Energy-band parameters of atomic-layer-deposition Al2O3/InGaAs heterostructure

The valence-band offset has been determined to be 3.83 +/- 0.05 eV at the atomic-layer-deposition Al2O3/InGaAs interface by x-ray photoelectron spectroscopy. The Au-Al2O3/InGaAs metal-oxide-semiconductor diode exhibits current-voltage characteristics dominated by Fowler-Nordheim tunneling. From the current-voltage data at forward and reverse biases, a conduction-band offset of 1.6 +/- 0.1 eV at the Al2O3-InGaAs interface and an electron effective mass similar to 0.28 +/- 0.04m(0) of the Al2O3 layer have been extracted. Consequently, combining the valence-band offset, the conduction-band offset, and the energy-band gap of the InGaAs, the energy-band gap of the atomic-layer-deposited Al2O3 is 6.65 +/- 0.11 eV. (c) 2006 American Institute of Physics.