3MeV质子辐照对AlGaN/GaN高电子迁移率晶体管的影响

Effects of 3 MeV proton irradiations on AlGaN/GaN high electron mobility transistors

研究了AlGaN/GaN高电子迁移率晶体管(HEMT)的质子辐照效应.在3 MeV质子辐照下,当辐照剂量达到1×10^(15)protons/cm^2时,漏极饱和电流下降了20%,最大跨导降低了5%.随着剂量增加,阈值电压向正向漂移,栅泄露电流增加.在相同辐照剂量下,1.8 MeV质子辐照要比3 MeV质子辐照退化严重.从SRIM软件仿真中得到不同能量质子在AlGaN/GaN异质结中的辐射损伤区,以及在一定深度形成的空位密度.结合变频C-V测试结果进行分析,表明了质子辐照引入空位缺陷可能是AlGaN/GaN HEMT器件电学特性退化的主要原因.

AlGaN/GaN high electron mobility transistors （HEMT） are exposed to 3 MeV protons irradiation. The drain saturation current decreases 20% and the maximum transconductance decreases 5% at a fluence of 1×10^15 protons/cm2. As fluence increases, the thread voltage is shifted toward more positive values. After proton irradiation, the gate leakage current increases. The degradation caused by 1.8 MeV proton is significantly higher than by 3 MeV proton irradiation at the same fluence. The radiation damage area and the density of vacancies at a given depth are obtained from software SRIM. As the energy of the incident proton increases, the non-ionizing energy transferred to the crystal lattice decreases. It is concluded that vacancies introduced by proton irradiation may be the primary reason for the degradations of electrical characteristics of AlGaN/GaN HEMT.