Reduction of Schottky reverse leakage current using GaAs surface cleaning with UVO3 treatment

A GaAs surface-cleaning method using UVO3 treatment was developed. The UVO3 treatment involves two processes: GaAs surface oxidation and oxide removal . Surface oxidation is performed by using a mercury lamp at high temperatur e, such as 180 degrees C. GaAs oxide is removed by NH4OH solution dipping. Spectroscopic ellipsometry and X-ray photoelectron spectroscopy (XPS) study showed that thermally unstable As oxides exist on a non-treated surface; h owever, surface GaAs oxides are almost completely removed by this treatment . This cleaning method was applied in the field effect transistor (FET)-gat e-formation process and, consequently, Schottky leakage current was signifi cantly reduced.