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GaN epitaxial lateral overgrowth on laser‐textured sapphire
Author(s) -
Jelmakas Edgaras,
Alsys Marius,
Gečys Paulius,
Kadys Arūnas,
Račiukaitis Gediminas,
Margueron Samuel,
Tomašiūnas Roland
Publication year - 2014
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201431360
Subject(s) - materials science , cathodoluminescence , epitaxy , metalorganic vapour phase epitaxy , optoelectronics , photoluminescence , sapphire , luminescence , chemical vapor deposition , laser , fluence , optics , layer (electronics) , nanotechnology , physics
Laser‐patterned (0001) sapphire has been evaluated as a substrate to perform GaN epitaxial lateral overgrowth (ELO) by metal‐organic chemical vapor deposition (MOCVD). Several conditions of trench ablation were tested by varying scanning speed and laser fluence of a 266‐nm picosecond laser. Growth of GaN epilayers was characterized by micro photoluminescence and cathodoluminescence (CL) spectroscopy. The spectra revealed a strain relaxation in the epitaxially overgrown GaN layer with improved quality expressed by enhanced intensity and redshift of the bandgap luminescence (from 3.44 to 3.40 eV). The bandgap against yellow luminescence (YL) intensity ratio also revealed that a defect‐depleted area exists at the edge of the trench.