Analysis of nanometer-scale InGaAs/InAs/InGaAs composite channel MOSFETs using high-K dielectrics for high speed applications

The outstanding electron transport properties of InGaAs and InAs semiconductor materials, makes them attractive candidates for future nano-scale CMOS. In this paper, the ON state and OFF state performance of 30 nm gate length InGaAs/InAs/InGaAs buried composite channel MOSFETs using various high-K dielectric materials is analyzed using Synopsys TCAD tool. The device features a composite channel to enhance the mobility, an InP spacer layer to minimize the defect density and a heavily doped multilayer cap. The simulation results show that MOSFETs with Al2O3/ZrO2 bilayer gate oxide exhibits higher gm/ID ratio and lower sub threshold swing than with the other dielectric materials. The measured values of threshold voltage (VT), on resistance (RON) and DIBL for Lg = 30 nm In0.53Ga0.47As/InAs/In0.53Ga0.47As composite channel MOSFET having Al2O3/ZrO2 (EOT = 1.2 nm) bilayer dielectric as gate oxide are 0.17 V, 290 Ω-µm, and 65 mV/V respectively. The device displays a transconductance of 2 mS/µm.