Comparative Study Between AlGaN/GaN and AlInN/GaN High Electron Mobility Transistors

Different characteristics of AlGaN/GaN and AlInN/GaN high electron mobility transistors (HEMTs) are compared in this paper. For two dimensional electron gas (2DEG) density calculation of AlGaN/GaN HEMT, we used AlGaN barrier with different Al composition on GaN substrate with thickness varying from 20nm to 30nm. For AlInN/GaN HEMT, we used AlInN barrier with different In composition on GaN substrate with thickness varying from 5nm to 10nm. Threshold voltage calculation for alloy composition of 0.1≤x≤0.45 for AlGaN/GaN HEMT and 0.08≤x≤0.26 for AlInN/GaN HEMT were performed. Variations of sheet carrier concentration in 2DEG with gate voltages at different alloy composition and with alloy composition at different barrier thickness for both systems are observed. The lattice matched AlInN/GaN HEMT always exhibits larger sheet carrier density and less strain than that of the AlGaN/GaN HEMT. By comparing different parametric variations it is concluded that the usage of AlInN/GaN HEMT is much more convenient for future devices.