Atomic-layer-deposited Hf O2 on In0.53 Ga0.47 As: Passivation and energy-band parameters
Journal
Applied Physics Letters
Journal Volume
92
Journal Issue
7
Date Issued
2008
Author(s)
Chang, Y.C.
Huang, M.L.
Lee, K.Y.
Lee, Y.J.
Lin, T.D.
Kwo, J.
Lay, T.S.
Liao, C.C.
Cheng, K.Y.
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 7.8nm thick follows the Fowler–Nordheim tunneling mechanism and shows a low leakage current density of ∼10−8A∕cm2 at VFB+1V. Well behaved frequency-varying capacitance-voltage curves were measured and an interfacial density of states of 2×1012cm−2eV−1 was derived. A conduction-band offset of 1.8±0.1eV and a valence-band offset of 2.9±0.1eV have been determined using the current transport data and XPS, respectively.
SDGs
Type
journal article