Thermal and statistical analysis of various AlN/GaN HEMT geometries for millimeter Wave applications

Abstract

Downscaling HEMT devices is nowadays substantial to allow their operation in the millimeter wave frequency domain. In this work, the electrical parameters of three different AlN/GaN structures featuring various GaN channel thicknesses were compared. After a DC electrical stabilization procedure, 96 HEMT devices under test exhibit a minor dispersion in DIBL and lag rates, which reflects an undeniable technological mastering and maturity. Evaluation of the sensitivity of devices with different geometries at temperatures of up to 200°C revealed that the gate-drain distance impacts Ron variation and not Idss variation with temperature. We also showed that DIBL at moderate electrical field and the drain lags exhibit athermal behavior; unlike gate lag delays which can be thermally activated and exhibit a linear temperature dependence regardless of the size of the gate length and gate-to-drain distance.