Suitability of high-k gate oxides for III–V devices: A PBTI study in In0.53Ga0.47As devices with Al2O3

We present a comprehensive study of Positive Bias Temperature Instability (PBTI) in In
_0.53
Ga
_0.47
As devices with Al
₂
O
₃
gate oxide, and with varying thickness of the channel quantum well. We show significant instability of the device electrical parameters induced by electron trapping into a wide distribution of defects in the high-k layer, with energy levels just above the InGaAs conduction band. A significant PBTI dependence on the channel thickness is found and ascribed to quantization effects. We argue that, in order to be relevant for production, the superior transport properties of III-V channels will need to be demonstrated with more stable high-k gate stacks.