Emphasis on trap activity in AlGaN/GaN HEMTs through temperature dependent pulsed I-V characteristics

IEMN-CNRS, UMR-8520, 59652 Villeneuve d’Ascq, France

^a e-mail: nicolas.defrance@iemn.univ-lille1.fr

Received: 7 October 2013
Accepted: 14 October 2013
Published online: 15 November 2013

Abstract

This paper reports on the temperature dependent threshold voltage analysis of AlGaN/GaN High electron mobility transistors (HEMTs) in order to investigate the trap effects occurring in these devices. Measurements are performed in pulse configuration to emphasize the gate-lag and drain-lag effects involving current collapses. A quantitative extraction of the interface traps density is performed through the observation of the pinch-off voltage shifts in cold bias conditions. Additionally, a thermally activated energy level of 0.25 eV is evaluated whatever the bias condition. It is also shown that the trap density increases drastically when the drain is biased, limiting the performance of AlGaN/GaN devices through drain-lag effect.