Preparation method of indium phosphide substrate

Abstract

The invention discloses a preparation method of an indium phosphide substrate. The preparation method sequentially comprises the steps of cutting, back grinding, front thinning, corrosion, polishing, cleaning and packaging. According to the preparation method of the indium phosphide substrate, a grinding and thinning combined method is creatively developed to respectively process the front surface and the back surface of the wafer, and a main surface incoming material with the roughness Ra value of 100-150nm can be obtained before the wafer is subjected to CMP, so that the thickness of a damaged layer of the substrate before polishing is greatly reduced; the CMP polishing time of the indium phosphide substrate is greatly shortened; a series of problems of high substrate surface mechanical damage rate, thick mechanical damage layer, poor surface roughness, poor flatness consistency and the like caused by a double-sided grinding process in the current indium phosphide substrate manufacturing process are solved; and through the improvement of the corrosive liquid, the environmental pollution is reduced, the working environment is improved, the effective life of the corrosive liquid is greatly prolonged, and meanwhile, the corrosion efficiency is improved.

Description

technical field [0001] The invention relates to a method for preparing an indium phosphide substrate, belonging to the technical field of indium phosphide substrate preparation. Background technique [0002] Indium phosphide (InP) is a second-generation semiconductor material with a zinc blende crystal structure and a band gap of 1.34eV. It is used as a substrate material for optoelectronic chips with high electron mobility, high band gap, and high thermal conductivity. It is the key material of optical module semiconductor laser and receiver. According to the semiconductor LD and LED, the flatness of the substrate has a decisive influence on the formation of the epitaxial film and when it is made into a device. [0003] According to the status quo in the industry, the current processing of indium phosphide substrates is double-sided grinding, and a considerable part of the wafer thickness needs to be removed during the processing, resulting in waste of crystal materials, a...

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Problems solved by technology

[0004] The invention provides a method for preparing an indium phosphide substrate. The front and back sides of the wafer are respectively processed by grinding and thinning, and the main surface with a roughness Ra value of 100-150 nm can be obtained before the wafer is subjected to CMP polishing. materials, greatly reducing the thickness of the damaged layer of the substrate before polishing, and greatly shortening the CMP polishing time of the indium phosphide substrate; A series of problems such as high mechanical damage rate on the bottom surface, thick mechanical damage layer, poor surface roughness, and poor flatness consistency; through the improvement and optimization of the composition of the corrosion solution, it has solved the problems of hydrochloric acid, glacial acetic acid, bromine and other acids in the corrosion solution in the past. During the operation process, the environmental pollution caused by volatilization and the health and safety hazards brought to the operators, at the same time, the effective life of the new component corrosive solution has been greatly improved.

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