Electrically active defects in Al2O3-InGaAs MOS stacks at cryogenic temperatures

The effects of defects in In
0.47
Ga
0.53
As/Al
2
O
3
/Ni metal-oxide-semiconductor (MOS) stacks at cryogenic temperatures are investigated. The MOS stacks exhibit a hysteresis in the capacitance-voltage (CV) curve, both at room temperature and at 100K, indicating the presence of effective charge capture/emission dynamics in the oxide even at cryogenic temperatures. Border traps (BTs) in the Al
2
O
3
close to the In
0.47
Ga
0.53
As/Al
2
O
3
interface are recognized as the best candidate for explaining the experimental CV. The hysteresis shape and its temperature dependence are used to profile the oxide defects’ properties, which allow correctly predicting the MOS stacks CV and conductance-voltage (GV) frequency dispersions and gaining insights on the hysteresis dynamics.