Abstract
The microstructure of GaN films grown by electron cyclotron resonance (ECR) molecular-beam epitaxy (MBE) and hydride vapor-phase epitaxy (HVPE) is studied using x-ray-absorption measurements at the N edge. The local microstructure around the N atom is found to be distorted. The nearest neighbors of the N atom are four Ga atoms, of which are located at a distance which is expected, and at a distance This distortion is more pronounced in the cubic ECR-MBE and the HVPE hexagonal samples where the ratio is equal to 1. In the rest of the samples the distortion is smaller and the ratio takes the value 0.33. Nitrogen deficiency is not detected in the second nearest-neighbor shell and the N atoms are found at the expected distance of 3.11 Å.
- Received 10 February 1997
DOI:https://doi.org/10.1103/PhysRevB.56.13380
©1997 American Physical Society