Growth of β-Ga2O3 on Al2O3 and GaAs using metal-organic vapor-phase epitaxy

• Published in: Physica status solidi. A, Applications and materials science Applications and materials science, 2009-02, Vol.206 (2), p.243-249
• Main Authors: Gottschalch, Volker, Mergenthaler, Kilian, Wagner, Gerald, Bauer, Jens, Paetzelt, Hendrik, Sturm, Chris, Teschner, Ulrike
• Format: Article
• Language: English
• Subjects: 61.05.cp; 68.37.Hk; 68.37.Lp; 68.37.Og; 81.05.Hd; 81.15.Gh; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; 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 specific thin films; Other semiconductors; Physics; Vapor phase epitaxy; growth from vapor phase
• ISSN: 1862-6300; 0031-8965; 1862-6319
• DOI: 10.1002/pssa.200824436

Epitaxial layers of monoclinic β‐Ga2O3 were successfully grown on (0001) sapphire and ($ \bar 1 $11)As GaAs substrates using metal‐organic vapor‐phase epitaxy (MOVPE). Triethylgallium (TEGa) and N2O were used as precursors for gallium and oxygen, respectively. Growth conditions could be determined, where β‐Ga2O3 grows epitaxially on c ‐plane sapphire and ($ \bar 1 $11)As GaAs substrates. X‐ray diffraction (XRD) and transmission electron microscopy (TEM) measurements identify a epitaxial relationship with ($ \bar 2 $01) β‐Ga2O3 || (0001) sapphire and ($ \bar 2 $01) β‐Ga2O3 || ($ \bar 1 $11)As GaAs. The observed sixfold rotational in‐plane symmetry results from differently oriented rotational domains of monoclinic β‐Ga2O3 with twofold symmetry. Thin films deposited on substrates of other orientation show the formation of the low‐temperature modification α‐Ga2O3. Optical transmission spectra measured in the spectral range from 200 nm to 2000 nm show a well‐distinct absorption edge at about 5 eV for layers grown on c ‐ and a ‐plane sapphire. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)