Simulation Study on Current Collapse Effect of E GaN HEMT

Abstract

GaN high electron mobility transistor(GaN HEMT) has high channel electron concentration, high electron mobility and high breakdown voltage, which makes it have great development prospects in high frequency, microwave and other fields. In the development of GaN HEMT, suppressing current collapse has always been the focus and difficulty of research. Based on SILVACO TCAD simulation software, the current collapse suppression by field plate structure is studied and discussed in this paper. Firstly, the model of enhanced GaN HEMT device is established and its correctness is verified. Then, the phenomenon of current collapse and virtual gate model are introduced. From the theory of improving breakdown voltage of device by field plate structure as the starting point, field plate structure is added to the device model and simulation experiments are carried out. According to the results, the principle of suppression current collapse by field plate structure is analyzed, and the correctness of virtual grid model is verified.