Photo-etching of HVPE-grown GaN: Revealing extended non-homogeneities induced by periodic carrier gas exchange

• Published in: Journal of crystal growth Vol. 403; pp. 77 - 82
• Main Authors: Weyher, J.L., Sochacki, T., Amilusik, M., Fijałkowski, M., Łucznik, B., Jakieła, R., Staszczak, G., Nikolenko, A., Strelchuk, V., Sadovyi, B., Boćkowski, M., Grzegory, I.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.10.2014; Elsevier
• Subjects: A1. Crystal structure; A1. Etching; B1. Nitrides; B2. Semiconductor III-V Materials; Carrier density; Carriers; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Crystal defects; Exact sciences and technology; Gallium nitrides; Gas composition; Gas exchange; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of bulk materials and thin films; Photoluminescence; Physics; Secondary ion mass spectrometry; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Vapor phase epitaxy; growth from vapor phase; A1. Etching; B1. Nitrides; A1. Crystal structure; B2. Semiconductor III-V Materials; Luminescence; Photoluminescence; Photoetching; Secondary ion mass spectrometry; VPE; Hydrides; Raman spectroscopy; Physical properties; III-V compound; Nitrides; Optical properties; Cleavage; Selective etching; Carrier density; Impurity states; III-V semiconductors; Crystal structure
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2014.06.009

The influence of periodic changes of carrier gas composition (H2 and N2+10%H2) on structural and physical properties of GaN crystals grown by Hydride Vapor Phase Epitaxy (HVPE) was studied using photo-etching, defect-selective etching (DSE), secondary ions mass spectroscopy (SIMS), low temperature photo-luminescence (LTPL) and Raman spectroscopy. The studies were performed on (1–100) cleavage planes of thick crystals grown with short (a few minutes) and long (one hour) periods of the carrier gas exchange. Markedly large differences between the level of impurities (Si, C, O2, H2) were measured by SIMS in the GaN grown in [0001] direction and inside the V-shape defects, that well correlates with corresponding different carrier concentration levels revealed by Raman and photo-etching. Small differences in carrier concentration across the striations in the [0001] direction were clearly revealed by photo-etching, while PL and Raman appeared to be not sensitive to them.