GaAs (111) wafer cleaning method

Abstract

The invention discloses a GaAs (111) wafer cleaning method. The GaAs (111) wafer cleaning method comprises steps that, a GaAs (111) substrate is treated by an organic solvent to remove oil stain and organic matters on the surface; the GaAs (111) substrate is immersed in hydrogen peroxide, is then taken out, is cleaned by deionized water, is immersed in hydrochloric acid, is taken out and is cleaned by deionized water; the acquired GaAs (111) substrate is immersed in hydrogen peroxide, is cleaned by deionized water, is immersed in hydrochloric acid and is cleaned by deionized water for at least one time. According to the method, the surface of the GaAs (111) substrate is treated by the hydrogen peroxide to acquire a structured nature oxide layer and is then corroded by the hydrochloric acid, as the GaAs (111) surface is the structured nature oxide layer, GaAs defects with bad quality in the surface can be effectively removed, so oxide quantity and roughness of the GaAs surface can be greatly reduced. The cleaning method is employed in combination with an ammonium sulphide solution for passivation, so the clean GaAs surface can be prevented from being oxided by oxygen in the air for long time.

Description

technical field [0001] The invention relates to the preparation of GaAsMOSCAP (MOS capacitor), in particular to a method for cleaning a GaAs (111) wafer. Background technique [0002] In recent years, with the continuous breakthrough of semiconductor technology nodes, the requirements for device size have become more stringent, and further reducing the physical size of devices according to conventional methods has been challenged in many ways. People began to look for new materials to replace Si. Among them, GaAs and other III-V compound semiconductor materials have attracted extensive attention due to their high electron mobility and critical field strength. However, oxides of III-V compound semiconductor materials cannot compare with SiO in terms of stability and quality. 2 In contrast, this seriously affects the performance of III-V compound semiconductor field effect transistors, so people use high-K dielectrics instead of their oxides as gate dielectric materials, and ...

AI Technical Summary

Problems solved by technology

However, the method of treating GaAs surface with hydrochloric acid solution alone cannot obtain the desired effect.

The main reason is that the natural oxide layer on the surface of GaAs is irregular, and the hydrochloric acid solution also reacts with GaAs while corroding the oxide, thus destroying the morphology of the substrate surface and increasing the surface roughness of the material.

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