Proton Irradiation Effects on Dual Delta-Doped AlGaAs/InGaAs/AlGaAs Pseudomorphic High-Electron-Mobility Transistors

In this article, we mainly studied the proton irradiation effects on novel dual delta-doping GaAs-based pseudomorphic high-electron-mobility transistors (PHEMTs). The conventional heterojunction high-electron-mobility transistors (HFETs) were selected as control. The insensitivity of Co
$^{60}~\gamma $
-rays (up to 100 Mrad) indicates that displacement effects predominate in the degradation of threshold voltages (
$V_{\mathrm {TH}}$
) and drain current (
$I_{\mathrm {DS}}$
). Based on the incident depth of protons in device, there are two types of irradiation effects: uniform (thin target) and nonuniform (thick target). For the former, 3-, 40-, and 80-MeV protons were employed to explore the energy dependence in PHEMTs. It was found that the effect of protons on PHEMTs depends on nonionizing energy loss (NIEL), and it is possible to predict the impact of different protons on
$V_{\mathrm {TH}}$
by NIEL alone. As for nonuniform irradiation, the incident range of 150-keV protons in gated and ungated regions of both PHEMTs and HFETs determines the case in which
$I_{\mathrm {DS}}$
decreases, while
$V_{\mathrm {TH}}$
remains constant as the fluence increases. Finally, this novel PHEMT with a higher donor concentration (provided by double delta doping) and higher mobility (InGaAs channel) was found to have a greater radiation hardness than HFETs.