The dynamics of surface donor traps in AlGaN/GaN MISFETs using transient measurements and TCAD modelling

Abstract

This paper presents a detailed and correlated (i) Id-Vg, (ii) Cgg-Vg, and (iii) transient analysis of donor traps in a SiN/GaN/AlGaN/GaN Metal-Insulator-Semiconductor Field-Effect Transistor (MISFET) fabricated on a silicon substrate. We explain for the first time that the long-time constants are due to the close coupling between the emission/capture processes on one hand and the transient transport of electrons across the GaN/AlGaN barrier on the other. Emission and capture time constants were extracted for several bias conditions and temperatures. Moreover, we have developed a TCAD model that consistently gives a good match to DC, AC, and transient experimental results.