Study on structure of AlGaN on AlN interlayer by synchrotron radiation XRD and RBS

The AlGaN samples have been grown on AlN interlayer (IL) by metalorganic vapor phase epitaxy (MOVPE). The effects of AlN interlayer (IL) on improvement of crystalline quality of AlGaN and Al incorporation efficiency were investigated. The samples were characterized by synchrotron radiation X-ray diffraction (XRD) and MeV He ion Rutherford backscattering spectrometry (RBS). The AlN IL played a role in suppressing edge threading dislocations (TDs) and enhancing the screw ones. It also changed the state of stress in AlGaN from tension to compression. Crack-free AlGaN films were grown successfully by inserting AlN IL.