Investigation and development of the high-temperature vapour phase epitaxy for producing single-crystalline GaN layers.

• Applicants: Dr. Olf Pätzold; Professor Dr. David Rafaja
• Subject Area: Synthesis and Properties of Functional Materials
• Term: from 2014 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 257632561

The proposal aims at a further development of the High Temperature Vapor Phase Epitaxy (HTVPE) as an efficient and environment-friendly method for a deposition of GaN layers on sapphire substrates. The HTVPE, which is based on the physical vapor transport of gallium, is of increasing interest, because both GaN templates and GaN bulk layers can be produced. The main objectives of the proposal are the investigation and clarification of the GaN defect interaction, the development of methods for a reproducible defect and stress engineering, and the improvement of the stability of the HTVPE process at high deposition rates. Systematic growth experiments and a detailed and comprehensive structural characterization of the GaN layers are planned to achieve the objectives of the proposal. Finally, the following questions have to be answered as a result of the project:1) Is it possible to produce thick GaN bulk layers by HTVPE?2) Is it possible to produce GaN-on-sapphire layers with a sufficient layer quality for the use as templates?This proposal is a revised version of a rejected renewal proposal, where the comments of the reviewers and the recommendations of the DFG are taken into account. The proposal describes a joint project of two institutes of the TU Bergakademie Freiberg. Prospects arise from the expertise of the involved institutes in the fields of growth and characterization of GaN, as well as from the results achieved in the preceding project on the HTVPE of GaN. For instance, first experiments with high growth rates >100µm/h and first studies on the in-situ defect engineering were already performed, demonstrating the feasibility of the proposal.

• DFG Programme: Research Grants