A method for preparing high-quality semi-insulating silicon carbide single crystal substrate

Abstract

The invention discloses a method for preparing a high-quality semi-insulation silicon carbide monocrystalline substrate, which belongs to the field of semiconductor materials. According to the preparation method disclosed by the invention, a high-temperature rapid heat treatment technology and a surface leaser annealing technology are performed on a high-purity silicon carbide monocrystalline wafer, thus a spot defect introduced in a certain area of the surface of the high-purity semi-insulation silicon carbide substrate can be eliminated, and an internal spot defect with a distance from the substrate surface is reserved, so that in a surface layer clean area of the defect-free silicon carbide monocrystalline substrate, the semi-insulation characteristic of the silicon carbide monocrystalline substrate is reserved, and a prepared GaN epitaxial layer is optimal in quality.

Description

technical field [0001] The application relates to a method for preparing a high-quality semi-insulating silicon carbide single crystal substrate, which belongs to the field of semiconductor materials. Background technique [0002] Semi-insulating silicon carbide (silicon carbide) single crystal substrates are the preferred semiconductor substrate materials for GaN high-frequency microwave devices. This aspect depends on the excellent properties of semi-insulating silicon carbide single crystal substrates such as high resistivity, which can be prepared with excellent performance On the other hand, it depends on the high matching degree of the lattice constant of silicon carbide and GaN, which can make the heteroepitaxial layer obtain good crystal quality. [0003] In terms of implementation methods, there are two implementation methods for the preparation of semi-insulating silicon carbide single crystal substrates: doping and high purity. A large number of deep energy level...

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Problems solved by technology

Intrinsic point defects are an indispensable feature to achieve the electrical properties of high-purity semi-insulating crystals, however, these point defects themselves will introduce large lattice stress, causing lattice distortion, and thus destroying the SiC single crystal lattice Integrity, to a certain extent, affects the lattice parameters of SiC single crystal

Considering that one of the main reasons why GaN uses silicon carbide single crystal substrates as epitaxy is the small mismatch of the lattice parameters between the two, the introduction of point defects will lead to an increase in the lattice fit between GaN and silicon carbide, This in turn reduces the quality of the GaN epitaxial layer

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