Graphite ring for silicon carbide epitaxial growth

Abstract

The utility model provides a kind of graphite ring for silicon carbide epitaxial growth, comprising: outer ring and the inner ring of laminated connection below outer ring;The outer ring is concentrically arranged with inner ring;The outer ring is provided with positioning straight edge at the same position with inner ring;At the positioning straight edge, the top surface of inner ring and the top surface of outer ring are set as arc curved surface.The utility model is positioned by chamfering treatment to graphite ring positioning edge, and 3C-SiC convex growth is not easy to form in the edge area of main positioning edge in chamfer structure, to improve card phenomenon;And in the process of rotation, chamfer structure can avoid graphite ring directly with wafer rigid contact, but through certain radian, reduce the relative friction of wafer rotation and graphite ring, reduce the probability of wafer positioning edge damage.

Description

Technical Field

[0001] This utility model belongs to the technical field of graphite rings for semiconductor epitaxial growth, and relates to a graphite ring for silicon carbide epitaxial growth, and more particularly to a novel graphite ring structure for silicon carbide epitaxial growth. Background Technology

[0002] Epitaxial growth refers to the growth of a single-crystal layer with specific requirements and the same crystal orientation as the substrate on a single-crystal substrate, as if the original crystal has been extended outward. Epitaxial growth technology has been developing for several decades. The newly grown single-crystal layer can differ from the substrate in terms of conductivity, resistivity, etc., and multilayer single crystals of different thicknesses and requirements can also be grown, thereby greatly improving the flexibility of device design and device performance. It is widely used in semiconductor single-crystal growth, PN junction isolation technology in integrated circuits, and improving material quality in large-scale integrated circuits.

[0003] During epitaxial growth, the graphite ring supporting the substrate is one of the important components that contacts the substrate. Due to airflow, 3C-SiC is more likely to grow at the junction of the arc region and the straight edge region of the graphite ring, which leads to the card phenomenon after growth. Moreover, during the growth process, contact between the wafer and by-products can cause wafer cracking or edge breakage during wafer removal, thus causing the epitaxial wafer to be scrapped.

[0004] Therefore, how to develop a novel graphite ring structure to solve the aforementioned problems of existing graphite rings has become a major concern for many R&D companies and front-line researchers in the industry. Utility Model Content

[0005] In view of this, the technical problem to be solved by this utility model is to provide a graphite ring for silicon carbide epitaxial growth. The novel graphite ring structure designed in this utility model has a chamfered edge structure at the corner position of the graphite ring, which can effectively avoid the carding phenomenon caused by the growth of 3C-SiC on the inner side of the main positioning edge ring, thus reducing the risk of wafer cracking and edge chipping.

[0006] This utility model provides a graphite ring for silicon carbide epitaxial growth, comprising: an outer ring and an inner ring stacked and connected below the outer ring;

[0007] The outer ring and the inner ring are concentrically arranged;

[0008] The outer ring and the inner ring are provided with positioning straight edges at the same position;

[0009] At the positioning straight edge, the top surface of the inner ring and the top surface of the outer ring are set as an arc-shaped curved surface.

[0010] Preferably, the inner diameter of the inner ring is 145–149 mm;

[0011] The outer diameter of the inner ring is 164–166 mm;

[0012] The positioning plane of the positioning straight edge of the inner ring is located in the inner circle of the inner ring, and the two ends of the positioning plane are directly connected to the two ends of the inner ring annular surface.

[0013] Preferably, the height of the inner ring is 1.0 to 1.5 mm;

[0014] The annular top surface of the inner ring, which protrudes from the inner diameter of the outer ring, is used to place the wafer.

[0015] Preferably, the inner diameter of the outer ring is 149–151 mm;

[0016] The outer diameter of the outer ring is 160–170 mm;

[0017] The positioning plane of the positioning straight edge of the outer ring is located in the inner ring of the outer ring, and the two ends of the positioning plane are directly connected to the two ends of the inner ring annular surface.

[0018] Preferably, the height of the outer ring is 1.8–2.5 mm;

[0019] The inner diameter of the inner ring is smaller than the inner diameter of the outer ring.

[0020] Preferably, the length of the positioning straight edge is 44-46 mm;

[0021] The height of the positioning straight edge of the inner ring is the height of the inner ring;

[0022] The height of the positioning straight edge of the outer ring is the height of the outer ring.

[0023] Preferably, the arcuate surface includes a circular arcuate surface or an elliptical arcuate surface;

[0024] The arc shape is a concave arc;

[0025] The arcuate radius of the curved surface is greater than 0 and less than π.

[0026] Preferably, the length of the arc-shaped surface is the same as the length of the positioning straight edge;

[0027] The height of the arc-shaped surface is the same as the height of the outer ring;

[0028] The stacked connection specifically refers to the bottom surface of the outer ring being stacked and contacted with the top surface of the inner ring.

[0029] Preferably, the top surface of the outer ring is parallel to the top surface of the inner ring;

[0030] At the non-positioning straight edge of the graphite ring, an annular inclined surface is provided in the height direction of the outer ring.

[0031] Preferably, the vertical height of the annular inclined plane is less than the height of the outer ring;

[0032] The top edge of the annular inclined plane is located on the top surface of the outer ring.

[0033] This invention provides a graphite ring for silicon carbide epitaxial growth, comprising: an outer ring and an inner ring stacked and connected below the outer ring; the outer ring and the inner ring are concentrically arranged; the outer ring and the inner ring are provided with a positioning straight edge at the same position; at the positioning straight edge, the top surface of the inner ring and the top surface of the outer ring are set as an arc-shaped curved surface. Compared with the prior art, this invention specifically designs a graphite ring with a specific structure for silicon carbide epitaxial growth to address problems such as carding and chipping in existing silicon carbide epitaxial growth processes.

[0034] The novel graphite ring structure provided by this invention, compared with the previous graphite ring, features a chamfered edge structure (arc surface structure) at the corner between the positioning edge and the arc of the graphite ring. This can effectively avoid the carding phenomenon caused by the growth of 3C-SiC on the inner side of the main positioning edge ring, thus reducing the risk of chipping and edge breakage.

[0035] This invention improves the carding phenomenon by chamfering (arc-surface) the positioning edge of the graphite ring. The chamfered structure reduces the likelihood of 3C-SiC protrusion growth in the edge region of the main positioning edge. Furthermore, during rotation, the chamfered structure prevents the graphite ring from directly and rigidly contacting the wafer; instead, the curvature reduces relative friction between the wafer and the graphite ring during rotation, lowering the probability of damage to the wafer's positioning edge. This invention adds a chamfered structure to the main positioning edge of the graphite ring for the transition between the arc-shaped and straight-edge regions, changing the direct connection between the arc-shaped and straight-edge regions of existing graphite rings. Attached Figure Description

[0036] Figure 1 A simplified top view of the original graphite ring provided by this utility model;

[0037] Figure 2 A simplified side view of the main positioning edge of the graphite ring before the improvement provided by this utility model;

[0038] Figure 3 This is a simplified top view of the improved graphite ring of this utility model.

[0039] Figure 4 This is a simplified side view of the main positioning edge of the improved graphite ring of this utility model.

[0040] Figure 5 This is a statistical chart showing the production data before and after the improvement of the graphite ring of this utility model. Detailed Implementation

[0041] To further understand this utility model, the technical solution of this utility model will be clearly and completely described below with reference to its embodiments. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0042] This utility model provides a graphite ring for silicon carbide epitaxial growth, comprising: an outer ring and an inner ring stacked and connected below the outer ring;

[0043] The outer ring and the inner ring are concentrically arranged;

[0044] The outer ring and the inner ring are provided with positioning straight edges at the same position;

[0045] At the positioning straight edge, the top surface of the inner ring and the top surface of the outer ring are set as an arc-shaped curved surface.

[0046] In this invention, the outer ring is preferably a circular ring. The inner ring is preferably a circular ring.

[0047] In this invention, the inner diameter of the inner ring is preferably 145-149 mm, more preferably 145.5-148.5 mm, even more preferably 146-148 mm, and even more preferably 146.5-147.5 mm.

[0048] In this invention, the outer diameter of the inner ring is preferably 164-166 mm, more preferably 164.4-165.6 mm, and even more preferably 164.8-165.2 mm.

[0049] In this invention, the positioning plane of the positioning straight edge of the inner ring is located in the inner circle of the inner ring, and the two ends of the positioning plane are preferably directly connected to the two ends of the inner ring annular surface.

[0050] In this invention, the height of the inner ring is preferably 1.0 to 1.5 mm, more preferably 1.1 to 1.4 mm, and even more preferably 1.2 to 1.3 mm.

[0051] In this invention, the annular top surface of the inner ring protruding from the inner diameter of the outer ring is preferably used for placing a wafer.

[0052] In this invention, the inner diameter of the outer ring is preferably 149-151 mm, more preferably 149.4-150.6 mm, and even more preferably 149.8-150.2 mm.

[0053] In this invention, the outer diameter of the outer ring is preferably 160-170 mm, more preferably 162-168 mm, and even more preferably 164-166 mm.

[0054] In this invention, the positioning plane of the positioning straight edge of the outer ring is located in the inner ring of the outer ring, and the two ends of the positioning plane are preferably directly connected to the two ends of the inner ring annular surface.

[0055] In this invention, the height of the outer ring is preferably 1.8-2.5 mm, more preferably 1.9-2.4 mm, more preferably 2.0-2.3 mm, and even more preferably 2.1-2.2 mm.

[0056] In this invention, the inner diameter of the inner ring is preferably smaller than the inner diameter of the outer ring.

[0057] In this invention, the length of the positioning straight edge is preferably 44-46 mm, more preferably 44.4-45.6 mm, and even more preferably 44.8-45.2 mm.

[0058] In this invention, the height of the positioning straight edge of the inner ring is preferably the height of the inner ring itself.

[0059] In this invention, the height of the positioning straight edge of the outer ring is preferably the height of the outer ring itself.

[0060] In this invention, the arc-shaped surface preferably includes a circular arc-shaped surface or an elliptical arc-shaped surface.

[0061] In this invention, the arc shape is preferably a concave arc.

[0062] In this invention, the curvature of the arc surface is preferably greater than 0 and less than π, and can be π / 10 to 9π / 10, or π / 5 to 4π / 5, or 2π / 5 to 3π / 5, or π / 2.

[0063] In this invention, the length of the arc-shaped surface is preferably the same as the length of the positioning straight edge.

[0064] In this invention, the height of the arc-shaped surface is preferably the same as the height of the outer ring.

[0065] In this invention, the stacked connection is preferably wherein the bottom surface of the outer ring is stacked and contacted with the top surface of the inner ring.

[0066] In this invention, the top surface of the outer ring is preferably parallel to the top surface of the inner ring.

[0067] In this invention, the non-positioning straight edge of the graphite ring preferably has an annular inclined surface in the height direction of the outer ring.

[0068] In this invention, the vertical height of the annular inclined surface is preferably less than the height of the outer ring.

[0069] In this invention, the top edge of the annular inclined surface is preferably located on the top surface of the outer ring.

[0070] This utility model provides a complete and refined overall technical solution to better ensure the structure of the graphite ring. The above-mentioned novel silicon carbide epitaxially grown graphite ring structure may specifically include the following:

[0071] See Figure 1 , Figure 1 A simplified top view of the original graphite ring provided by this utility model.

[0072] Figure 1 The image shown is a top view of the graphite ring before the improvement, with the red area indicating the main positioning edge. The arc area and the straight line area are directly joined, which can easily lead to carding issues during production.

[0073] Figure 2 A simplified side view of the main positioning edge of the graphite ring before the improvement provided by this utility model.

[0074] Figure 2 The image shown is a side view of the graphite ring before the improvement. The wafer and the graphite ring are in direct contact at right angles, which increases the area of ​​force application and the risk of damage to the chamfer during wafer growth.

[0075] See Figure 3 , Figure 3 This is a simplified top view of the improved graphite ring of this utility model.

[0076] like Figure 3 As shown, this utility model features a chamfered structure on the main positioning edge.

[0077] See Figure 4 , Figure 4 This is a simplified side view of the main positioning edge of the improved graphite ring of this utility model.

[0078] like Figure 4 As shown, the graphite ring structure with added chamfers reduces the contact area when the wafer comes into contact with it, thus reducing the risk of damage.

[0079] The present invention provides a novel silicon carbide epitaxial growth graphite ring structure. Compared with the previous graphite ring, the present invention has a chamfered edge structure at the corner between the positioning edge and the arc of the graphite ring, which can effectively avoid the carding phenomenon caused by the growth of 3C-SiC on the inner side of the main positioning edge ring, thus reducing the risk of cracking and edge breakage.

[0080] This invention improves the carding phenomenon by chamfering the positioning edge of the graphite ring. The chamfered structure reduces the likelihood of 3C-SiC protrusion growth at the edge of the main positioning edge. Furthermore, during rotation, the chamfered structure prevents the graphite ring from directly and rigidly contacting the wafer; instead, the curvature reduces relative friction between the wafer and the graphite ring during rotation, lowering the probability of damage to the wafer's positioning edge. This invention adds a chamfered structure to the main positioning edge of the graphite ring for the transition between the arc and straight edge regions, changing the direct connection between the arc and straight edge regions of existing graphite rings.

[0081] To further illustrate this utility model, the following describes in detail a graphite ring for silicon carbide epitaxial growth provided by this utility model with reference to embodiments. However, it should be understood that these embodiments are implemented under the premise of the technical solution of this utility model, and detailed implementation methods and specific operation processes are given. They are only for further illustrating the features and advantages of this utility model, and are not intended to limit the scope of protection of the claims of this utility model. The scope of protection of this utility model is not limited to the following embodiments.

[0082] Example 1

[0083] like Figure 3 and 4 As shown, silicon carbide epitaxial growth is performed using an improved graphite ring.

[0084] The process parameters for silicon carbide epitaxial growth are the same as before the improvement. Figure 1 and 2 The production data of the graphite rings shown are compared.

[0085] The graphite ring provided by this invention greatly reduces the chipping damage rate, decreasing the proportion of chipping damage from 1.12% to 0.29%.

[0086] See Figure 5 , Figure 5 This is a statistical chart showing the production data before and after the improvement of the graphite ring of this utility model.

[0087] The above provides a detailed description of a novel silicon carbide epitaxial graphite ring structure provided by this utility model. Specific examples have been used to illustrate the principles and implementation methods of this utility model. The descriptions of the embodiments are merely for the purpose of helping to understand the method and core ideas of this utility model, including the best mode, and also to enable any person skilled in the art to practice this utility model, including manufacturing and using any device or system, and implementing any combined method. It should be noted that for those skilled in the art, several improvements and modifications can be made to this utility model without departing from the principles of this utility model, and these improvements and modifications also fall within the protection scope of the claims of this utility model. The scope of patent protection of this utility model is defined by the claims and may include other embodiments that can be conceived by those skilled in the art. If these other embodiments have structural elements similar to the wording of the claims, or if they include equivalent structural elements that are not substantially different from the wording of the claims, then these other embodiments should also be included within the scope of the claims.

Claims

1. A graphite ring for silicon carbide epitaxial growth, characterized in that, include: The outer ring and the inner ring stacked below the outer ring; The outer ring and the inner ring are concentrically arranged; The outer ring and the inner ring are provided with positioning straight edges at the same position; At the positioning straight edge, the top surface of the inner ring and the top surface of the outer ring are set as an arc-shaped curved surface.

2. The graphite ring according to claim 1, characterized in that, The inner diameter of the inner ring is 145–149 mm; The outer diameter of the inner ring is 164–166 mm; The positioning plane of the positioning straight edge of the inner ring is located in the inner circle of the inner ring, and the two ends of the positioning plane are directly connected to the two ends of the inner ring annular surface.

3. The graphite ring according to claim 1, characterized in that, The height of the inner ring is 1.0–1.5 mm; The annular top surface of the inner ring, which protrudes from the inner diameter of the outer ring, is used to place the wafer.

4. The graphite ring according to claim 1, characterized in that, The inner diameter of the outer ring is 149–151 mm; The outer diameter of the outer ring is 160–170 mm; The positioning plane of the positioning straight edge of the outer ring is located in the inner ring of the outer ring, and the two ends of the positioning plane are directly connected to the two ends of the inner ring annular surface.

5. The graphite ring according to claim 1, characterized in that, The height of the outer ring is 1.8–2.5 mm; The inner diameter of the inner ring is smaller than the inner diameter of the outer ring.

6. The graphite ring according to claim 1, characterized in that, The length of the positioning straight edge is 44–46 mm; The height of the positioning straight edge of the inner ring is the height of the inner ring; The height of the positioning straight edge of the outer ring is the height of the outer ring.

7. The graphite ring according to claim 1, characterized in that, The arc-shaped surface includes a circular arc-shaped surface or an elliptical arc-shaped surface; The arc shape is a concave arc; The arc of the curved surface is greater than 0 and less than π.

8. The graphite ring according to claim 1, characterized in that, The length of the arc-shaped surface is the same as the length of the positioning straight edge; The height of the arc-shaped surface is the same as the height of the outer ring; The stacked connection specifically refers to the bottom surface of the outer ring being stacked and contacted with the top surface of the inner ring.

9. The graphite ring according to claim 1, characterized in that, The top surface of the outer ring is parallel to the top surface of the inner ring; At the non-positioning straight edge of the graphite ring, an annular inclined surface is provided in the height direction of the outer ring.

10. The graphite ring according to claim 9, characterized in that, The vertical height of the annular inclined plane is less than the height of the outer ring; The top edge of the annular inclined plane is located on the top surface of the outer ring.

Images