High mobility Ge pMOSFETs with 0.7 nm ultrathin EOT using HfO2/Al2O3/GeOx/Ge gate stacks fabricated by plasma post oxidation

HfO
₂
/Al
₂
O
₃
/GeO
_x
/Ge gate stacks were fabricated by applying the plasma post oxidation to HfO
₂
/Al
₂
O
₃
/Ge structures. These Ge gate stack are shown to simultaneously realize both ultrathin EOT of ~0.7 nm and low D
_it
of 10
¹¹
cm
^-2
eV
^-1
order. The superior operation of (100) Ge pMOSFETs with these gate stacks has been demonstrated with record high hole mobility of 596 cm
²
/Vs under ~0.8 nm EOT among the Ge pMOSFETs reported so far.