Structural, optical and annealing studies of nitrogen implanted GaAs

Nitrogen implanted III-V compounds semiconductors have attracted a great deal of attention of the research community due to their interesting fundamental physical properties and potential applications in optoelectronic devices. A small amount of nitrogen incorporation in gallium arsenide (GaAs) causes significant reduction in the band gap energy of fabricated alloys. In this study the GaAsN layer was prepared by implantation of nitrogen ion on thick GaAs wafer and the samples were thermally annealed for studying annealing effects. The structural, compositional and optical properties have been investigated by X-Ray Diffraction (XRD), Rutherford Backscattering Spectroscopy (RBS), Scanning Electron Microscopy (SEM), Photoluminescence (PL) and Photo-thermal Deflection Spectroscopy (PDS). The results reveal that the samples prepared with higher implantation dose and annealed at higher temperature exhibit strong optical signal of GaN, while the samples annealed at lower temperature show weak optical signal. Furthermore in PDS spectra, the band gap reduction was observed indicating the diluted nitrogen content in GaAs. We have demonstrated that annealing conditions and implanted nitrogen doses could be helpful to achieve the desired variation in band gap and low physical damages on surface.