Work-Function Engineering for 32-nm-Node pMOS Devices: High-Performance TaCNO-Gated Films

Abstract

We have demonstrated p-type field effect transistors (p-FETs) devices using a TaCNO metal gate for the first time. These p-FETs have threshold voltage values of - 0.4 and - 0.25 V for HfSiON and HfSiO gate dielectrics, respectively, with equivalent oxide thickness of 1.6-1.7 nm. The TaCNO metal shows a high effective work function (eWF) of 4.89 eV on thick SiO2 interface layer, although the eWF rolls off with reducing EOT. Excellent transistor characteristics are achieved, with Ion of 375 muA/mum at Ioff = 60 nA, for Vdd = 1.1V .