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

Abstract

Fourier-transform infrared absorption measurements have been carried out in the two-phonon region of GaAs. Implantation of the nitrogen isotopes N14 and N15, respectively, into bulk GaAs shows that a local vibrational mode at 471 cm−1 (14N) 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 the lattice parameter determined by x-ray diffraction for x<0.01 and can be used for the assessment of the nitrogen fraction incorporated substitutionally on anion lattice sites.