High Performance Hybrid Conduction Enhancement Mode High Electron Mobility Transistors

In this work, we present a novel structure of high performance hybrid charge plasma based enhancement mode high electron mobility transistor (HEMT). The novelty of this HEMT structure is the realization of its enhancement mode behavior by employing a p-type doped GaN pocket just below hetero interface, aligned with respect to the top gate. The realization of enhancement mode operation is a big issue in HEMTs. Further, the ON current boosting is achieved by using the concept of charge plasma (CP), wherein two metal electrodes at the source and drain terminals induce two electron layers, called as charge plasma electron gas (CPEG). The CPEG creation is in addition to the two dimensional electron gas (2DEG) created by the GaN/AlGaN heterostructures. The combination of 2DEG and the CPEG results in a significant enhancement in the ON current (ION) of the proposed HEMT. A two dimensional calibrated simulations have revealed that the ON state current of the proposed device is 7 times larger than the conventional GaN HEMT, which in turn enhances the transconductance, cut off frequency, maximum oscillation frequency and maximum available bandwidth of the proposed HEMT by 272%, 73.72%, 87% and 122% respectively when compared to the conventional GaN-HEMT.