Universal behavior in irradiated high-electron-mobility transistors

Abstract

Radiation-induced decreases in the drain current I d in a wide range of GaAs/AlGaAs high-electron-mobility transistors ͑HEMTs͒ are shown to be directly proportional to the induced defect concentration. The constant of proportionality depends only weakly on gate length, doping profile and concentration, layer thickness, device geometry, and operating voltages, and is hence nearly device independent. The same proportionality holds when the channel layer material is changed from GaAs to InGaAs. However, when the donor layer material is switched to InGaP ͑in InGaAs/InGaP HEMTs͒, the constant of proportionality changes, and the drain current becomes 16 -17 times more radiation tolerant. The drain current in InGaAs/InAlAs HEMTs is about 30 times more radiation tolerant than in InGaAs/AlGaAs. We propose that the linear dependence of I d on defect concentration arises from high-efficiency scattering of carriers out of the two-dimensional electron gas in the channel layer, and that the slope of the linear relationship is determined by the efficiency with which the donor layer reinjects scattered carriers.

Review—Ionizing Radiation Damage Effects on GaN Devices

“…33,34,42,50 For example, in AlGaN/GaN HEMTs at low proton fluences, the degradation is dominated by changes in device regions other than the two-dimensional electron gas (2DEG), such as the electrical contacts, while at higher fluences, displacement damage in the region of the 2DEG and surrounding layers becomes a more significant contributing factor. In the case of high-fluence proton irradiation (at an energy of 1.8 MeV), the vast majority of recoil atoms have energy less than 20 eV.…”

“…5,12,16,[21][22][23][24][25][27][28][29][30][31][32][33][34][35][36][37][42][43][44][45][46][47][49][50][51][52][53][54][55][56][57][58]79 For the high energy protons encountered in space-based applications, AlGaN/GaN HEMTs show decreases in tranconductance (g m ), drain-source current (I DS ), shifts in threshold voltage (V T ) and gate current (I G ) after irradiation with 40 MeV protons at doses equivalent to decades in low-earth orbit. These protons create deep electron traps that increase the HEMT channel resistance and decrease carrier mobility.…”

Proton Tolerance of InAs Based HEMT and DHBT Devices

“…This seems an unlikely result, given the common observation of decreasing Id with increasing radiation in IIEMT devices, owing to the decreased mobility and channel charge resulting from the induced atomic displacement damage [15]. Recent published results of drain current changes in similar InAs channel HIEMT devices subjected to a wider range of proton fluence (up to 7x1 014 p/cm2) show minimal Id changes at fluences comparable to the maximum used in our experiments (6x10l3 p/cm2), even with significantly lower proton energy (2 MeV) and hence increased damage within the semiconductor volume near the surface [9].…”

Radiation Effects in Iii-v Semiconductor Electronics

“…Thus the linear decrease of I d arises from high-efficiency scattering out of the 2DEG, but the slope is determined by the reinjection rate, which depends on the specific material system. 39 Multi-quantum-well and superlattice devices. Though currently used only in photonic and optoelectronic applications, MQW and superlattice devices are excellent examples of the state of the art in bandgap engineering and fabrication.…”