Maruf Sarkar, Francesca Adams, Sidra A Dar, Jordan Penn, Yihong Ji, Abhiram Gundimeda, Tongtong Zhu, Chaowang Liu, Hassan Hirshy, Fabien C-P Massabuau, Thomas O'Hanlon, Menno J Kappers, Saptarsi Ghosh, Gunnar Kusch, Rachel A Oliver
In this article, porous GaN distributed Bragg reflectors (DBRs) were fabricated by epitaxy of undoped/doped multilayers followed by electrochemical etching. We present backscattered electron scanning electron microscopy (BSE-SEM) for sub-surface plan-view imaging, enabling efficient, non-destructive pore morphology characterization. In mesoporous GaN DBRs, BSE-SEM images the same branching pores and Voronoi-like domains as scanning transmission electron microscopy. In microporous GaN DBRs, micrographs were dominated by first porous layer features (45 nm to 108 nm sub-surface) with diffuse second layer (153 nm to 216 nm sub-surface) contributions...
April 5, 2024: Microscopy and Microanalysis