GaAsN formation by implantation of nitrogen into GaAs studied by infrared spectroscopy

Fourier transform infrared absorption measurements of nitrogen-implanted GaAs layers have been carried out for studying the incorporation of nitrogen into the lattice. Samples are implanted with different ion energies providing nitrogen concentrations up to 2.2 x 10(20)cm(-3) (x = 0.01) and annealed in the temperature range between 450degreesC and 900degreesC. The substitutional nitrogen fraction is determined by the strength of the local vibrational mode due to isolated nitrogen, N-As, at 471 cm(-1). In samples implanted at low temperature, almost 100% activation of nitrogen can be achieved, although the observed line broadening is indicative of residual irradiation damage. An additional small band at 638 cm(-1) is attributed to a nitrogen-gallium vacancy complex. (C) 2003 Elsevier B.V. All rights reserved.