Metal gate electrode, channel and gate oxide engineering to improve DC and analog/RF performance of double-gate MOSFET for high-speed applications

Abstract

In the present work, for high-speed and high-frequency applications, various DC and analog/RF parameters like drain current ( $$I_{{\text{D}}}$$ ), transconductance $$(g_{m} )$$ , output conductance $$(g_{d} )$$ , transconductance generation factor (TGF), the cutoff frequency $$(f_{T} )$$ , transit time $$\left( \tau \right)$$ , frequency transconductance product (FTP), channel resistance $$(R_{{{\text{ch}}}} )$$ , direct tunneling current ( $$I_{{\text{G}}}$$ ) and quasi-static capacitance–voltage (QSCV) characteristics for 10-nm double-gate NMOSFETs of Si and $${\text{In}}_{0.53} {\text{Ga}}_{0.47} {\text{As}}$$ have been studied and simulation results are reported using Silvaco ATLAS 3D TCAD. In this device, we consider the drift diffusion approach and the self-consistent solution of Poisson’s equation with Schrodinger’s equation (to account for quantization). The effect of including conduction band splitting into multiple sub-bands has been taken into account, and the channel region is very lightly doped. The effect of metal gate electrode, channel and gate oxide engineering on $$I_{{\text{D}}}$$ , $$g_{m}$$ , TGF, $$g_{d}$$ , $$f_{T}$$ , $$\tau$$ , TFP, $$R_{{{\text{ch}}}}$$ , $$I_{{\text{G}}}$$ and QSCV has been simulated. Also, a comparison of these parameters has been done between Si and $${\text{In}}_{0.53} {\text{Ga}}_{0.47} {\text{As}}$$ . It was found that except TGF at the higher $$V_{{{\text{GS}}}}$$ and $$I_{{\text{G}}}$$ values for Si, all the other above-mentioned parameters are higher for $${\text{In}}_{0.53} {\text{Ga}}_{0.47} {\text{As}}$$ . It was found that there is about 7.99 × 105% increase in $$I_{{{\text{ON}}}}$$ for $${\text{In}}_{0.53} {\text{Ga}}_{0.47} {\text{As}}$$ as compared to Si. Also, the device has a small drain-induced barrier lowering ~ 8.44 mV/V, almost an ideal subthreshold slope ~ 60 mV/dec and high ION/IOFF ratio ~ 6.30 × 107.