KOH based selective wet chemical etching of AlN, Al{sub x}Ga{sub 1−x}N, and GaN crystals: A way towards substrate removal in deep ultraviolet-light emitting diode

Journal Article · Mon Feb 23 00:00:00 EST 2015 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4913705· OSTI ID:22412700

Kirste, R.; Bryan, I.; Bryan, Z.; Hussey, L.; Reddy, P.; Collazo, R.; Sitar, Z. ^[1]; Tweedie, J. ^[2]

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1. Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695-7919 (United States)
2. Adroit Materials, Apex, North Carolina 27539 (United States)

A controllable and smooth potassium hydroxide-based wet etching technique was developed for the AlGaN system. High selectivity between AlN and Al{sub x}Ga{sub 1−x}N (up to 12×) was found to be critical in achieving effective substrate thinning or removal for AlGaN-based deep ultraviolet light emitting diodes, thus increasing light extraction efficiency. The mechanism of high selectivity of AlGaN as a function of Al composition can be explained as related to the formation and dissolution of oxide/hydroxide on top of N-polar surface. Cross-sectional transmission electron microscopic analysis served as ultimate proof that these hillocks were not related to underlying threading dislocations.

• OSTI ID: 22412700
• Journal Information: Applied Physics Letters, Vol. 106, Issue 8; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALUMINIUM NITRIDES
CRYSTALS
DISLOCATIONS
DISSOLUTION
GALLIUM NITRIDES
LIGHT EMITTING DIODES
POTASSIUM HYDROXIDES
SUBSTRATES
SURFACES
TRANSMISSION ELECTRON MICROSCOPY
ULTRAVIOLET RADIATION
VISIBLE RADIATION