Photoelectrochemical etching of gallium nitride surface by complexation dissolution mechanism

• Published in: Applied surface science 2017-07, Vol.410, p.332-335
• Main Authors: Zhang, Miao-Rong, Hou, Fei, Wang, Zu-Gang, Zhang, Shao-Hui, Pan, Ge-Bo
• Format: Article
• Language: English
• Subjects: Complexation dissolution mechanism; EDTA-2Na; Gallium nitride; Photoelectrochemical etching
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2017.03.063

GaN surface was etched by 0.3M EDTA-2Na. The proposed complexation dissolution mechanism can be applicable to almost all neutral etchants under the prerequisite of strong light and electric field. [Display omitted] •GaN surface was etched by EDTA-2Na.•GaN may be dissolved into EDTA-2Na by forming Ga–EDTA complex.•We propose the complexation dissolution mechanism for the first time. Gallium nitride (GaN) surface was etched by 0.3M ethylenediamine tetraacetic acid disodium (EDTA-2Na) via photoelectrochemical etching technique. SEM images reveal the etched GaN surface becomes rough and irregular. The pore density is up to 1.9×109 per square centimeter after simple acid post-treatment. The difference of XPS spectra of Ga 3d, N 1s and O 1s between the non-etched and freshly etched GaN surfaces can be attributed to the formation of Ga–EDTA complex at the etching interface between GaN and EDTA-2Na. The proposed complexation dissolution mechanism can be broadly applicable to almost all neutral etchants under the prerequisite of strong light and electric field. From the point of view of environment, safety and energy, EDTA-2Na has obvious advantages over conventionally corrosive etchants. Moreover, as the further and deeper study of such nearly neutral etchants, GaN etching technology has better application prospect in photoelectric micro-device fabrication.