IMPACT OF DELTA-DOPED POSITION ON THE PERFORMANCE OF AlGaAs/InGaAs/GaAs PSEUDOMORPHIC HIGH ELECTRON MOBILITY TRANSISTOR

Abstract

This paper reports on simulation of delta-doped AlGaAs/InGaAs/GaAs Pseudomorphic High Electron Mobility Transistors (PHEMT’s) by means of two-dimensional device simulations. The commercial two-dimensional device simulator Taurus-MEDICI was used to study the band-diagram, threshold voltage (Vth), transconductance (G_m) and cut off frequency (f_T) of the PHEMT. Three different devices with single delta-doped layer located at three different positions in the pHEMT layer are simulated. The result shows that the position of delta-doped layer can be optimised to maximise the drain current, transconductance and cut-off frequency. It also can determine the device operation mode, whether as enhancement mode or depletion mode.