A method for preparing a patterned sapphire substrate for gan growth

Abstract

The invention discloses a method for preparing a graphic sapphire substrate for GaN growth. Firstly, a SiO2 thin film is prepared on a sapphire substrate, graphic optical resist serves as a mask, the SiO2 is etched through a BOE solution, and a SiO2 mask graph is formed; then wet etching is conducted on the sapphire substrate, and the graphic sapphire substrate is obtained. The method is characterized in that before the SiO2 is etched through the BOE solution, the substrate is placed into a specific buffer solution to be soaked and preprocessed, so that the unevenness phenomenon occurring when the exposed SiO2 is etched through the BOE solution is solved effectively, partial falling off of the SiO2 is prevented, the even and regular SiO2 mask is formed, sapphire graphs prepared by follow-up processes are even, the graphic sapphire substrate which is perfect in appearance and even is provided for epitaxial growth, the quality of the epitaxial growth is improved effectively, and dislocation density is reduced greatly.

Description

technical field [0001] The present invention relates to the technique of preparing patterned sapphire substrate by wet etching method, in particular to a method of preparing patterned sapphire substrate for GaN material growth by wet etching method, avoiding when BOE solution etches silicon dioxide mask The method for the problem of uneven corrosion belongs to the field of semiconductor optoelectronics. Background technique [0002] At present, yellow, green, blue, white and ultraviolet light-emitting diodes and laser diode optoelectronic devices are mainly made of GaN materials. Traditional GaN growth is carried out on substrates such as sapphire, silicon, and silicon carbide, but the lattice constants and thermal expansion coefficients of these substrates are very different from those of GaN, resulting in threading dislocations in the GaN-based growth layer. Density up to 10 8 -10 10 cm -2 。 The existence of high dislocation density limits the further improvement of t...

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Problems solved by technology

However, when the above-mentioned silicon dioxide mask is etched with BOE solution, defects such as uneven etching, partial peeling of silicon dioxide, pinholes and imprints are prone to occur.

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