An Alternative X-ray Diffraction Analysis for Comprehensive Determination of Structural Properties in Compositionally Graded Strained AlGaN Epilayers
Abstract
In this letter, a standard deviation based optimization technique has been applied on High Resolution X-ray Diffraction symmetric and asymmetric scan results to accurately determine the Aluminum molar fraction and lattice relaxation of Molecular Beam Epitaxy grown compositionally graded Aluminum Gallium Nitride (AlGaN)/Aluminum Nitride/Gallium Nitride (GaN) heterostructures. Mathews-Blakeslee critical thickness model has been applied in an alternative way to determine the partially relaxed AlGaN epilayer thicknesses. The coupling coefficient determination has been presented in a different perspective involving sample tilt method by offset between the asymmetric planes of GaN and AlGaN. Sample tilt is further increased to determine mosaic tilt ranging between 0.01° and 0.1°.
- Publication:
-
Electronic Materials Letters
- Pub Date:
- November 2018
- DOI:
- 10.1007/s13391-018-0074-6
- Bibcode:
- 2018EML....14..784D
- Keywords:
-
- HRXRD;
- AlGaN/GaN;
- Graded barrier;
- Mosaic tilt