High performance GaAs metal-insulator–semiconductor devices using TiO2 as insulator layer

Abstract

In the present study, Cu/TiO2/n-GaAs Metal-Insulator–Semiconductor (MIS) structure was fabricated and the variation in electrical characteristics of this structure have been analyzed as a function of temperature using current–voltage (I–V) measurements in the temperature range 50–290 K with a steps of 40 K. It has shown that the ideality factor (n) was decreased with increasing temperature, however, the zero-bias barrier height (ϕb,0) was increased with increasing temperature. Furthermore, Gaussian potential model was used in order to explain the barrier height inhomogeneity observed in this structure. This discrepancy could be explained by local inhomogeneities at the metal-semiconductor interface by considering fluctuations in the local surface potential. This value of Richardson constant, obtained the modified Richardson plot in the first region (290–170 K) according to the Gaussian distribution (GD), is in excellent agreement with the theoretical value for n-type GaAs. These results show that understanding the temperature dependence electrical characteristics of this structure may be of great help in improving the quality of TiO2 grown on GaAs substrates for the future of the device technology.