Mechanism of high-fluence proton induced electrical degradation in AlGaN/GaN high-electron-mobility transistors

Abstract

The effects of displacement damage induced by 3 and 6 MeV protons in AlGaN/GaN high-electron-mobility transistors (HEMTs) are investigated. For the 6 MeV protons at a dose of 5 ' 10 14 cm %2 , a 12% decrease in saturation current, a 3.8% decrease in the peak transconductance, a 0.3 V positive shift of the threshold voltage, and a three-to fourfold decrease in reverse gate leakage current are observed compared with the preirradiation values. The main degradation mechanism is considered to be the generation of deep trap states in the band gap, which remove electrons and reduce the carrier mobility in a two-dimensional electron gas (2DEG). Both the carrier removal rate and negatively charged trap density can be extracted, which shows that about 3500 proton injections lead to one carrier removal. Proton fluence and energy are found to be two key parameters that affect the degradation characteristics of irradiated GaN HEMTs.

Heavy ion irradiation induced failure of gallium nitride high electron mobility transistors: effects of in-situ biasing

“…Gold heavy ions with mid-level energy (1.5 MeV) and 6.5 × 10 15 gold cm −2 fluence are shown to generate defect clusters that decrease saturation current by four orders of magnitude and cause loss of gate control [12]. Some studies claimed that the presence of an electric field has no impact on incoming ion radiation [19], whereas others show dissimilar behavior in transport properties between ON and OFF conditions [20][21][22][23][24]. Ionizing sources, such as X-ray and 60 Co, have been employed to evaluate the influence of irradiation at various bias conditions in HEMTs.…”