Three-dimensional visualization of lattice defects in $\beta$-Ga$_2$O$_3$ via synchrotron-radiation Borrmann-effect X-ray topo-tomography

TL;DR

This paper introduces a novel 3D visualization technique for lattice dislocations in beta-Ga2O3 using synchrotron X-ray topo-tomography under Borrmann-effect conditions, providing detailed insights into defect structures.

Contribution

First demonstration of 3D dislocation reconstruction in beta-Ga2O3 using synchrotron X-ray topo-tomography with Borrmann-effect, enabling depth-resolved defect analysis.

Findings

Successful 3D visualization of dislocations in beta-Ga2O3.

Clear separation of dislocations in epilayer and substrate.

Insight into dislocation propagation affecting device performance.

Abstract

beta-Ga2O3 is a promising material for next-generation power electronics; however, its performance is strongly affected by lattice defects such as dislocations. In this study, we demonstrate three-dimensional (3D) visualization of dislocations in \b{eta}-Ga2O3 using synchrotron-radiation X-ray topo-tomography under a two-beam Borrmann-effect condition in transmission X-ray topography. By rotating the sample about the diffraction vector and acquiring a series of topo-tomographic images at different rotation angles, the evolution of dislocation contrast is captured, providing intuitive, depth-resolved visualization of dislocations. This method enables clear separation of dislocations in the epilayer and substrate in Schottky barrier diode structures, offering insight into dislocation propagation and their impact on epitaxial growth and device performance. This study represents the first demonstration of 3D dislocation reconstruction in beta-Ga2O3.