Analytical modeling and simulation of subthreshold behavior of dual material gate (DMG) Al0.7Ga0.3Sb/InAs HEMT

In this work, a two dimensional (2-D) analytical model and simulation of dual material gate (DMG) Al_0.7Ga_0.3Sb/InAs High Electron Mobility Transistor (HEMT) has been presented. Superiority of DMG over single material gate (SMG) structure for this kind of HEMTs has been highlighted. Simulation results show the suppression of short channel effects (SCEs) and improvement of carrier transport efficiency. Material with lower work function works as a screening gate while material with higher work function works as a control gate and thus suppresses the short channel effects. The electric field also becomes more uniform and so the carrier transport efficiency improves. This work shows the variation of channel potential and electric field with channel length for both double material gate (DMG) and single material gate (SMG) Al_0.7Ga_0.3Sb/InAs HEMT. All the results have been verified using ATLAS device simulator. So this work shows a simple model to effectively analyze the sub-threshold behavior of DMG Al_0.7Ga_0.3Sb/InAs HEMTs.