Effect of Surface Preparation on the Residual Oxide Thickness and Material Loss of InGaAs Layer

Abstract

Indium gallium arsenide (InGaAs) can be introduced as a new channel material for improving device performance due to its high electron mobility. Surface preparation of InGaAs in wet chemical processes should be controlled because InGaAs is not as robust as Si against the wet chemistries. In this work, oxidation and etching behavior on InGaAs surface were investigated for acidic and basic treatments. It was observed that the oxidation states decreased after HCl treatment as compared to as-received InGaAs surface, while they increased after NH4OH treatment. The oxidation states increased after addition of H2O2 in both acidic and basic solutions. It is suggested that dissolution of the oxidized InGaAs layer is dominant in acidic solution, while it is a rate limiting step in the basic solution. Therefore, the concentration of oxidant such as H2O2 in acidic solution is important factor to determine residual oxidation and overall etching rate of InGaAs layer.