Open AccessAnomalous dislocation annihilation behavior observed in a GaN crystal grown on point seeds by the Na-flux method
Author(s) -
Masayuki Imanishi,
Kanako Okumura,
Kengo Nakamura,
Tomoko Kitamura,
Keisuke Kakinouchi,
Kosuke Murakami,
Masashi Yoshimura,
Y. Fujita,
Yoshiyuki Tsusaka,
Junji Matsui,
Yusuke Mori
Publication year - 2020
Publication title -
applied physics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.911
H-Index - 94
eISSN - 1882-0786
pISSN - 1882-0778
DOI - 10.35848/1882-0786/aba58e
Subject(s) - dislocation , wafer , annihilation , materials science , crystallographic defect , flux (metallurgy) , photoluminescence , condensed matter physics , crystal (programming language) , flux method , crystallography , optoelectronics , single crystal , chemistry , composite material , physics , metallurgy , quantum mechanics , computer science , programming language
We recently invented a method called the flux-film-coated technique for purifying a GaN wafer with low dislocation density grown from point-seed crystals. In this study, we investigated the mechanism behind the reduction of dislocation density in the GaN wafer by evaluating the three-dimensional behavior of dislocations using multiphoton-excitation photoluminescence images. We made the surprising discovery that dislocations more than 50 μ m away disappeared by annihilating each other as growth proceeded, and this is one of the mechanisms underlying the dislocation density reduction. The moving distance of dislocations before annihilation is uncommon and a unique phenomenon in the Na-flux method.