Radiation damage in InGaP/InGaAs p-HEMTs by 20-MeV alpha rays

Irradiation damage in InGaP/InGaAs pseudomorphic HEMTs (High Electron Mobil ity Transistors) subjected to a 20-MeV alpha ray, is studied. The drain cur rent and the effective mobility decrease after irradiations while the thres hold voltage increases in the positive direction. The decrease in the mobil ity is thought to be due to the scattering of channel electrons from induce d lattice defects and also to the decrease in the electron density in the t wo-dimensional electron-gas (2DEG) region. The influence of the radiation s ource on the degradation is discussed with respect to the number of knock-o n atoms and the nonionizing energy loss (NIEL).