Design Considerations of GaN GIT Devices for High Speed Power Switching Applications

This paper designed and optimized Gallium nitride (GaN) GIT (gate-injection-transistor) devices for power switching applications. We proposed three kinds of structures namely gate insulator (SiN x ), field plate and AlGaN buffer to improve GaN GIT devices’ switching speed. The results of TCAD simulation indicated that all the three structures can effectively alter GaN GIT devices’ turn-on time (t on ) or turn-off time (t off ). The smallestt on and t off were identified as 0.58 ns and 0.59 ns respectively, when we introduced the specific structures into the devices. The GaN GIT device with gate insulator and AlGaN buffer (Al component of 0.25) was identified as the optimal structure design, which had small t on (0.76 ns) and small t off (0.59 ns) at the same time. For the device with the optimal structure, t on and t off were only 63% and 52% of the recorded results for GaN power switching devices, respectively.