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Reduction of Dislocations in GaN on Silicon Substrate Using In Situ Etching (Phys. Status Solidi B 5/2018)
Author(s) -
Matsumoto Koji,
Ono Toshiaki,
Honda Yoshio,
Yamamoto Tetsuya,
Usami Shigeyoshi,
Kushimoto Maki,
Murakami Satoshi,
Amano Hiroshi
Publication year - 2018
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.201870120
Subject(s) - materials science , etching (microfabrication) , layer (electronics) , epitaxy , silicon , optoelectronics , dislocation , metalorganic vapour phase epitaxy , substrate (aquarium) , gallium nitride , silicon nitride , nitride , dry etching , nanotechnology , composite material , oceanography , geology
A gallium nitride (GaN) epitaxial layer with a low density of threading dislocations was successfully grown by Matsumoto et al. (article no. 1700387 ) on a silicon substrate by using in‐situ gas etching. Silicon nitride (SiN x ) film was used as a mask, and ammonia was intermittently supplied in hydrogen ambient during the etching. High‐density deep pits corresponding to the threading dislocations in the GaN layer were formed by intermittently supplying NH 3 during H 2 etching with a SiN x layer. Before growing an additional GaN layer on the template GaN layer, a second SiN x layer is deposited after the etching process. This layer prevents GaN nuclei from growing on the upper side‐walls of the pits, and reduction of GaN nuclei leads to low threading dislocation density in the additional GaN layer. By using this method, the density of threading dislocations of the GaN surface was reduced to 6.7 × 10 7 cm −2 . This method is cost effective, completing all the necessary processes in one growth run without taking samples out from an MOCVD reactor.