MOVPE growth of semipolar (112¯2) Al1−xInxNAl1−xInxN across the alloy composition range (0≤x≤0.550≤x≤0.55)

• Synthesis of ((112¯2) ) oriented semipolar AlInN layers across most of the composition range on AlN buffer layers on m-sapphire.
• Comprehensive structural characterization including epitaxial relation between epilayer and substrate, and epilayer tilt.
• Discussion of indium incorporation in AlInN and phase separation observed at indium content >40%>40%.

We report the synthesis and characterization of semipolar (112¯2) oriented Al1−xInxN alloys over a wide composition range (0≤x≤0.550≤x≤0.55) using metalorganic vapour phase epitaxy (MOVPE) in a close-coupled showerhead reactor system. AlInN layers were deposited on AlN buffer layers on m  -plane (101¯0) sapphire substrates using trimethylaluminium (TMAl), trimethylindium (TMIn), and ammonia (NH3) precursors and the alloy composition tuned by changing the growth temperature from 860°C to 625°C, corresponding to an indium content from 2.9% to 54.6%. High resolution X-ray diffraction (HRXRD) measurements were used to determine the microstructure and anisotropic biaxial strain arising from the intrinsic tricilinic distortion of the unit cell in semipolar nitrides. The epilayers exhibit an overall tilt about the [11¯00] direction and phase separation was observed for samples with indium content over 40%. The ternary alloy compositions evaluated from HRXRD were compared with those obtained from optical transmission measurements.