2DEG modulation in double quantum well enhancement mode nitride HEMT

Abstract

A double quantum well (QW) based nitride HEMT has been conceptualized through numerical simulation of Schrödinger and Poisson's equations for enhancement mode operation by introduction of a deeper secondary QW along with primary AlGaN/GaN triangular potential well. The carriers for drain current are populated in the shallower primary QW through energy band bending with positive VGS. Participation of the concerned QW in drain current conduction depends upon the magnitude of the band offsets and polarization effects of the materials. Effect of the gate bias on energy band delineates the modulation of 2DEG carriers in the shallow energy quantum well from 1.6×10−3 cm−3 to 9.47×1017 cm−3 with gate bias from 0.5 V to 1.0 V to confirm the drain current conduction with Vth>+0.5 V at typical depth of source and drain Ohmic contacts.