Achieving high MgO content in wurtzite ZnO epilayer grown on ScAlMgO4 substrate

A series of wurtzite ZnO and Zn1−xMgxO (x=0.41-0.66) epilayers have been grown on ScAlMgO4 (SCAM) (0001) substrates by plasma-assisted molecular beam epitaxy. X-ray diffraction results indicate that only a barely recognized amount of rocksalt phase exists in the epilayer having the highest MgO content of 66%. The epilayers with 41% and 50% MgO exhibit reasonable full width at half maximum (FWHM) values of 1200-1800″ for the rocking curve of the (0002)wz reflection. However, both the surface morphology and the FWHM value deteriorate with further addition the MgO content to 66%.