Perfecting the Al2O3/In0.53Ga0.47As interfacial electronic structure in pushing metal-oxide-semiconductor field-effect-transistor device limits using in-situ atomic-layer-deposition

We performed interfacial electric and electronic studies of both in-situ and ex-situ atomic-layer deposited (ALD) Al2O3 films on InGaAs. Self-aligned inversion-channel metal-oxide-semiconductor field-effect-transistors (MOSFETs) with a 1 μm gate length (Lg) from the in-situ sample have extrinsic drain currents (Id) of 1.8 mA/μm, transconductances (Gm) of 0.98 mS/μm, and an effective mobility (μeff) of 1250 cm2/V s. MOSFETs that employ ex-situ ALD-Al2O3 have an Id of 0.56 mA/μm, Gm of 0.28 mS/μm, and μeff of 410 cm2/V s. Synchrotron radiation photoemission reveals no AsOx residue at the Al2O3/InGaAs interface using the in-situ approach, whereas some AsOx residue is detected using the ex-situ method.