Analysis of Novel Core-Shell Junctionless Nanosheet FET for CMOS Logic Applications

Abstract

A Rectangular core-shell (RCS) is analyzed on vertically stacked gate oxide junctionless nanosheet along with doping and gate/dielectric engineering. This paper also proposes an N-type three fins vertically stacked with gate oxide stack junctionless nanosheet with opposite core doping in the channel known as RCS. The simulation results show that gate oxide stack with RCS junctionless nanosheet exhibit reduced $I_{\mathrm {OFF}}$ is 6.913E-21, increased $I_{\mathrm {ON}}$ is 2.408E-07, $I_{\mathrm {ON}}$ / $I_{\mathrm {OFF}}$ ratio is $0.418\times 10^{6}$ , DIBL is 6.9mV and SS of 60.65 mV/dec respectively. The core shell width variations with various gate oxide dielectric towards better $I_{\mathrm {ON}}$ , $I_{\mathrm {OFF}}$ and $I_{\mathrm {ON}}$ / $I_{\mathrm {OFF}}$ are analyzed. Interestingly, it is noted that for smaller shell thickness, the thickness of core should be equivalent to shell thickness and for larger shell thickness, thicker core is required. The device robustness towards analog and RF metrics are also evaluated with varied gate dielectrics. It has been observed that RCS architecture with opposite doping with HfO2 as gate oxide material has given outstanding outcomes compared to other gate oxide materials and without RCS method. Further, simulated the P-type of three fins vertically stacked with gate oxide stack junctionless nanosheet and combined both N-type and P-type three fins vertically stacked with gate oxide stack junctionless nanosheet to construct the CMOS inverter circuit. The voltage transfer characteristics (VTC) characteristics of junctionless nanosheet with RCS having HfO2 as gate-oxide based inverter has been notably improved as compared to the SiO2, Al2O3 and conventional three fins vertically stacked with gate oxide stack junctionless nanosheet inverter.

Keywords

• Junctionless
• stacked quad gate
• gate oxide stack
• RCS architecture
• inverters