Vacancy defect distribution in heteroepitaxial a-plane GaN grown by hydride vapor phase epitaxy

• We have used positron annihilation spectroscopy to study the native vacancy distribution in a-plane heteroepitaxial GaN. We show that the Ga vacancy concentration is independent of the layer thickness in the range from 5 to 25 µ m. This is strikingly different from the behavior in c-plane GaN, where the Ga vacancy concentration decreases dramatically with the distance from the GaN/sapphire interface. This difference in the native vacancy profiles is tentatively correlated with the differences in the O impurity and dislocation density profiles in the polar and non-polar materials. © 2006 Elsevier B.V. All rights reserved.

Nyckelord

A1. Characterization

A1. Point defects

A3. Hydride vapor phase epitaxy

A3. Metalorganic chemical vapor deposition

B1. Nitrides

B2. Semiconducting gallium compounds

TECHNOLOGY

TEKNIKVETENSKAP

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