Method for cleaning sapphire substrate

Abstract

The invention relates to a method for cleaning a sapphire substrate. The surface of a sapphire epitaxial substrate has a larger quality difference of the substrate surface and has a difference in defects of an oxidation layer and a subsurface after being cleaned by organic impurities and inorganic metal impurities due to chemical-mechanical polishing (CMP). The sapphire substrate is generally classified according to the cleaning conditions of the substrate surface. And when an imaging (PSS (Poly(sodium-p-styrenesulfonate))) substrate is prepared or heteroepitaxy is directly carried out, the product uniformity is different so that the final yield of the product is decreased. The method provided by the invention is characterized in that the sapphire substrate is cleaned with the organic impurities and the inorganic metal impurities and then is cleaned with hydrogen-nitrogen plasmas. After the cleaning method provided by the invention is carried out, the surface of the sapphire substrate has no oxidation impurities, defection layers and no subsurface defection layers. The surface quality of the substrate is good in consistency. The cleaning method provided by the invention has high yield of the PSS substrate or high crystallization quality of a GaN layer subjected to the heteroepitaxy.

Description

technical field [0001] The invention relates to the technical field of crystal material processing, in particular to a method for cleaning a sapphire substrate. Background technique [0002] Sapphire crystal (Al 2 o 3 ) The lattice constant mismatch rate between the C plane and the epitaxially deposited films of III-V and II-VI groups is small, and it meets the high temperature resistance requirements in the GaN epitaxy process, making sapphire single crystal an ultra-high brightness sapphire , GaN is the most commonly used substrate material for white LED light emitting materials. In order to improve the quality of GaN epitaxy, the sapphire substrate can be patterned (PSS), and the crystal quality of GaN epitaxy and the processing quality of PSS are closely related to the surface cleaning quality of the sapphire substrate (substrate) used. [0003] At present, the general cleaning process uses organic solvents to clean the organic impurities on the surface of the sapphir...

AI Technical Summary

Problems solved by technology

The surface of the substrate cleaned by this method has less organic impurities and inorganic metal impurities, but the oxide layer and sub-surface damage layer on the substrate surface cannot be removed, and the existence of the oxide layer and sub-surface damage layer on the substrate surface will lead to PSS process And the GaN epitaxy process is unstable, and the yield is poor