Tuning of the tetragonal distortion in AlInGaN thin films by different contents of Al and In

• AlInGaN epilayers with a thick GaN intermediate layer were prepared on Al2O3.
• Tetragonal distortion in AlInGaN films is characterized by RBS/Channeling and HRXRD.
• The composition dependent tetragonal distortion eT in the epilayers is determined.

Systematic investigations were performed on a set of AlInGaN epilayers which were grown by metalorganic chemical vapor deposition on sapphire with a thick (3 μ  m) GaN intermediate layer. The chemical compositions (both In and Al contents) of AlInGaN layers were directly determined by Rutherford backscattering spectrometry and elastic recoil detection analysis. Using high resolution X-ray diffraction and the channeling scan around an off-normal 〈12¯13〉 axis in {101¯0} plane of the AlInGaN layers, the tetragonal distortion eT is determined. The results show that eT, ranging from negative to positive, is drastically influenced by the chemical composition in AlInGaN epilayers.