This award, made in the Advanced Materials and Processing Program of the Chemistry Division, is concerned with improving the quality of films of epitaxially-grown metals, silicon and germanium by means of kinetic energy-selected neutral beams. The beams will be produced by pulsed laser vaporization of solid substrate targets with intermediate deposition on a transparent window before laser ejection to form the high kinetic energy beam. Beams will be velocity selected by a high speed mechanical chopper to obtain well-defined neutral kinetic energies in the range of 1-10 eV. Epitaxial growth of the beams will be probed in situ by low energy ion scattering spectroscopy, Auger spectroscopy and low energy electron diffraction. Studies will address the effects of kinetic energy on film quality and growth modes for the low substrate temperature deposition of metals on silicon single crystals, the formation of silicides, the homoepitaxy of silicon, and the heteroepitaxy of silicon-germanium. %%% Fundamental knowledge of the the mechanism of layer-by layer growth of metals on refractory substrates will advance the technology of semiconductor contacts for VSLI microelectronics.
