Growth of <i>α</i>-Ga<sub>2</sub>O<sub>3</sub> on <i>α</i>-Al<sub>2</sub>O<sub>3</sub> by conventional molecular-beam epitaxy and metal–oxide-catalyzed epitaxy
Jonathan P. McCandless, Derek Rowe, Naomi Pieczulewski, V. Protasenko, Manuel Alonso‐Orts, Martin S. Williams, M. Eickhoff, H. G. Xing, D. A. Muller, Debdeep Jena, Patrick Vogt
Abstract
Abstract We report the growth of α -Ga 2 O 3 on m -plane α -Al 2 O 3 by conventional plasma-assisted molecular-beam epitaxy and In-mediated metal–oxide-catalyzed epitaxy (MOCATAXY). We report a growth rate diagram for α -Ga 2 O 3 ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>10</mml:mn> <mml:mover accent="true"> <mml:mrow> <mml:mn>1</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>¯</mml:mo> </mml:mrow> </mml:mover> <mml:mn>0</mml:mn> </mml:math> ), and observe (i) a growth rate increase, (ii) an expanded growth window, and (iii) reduced out-of-plane mosaic spread when MOCATAXY is employed for the growth of α -Ga 2 O 3 . Through the use of In-mediated catalysis, growth rates over 0.2 μ m h −1 and rocking curves with full width at half maxima of Δ ω ≈ 0.45° are achieved. Faceting is observed along the α -Ga 2 O 3 film surface and explored through scanning transmission electron microscopy.