Thermoreflectance Study of GaAs and GaAs Passivated by the Method of Plasma Enhanced Chemical Vapor Deposition

Abstract

Being the second-generation semiconductor material, GaAs is widely used in high-power devices. In this paper, a new method of multi-temperature points linear fitting for the light intensity values of the surface of GaAs collected at different temperatures, which range from 40 °C to 100 °C and the temperature rise interval is 20 °C, was used in order to obtain the thermoreflectance property. Meanwhile, the thermoreflectance property of the passivated GaAs was analyzed because the surface of GaAs is very easy to be oxidized, which will affect the performance and stability of GaAs devices. Finally, we obtained the thermoreflectance coefficient of GaAs and the passivated GaAs in visible spectrum and near-ultraviolet illumination wavelengths. The result shows that the optical response of GaAs was changed by the presence of the passivation layer significantly because of the interference effects. The study solves the problem of selecting the appropriate illumination wavelength in the study of the thermoreflectance property of GaAs. Therefore, the research is of great significance for accurate temperature measurement of GaAs semiconductor power devices.