Method for preparing silicon carbide epitaxy substrate at low temperature

Abstract

The invention provides a method for preparing an ultrathin silicon carbide epitaxy substrate at low temperature. The method comprises the following steps: S1, coating a silicon carbide layer on the surface of a base to obtain a first structure body; S2, heating the first structur body to 800-1000 DEG C to obtain a second structural body; S3, simultaneously carrying out etching and illumination catalysis on the surface of the heated silicon carbide layer in the second structural body to obtain a third structural body, the etching gas being hydrogen chloride, H2, SF6 and O2; S4, performing laserpulse impact on the surface of the silicon carbide layer obtained after etching and illumination catalysis in the third structural body to obtain a fourth structural body; and S5, carrying out post-processing on the fourth structural body to obtain the silicon carbide epitaxy substrate. According to the method, the silicon carbide layer is subjected to illumination catalysis matched with etchingof hydrogen chloride, H2, SF6 and O2, so that the activity of the substrate is accelerated, and low-temperature rapid fluidization can be realized; and laser pulse impact enables impurities on the surface of the substrate to be removed quickly, and the thickness of the substrate is reduced.

Description

technical field [0001] The invention belongs to the technical field of silicon carbide epitaxial substrates, in particular to a method for preparing a silicon carbide epitaxial substrate at low temperature. Background technique [0002] Silicon carbide epitaxial wafer refers to the regular arrangement of silicon carbide material molecules under certain conditions and directional growth on the epitaxial substrate. [0003] At present, the commonly used epitaxial substrate is a silicon carbide epitaxial substrate. Silicon carbide epitaxial substrates are generally prepared at high temperatures. For example, chemical vapor deposition (CVD) technology needs to be prepared at about 2000°C, high-temperature sublimation method needs to be prepared at about 2400°C, and liquid phase epitaxy method needs to be prepared at about 1600°C. These The preparation method may have a large internal stress inside the substrate due to the high temperature, which will affect the later use; and t...

AI Technical Summary

Problems solved by technology

Silicon carbide epitaxial substrates are generally prepared at high temperatures. For example, chemical vapor deposition (CVD) technology needs to be prepared at about 2000°C, high-temperature sublimation method needs to be prepared at about 2400°C, and liquid phase epitaxy method needs to be prepared at about 1600°C. These The preparation method may have a large internal stress inside the substrate due to the high temperature, which will affect the later use; and the thickness of the prepared substrate is generally thick, with an average thickness of more than 20 μm, which hinders the development of silicon carbide epitaxial substrates. development application