Scaled ZrO2 dielectrics for In0.53Ga0.47As gate stacks with low interface trap densities

ZrO2 dielectrics were grown on n-In0.53Ga0.47As channels by atomic layer deposition, after employing an in-situ cyclic nitrogen plasma/trimethylaluminum surface cleaning procedure. By scaling the ZrO2 thickness, accumulation capacitance densities of 3.5 μF/cm2 at 1 MHz are achieved. The midgap interface trap density is estimated to be in the 1012 cm−2 eV−1 range. Using x-ray photoelectron spectroscopy, it was shown that the interface contained the oxides of In, Ga, and Al, but no As-oxides or As-As bonds within the detection limit. The results allow for insights into the effective passivation of these interfaces.