X-ray characterization of thick GaN layers grown by HVPE

The crystallographic structures of the various Metalorganic Vapour Phase Epitaxy (MOVPE) thin GaN epitaxial layers deposited on (00.1) sapphire substrates are described and compared with the structural properties of the thick gallium nitride layers deposited by Hydride Vapour Phase Epitaxy (HVPE) on the top of them. The crystallographic structure and the quality of epitaxial GaN layers obtained in this way are determined. Additionally thick HVPE GaN layers deposited on these composite substrates (MOVPE-GaN/sapphire) are compared with the thick HVPE GaN layers grown directly on sapphire substrates. It was found that HVPE thick GaN epilayers on sapphire are comparable with the HVPE thick GaN layers deposited on composite substrates.