Defect passivation with fluorine in a Ta/sub x/C/ high-K gate stack for enhanced device threshold voltage stability and performance

Using a novel fluorinated Ta
_x
C
_y
/high-k gate stack, we show breakthrough device reliability and performance improvements. This is a critical result since threshold voltage instability may be a fundamental problem and performance degradation for high-k is a concern. The novel fluorinated gate stack device exceeds the PBTI and NBTI targets with sufficient margin and has electron mobility comparable to the best polySi/SiON device on bulk Si reported so far