Nitridation of an InP 001/ surface by nitrogen ion beams

Nitridation of an InP 001. surface with low-energy nitrogen ion beams has been studied by X-ray photoelectron spectroscopy XPS.and atomic force microscopy AFM.. The efficiency N 1s intensityrtotal currents.of nitridation decreases monotonously as a function of the beam energy 0.1–3 keV.. We find three kinds of chemical states of nitrogen on the irradiated surface. The XPS result suggests that they correspond to In`N, In`N`P, and P`N bondings. The ratio of the In`N bonding for the surface is large at high beam energy. Upon annealing the sample irradiated at 1 keV at RT, the In`N`P bonding disappears and the ratio of the In`N bonding became about 95%. The angle-dependent XPS In 3d5r2 spectra suggest that penetrated nitrogen atoms exhibit the Gaussian distribution in the bulk. The surface irradiated by neutral nitrogen is flatter than that irradiated by the ions. q2000 Elsevier Science B.V. All rights reserved.