Photo-assisted thermally oxidized GaAs insulator layers deposited by photo-CVD

Photo-assisted thermally oxidized GaAs insulator layers are deposited by photo-chemical vapor deposition (photo-CVD) using a deuterium (D2) lamp as the excitation source. From AFM figure of thermally oxidized layers, the optimum roughness was 0.166 nm with process pressure of 1 Torr. Furthermore, from the analysis of XPS spectra thermally oxidized film produced Ga-rich oxide and composed of Ga2O3 with a small amount of As2O3. With a 1 MV/cm applied electric field, it is found that the leakage current density of thermally oxidized GaAs capacitor is 1 × 10− 7 A/cm2. It is found that the interface state density, Dit, is equal to 4.52 × 1011 cm− 2 eV− 1. The Dit is also found to be small for implementation of oxide–GaAs interface and the quality of gate oxide class for GaAs MOSFET capacitors.