Growth method of silicon carbide epitaxial layer with high surface quality

Abstract

The invention discloses a growing method for a high-surface-quality silicon carbide epitaxial layer. The method comprises the steps of 1) selecting a silicon-surface silicon carbide substrate at a deflecting <11-20> direction of 4 degrees, placing the substrate on a graphite base with a tantalum carbide coating inside a reaction chamber of a SiC epitaxial system; 2) heating the reaction chamber of the SiC epitaxial system to increase the temperature in the reaction chamber to be 1450 DEG C, setting the pressure in the reaction chamber to be 90-200 mbar, maintaining the temperature in the reaction chamber for 5-10 minutes with the flow rate of H2 to be 68-80 L / min, and etching the substrate by utilizing the pure hydrogen H2; 3) after the step 2), pumping a small amount of hydrogen chloride (HCl) gas into the reaction chamber to etch the substrate for facilitating the H2 at the flow ratio selection range of HCl / H2 is 0.01%-0.15%, continuously increasing the temperature till the growth temperature of a buffer layer reaches 1650 DEG C-1670 DEG C, wherein the heating process lasts for 10-30 minutes. Based on the above method, triangle defects occurred in epitaxial wafers are effectively reduced. Meanwhile, the formation of the stepped bunching morphology in the epitaxial layer is avoided by utilizing the low-temperature and low-carbon-silicon-ratio buffer layer.

Description

technical field [0001] The invention relates to a growth method of a silicon carbide epitaxial layer with high surface quality, which is mainly applicable to a silicon carbide substrate with a 4° off-axis silicon surface along the <11-20> direction. Mainly through the special buffer layer design, a SiC epitaxial film with no step bunching and less triangular defect density was prepared on a silicon carbide (SiC) substrate with a 4° off-axis along the <11-20> direction. It belongs to the technical field of semiconductor materials. Background technique [0002] SiC materials are suitable for the manufacture of electronic devices such as high temperature, high frequency, high power, radiation resistance, and corrosion resistance. They have broad application prospects in communications, automobiles, aviation, aerospace, oil exploration, and national defense. They are international high-end advanced materials. In order to realize the development of SiC electronic dev...

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Problems solved by technology

Triangular defects can cause device leakage failure, which is a fatal defect

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