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arXiv · 1109.2566

Electrical Properties of Atomic Layer Deposited Aluminum Oxide on Gallium Nitride

Michele Esposto·Sriram Krishnamoorthy·Digbijoy N. Nath·Sanyam Bajaj·Ting-Hsiang Hung·Siddharth Rajan
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Abstract

We report on our investigation of the electrical properties of metal/Al2O3/GaN metal-insulator-semiconductor (MIS) capacitors. We determined the conduction band offset and interface charge density of the alumina/GaN interface by analyzing capacitance-voltage characteristics of atomic layer deposited Al2O3 films on GaN substrates. The conduction band offset at the Al2O3/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 4.60x1012 cm-2 at the Al2O3/GaN interface. We provide hypotheses to explain the origin of this charge by analyzing the energy band line-up.

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Michele Esposto, Sriram Krishnamoorthy, Digbijoy N. Nath, Sanyam Bajaj, Ting-Hsiang Hung, Siddharth Rajan. 2011-09-12. Electrical Properties of Atomic Layer Deposited Aluminum Oxide on Gallium Nitride. https://doi.org/10.1063/1.3645616

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