DC electrical performance improvement of AlGaAs/InGaAs PHEMTs by using low thermal neutron radiation dose

Abstract

An original method is presented to improve DC electrical performance of AlGaAs/InGaAs PHEMTs by using a low neutron radiation dose. An increase of the drain -source saturation current, a decrease of the knee voltage and a reduction of the leakage current of the Schottky contact are observed without degrading the current-gain cutoff frequency when the devices are irradiated with a neutron radiation dose of 1.2 × 10 10 neutrons/cm 2 .Introduction: GaAs-based field effect transistors (FETs), and in particular pseudomorphic high electron mobility transistors (PHEMTs), are extensively used for millimetre-wave and optical communication systems owing to their excellent high-frequency and low-noise performances [1]. As these GaAs-based devices are intended to be used in military, nuclear industry and space applications [2], it is imperative to study their electrical and microwave behaviour in extreme radiation environments. Many previous papers have studied the neutron [3] and gamma [4] radiation effects on these devices. In general, the purpose of these studies is to show the high immunity of the transistors to radiationinduced degradation for doses lower than 2 × 10 14 neutrons/cm 2 . A degradation of electrical performance of devices has usually been observed for a total dose greater than 1 × 10 15 neutrons/cm 2 [5]. On the other hand, an improvement of the electronic properties of GaAs material has been observed after an irradiation with low neutron fluences (3 × 10 12 neutrons/cm 2 ) [6]. The improvement of some bulk properties of GaAs material at low fluence irradiation has also been correlated with a high defect removal rate [7].We have investigated the influence of low neutron radiation doses on DC electrical performances of AlGaAs/InGaAs PHEMTs in order to improve their performance even if the technology of these devices is mature and industrialised.

Annihilation of electrical trap effects by irradiating AlGaN/GaN HEMTs with low thermal neutrons radiation fluence

“…We think that the impact of neutrons radiation on dc electrical performances of component can be different when low neutrons fluences and energies are used. In fact we have already shown that it is possible to improve the dc electrical performances of AlGaAs/InGaAs PHEMTs by using low thermal neutrons radiation fluence [11]. This result was in opposite to most of papers, which report on the effect of neutrons on GaAs transistors [12].…”