ABSTRACT
The authors have reported about current suppression effect of nm-thin GaAs oxides, which were formed by UV & ozone process and tested as current-voltage characteristics of MIS diodes [7]. An X-ray photoelectron spectroscopy analysis of the oxide suggested that incorporation of oxygen and outdiffusion and decomposition of As is the main mechanism of the semiconductor-to-insulator conversion [7]. In which, an oxide thickness vs oxidation time relation obtained at a process (substrate stage) temperature of 300 °C was also shown. Solid bars in Fig. 1 shows the result. The data, being nearly proportional to square root of the process time, suggests that the oxidation is mainly dominated by diffusion. Current suppression rates of the oxide layers, obtained from comparison of reverse leakage currents of MIS and Schottky diodes [7] are shown in Fig. 2. In Fig. 1, the circular plot and the triangular plot obtained by 100°C for 240 min and room temperature for 480 min oxidations, respectively, are added. In this paper the UV & ozone process to form the insulating layer of the MIS structure was performed at room temperature.
