Improved Gate Reliability Normally-Off p-GaN/AlN/AlGaN/GaN HEMT With AlGaN Cap-Layer

In this work, the dual junction-high-electron-mobility-transistor (DJ-HEMT) was investigated. The thin AlGaN was grown between the p-GaN gate and gate metal. In the TCAD simulations, the band gap and electric field were shown in this letter, proving the dual junction forming. Moreover, DJ-HEMT shows the high gate voltage swing due to the dual junction at the gate region of device, which enhance gate performance. By contrast with standard p-GaN HEMT (ST-HEMT), DJ-HEMT shows higher VTH of 2V, saturation current of 187mA/mm, ION/IOFF ratio of 5.1 x 108 and gate swing voltage which is higher than 20V. In addition, DJ-HEMT also shows the lower device leakage current and superior life time measurement due to the thicker and higher barrier of AlGaN cap layer.