Polarity and threading dislocation dependence of the surface morphology of c-GaN films exposed to HCl vapor
| Autor: | Donghoi Kim, Dongsoo Jang, Chinkyo Kim, Hyunkyu Lee, Hwa Seob Kim |
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| Rok vydání: | 2018 |
| Předmět: |
Surface (mathematics)
Morphology (linguistics) Materials science Flat surface Polarity (physics) 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Etching (microfabrication) Transmission electron microscopy Materials Chemistry Threading (manufacturing) Composite material Dislocation 0210 nano-technology |
| Zdroj: | Journal of Materials Chemistry C. 6:6264-6269 |
| ISSN: | 2050-7534 2050-7526 |
| DOI: | 10.1039/c8tc01640b |
| Popis: | The polarity and threading dislocation dependence of the surface morphology of c-GaN films exposed to HCl vapor at temperatures of 750 and 810 °C was investigated. For N-polar GaN, some regions were severely etched in such a way that vertically-aligned nanopipes were formed while areas other than those occupied by the nanopipes were barely etched. A cross-sectional transmission electron microscopy analysis revealed that the bottom of the nanopipes was observed to be connected to threading dislocation(s) while no threading-dislocation was observed beneath the unetched surface of N-polar GaN. In comparison, the threading-dislocation-free region in Ga-polar GaN domains was heavily etched, and GaN nanoneedles were formed on a relatively flat surface at temperatures as low as 750 °C. In order to understand the etched surface morphology of Ga-polar GaN (nanoneedles on a relatively flat surface), we proposed a physical model to describe this etching behavior, and a computational simulation based on our proposed model could explain the etched surface morphology of a Ga-polar GaN film exposed to HCl vapor. |
| Databáze: | OpenAIRE |
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