Infrared absorption study of nitrogen in N-implanted GaAs and epitaxially grown GaAs1-xNx layers

Fourier-transform infrared absorption measurements have been carried out in the two-phonon region of GaAs. Implantation of the nitrogen isotopes N-14 and N-15, respectively, into bulk GaAs shows that a local vibrational mode at 471 cm(-1) (N-14) is due to isolated nitrogen. The band is also found in GaAs1-xNx(0 <x <0.03) layers grown by solid-source molecular beam epitaxy. The strength of the band correlates quantitatively with the decrease of th e lattice parameter determined by x-ray diffraction for x <0.01 and can be used for the assessment of the nitrogen fraction incorporated substitutiona lly on anion lattice sites. (C) 2000 American Institute of Physics. [S0003- 6951(00)03247-2].