Suppression of current collapse in AlGaN/GaN MISHFET with carbon‐ doped GaN/undoped GaN multi‐layered buffer structure

We present a new semi‐insulating carbon‐doped GaN/undoped GaN multi‐layered buffer structure for AlGaN/GaN heterojunction field effect transistors, which drastically suppresses current collapse in GaN MISHFET with improving the on‐current performance of the device but without degrading the breakdown characteristic. It is believed that spatial compensation between the multi‐layered GaN layers not only makes the multi‐layered buffer layer very highly resistive, but also prevents the electrons from the 2DEG channel from being captured into deep traps in the buffer layer, which maintains high‐high breakdown characteristic and leads to great suppression of current collapse in AlGaN/GaN‐based transistors, respectively.