In-situ etching method

Abstract

The invention provides an in-situ etching method. The method comprises steps: a processed SiC substrate processed by using ortho-axis 4H or 6H original silicon carbide SiC substrate is subjected to ultrasonic cleaning; an alkaline mixture is used for boiling the processed SiC substrate at a temperature of 85 DEG C for 20 m; a 5% hydrofluoric acid solution is used for immersing the processed SiC substrate for 10 m; an epitaxial furnace is used for carrying out in-situ etching on the processed SiC substrate with a zero deflection angle; when the temperature of the epitaxial furnace falls to about 700 DEG C, inrush of hydrogen is stopped; the processed SiC substrate with a SiC epitaxial layer is continuously cooled in an argon environment; and the processed SiC substrate is naturally cooled to a room temperature, and a SiC epitaxial wafer is taken out. According to the in-situ etching method of the invention, the best substrate surface morphology can be etched, and the SiC hetero epitaxial growth quality is enhanced.

Description

technical field [0001] The invention relates to the technical field of semiconductor materials, in particular to an in-situ etching method. Background technique [0002] As one of the representatives of wide band gap semiconductor materials, silicon carbide SiC has superior properties such as large band gap, high breakdown electric field, high thermal conductivity, high electron saturation drift velocity, strong radiation resistance and good chemical stability. It has become a key semiconductor material for the manufacture of a new generation of microelectronic devices and circuits after germanium, silicon, and gallium arsenide. Other heterojunctions such as SiC / Si and AlGaN / GaN are traditionally formed by changing chemical composition, while silicon carbide multi-type heterojunctions are prepared by changing the chemical composition and changing the crystal form. Therefore, the heterojunction of silicon carbide polymorph has the following advantages: [0003] 1) Negligibl...

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