Nickel silicide metal gate FDSOI devices with improved gate oxide leakage

Abstract

Fully depleted SOI (FDSOI) devices with undoped channel require metal gates to achieve correct threshold voltages. We demonstrate metal gate FDSOI devices using NiSi gates with symmetric V/sub t/ for both NMOS and PMOS devices. Metal gates are stable on 2 nm gate oxide and show capacitance equivalent gate oxide thickness (CET) 0.6 nm thinner than poly gates. The gate leakage current is up to two orders of magnitude lower and high mobility is achieved (peak electron mobility 670 cm/sup 2//Vs and 170 cm/sup 2//Vs for holes).