Afanas'ev, VV,Stesmans, A,Brammertz, G,Delabie, A,Sionke, S,O'Mahony, A,Povey, IM,Pemble, ME,O'Connor, E,Hurley, PK,Newcomb, SB;

2009

May

Applied Physics Letters

Energy barriers at interfaces between (100) InxGa1-xAs (0 <= x <= 0.53) and atomic-layer deposited Al2O3 and HfO2

Validated

()

alumina atomic layer deposition conduction bands energy gap gallium arsenide hafnium compounds III-V semiconductors indium compounds nanostructured materials oxidation photoconductivity photoemission semiconductor-insulator boundaries valence bands BAND OFFSETS SEMICONDUCTORS

94

The electron energy band alignment at interfaces of InxGa1-xAs (0 <= x <= 0.53) with atomic-layer deposited insulators Al2O3 and HfO2 is characterized using internal photoemission and photoconductivity experiments. The energy of the InxGa1-xAs valence band top is found to be only marginally influenced by the semiconductor composition. This result suggests that the known bandgap narrowing from 1.42 to 0.75 eV when the In content increases from 0 to 0.53 occurs mostly through downshift of the semiconductor conduction band bottom. It finds support from both electron and hole photoemission data. Similarly to the GaAs case, electron states originating from the interfacial oxidation of InxGa1-xAs lead to reduction in the electron barrier at the semiconductor/oxide interface.

ARTN 202110