GaN HEMT器件电子辐照效应研究

Electron beam irradiation effect on GaN HEMT

对GaN HEMT(High Electron Mobility Transistor)器件进行了0.8和1.2 MeV电子束的辐照效应研究。结果表明,0.8 MeV电子束对器件损伤甚于1.2 MeV电子束,饱和漏电流增大,阈值电压负向漂移主要是由于AlGaN层中电离辐射产生的俘获正电荷以及GaN层中非电离能量损失产生的N、Ga空位所引起的。栅电流增加主要是由于非电离能量损失在AlGaN势垒层形成的电子陷阱和俘获正电荷引起TAT效应(trap-assisted tunneling)所导致。

In this work,GaN HEMTs（High Electron Mobility Transistor） were irradiated by 0.8 and 1.2 MeV electron beams,and the irradiation effects were investigated.The results show that the device damage caused by 0.8 MeV electrons is more serious than that by 1.2 MeV electrons.Saturation drain current increase and threshold voltage negative shift are due to trapped positive charge from ionization in the AlGaN layer and N,Ga vacancy from non-ionizing energy loss in the GaN layer.Electron traps and trapped positive charges from non-ionizing in the AlGaN layer act as trap-assisted-tunneling centers that increase the gate leakage current.