A method, device and application of thinning silicon carbide sheet

Abstract

The application discloses a method, device and application for thinning a silicon carbide sheet. The method of the present application includes a deposition step of depositing a metal layer on the back of the silicon carbide wafer; a thermal reaction step of performing high-temperature heat treatment in an inert atmosphere; a film protection step of pasting a protective film on the front of the silicon carbide wafer; an acid etching step of using an acidic solution Soak the silicon carbide wafer; washing step, rinse the silicon carbide wafer with water and dry; mechanical grinding step, use the grinding head to grind the back of the silicon carbide wafer; remove the protective film step, remove the paste on the front of the silicon carbide wafer protective film. The method of the present application uses the metal in the metal layer to react with the silicon in the silicon carbide at high temperature to change the physical and chemical properties of the surface layer on the back of the silicon carbide, reduce the hardness of the surface layer, and make it possible to use silicon wafer thinning equipment normally. Thinning, not only has a good thinning effect, but also greatly reduces the production cost of silicon carbide wafer products.

Description

technical field [0001] The present application relates to the field of silicon carbide wafer preparation, in particular to a method, device and application for thinning silicon carbide wafers. Background technique [0002] As a new generation of wide bandgap semiconductor material, silicon carbide (SIC) has extremely excellent performance in the field of power semiconductors, and is the frontier and future direction of the development of power semiconductor devices. SiC (silicon carbide) is a compound semiconductor material composed of silicon (Si) and carbon (C), which has excellent electrical properties: for example, the forbidden band width is 2.3-3.3eV, which is 3 times that of Si; the breakdown field The strength is 0.8E16~3E16V / cm, which is 10 times that of Si; the saturation drift velocity is 2E7cm / s, which is 2.7 times that of Si; the thermal conductivity is 4.9W / cm K, which is about 3.2 times that of Si. These characteristics make silicon carbide materials have exc...

AI Technical Summary

Problems solved by technology

In the process of manufacturing silicon carbide semiconductors, especially in the latter part of the manufacturing process of silicon carbide power semiconductor products, the backside thinning back gold process will be carried out; however, there is currently no effective thinning method for silicon carbide wafers or silicon carbide wafers. Program

A similar thinning method is the thinning process of silicon wafers, but this solution is not suitable for silicon carbide wafers

Because the existing silicon wafer thinning process adopts a mechanical thinning method, that is, a silicon dioxide grinding head is used to grind and thin the silicon wafer; however, the hardness of the silicon dioxide grinding head is lower than that of the silicon carbide wafer. , so if you refer to the silicon wafer thinning method and perform mechanical thinning, not only can you not get a satisfactory thinning effect, but also the thinning grinding head of the silicon wafer will be scrapped, which greatly improves the production of silicon carbide wafer products cost

[0004] Therefore, there is currently no simple and effective thinning method for silicon carbide wafers, which is not conducive to the preparation and post-processing of silicon carbide wafers.

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