Circular ring and base suitable for thick epitaxial growth of silicon carbide
By using a beveled ring structure and splicing with a silicon carbide substrate in thick silicon carbide epitaxial growth, the problems of by-product accumulation and particle shedding were solved, thus improving the yield and product quality of silicon carbide epitaxy.
Patent Information
- Application Number
- CN202423075616.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-13
- Publication Date
- 2025-11-28
- Estimated Expiration
- 2034-12-13
AI Technical Summary
During the thick epitaxial growth of silicon carbide, the rapid accumulation of by-products leads to airflow disturbances and the shedding of by-product particles, affecting wafer quality and reducing yield.
The structure employs a beveled ring structure, which includes first and second annular protrusions on the ring body. The cross-section of the second protrusion gradually decreases. Combined with a silicon carbide substrate and a graphite support disk, it forms a beveled splice, reducing the accumulation of by-products and the shedding of particles.
This reduces the disturbance of airflow caused by by-product accumulation, reduces the fall of by-product particles on the wafer surface, and improves the yield and product value of silicon carbide epitaxy.
Smart Images
Figure CN223607435U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to a kind of circular ring and pedestal suitable for silicon carbide thick epitaxial growth, belong to semiconductor technical field. BACKGROUND
[0002] As the third generation semiconductor material, silicon carbide (SiC) has unique physical and electrical properties compared with silicon, with high breakdown field strength, high electron saturation drift rate, high electron mobility, high thermal conductivity, high melting point, strong radiation resistance and good chemical stability, etc., thus having very broad application prospects in the production of electronic devices working under extreme conditions such as high temperature, high pressure, high speed, high frequency and strong radiation.
[0003] In silicon carbide epitaxial production, the circular ring used for growing thin epitaxy and the circular ring used for growing thick epitaxy are universal. However, thick epitaxy has long growth time and high growth rate, which leads to rapid accumulation of by-products on the circular ring, especially in the outermost circle of the circular ring, forming an exceptionally high by-product accumulation layer. The high growth rate also causes the generated by-products to be very loose, which affects gas transportation and causes by-product particles to fall on the silicon carbide wafer during the long growth process, affecting subsequent yield. SUMMARY
[0004] To solve the above technical problems, the utility model provides a kind of circular ring and pedestal suitable for silicon carbide thick epitaxial growth, the circular ring uses bevel circular ring structure, can reduce the disturbance of by-product accumulation too high to airflow during growth and reduce the probability of by-product particles falling on the wafer surface.
[0005] To achieve the above purpose, the utility model adopts the following technical solutions:
[0006] A circular ring suitable for silicon carbide thick epitaxial growth, comprising:
[0007] The lower end surface of the circular ring body is provided with a first annular protrusion extending downward, and the cross-sectional width of the first annular protrusion is less than the cross-sectional width of the circular ring body;
[0008] The upper end surface of the circular ring body is provided with a second annular protrusion extending upward; the cross-sectional width of the second annular protrusion is less than the cross-sectional width of the circular ring body but greater than the cross-sectional width of the first annular protrusion, the cross-section of the second annular protrusion is triangular, and the cross-sectional height of the second annular protrusion gradually decreases from one end close to the inner wall surface of the circular ring body to the other end of the outer wall surface of the circular ring body.
[0009] A circular ring suitable for silicon carbide thick epitaxial growth, comprising:
[0010] The lower end surface of the circular ring body is provided with a first annular protrusion extending downward, and the cross-sectional width of the first annular protrusion is smaller than the cross-sectional width of the circular ring body;
[0011] The upper end surface of the circular ring body is provided with a second annular protrusion extending upward, the cross-sectional width of the second annular protrusion is smaller than the cross-sectional width of the circular ring body but larger than the cross-sectional width of the first annular protrusion, the cross section of the second annular protrusion is a sector, and the cross-sectional height of the second annular protrusion gradually decreases from one end close to the inner wall surface of the circular ring body to the other end close to the outer wall surface of the circular ring body.
[0012] The circular ring suitable for thick epitaxial growth of silicon carbide, preferably, the lower end surface of the first annular protrusion is a plane.
[0013] The circular ring suitable for thick epitaxial growth of silicon carbide, preferably, the circular ring is a silicon carbide circular ring.
[0014] The circular ring suitable for thick epitaxial growth of silicon carbide, preferably, the circular ring is a graphite circular ring.
[0015] A susceptor suitable for thick epitaxial growth of silicon carbide, comprising the circular ring according to any one of the above, further comprising:
[0016] The susceptor suitable for thick epitaxial growth of silicon carbide, preferably, the thickness of the annular boss is the same as the thickness of the circular ring body.
[0017] The susceptor suitable for thick epitaxial growth of silicon carbide, preferably, the thickness of the annular boss is the same as the thickness of the circular ring body.
[0018] The susceptor suitable for thick epitaxial growth of silicon carbide, preferably, the thickness of the annular boss is the same as the thickness of the circular ring body.
[0019] The susceptor suitable for thick epitaxial growth of silicon carbide, preferably, the carrier disc is a graphite carrier disc.
[0020] The susceptor suitable for thick epitaxial growth of silicon carbide, preferably, the carrier disc is provided with a silicon carbide coating.
[0021] The utility model discloses a circular ring suitable for thick epitaxial growth of silicon carbide, which has the following advantages:
[0022] 1. The annular ring and the silicon carbide substrate are radially spliced, the thickness of the silicon carbide substrate at the splicing position is lower than the thickness of the annular ring, the annular ring is a bevel edge type annular ring structure with a slope transition from one side of the silicon carbide substrate to the other side, which can reduce the disturbance of the accumulated by-products to the airflow during growth and reduce the probability of by-product particles falling on the wafer surface.
[0023] 2. The bevel edge type annular ring structure is used when growing thick epitaxy, which can reduce the disturbance of the accumulated by-products to the airflow during growth and reduce the probability of by-product particles falling on the wafer surface, thereby improving the yield of silicon carbide epitaxy and creating higher value of products. BRIEF DESCRIPTION OF DRAWINGS
[0024] Figure 1 The present utility model provides a cross section schematic view of the existing annular ring for silicon carbide thick epitaxial growth;
[0025] Figure 2 The present utility model provides a cross section schematic view of the existing annular ring for silicon carbide thick epitaxial growth;
[0026] Figure 3 The present utility model provides a cross section schematic view of the existing annular ring for silicon carbide thick epitaxial growth; Figure 2
[0027] Figure 4 The present utility model provides a cross section schematic view of the existing annular ring for silicon carbide thick epitaxial growth;
[0028] Figure 5 The present utility model provides a cross section schematic view of the existing annular ring for silicon carbide thick epitaxial growth; Figure 4
[0029] Figure 6 The present utility model provides a cross section schematic view of the existing annular ring for silicon carbide thick epitaxial growth;
[0030] The reference signs in the drawings are as follows:
[0031] 1-annular ring body, 101-first annular protrusion, 102-second annular protrusion; 2-bearing disc, 201-annular boss; 3-silicon carbide substrate. DETAILED DESCRIPTION
[0032] In order to make the purpose, technical scheme and advantages of the present utility model more clear, the technical scheme in the present utility model is described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present utility model, not all the embodiments. Based on the embodiments in the present utility model, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the present utility model.
[0033] Unless otherwise defined, technical terms or scientific terms used in the present application shall have the ordinary meaning as understood by a person of ordinary skill in the art to which the present application pertains. The terms "first", "second", "third", "fourth" and similar terms used in the present application do not denote any order, quantity, or importance, but are used to distinguish different components. The terms "comprising" or "including" or similar terms mean that the elements or objects before the term encompass the elements or objects listed after the term and their equivalents, and do not exclude other elements or objects. The terms "connected" or "connected" or similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect.
[0034] For ease of description, spatial relative terms can be used in the description to describe the relationship of one element or feature to another element or feature as shown in the drawings, such as "inner", "outer", "inside", "outside", "below", "above", etc. Such spatial relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the drawings.
[0035] Silicon carbide has stable chemical properties, high thermal conductivity, small thermal expansion coefficient, good wear resistance, in addition to abrasive, it also has many other uses, for example: special process to coat silicon carbide powder on the inner wall of the water turbine impeller or cylinder body, can improve its wear resistance and prolong its service life by 1-2 times, the high-grade refractory material made of it has good heat shock resistance, small volume, light weight and high strength, good energy saving effect. Low-grade silicon carbide (containing about 85% SiC) is an excellent deoxidizer, which can speed up the steelmaking process, facilitate the control of chemical composition, and improve the quality of steel. In addition, silicon carbide is also widely used to make silicon carbide rods for electric heating elements.
[0036] There are at least 70 crystalline forms of silicon carbide. Alpha-silicon carbide is the most common polymorph, which forms at temperatures above 2000°C and has a hexagonal crystal structure (similar to wurtzite). Beta-silicon carbide, which has a cubic structure similar to diamond, forms at temperatures below 2000°C. Although the use of heterogeneous catalyst supports is promising due to its higher unit surface area than alpha polymorph, another silicon carbide, mu-silicon carbide, is the most stable and has a more pleasant sound when collided, but to date, these two forms have not been commercially used. Pure silicon carbide is colorless and transparent crystal. Industrial silicon carbide is light yellow, green, blue and even black due to the type and content of impurities, and the transparency varies with the purity. Silicon carbide crystal structure is divided into hexagonal or rhombohedral alpha-SiC and cubic beta-SiC (called cubic silicon carbide). Alpha-SiC forms many different variants due to the different stacking sequences of carbon and silicon atoms in its crystal structure, and more than 70 variants have been found. Beta-SiC is converted to alpha-SiC at temperatures above 2100°C. The industrial method of silicon carbide is to use high-quality quartz sand and petroleum coke in an electric resistance furnace. The silicon carbide block obtained by smelting is crushed, washed with acid and alkali, magnetically separated and sieved or water selected to produce products of various particle sizes.
[0037] Silicon carbide semiconductor has large band gap, excellent stability, high thermal conductivity, high critical breakdown field strength, high saturated electron drift velocity and other excellent characteristics, and is an ideal semiconductor material for making high-temperature, high-frequency, high-power and strong radiation power electronic devices. Compared with traditional silicon devices, silicon carbide devices can work normally at 10 times the electric field strength of silicon devices. The silicon carbide material used to make silicon carbide devices is usually a silicon carbide epitaxial wafer grown on a silicon carbide substrate. At present, silicon carbide epitaxial growth has been commercialized, and the method of CVD (chemical vapor deposition) is usually used to grow silicon carbide epitaxial wafers.
[0038] At present, in the production of silicon carbide epitaxy, the circular ring used for growing thin epitaxy and the circular ring used for growing thick epitaxy are universal. However, due to the long growth time and high growth rate of thick epitaxy, the accumulation of by-products on the circular ring is too fast, especially the outermost circle of the circular ring will form an extra high by-product accumulation layer. The high growth rate also causes the generated by-products to be very loose, which will affect the transportation of gas and the falling of by-product particles on the silicon carbide wafer during the long growth process, thereby affecting the subsequent yield.
[0039] Based on the above technical problems, the utility model provides a circular ring and a base suitable for silicon carbide thick epitaxial growth, which uses a bevel type circular ring structure when growing thick epitaxy, which can reduce the disturbance of the accumulation of by-products on the circular ring during growth and reduce the probability of by-product particles falling on the wafer surface. Further improve the yield of silicon carbide epitaxy and create higher value of products.
[0040] As Figure 1The existing annular ring for thick epitaxial growth of silicon carbide is a planar ring structure, which is easy to cause the accumulation of by-products on the annular ring, especially the outermost circle of the annular ring, and form an extra-high by-product accumulation layer. To solve this problem, the application provides the following solutions.
[0041] As shown in Figure 2 , 3 The utility model relates to a kind of annular ring suitable for thick epitaxial growth of silicon carbide, comprising:
[0042] The lower end surface of the annular body 1 is provided with a first annular protrusion 101 extending downward, and the cross-sectional width of the first annular protrusion 101 is smaller than the cross-sectional width of the annular body 1. The upper end surface of the annular body 1 is provided with a second annular protrusion 102 extending upward. The cross-sectional width of the second annular protrusion 102 is smaller than the cross-sectional width of the annular body 1 but larger than the cross-sectional width of the first annular protrusion 101. The cross-section of the second annular protrusion 102 is triangular, and the cross-sectional height of the second annular protrusion 102 gradually decreases from one end close to the inner wall surface of the annular body 1 to the other end of the outer wall surface of the annular body 1.
[0043] As shown in Figure 4 , 5 The utility model further provides another annular ring suitable for thick epitaxial growth of silicon carbide, comprising:
[0044] The lower end surface of the annular body 1 is provided with a first annular protrusion 101 extending downward, and the cross-sectional width of the first annular protrusion 101 is smaller than the cross-sectional width of the annular body 1. The upper end surface of the annular body 1 is provided with a second annular protrusion 102 extending upward. The cross-sectional width of the second annular protrusion 102 is smaller than the cross-sectional width of the annular body 1 but larger than the cross-sectional width of the first annular protrusion 101. The cross-section of the second annular protrusion 102 is triangular, and the cross-sectional height of the second annular protrusion 102 gradually decreases from one end close to the inner wall surface of the annular body 1 to the other end of the outer wall surface of the annular body 1.
[0045] Further, as shown in Figure 3 , 5 The lower end surface of the first annular protrusion 101 is a plane.
[0046] Further, the annular ring suitable for thick epitaxial growth of silicon carbide provided by the utility model is a silicon carbide annular ring or a graphite annular ring.
[0047] As shown in Figure 6 The utility model further provides a susceptor suitable for thick epitaxial growth of silicon carbide, and the annular ring mentioned above further comprises:
[0048] The carrier disc 2 is provided with an annular boss 201, the diameter of the annular boss 201 is smaller than the diameter of the carrier disc 2, a circular ring is sleeved on the outer edge of the annular boss 201, and the silicon carbide substrate 3 is placed on the annular boss 201.
[0049] In one specific example of the utility model, the thickness of the annular boss 201 is the same as the thickness of the circular ring body 1.
[0050] Further, the carrier disc 2 is a graphite carrier disc, and the carrier disc 2 is provided with a silicon carbide coating.
[0051] The circular ring and the silicon carbide substrate are radially spliced, the thickness of the silicon carbide substrate at the splicing position is lower than the thickness of the circular ring, the circular ring is a bevel edge type circular ring structure that is inclined from the side where the silicon carbide substrate is located to the other side, which can reduce the disturbance of the gas flow caused by the accumulation of by-products and reduce the probability of by-product particles falling on the wafer surface during growth.
[0052] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the utility model, and not to limit them; although the utility model has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the utility model.
Claims
1. A torus suitable for thick epitaxial growth of silicon carbide, characterized in that, Comprising: a circular ring body (1), a lower end surface of the circular ring body (1) is provided with a first annular protrusion (101) extending downward, a cross-sectional width of the first annular protrusion (101) is less than a cross-sectional width of the circular ring body (1); an upper end surface of the circular ring body (1) is provided with a second annular protrusion (102) extending upward; a cross-sectional width of the second annular protrusion (102) is less than the cross-sectional width of the circular ring body (1) but greater than the cross-sectional width of the first annular protrusion (101), a cross section of the second annular protrusion (102) is triangular, and a cross-sectional height of the second annular protrusion (102) gradually decreases from one end close to an inner wall surface of the circular ring body (1) to one end of an outer wall surface of the circular ring body (1).
2. The annulus suitable for thick epitaxial growth of silicon carbide according to claim 1, characterized in that, A lower end surface of the first annular protrusion (101) is a plane.
3. The annulus suitable for thick epitaxial growth of silicon carbide according to claim 1, wherein The circular ring is a silicon carbide circular ring.
4. The annulus suitable for thick epitaxial growth of silicon carbide according to claim 1, wherein The circular ring is a graphite circular ring.
5. A circular ring suitable for thick epitaxial growth of silicon carbide, characterized in that, Comprising: a circular ring body (1), a lower end surface of the circular ring body (1) is provided with a first annular protrusion (101) extending downward, a cross-sectional width of the first annular protrusion (101) is less than a cross-sectional width of the circular ring body (1); an upper end surface of the circular ring body (1) is provided with a second annular protrusion (102) extending upward; a cross-sectional width of the second annular protrusion (102) is less than the cross-sectional width of the circular ring body (1) but greater than the cross-sectional width of the first annular protrusion (101), and a cross section of the second annular protrusion (102) is a sector, and a cross-sectional height of the second annular protrusion (102) gradually decreases from one end close to an inner wall surface of the circular ring body (1) to one end of an outer wall surface of the circular ring body (1).
6. A susceptor suitable for thick epitaxial growth of silicon carbide comprising the torus of any one of claims 1 to 5, characterized in that Further comprising: a carrier disc (2) and a silicon carbide substrate (3), the carrier disc (2) is provided with an annular boss (201), a diameter of the annular boss (201) is less than a diameter of the carrier disc (2), the circular ring is sleeved on an outer edge of the annular boss (201), and the silicon carbide substrate (3) is placed on the annular boss (201).
7. A susceptor suitable for thick epitaxial growth of silicon carbide according to claim 6, wherein A thickness of the annular boss (201) is the same as a thickness of the circular ring body (1).
8. A susceptor suitable for thick epitaxial growth of silicon carbide as defined in claim 6, wherein A thickness of the silicon carbide substrate (3) is less than a thickness of the second annular protrusion (102) close to the inner wall surface of the circular ring body (1).
9. A susceptor suitable for thick epitaxial growth of silicon carbide as defined in claim 6, wherein The carrier disc (2) is a graphite carrier disc.
10. A susceptor suitable for thick epitaxial growth of silicon carbide as defined in claim 9, wherein The carrier disc (2) is provided with a silicon carbide coating.