A Simulation Study of 2-D Electron Gas in GaN HEMT for High- Speed Applications

The high-power GaN High Electron Mobility Transistors (HEMT) are used for next-generation high-speed R.F. applications. This work intends to simulate and analyze the Al_xGa_1-xN/GaN HEMT to obtain two-dimensional electron gas (2DEG). The variation of 2DEG concentration by varying the Al concentrations and width of the Al_xGa_1-xN layer has been explored. This exhibits the importance of a polarization-induced inbuilt electric field. Our results confirm that the inbuilt electric field facilitates the high 2DEG density in nitride systems due to the transfer of carriers from the surface states, and it can be utilized to calculate the subband electron mobility of GaN HEMT structures.