On Stress-Induced Polarization Effect in Ammonothermally Grown GaN Crystals
Abstract
The results of basic ammonothermal crystallization of gallium nitride are described. The material is mainly analyzed in terms of the formation of stress (called stress-induced polarization effect) and defects (threading dislocations) appearing due to a stress relaxation process. Gallium nitride grown in different positions of the crystallization zone is examined in cross-polarized light. Interfaces between native ammonothermal seeds and new-grown gallium nitride layers are investigated in ultraviolet light. The etch pit densities in the seeds and the layers is determined and compared. Based on the obtained results a model of stress and defect formation is presented. New solutions for improving the structural quality of basic ammonothermal gallium nitride crystals are proposed.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Apr 15, 2022
- Source ID
- 10.3390/cryst12040554
Entities
People
- Izabella Grzegory
- J.L. Weyher
- Karolina Grabiańska
- Małgorzata Iwińska
- Michal Boćkowski
- Robert Kucharski
- Tomasz Sochacki
Organizations
- ECSEL Joint Undertaking
- United States Navy