Open AccessGaN substrates having a low dislocation density and a small off-angle variation prepared by hydride vapor phase epitaxy and maskless-3D
Author(s) -
Takehiro Yoshida,
Masatomo Shibata
Publication year - 2020
Publication title -
japanese journal of applied physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.487
H-Index - 129
eISSN - 1347-4065
pISSN - 0021-4922
DOI - 10.35848/1347-4065/ab9d5f
Subject(s) - materials science , vapor phase , epitaxy , dislocation , substrate (aquarium) , optoelectronics , hydride , phase (matter) , crystallography , nanotechnology , composite material , chemistry , metallurgy , oceanography , physics , organic chemistry , layer (electronics) , geology , metal , thermodynamics
To produce high-quality GaN (0001) substrates with a low threading dislocation density (TDD) and a small off-angle variation, we have developed a technique named the “maskless-3D method.” This method, which is applied during GaN boule growth by hydride vapor phase epitaxy (HVPE), induces three-dimensional (3D) growth on a normal GaN (0001) seed substrate. We showed that by an appropriate choice of HVPE conditions, and without using a mask, the 3D growth shape was controlled to eliminate the c -plane and thereby suppress the propagation of dislocations from the seed. Subsequently, two-dimensional (2D) growth was carried out on the 3D structure. This 2D growth area was machined to produce a 2 inch GaN substrate with a TDD of about 4 × 10 5 cm −2 and an off-angle variation of 0.05°. We also confirmed that it was possible to insert the 3D growth area twice, thereby further reducing the TDD to 10 4 cm −2 .