METHOD FOR PRODUCING SUBSTRATE BASED ON SILICON CARBIDE AND SILICON CARBIDE SUBSTRATE Russian patent published in 2021 - IPC C30B29/36 C30B25/18 C30B25/20 C30B25/22 C30B33/10 C23C16/01 C23C16/32 C23C28/04 H01L21/02 H01L21/205 H01L29/16 

FIELD: chemistry.

SUBSTANCE: invention relates to the technology of producing substrate from polycrystalline silicon carbide. A method consists of stages of providing coating layers 1b, each of which contains silicon oxide, silicon nitride, silicon carbonitride or metal silicide selected from a group consisting of nickel, cobalt, molybdenum and tungsten, or coating layers, each of which is made of phosphorosilicate glass (PSG) or borophosphorosilicate glass (BPSG) having flow properties of doped P₂O₅ or B₂O₃ and P₂O₅, on both surfaces of main substrate 1a made of carbon, silicon or silicon carbide for the preparation of supporting substrate 1 having covering layers, each of which has a smooth surface; forming films 10 of polycrystalline silicon carbide on both surfaces of supporting substrate 1 by precipitation from a gas phase or growing from a liquid phase; and chemical removing at least coating layers 1b in the supporting substrate to separate films of polycrystalline silicon carbide 10a, 10b from supporting substrate 1 in a state of displaying the smoothness of surfaces of coating layers 1b on the surface of films of polycrystalline silicon carbide 10a, 10b, and to obtain films of polycrystalline silicon carbide 10a, 10b as substrates of polycrystalline silicon carbide. Obtained substrates containing films of polycrystalline silicon carbide have a crystal grain size of 10 nm or more and 10 mcm or less, and an average roughness value Ra of at least one of its two surfaces is 0.3 nm or less.

EFFECT: flat and smooth surface of substrate based on silicon carbide is achieved, and the internal tension is reduced.

8 cl, 14 dwg, 4 ex