Charge-pumping characterization of interface traps in Al2O3/In0.75Ga0.25As metal-oxide-semiconductor field-effect transistors

Charge pumping was used to characterize the interface traps between Al2O3 and In0.75Ga0.25As in an n-channel inversion-mode metal-oxide-semiconductor field-effect transistor (MOSFET). By analyzing the charge pumped under gate voltage pulses of different rise and fall times, the interface trap density was extracted across the band gap of In0.75Ga0.25As. The interface trap density was found to be 4×1012 cm−2 eV−1 near the conduction band and to peak at 3×1013 cm−2 eV−1 mid-gap. The result helps explain the promising on-state performance of the Al2O3/In0.75Ga0.25As MOSFET and the need to further improve the interface so that its off-state performance can be on par with that of the Si MOSFET.