Positive and negative bias temperature instability in La2O3 and Al2O3 capped high-k MOSFETs

PBTI and NBTI reliability is investigated on La
₂
O
₃
and Al
₂
O
₃
capped n and pMOSFETs, respectively. Low V
_th
devices are achieved using the capping layers without degrading BTI reliability. For the Al
₂
O
₃
capped pMOSFETs no additional defects related to the capping are observed. The La
₂
O
₃
capping layer for nMOSFETs induces shallow traps, which however are not critical at operating conditions.