Structure and Thermal Stability of ε/κ-Ga2O3 Films Deposited by Liquid-Injection MOCVD

Autor: Edmund Dobročka, Filip Gucmann, Kristína Hušeková, Peter Nádaždy, Fedor Hrubišák, Fridrich Egyenes, Alica Rosová, Miroslav Mikolášek, Milan Ťapajna
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Materials, Vol 16, Iss 1, p 20 (2022)
Druh dokumentu: article
ISSN: 1996-1944
DOI: 10.3390/ma16010020
Popis: We report on crystal structure and thermal stability of epitaxial ε/κ-Ga2O3 thin films grown by liquid-injection metal–organic chemical vapor deposition (LI-MOCVD). Si-doped Ga2O3 films with a thickness of 120 nm and root mean square surface roughness of ~1 nm were grown using gallium-tetramethylheptanedionate (Ga(thd)3) and tetraethyl orthosilicate (TEOS) as Ga and Si precursor, respectively, on c-plane sapphire substrates at 600 °C. In particular, the possibility to discriminate between ε and κ-phase Ga2O3 using X-ray diffraction (XRD) φ-scan analysis or electron diffraction analysis using conventional TEM was investigated. It is shown that the hexagonal ε-phase can be unambiguously identified by XRD or TEM only in the case that the orthorhombic κ-phase is completely suppressed. Additionally, thermal stability of prepared ε/κ-Ga2O3 films was studied by in situ and ex situ XRD analysis and atomic force microscopy. The films were found to preserve their crystal structure at temperatures as high as 1100 °C for 5 min or annealing at 900 °C for 10 min in vacuum ambient (2O3 and possible amorphization of the films.
Databáze: Directory of Open Access Journals
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