characterized in that: The center of the bottom of the base is recessed toward the top of the base to form a fixing groove for clamping and fixing the base body.

10. The wafer supporting and limiting assembly for epitaxial reaction according to claim 9, characterized in that: The bottom of the base is provided with a guide groove for maintaining the stable rotation of the base, and the guide groove is spirally symmetrical with the fixing groove as the axis.

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