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Title: Electrical properties of atomic layer deposited aluminum oxide on gallium nitride

Journal Article · · Applied Physics Letters
DOI:https://doi.org/10.1063/1.3645616· OSTI ID:22027757

We report on our investigation of the electrical properties of metal/Al{sub 2}O{sub 3}/GaN metal-insulator-semiconductor capacitors. We determined the conduction band offset and interface charge density of the alumina/GaN interface by analyzing the capacitance-voltage characteristics of atomic layer deposited Al{sub 2}O{sub 3} films on GaN substrates. The conduction band offset at the Al{sub 2}O{sub 3}/GaN interface was calculated to be 2.13 eV, in agreement with theoretical predications. A non-zero field of 0.93 MV/cm in the oxide under flat-band conditions in the GaN was inferred, which we attribute to a fixed net positive charge density of magnitude 4.60 x 10{sup 12 }cm{sup -2} at the Al{sub 2}O{sub 3}/GaN interface. We provide hypotheses to explain the origin of this charge by analyzing the energy band line-up.

OSTI ID:
22027757
Journal Information:
Applied Physics Letters, Vol. 99, Issue 13; Other Information: (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
Country of Publication:
United States
Language:
English