Polishing solution for silicon carbide substrate

Abstract

The invention relates to a chemically mechanical polishing solution for a silicon carbide substrate. The chemically mechanism polishing solution comprises the following components in percentage by weight: 1-50 percent of grinding material, 0.01-8 percent of chelant, 0.01-10 percent of surfactant, 0.01-10 percent of dispersing agent, 0.1-20 percent of oxidant and the balance of deionized water. The polishing solution has little damage to the surface of the silicon carbide substrate; the silicon carbide substrate has low roughness degree value and can reach the roughness Ra of being less than 0.5nm; no scratch and corrosion pit defect exists on the surface of the silicon carbide substrate; and the chemically mechanical polishing solution has high removing speed of scratch and corrosion pit, is easy to clean, does not corrode processing equipment and pollute the environment, and is low is price of raw materials, low in cost and easy to store. The chemically mechanical polishing solution is mainly used for chemically mechanical polishing of a silicon carbide wafer for the substrate.

Description

technical field [0001] The invention belongs to a special chemical mechanical polishing liquid, in particular to the surface treatment of silicon carbide materials for epitaxial substrates. Background technique [0002] The application of wide bandgap semiconductor SiC crystal material requires ultra-smooth wafer surface, no defect, no damage, and the quality and precision of SiC crystal processing directly affect the performance of the device. However, due to the extremely high hardness of SiC crystals, with a Mohs hardness of 9.2, second only to diamond, it is extremely difficult to process the surface, and it is difficult to obtain a high-quality surface with low roughness, which greatly limits its wide application. To prepare high-quality epitaxial wafers, the requirements for the substrate are not only low warpage, low curvature, and small total thickness deviation, but also special requirements for the surface of the substrate: low obvious surface defects, low subsurfa...

AI Technical Summary

Problems solved by technology

At present, none of the chemical mechanical polishing fluids produced in China are designed for SiC single crystals. The chemical inertness of SiC determines that the general chemical mechanical polishing fluids cannot meet the requirements.

[0004] The published patent literature and non-patent literature do not provide the polishing liquid and preparation method for successfully obtaining the SiC substrate surface