Effect of Electron Irradiation Fluence on InP-Based High Electron Mobility Transistors.

Sun Sun,Wei Wei,Ding Ding,Li Li,Zhong Zhong,Jin Jin

doi:10.3390/nano9070967

Abstract

In this paper, the effect of electron irradiation fluence on direct current (DC) and radio frequency (RF) of InP-based high electron mobility transistors (HEMTs) was investigated comprehensively. The devices were exposed to a 1 MeV electron beam with varied irradiation fluences from 1 × 1014 cm−2, 1 × 1015 cm−2, to 1 × 1016 cm−2. Both the channel current and transconductance dramatically decreased as the irradiation fluence rose up to 1 × 1016 cm−2, whereas the specific channel on-resistance (Ron) exhibited an apparent increasing trend. These changes could be responsible for the reduction of mobility in the channel by the irradiation-induced trap charges. However, the kink effect became weaker with the increase of the electron fluence. Additionally, the current gain cut-off frequency (fT) and maximum oscillation frequency (fmax) demonstrated a slightly downward trend as the irradiation fluence rose up to 1 × 1016 cm−2. The degradation of frequency properties was mainly due to the increase of gate-drain capacitance (CGD) and the ratio of gate-drain capacitance and gate-source capacitance (CGD/CGS). Moreover, the increase of Ron may be another important factor for fmax reduction.

Highlights

With the development of high-precision detection and high-speed data transmission applications, the operating frequency of the core chips in transceiver systems has increased from W band to G band and even terahertz [1,2,3]
The results showed that the gate leakage current significantly decreased, which was due to the neutralization of nitrogen vacancies, and that the removal of oxygen impurities induced the defects after electron irradiation [14]
Kimura et al performed a systematic study of electron irradiation effects on the Schottky gate of InGaAs/GaAs high electron mobility transistors (HEMTs) which showed that deep traps were introduced at the gate metal and GaAs layer [15]

Summary

Introduction

With the development of high-precision detection and high-speed data transmission applications, the operating frequency of the core chips in transceiver systems has increased from W band to G band and even terahertz [1,2,3]. The impact of proton irradiation on the direct current (DC) performance of AlGaN/GaN HEMTs was investigated by Liu et al, which indicated that the DC characteristics were degraded more seriously at high proton fluence. 1 MeV electron irradiation was carried out on InP-based HEMTs at fluences ranging from 1 × 1014 cm−2, 1 × 1015 cm−2, to 1 × 1016 cm−2 On this basis, the changes and damage mechanism of direct current (DC) and radio frequency (RF) properties were analyzed before and after electron irradiation. The changes and damage mechanism of direct current (DC) and radio frequency (RF) properties were analyzed before and after electron irradiation These studies serve as a theoretical underpinning for radiation-harden design of devices and integrated circuits, further improving the stability and durability of related electronic systems

Materials and Methods

Results and Discussion

X 1016cm-2

Conclusions