LASER-ASSISTED CHEMICAL-VAPOR-DEPOSITION OF INN ON SI(100)

Laser-assisted chemical vapor deposition of InN on Si(100) using HN3 and trimethyl indium (TMIn) with and without 308-nm photon excitation has been studied with x-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), and scanning electron microscopy (SEM). Without 308-nm excimer laser irradiation, no InN film was built on the surface under the present low-pressure conditions. When the photon beam was introduced, InN films with In:N atomic ratio of 1.0 +/- 0.1 and a thickness of more than 20 angstrom (the limit of the electron escaping depth for the In 3d x-ray photoelectrons) were formed at temperatures of 300-700 K. The He II UP spectra taken from these InN films agree well with the result of a pseudopotential calculation for the InN valence band. Our XPS measurements indicate a three-dimensional (3D) island growth of InN on Si(100) at 700 K, which is confirmed by the SEM images. Although the SEM images taken from the same samples with 2000 X magnification showed very smooth InN films, InN islands of about 100 nm in diameter could be clearly observed with a magnification of greater-than-or-equal-to 20 000 X. In contrast, the InN film grown at 300 K showed valleys of uncovered substrate instead of InN islands. These uncovered substrate areas, corresponding to about 5% of the surface exposed to the probing x-ray radiation, probably result from incomplete decomposition of In-C bonds and poor diffusion kinetics at this temperature. Above 800 K, dissociation and desorption of In- and N- containing species occurred and thus no InN film was formed on the surface.