Zero-thickness multi work function solutions for N7 bulk FinFETs

Abstract

A novel multi work function process is used to demonstrate up to 250 mV effective work function shifts of nMOS devices. The process use SiH4-soak of ALD TiN to change its barrier properties with ALD TiAl. FinFET devices are demonstrated with ~100 mV VT-shift for 24-nm-LG devices resulting in 20× reduction in off-state leakage at unaffected sub threshold slope and improved mismatch behavior. A patterning scheme using an nMOS first RMG process is proposed and demonstrated.