A High Performance Normally-Off AlGaN/GaN Split-Gate Metal-Insulator-Semiconductor High Electron Mobility Transistor (MIS-HEMT) Using Piezo Neutralization Technique

Abstract

In this paper, we propose a novel normally-off MIS-HEMT structure, mainly using Split-Gate Technology, Piezo Neutralization Technique (PNT), Field Plate Technology. By analyzing the effects of different Al composition in the PNT layer and buffer layer on devices, the Piezo Neutralization Technique is optimized. The current turn-on/off is controlled by changing gate voltage to regulate the horizontal conduction band between the double gates. The effects of gate length and block barrier size between the double gates on device performance are studied. Through two-dimensional device simulation, the operation principle and internal mechanism are analyzed. An improved device with good performance is presented. The threshold voltage Vth is 4.1 V, the peak transconductance is 0.3 S/mm, the maximum drain current is 1.1 A/mm and the breakdown voltage is 1200 V.