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Preparation of sapphire substrates for Gas phase GaN epitaxial processes
Author(s) -
Kaliński Zb.
Publication year - 1977
Publication title -
kristall und technik
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0023-4753
DOI - 10.1002/crat.19770121016
Subject(s) - epitaxy , sapphire , materials science , polishing , etching (microfabrication) , dislocation , layer (electronics) , phase (matter) , optoelectronics , composite material , chemical engineering , optics , chemistry , laser , physics , organic chemistry , engineering
After mechanical treatment the surface of α‐Al 2 O 3 plates with orientation (0001) for GaN epitaxy was polished in a mixture of H 3 PO 4 and H 2 SO 4 . The best mixture H 2 SO 4 /H 3 PO 4 and the best temperature for polishing were chosen. — The quality of the polished substrates was determined by structural etching in KOH. The optimum structural etching time was 3 min. at 320°C. The thickness of the layer which should be removed after mechanical treatment and the dislocation density of the starting material for GaN epitaxy was determined.