Effect of gate length variation on DC performance of Ino.7Gao.3As/InAs/Ino.7Gao.3As composite channel HEMT

Abstract

In this paper we have analyzed the effect of gate length variation on the DC parameters of Ino.7Gao.3As/InAs/Ino.7Gao.3As composite channel HEMT using 2D Sentaurus TCAD simulation. Hydrodynamic model is used for the simulation. The simulation model is calibrated with the previously published experimentally. Extensive device simulation of major device performance metrics such as drain induced barrier lowering, subthreshold slope, delay, threshold voltage, ON current to OFF current ratio and energy delay product have been done for wide range of gate length. As gate length is scaled the heterostructure devices using composite channel, with high-k dielectric provides higher ON current, lower delay and energy delay product. With gate length scaling there is a moderate increase in short channel effects such as DIBL, and SS. The result indicates the need to improve the Ion/Ioff ratio, Vt and SS as these are deviating slightly from the desired results. The proposed composite channel HEMT shows excellent promise as one of the candidates for future high speed applications.