Positive bias temperature instability degradation of InGaAs n-MOSFETs with Al2O3 gate dielectric

CP measurements show that PBTI stress induced interface trap area density ΔN
_it
in InGaAs/Al
₂
O
₃
n-MOSFET is very small and has power law time evolution At
^0.22
in the stress phase, and is partially recovered in the recovery phase. However the DC I
_s
-V
_g
measurements show large degradations of negative ΔV
_g
and sub-threshold swing S in the sub-threshold region and are recovered in the recovery phase, also show degradation of positive ΔV
_g
in the on-current region and continuing degradation in the recovery phase until reaching a stable state. The I
_s
-V
_g
degradation is mainly contributed by generation of near interface slow oxide traps under stress with recoverable donor trap energy density ΔD
_SOX
^DONOR
in the InGaAs energy gap with a tail extended to the conduction band energy, and permanent acceptor trap energy density ΔD
_SOX
^ACCEPTOR
in the conduction band energy with a tail extended to the energy gap. This trap model explains all experimental details perfectly.