The effects and mechanisms of 2 MeV proton irradiation on InP-based high electron mobility transistors

Abstract

InP-based high electron mobility transistors (HEMTs) are potential candidates for sub-millimeter wave and terahertz satellite communications due to their ultrahigh frequency performance. Therefore, the study of their irradiation reliability is extremely urgent. In this paper, a 2 MeV proton irradiation experiment has been carried out in InP-based HEMTs, and damage mechanisms have been systematically studied, including dc and rf characteristics. The experimental results show that InP-based HEMTs have wondrously excellent radiation tolerance. The degradation of electrical characteristics occurs only when the irradiation fluence is higher than 1 × 1013 H+/cm2. The drain saturation current and the maximum transconductance have, respectively, decreased by 7.1% and 5.4% at a fluence of 1 × 1014 H+/cm2. Different from the other III–V HEMTs, the irradiated InP-based HEMTs exhibited an abnormality in the “peak collapse” of transconductance. Rf characteristics' parameters demonstrate slighter degradation compared to dc transconductance. Transmission line model (TLM) measurement and Schottky barrier calculation have shown that there is no noticeable degradation of an Ohmic contact and a Schottky contact; therefore, the main possible reason for device degradation comes from the interior of a semiconductor structure. Furthermore, device simulation indicates that defects introduced by irradiation on the upper and lower heterojunction interface of the channel and the interface of the gate recess should be responsible for degradation. Our experiments show that InP-based HEMTs have excellent radiation resistance, and they have good prospects for applications in radiation environments.