Simulation of ultra-short channel HEMTs with different gate concepts by 2D/3D-hydrodynamic models

Abstract – Numerical simulations of In0.52Al0.48As/In0.7Ga0.3As/InP HEMTs have been carried out with a 2D/3D-hydrodynamic model. The investigation of double gate and striped-channel devices with the same layer structure results in an increase of cut-off frequencies. At a reduce of gate lengths down to 5 nm short channel effects becomes important in particular for the single gate device. Transistors with alternative gate structures can suppress these effects and improve simultaneously the RF-behavior. At a gate length LG = 5 nm transit frequencies of about 690 GHz, 790 GHz and 890 GHz can be attained with the single gate, striped-channel and double gate HEMT, respectively. Double pulse-doped devices can achieve THz transit frequencies.