A Sub-Critical Barrier Thickness Normally-Off AlGaN/GaN MOS-HEMT Based-HfLaO Gate Oxide

The article presents the results of modelling and simulation of normally-off AlGaN/GaN MOS-HEMT transistors.The use of high-k dielectrics at thicknesses of 5, 10, and 20 nm and ultrathin sub-critical 3 nm Al0.25Ga0.75N barrier layer on the electrical characteristics of the transistor has been examined. The electrical performances of, threshold voltage, on- and off- currents and transconductance of the device were extracted from TCAD Silvaco-Atlas simulator tool.It was found that the maximum current of the device can reach 426 mA at Vgs = 5V with an off-state current of less than 3.26×10-16A, leads to an on/off current ratio of 1.3× 1015, at 5 nm insulator thick. The device shows a high transconductance of 130 mS/mm and threshold voltage of 1.36 V. It has been demonstrated that the use of HfLaO, instead of HfO2 and La2O3, as GOX (gate oxide) increases on-state current above 0.4 A and reduces the negative influence of the charge accumulated in the dielectric layer

کلیدواژه ها:

HfLaO ، MOS–HEMT ، GaN ، on ، off current ratio ، 2DEG ، transconductance