Three-dimensional visualization of threading dislocations in GaN by polarized-light microscopy
Year: 2026
Type: article
Abstract: We demonstrate high-throughput three-dimensional imaging of threading dislocations in an ammonothermal gallium nitride (GaN) wafer using polarized-light microscopy with collimated LED illumination. Threading dislocations exhibited focal-depth-dependent in-plane shifts, enabling visualization of their three-dimensional inclination behavior over large areas. The experimentally observed trace geometries were reproduced by a geometrical model with a characteristic inclination of approximately 3.3° from the c axis. For the threading edge dislocations constituting the honeycomb defects, the inclination directions were approximately perpendicular to their x-ray topography-determined Burgers-vector directions, consistent with a climb component. Isolated dislocations with similar trace geometries showed corresponding relationships between their trace directions and assigned Burgers-vector directions under the assumption of edge character. These results demonstrate a simple nondestructive approach for large-area three-dimensional characterization of dislocations in GaN wafers.
Source: Applied Physics Letters
DOI: 10.1063/5.0349863
Institutions: Japan Fine Ceramics Center, Mie University
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7223125765