Atomic-layer-deposited HfO2 on In0.53Ga0.47As: Passivation and energy-band parameters

[[abstract]]Atomic-layer-deposited high κ dielectric HfO2 films on air-exposed In0.53Ga0.47As/InP (100), using Hf(NCH3C2H5)4 and H2O as the precursors, were found to have an atomically sharp interface free of arsenic oxides, an important aspect for Fermi level unpinning. A careful and thorough probing, using high-resolution angular-resolved x-ray photoelectron spectroscopy (XPS) with synchrotron radiation, however, observed the existence of Ga2O3, In2O3, and In(OH)3 at the interface. The current transport of the metal-oxide-semiconductor capacitor for an oxide 7.8 nm thick follows the Fowler–Nordheim tunneling mechanism and shows a low leakage current density of ∼ 10−8 A/cm2 at VFB+1 V. Well behaved frequency-varying capacitance-voltage curves were measured and an interfacial density of states of 2×1012 cm−2 eV−1 was derived. A conduction-band offset of 1.8±0.1 eV and a valence-band offset of 2.9±0.1 eV have been determined using the current transport data and XPS, respectively.[[fileno]]2030161010007[[department]]電機工程學