The authors report on the direct comparison of the chemical etch characteristics on both Ga- and N-face gallium nitride (GaN) by phosphoric acid. First, Ga-face GaN was grown next to N-face GaN by a polarity inversion method in a metal-organic chemical vapor deposition reactor. Micro-photoluminescence, atomic force microscopy, scanning electron microscopy, and micro-Raman spectroscopy were used to analyze the etch characteristics of Ga- and N-face GaN before and after a H3PO4-based chemical etch. Ga-face was chemically stable in a phosphoric acid solution. However, the chemical etch continued proceeding on the N-face GaN due to the weak repulsive force to OH- ions. Dodecagonal nano-pyramids which dramatically enhanced the photoluminescence intensity were observed on N-face GaN after a H 3PO4-based chemical etch.
|Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films
|Published - 2012 Jul
Bibliographical noteFunding Information:
The research at Korea University was supported by a Korea University Grant, the Center for Inorganic Photovoltaic Materials (No. 2012-0001171) grant funded by the Korea government (MEST), and a Human Resources Development grant from the Korea Institute of Energy Technology Evaluation and Planning (KETEP) funded by the Ministry of Knowledge Economy (No. 20104010100640). The research at U.S. Naval Research Lab was partially supported by ONR.
ASJC Scopus subject areas
- Condensed Matter Physics
- Surfaces and Interfaces
- Surfaces, Coatings and Films