Avoiding plasma induced damage to gate oxide with conductive top film (CTF) on PECVD contact etch stop layer

Significantly reduced plasma damage is demonstrated by including a thin conductive top film (CTF) on the contact etch stop layer (ESL) for the first time, which effectively blocks radiation generated by subsequent high density plasma processes. We also show that plasma damage exacerbates negative bias temperature instability (NBTI) in PMOSFETs and can be effectively suppressed by the CTF process.