Characteristics Of Multi-channel HEMT With P-GaN Gate

GaN materials have broad application prospects in the field of microelectronic devices because of their performance advantages such as wide band gap,high saturation electron velocity,high thermal conductivity,and high temperature operation.Among them,the high electron mobility transistor(HEMT)with the two-dimensional electron gas at the Al GaN/GaN heterojunction as the core has also attracted wide attention.In this paper,device simulation research is carried out for p-GaN gate HEMT,mainly studying the electrical characteristics of multi-channel p-GaN gate HEMT.The research results obtained are as follows:Using Silvaco software,we conducted a simulation study on the electrical characteristics of single-channel p-GaN gate HEMT devices,specifically studied the Al composition in the Al GaN barrier layer,GaN gate carrier concentration,p-GaN gate thickness,Al GaN barrier layer Several factors,such as thickness,electrode depth and substrate offset,affect the device characteristics.The results show that the Al composition and the thickness of the Al GaN barrier layer have an effect on the threshold voltage of the device,and the other parameters have little effect on the threshold voltage.As the Al composition increases or the thickness of the Al GaN barrier layer increases,the device threshold voltage decreases.The electrical characteristics of our dual-channel and multi-channel p-GaN gate HEMT devices were studied.Several factors including the two-channel spacing,electrode depth,p-GaN gate carrier concentration,and Al composition in the Al GaN barrier layer were investigated.For the effect of dual-channel HEMT device characteristics,the effect of multi-channel spacing changes on the device characteristics was studied.The research results show that the dual channel device's lower channel turn-on voltage is always negative and the upper channel turn-on voltage is positive.And the threshold voltage of the device is related to the position of the two-dimensional electron gas,and the electrode depth has no effect on it.In addition,as the p-GaN gate carrier concentration increases,the device pinch-off voltage increases,while the upper channel turn-on voltage remains unchanged.The change of the Al composition of the upper channel only affects the lower channel,and the change of the Al composition of the lower channel will change the threshold voltage of the two channels.When the Al composition of the two channels changes at the same time,the threshold voltage of the upper and lower channels Both will be affected,and the lower channel changes more drastically.For multi-channel p-GaN gate HEMT devices,the results show that the channel spacingcan significantly affect and regulate the threshold voltage.