The analog/RF performance of a strained-Si graded-channel dual-material double-gate MOSFET with interface charges

Abstract

The analog/radiofrequency (RF) performance of a strained-silicon (s-Si) graded-channel dual-material double gate (GC-DMDG) metal–oxide–semiconductor field-effect transistor (MOSFET) with interface charges is investigated by using Sentaurus technology computer-aided design (TCAD) software. The analog/RF figures of merit of the proposed s-Si GC-DMDG MOSFET, including the intrinsic voltage gain, transconductance generation factor, early voltage, unity-current gain frequency ( $$f_{\rm t}$$ ), transconductance–frequency product (TFP), gain–frequency product (GFP), and gain–transconductance–frequency product (GTFP), are evaluated for different values of device parameters such as the strain in the silicon, the interface charge density, and the thicknesses of the oxide and substrate layers. The simulation results exhibit that the proposed s-Si GC-DMDG MOSFET device attains lower values of transconductance and output conductance and a higher value of early voltage compared with the s-Si graded-channel double-gate (GC-DG) MOSFET. Besides, the proposed s-Si GC-DMDG MOSFET device provides better performance in terms of $$f_{\rm t}$$ , TFP, GFP, and GTFP in comparison with the s-Si GC-DG MOSFET in the strong inversion region, and vice versa in the subthreshold region.