Saved in:
Bibliographic Details
Main Authors: Ishiakwa, Yukari, Hattori, Ryo, Yao, Yongzhao, Katsube, Daiki, Sato, Koji
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2511.08989
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866910161194450944
author Ishiakwa, Yukari
Hattori, Ryo
Yao, Yongzhao
Katsube, Daiki
Sato, Koji
author_facet Ishiakwa, Yukari
Hattori, Ryo
Yao, Yongzhao
Katsube, Daiki
Sato, Koji
contents We demonstrate a nondestructive, high-throughput method for observing dislocations in GaN (0001) using phase-contrast microscopy (PCM). The PCM images (359x300 $μ$m$^2$) analyzed in this study were acquired with an exposure time of 3 ms per image. The one-to-one correspondence between threading dislocation (TD) contrasts in PCM images and the corresponding contrasts in multiphoton excitation photoluminescence (MPPL) images provides clear evidence that PCM can detect TDs with in-plane Burgers vector components. The contrast shape in PCM reflects the inclination of dislocations with respect to the surface normal: dot contrasts correspond to vertical dislocations, whereas line contrasts correspond to inclined dislocations. By shifting the focal plane from the top surface to the back surface, the three-dimensional propagation paths of dislocations can be visualized. The PCM image obtained represents a projection of threading dislocations within a thickness of approximately 43 $μ$m. Dislocations spaced as close as 1.3 $μ$m can be individually resolved. In addition, the capability of PCM to detect scratches, subsurface scratches, facet boundaries, and voids was demonstrated. This study establishes PCM as a versatile and laboratory-accessible technique for three-dimensional, nondestructive characterization of dislocations and other defects in wide-bandgap semiconductors.
format Preprint
id arxiv_https___arxiv_org_abs_2511_08989
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle High-throughput, Non-Destructive, Three-Dimensional Imaging of GaN Threading Dislocations with in-Plane Burgers Vector Component via Phase-Contrast Microscopy
Ishiakwa, Yukari
Hattori, Ryo
Yao, Yongzhao
Katsube, Daiki
Sato, Koji
Materials Science
We demonstrate a nondestructive, high-throughput method for observing dislocations in GaN (0001) using phase-contrast microscopy (PCM). The PCM images (359x300 $μ$m$^2$) analyzed in this study were acquired with an exposure time of 3 ms per image. The one-to-one correspondence between threading dislocation (TD) contrasts in PCM images and the corresponding contrasts in multiphoton excitation photoluminescence (MPPL) images provides clear evidence that PCM can detect TDs with in-plane Burgers vector components. The contrast shape in PCM reflects the inclination of dislocations with respect to the surface normal: dot contrasts correspond to vertical dislocations, whereas line contrasts correspond to inclined dislocations. By shifting the focal plane from the top surface to the back surface, the three-dimensional propagation paths of dislocations can be visualized. The PCM image obtained represents a projection of threading dislocations within a thickness of approximately 43 $μ$m. Dislocations spaced as close as 1.3 $μ$m can be individually resolved. In addition, the capability of PCM to detect scratches, subsurface scratches, facet boundaries, and voids was demonstrated. This study establishes PCM as a versatile and laboratory-accessible technique for three-dimensional, nondestructive characterization of dislocations and other defects in wide-bandgap semiconductors.
title High-throughput, Non-Destructive, Three-Dimensional Imaging of GaN Threading Dislocations with in-Plane Burgers Vector Component via Phase-Contrast Microscopy
topic Materials Science
url https://arxiv.org/abs/2511.08989