Systematic study on bias temperature instability of various high-k gate dielectrics ; HfO2, HfZrxOy and ZrO2

HfO
2
, HfZr
x
O
y
and ZrO
2
gate dielectrics are systematically compared in terms of the nMOS PBTI and pMOS NBTI. Compared to HfO
2
, ZrO
2
exhibits higher capacitance and superior nMOS mobility characteristics. In addition, as the ZrO
2
content increases, V
th
shift under the nMOS PBTI stress is dramatically reduced. This is mainly contributed to the lower density of pre-existing bulk traps related to the oxygen vacancies.