Liquid Phase Chemical Enhanced Oxidation on AlGaAs and Its Application

Abstract

A new method named the liquid phase chemical enhanced oxidation (LPCEO) technique has been proposed for the oxidation of aluminum gallium arsenide (AlGaAs) near room temperature. The initial stage of AlGaAs oxidation by this method has been investigated. The native oxide film composition is determined on the basis of the results of Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. Based on current–voltage ( I – V ) characteristics of the metal–oxide–semiconductor (MOS) structure, the leakage current density is approximately 5×10 -9 A/cm 2 at the electric field of 1 MV/cm, and the breakdown field is at least 10 MV/cm after rapid temperature annealing. In addition, the oxide film properties can be improved after thermal annealing based on capacitance–voltage ( C – V ) measurements. Finally, the application of the new method to the AlGaAs/InGaAs metal–oxide–semiconductor pseudomorphic high-electronic-mobility transistor (MOS-PHEMT) is demonstrated.