Device Scaling Issues in GaN Based Double Heterojunction Field-Effect Transistor and Performance Analysis

The device performance of GaN based Double Heterojunction Field-Effect Transistor(DHFET) is largely dependent on device scaling issues. The authors´ simulation results show that a decrease in source-gate spacing can improve device performance, enhancing the device output current and the trans conductance. On the contrary, the gate-drain distance does not have significant effect on device performance. It is also observed that an increase in the Aluminium mole fraction of AlGaN buffer causes reduced device transconductance for both AlN/GaN/AlGaN DHFET and AlGaN/GaN/AlGaN DHFET devices and increased gate leakage current for the later one. Based on these results, new optimization strategies for GaN based DHFETs could be defined.