Effect of high‐ k dielectric on the performance of Si, InAs and CNT FET

Abstract

The important issue of selection of gate dielectrics to reduce short channel effects (SCEs) is presented along with the study of different channel materials in transistors. A comparative study of performance was carried out of silicon dioxide (SiO2), aluminium oxide (Al2O3), hafnium oxide (HfO2), lanthanum oxide (La2O3) and titanium dioxide (TiO2) as gate dielectrics for Si double gate field-effect transistor (FET), Si gate all around (GAA) nanowire FET (NWFET), indium arsenide GAA NWFET and carbon nanotube (CNT) FETs within non-equilibrium Green's function formalism. Simulated results show that TiO2 is better gate dielectric as compared with SiO2, Al2O3, HfO2 and La2O3, with near ideal subthreshold swing (60 mV/decade), lower I off, improved drain-induced barrier lowering and high transconductance (gm ). Also, the gate capacitance (C g), cut-off frequency (f T) and switching time (τ) improve with the high-k dielectric materials. Furthermore, the study of different channel material shows that CNT has better SCEs, smaller C g with τ ranging from 13.5 to 12.5 fs suitable for digital applications and f T of about 7–9 THz.