Structural and Elastic Properties of α‐(Al_xGa_1−x)₂O₃ Thin Films on (11.0) Al₂O₃ Substrates for the Entire Composition Range

Abstract

Structural properties of rhombohedral α‐(AlxGa1−x)2O3 thin films grown by two combinatorial pulsed laser deposition (PLD) techniques are investigated for the entire composition range. One α‐(AlxGa1−x)2O3 thin film is deposited on a 2 inch in diameter large a‐plane sapphire substrate using the continuous composition spread (CCS) PLD technique to fabricate a thin film with varying Al content ranging between x = 0.13 and x = 0.84. Laterally homogeneous α‐(AlxGa1−x)2O3 thin films exhibiting discrete Al contents are fabricated using radially segmented PLD targets on (11.0) Al2O3. Independent of the PLD technique, for x ≈ 0.55, a change from relaxed to pseudomorphic growth is observed as confirmed by the evolution of in‐ and out‐of‐plane lattice constants. The crystal structure is studied depending on the cation composition by X‐ray diffraction confirming the fabrication of epitaxial, corundum‐structured thin films.

Azimuthal Anisotropy of Rhombohedral (Corundum Phase) Heterostructures

“…For c plane, naturally no angular dependence exists. For the m / a azimuth, results on m plane [ 19 ] and a plane [ 20 ] have been included and are very similar.…”

“…Polar plot of the mismatch of the out‐of‐plane lattice spacing divided by of α ‐ layers for on r ‐plane (blue), ‐plane (red), a plane (purple square, from the study by Hassa et al [ 20 ] ), m plane (purple diamond, from the study by Kneiss et al [ 19 ] ), and c plane (green) Al 2 O 3 . The lines are the expectations from elastic strain theory for (green), (black), and (purple).…”

Realization of Conductive n‐Type Doped α‐Ga2O3 on m‐Plane Sapphire Grown by a Two‐Step Pulsed Laser Deposition Process

“…Numerous reports exist on the deposition of α ‐Ga 2 O 3 by various deposition techniques such as mist chemical vapor deposition (CVD), [ 9–11 ] molecular beam epitaxy (MBE), [ 12 ] and pulsed laser deposition (PLD). [ 13–15 ]…”

“…Homoepitaxially grown with aluminum contents deposited by PLD were described in 2018 by Lorenz et al [ 13 ] In 2020, Hassa et al presented results on the deposition of by PLD in the entire composition range. [ 1,15 ]…”

Correction to: Structural and Elastic Properties of α‐(AlxGa1−x)2O3 Thin Films on (11.0) Al2O3 Substrates for the Entire Composition Range

“…Due to a typo in our theoretical calculations of the pseudomorphic out‐of‐plane lattice constant a , the “theory pseudomorphic” curve (orange dashed line) in Figure 4b of the original article [ 1 ] was unfortunately plotted incorrectly. We corrected our calculations and plotted the modified graph below, which replaces the original Figure 4b.…”