Silicon carbide substrate with optimized surface layer and forming method thereof

Abstract

The invention discloses a silicon carbide substrate with optimized surface layers and a forming method thereof, the silicon carbide substrate comprises a substrate body and at least one optimized surface layer, the substrate body is provided with at least one flaw surface, each optimized surface layer is integrally formed on each flaw surface of the substrate body, and the optimized surface layers are arranged on the flaw surfaces of the substrate body. Each optimized surface layer is made of silicon carbide, and is formed by forming at least one unpolished silicon carbide layer on each flaw surface of the substrate body through a physical vapor deposition technology or a chemical vapor deposition technology, and then performing secondary polishing operation on each unpolished silicon carbide layer to form each optimized surface layer; therefore, the silicon carbide substrate with the optimized surface layer is formed, the problem of manufacturing end profit loss caused by the existing silicon carbide substrate with flaws on the surface is effectively solved, and the profit of the manufacturing end is favorably improved.

Description

Technical Field

[0001] The invention relates to a silicon carbide substrate and a molding method thereof, and in particular to a silicon carbide substrate with an optimized surface layer and a molding method thereof. Background Art

[0002] In the existing semiconductor wafer manufacturing process, the silicon carbide substrate is generally formed by dividing the silicon carbide ingot through a segmentation operation and then grinding the silicon carbide substrate. After that, the silicon carbide substrate is then subjected to subsequent epitaxial processes and device manufacturing.

[0003] However, before the silicon carbide substrate is provided for subsequent epitaxial process and device manufacturing, it will first be inspected to screen out silicon carbide substrates with surface defects. Silicon carbide substrates with surface defects will become lower-priced secondary products. When silicon carbide substrates are sold at the price of secondary products, the profit loss caused to the manufacturing end can be as high as about 70% of the original silicon carbide substrate price, which is quite unfavorable to the profit of the manufacturing end.

[0004] Therefore, a silicon carbide substrate with an optimized surface layer and a molding method thereof that can solve the problem of profit loss at the manufacturing end caused by silicon carbide substrates with surface defects are urgently expected by the relevant industries. Summary of the invention

[0005] The main purpose of the present invention is to provide a silicon carbide substrate with an optimized surface layer and a forming method thereof, wherein the silicon carbide substrate comprises a substrate body and at least one optimized surface layer, the substrate body having at least one defective surface, each of the optimized surface layers being integrally formed on each of the defective surfaces of the substrate body, each of the optimized surface layers being composed of silicon carbide, each of the optimized surface layers being formed by first forming at least one unpolished silicon carbide layer on each of the defective surfaces of the substrate body by physical vapor deposition technology or chemical vapor deposition technology, and then each of the unpolished silicon carbide layers being subjected to a second polishing operation to form each of the optimized surface layers, thereby forming a silicon carbide substrate with an optimized surface layer, effectively solving the problem of profit loss at the manufacturing end caused by the existing silicon carbide substrates having defects on the surface.

[0006] To achieve the above-mentioned object, the present invention provides a silicon carbide substrate with an optimized surface layer, the silicon carbide substrate comprising a substrate body (Substrate) and at least one optimized surface layer; wherein the substrate body is composed of silicon carbide (SiC), the substrate body has at least one defective surface, wherein the substrate body is formed by a silicon carbide ingot (Ingot) being divided by a dividing operation and then respectively subjected to a first grinding operation, and after the first grinding operation, each of the defective surfaces of the substrate body is further determined to have defects by a detection operation; wherein each of the optimized surface layers is composed of silicon carbide, each of the optimized surface layers is integrally formed on each of the defective surfaces of the substrate body, wherein each of the optimized surface layers is formed by physical vapor deposition (PCD, Physical vapor deposition) technology or chemical vapor deposition (CVD, chemical vapor deposition) technology. After at least one unpolished silicon carbide layer is first formed on each of the defective surfaces of the substrate body by using a deposition process, each of the unpolished silicon carbide layers is then subjected to a second polishing operation to form each of the optimized surface layers, which helps to increase the profitability of the manufacturing end.

[0007] The present invention further provides a method for forming a silicon carbide substrate with an optimized surface layer, the method comprising the following steps: step S1: providing a substrate body (Substrate) determined to have at least one defective surface by an inspection operation, wherein the substrate body is formed by dividing a silicon carbide ingot (Ingot) by a dividing operation and then respectively undergoing a first grinding operation; step S2: forming at least one un-grinded silicon carbide layer on each of the defective surfaces of the substrate body by a physical vapor deposition (PCD) technique or a chemical vapor deposition (CVD) technique; and step S3: performing a second grinding operation on each of the un-grinded silicon carbide layers, so that each of the un-grinded silicon carbide layers is ground and formed into at least one optimized surface layer on each of the defective surfaces of each of the substrate bodies by the second grinding operation, thereby forming a silicon carbide substrate with an optimized surface layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a schematic plan view of a side cross section of the silicon carbide substrate of the present invention.

[0009] Figure 2 for Figure 1 A partial enlarged schematic diagram of .

[0010] Figure 3 The schematic diagram is a three-dimensional diagram showing that the substrate body of the present invention is formed by cutting a silicon carbide ingot.

[0011] Figure 4 It is a schematic plan view of a side cross-section of an un-grinded silicon carbide layer of the present invention that undergoes a second grinding operation to form an optimized surface layer.

[0012] Figure 5 It is a schematic diagram of the process of the molding method of the silicon carbide substrate of the present invention.

[0013] Description of Figure Numbers:

[0014] 1-silicon carbide substrate; 1a-silicon carbide ingot; 10-substrate body; 11-defective surface; 20-optimized surface layer; 20a-unpolished silicon carbide layer. DETAILED DESCRIPTION

[0015] With reference to the accompanying drawings, the structure and technical features of the present invention are now described in detail as follows, wherein each drawing is only used to illustrate the structural relationship and related functions of the present invention, so the size of each element in each drawing is not drawn according to the actual scale and is not used to limit the present invention.

[0016] Please refer to Figure 1 and Figure 2 The present invention provides a silicon carbide substrate 1 with an optimized surface layer. The silicon carbide substrate 1 includes a substrate body 10 and at least one optimized surface layer 20.

[0017] The substrate body 10 is made of silicon carbide (SiC). The substrate body 10 has at least one defective surface 11 (such as Figure 1 and Figure 2 wherein the substrate body 10 is formed by a silicon carbide ingot (Ingot) 1a which is divided by a splitting operation and then respectively subjected to a first grinding operation (such as Figure 3 As shown), and after the first grinding operation, each defective surface 11 of the substrate body 10 is further determined to have a defect (such as Figure 5 The silicon carbide ingot 1a, also called a crystal rod, is formed in a crystal growth furnace. Since the silicon carbide ingot is a common technology in the prior art, it will not be described in detail here.

[0018] Each of the optimized surface layers 20 is made of silicon carbide and is integrally formed on each of the defective surfaces 11 of the substrate body 10 (eg Figure 1 and Figure 2); wherein each optimized surface layer 20 is formed by first forming at least one unpolished silicon carbide layer 20a on each defective surface 11 of the substrate body 10 by physical vapor deposition (PCD) technology or chemical vapor deposition (CVD) technology, and then each unpolished silicon carbide layer 20a is subjected to a second polishing operation to form each optimized surface layer 20 (such as Figure 4 The physical vapor deposition technique or chemical vapor deposition technique is a technique for forming a thin film. Since both are common techniques, they will not be described in detail here.

[0019] Please refer to Figure 5 The forming method of the silicon carbide substrate 1 comprises the following steps:

[0020] Step S1: Provide a substrate body 10 (such as Figure 5 wherein the substrate body 10 is formed by a silicon carbide ingot 1a and is divided by a division operation (eg Figure 3 As shown) and then undergo a first grinding operation to form (as shown Figure 5 shown).

[0021] Step S2: Forming at least one unpolished silicon carbide layer 20a (such as Figure 4 and Figure 5 shown).

[0022] Step S3: Perform a second grinding operation on each of the unpolished silicon carbide layers 20a, so that each of the unpolished silicon carbide layers 20a is ground and formed into at least one optimized surface layer 20 on each of the defective surfaces 11 of each of the substrate bodies 10 by the second grinding operation, thereby forming a silicon carbide substrate 1 having an optimized surface layer (such as Figure 4 and Figure 5 shown).

[0023] Compared with the existing silicon carbide substrate, the silicon carbide substrate 1 of the present invention has each optimized surface layer 20 integrally formed on each defective surface 11 of the substrate body 10, each optimized surface layer 20 is composed of silicon carbide, each optimized surface layer 20 is formed by first forming each unpolished silicon carbide layer 20a on each defective surface 11 of the substrate body 10 by physical vapor deposition technology or chemical vapor deposition technology, and then each unpolished silicon carbide layer 20a is subjected to the second polishing operation to form each optimized surface layer 20, thereby forming the silicon carbide substrate 1 with the optimized surface layer, so that the silicon carbide substrate 1 of the present invention has the following advantages:

[0024] (1) The silicon carbide substrate 1 of the present invention has the optimized surface layer 20, which effectively solves the problem of profit loss at the manufacturing end caused by the existing silicon carbide substrates with surface defects, thereby helping to increase the profit at the manufacturing end.

[0025] (2) Each of the optimized surface layers 20 of the present invention is integrally formed on each of the defective surfaces 11 of the substrate body 10 to optimize each of the defective surfaces 11 that were originally determined to be defects by the detection operation, which is beneficial to strengthening the strength of the structure and improving the yield of the product, and helps to increase the market competitiveness of the products at the manufacturing end.

[0026] The above description is only a preferred embodiment of the present invention, which is only illustrative and not restrictive of the present invention. A person skilled in the art will understand that many changes, modifications and even equivalent changes may be made to the present invention within the spirit and scope defined by the claims of the present invention, but all of them will fall within the scope of protection of the present invention.

Claims

1. A silicon carbide substrate with an optimized surface layer, characterized in that: Include: A substrate body, the substrate body is made of silicon carbide (SiC), and the substrate body has at least one defective surface; wherein the substrate body is formed by dividing a silicon carbide ingot through a dividing operation and then undergoing a first grinding operation, and after the first grinding operation, each of the defective surfaces of the substrate body is further determined to have defects through an inspection operation; and At least one optimized surface layer, each of which is composed of silicon carbide, is integrally formed on each of the defective surfaces of the substrate body; wherein each of the optimized surface layers is formed by first forming at least one unpolished silicon carbide layer on each of the defective surfaces of the substrate body by physical vapor deposition (PCD) technology or chemical vapor deposition (CVD) technology, and then each of the unpolished silicon carbide layers is subjected to a second polishing operation to form each of the optimized surface layers.

2. A method for forming a silicon carbide substrate with an optimized surface layer, characterized in that: It includes the following steps: Step S1: providing a substrate body (Substrate) having at least one defective surface determined by an inspection operation; wherein the substrate body is formed by dividing a silicon carbide ingot (Ingot) through a dividing operation and then undergoing a first grinding operation respectively; Step S2: forming at least one unpolished silicon carbide layer on each of the defective surfaces of the substrate body by using a physical vapor deposition (PCD) technique or a chemical vapor deposition (CVD) technique; and Step S3: performing a second grinding operation on each of the unpolished silicon carbide layers, so that each of the unpolished silicon carbide layers is ground into at least one optimized surface layer on each of the defective surfaces of each of the substrate bodies by the second grinding operation, thereby forming a silicon carbide substrate with an optimized surface layer.

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