Low interfacial density of states around midgap in MBE-Ga2O 3(Gd2O3)/In0.2Ga0.8As
Journal
Journal of Crystal Growth
Journal Volume
323
Journal Issue
1
Pages
99-102
Date Issued
2011
Author(s)
Lin, C.A.
Chiu, H.C.
Chiang, T.H.
Chang, Y.C.
Lin, T.D.
Kwo, J.
Wang, W.-E.
Dekoster, J.
Heyns, M.
Hong, M.
Abstract
Systematic temperature-dependent capacitance-voltage and conductance measurements were used to study the electrical characteristics of molecular beam epitaxy (MBE) and atomic layer deposition (ALD) oxides on In 0.2Ga0.8As/GaAs. The distribution of interfacial density of states (Dit) within the band gap of In0.2Ga 0.8As was deduced with the conductance method. The MBE-grown Ga 2O3(Gd2O3)/In0.2Ga 0.8As, with an excellent tailored interface, has given Dit values of ∼5×1011 eV-1 cm-2 above, ∼2×1012 eV-1 cm-2 below, and 17×1012 eV-1 cm-2 around the mid-gap region (0.50.7 eV above valence band maximum (EV)); the high D it value near the mid-gap, extracted at 100 and 150°C, may be related to the temperature effect, which tends to induce more trap excitations. In contrast, the ALD-Al2O3/In0.2Ga 0.8As has yielded higher Dit values of>1013 eV-1 cm-2 around the mid-gap region. © 2010 Elsevier B.V. All rights reserved.
Type
journal article