Influence of NH3 plasma pretreatment on the properties of plasma enhanced chemical vapor deposited SiON on GaAs interface

Interface properties of plasma‐enhanced chemical‐vapor‐deposited dielectric SiON on GaAs systems pretreated by NH3 plasma were studied. The effects of the process parameters in the NH3 plasma pretreatment, such as total pressure, radio‐frequency power, substrate temperature, NH3 flow rate and pretreatment time, were investigated by the measurements of Auger electron spectroscopy, Raman spectroscopy, current‐voltage, and capacitance‐voltage characteristics. The transient region width and the surface strain field, surface leakage current, hysteresis, and degree of Fermi‐level pinning evidently related to interface properties, are increased with increasing total pressure, decreased with increasing radio‐frequency power, substrate temperature, and pretreatment time, and independent of NH3 flow rate. The physical and electrical properties of SiON/GaAs interface have been significantly improved under an optimum NH3 plasma pretreatment condition. The correlation of these parameters in pretreatment process with t...