Design and Fabrication of GaAs Based MOSFET by Physical Vapor Deposition Method

This paper investigates the current–voltage performance of FET where III–V GaAs as channel. GaAs thin film was deposited by physical vapor deposition method. The conventional Si channel is replaced with GaAs based on which uses an active layer and Al₂O₃ as an oxide layer for isolation. It was found out that, the current–voltage characteristics of III–V GaAs channel FET shows the characteristics analogous to that of a MOSFET. In this research, it was found out that GaAs has a band gap of 3 eV. It was also found out that, as compared to silicon, GaAs film has very less dislocation density and very less micro strain, so it shows more improvement in crystalline form at an annealing temperature of 550 °C, which can be helpful in making transistors with better performance. It was observed that the optical energy band gap of GaAs film was found to be 3 eV and decreases at an annealing temperature of 550 °C. This optical band gap can be useful in utilization of solar spectrum. GaAs film shows remarkable values of emission and band gap. Here, GaAs FET was operated as a MOSFET, and it shows high drain current performance when operated in the enhancement mode due to high channel conductivity of GaAs which gives good performance as an amplifier and can be benefited from many of the developments in nano electronic devices and easy to use in integrated circuit fabrication processes.