Raman scattering studies on manganese ion-implanted GaN

This paper reports that the Raman spectra have been recorded on the metal-organic chemical vapour deposition epitaxially grown GaN before and after the Mn ions implanted. Several Raman defect modes have emerged from the implanted samples. The structures around 182 cm-1 modes are attributed to the disorder-activated Raman scattering, whereas the 361 cm-1 and 660 cm-1 peaks are assigned to nitrogen vacancy-related defect scattering. One additional peak at 280 cm-1 is attributed to the vibrational mode of gallium vacancy-related defects and/or to disorder activated Raman scattering. A Raman-scattering study of lattice recovery is also presented by rapid thermal annealing at different temperatures between 700°C and 1050°C on Mn implanted GaN epilayers. The behaviour of peak-shape change and full width at half maximum (FWHM) of the A1(LO) (733 cm-1) and E2H (566 cm-1) Raman modes are explained on the basis of implantation-induced lattice damage in GaN epilayers.