2015 journal article

KOH based selective wet chemical etching of AlN, AlxGa1-xN, and GaN crystals: A way towards substrate removal in deep ultraviolet-light emitting diode

APPLIED PHYSICS LETTERS, 106(8).

By: W. Guo n, R. Kirste n, I. Bryan n, Z. Bryan n, L. Hussey n, P. Reddy n, J. Tweedie, R. Collazo n, Z. Sitar n

co-author countries: United States of America 🇺🇸
Source: Web Of Science
Added: August 6, 2018

A controllable and smooth potassium hydroxide-based wet etching technique was developed for the AlGaN system. High selectivity between AlN and AlxGa1−xN (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.