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N‐GaN column arrays on the vertical InGaN/GaN blue LEDs formed by maskless dry etching
Author(s) -
Doan ManhHa,
Lee Jaejin
Publication year - 2014
Publication title -
crystal research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0232-1300
DOI - 10.1002/crat.201300316
Subject(s) - materials science , cathodoluminescence , sapphire , light emitting diode , etching (microfabrication) , optoelectronics , dry etching , chemical vapor deposition , metalorganic vapour phase epitaxy , layer (electronics) , isotropic etching , gallium nitride , reactive ion etching , diode , laser , nanotechnology , optics , epitaxy , luminescence , physics
The InGaN/GaN blue light emitting diodes (LED) structures have been grown on sapphire substrates with a hexagonal array of hemispherical patterns by low‐pressure metalorganic chemical vapor deposition. Vertical LED structures on Cu carriers are fabricated using electroplating and KrF laser lift‐off techniques. After removal of the patterned sapphire substrate, an inductively coupled plasma etching is carried out to expose the n‐GaN layer for n‐metal contact. It is observed that GaN columns are formed at the center of the concave hemispheres after dry etching processes. Cathodoluminescence and wet chemical etching investigations reveal that a high density of dislocations is found to be generated at these specific positions. The possible mechanism for these observations is attributed to the defect distribution and defect‐dependent selective etching of the GaN.