Novel N/PFET Vt control by TiN plasma nitridation for aggressive gate scaling

Abstract

A novel N/PFET threshold voltage (Vt) control scheme was developed for aggressive gate scaling. TiN plasma nitridation reduces absolute Vt by 100mV for both NFETs and PFETs at the same time without photolithography step increase and performance or reliability penalty. TiN plasma nitridation does not need additional work function metal (WFM) to control Vt and hence allows thicker gate contact metal for low gate resistance and improved AC performance.