This award is made in the Office of Special Projects in support of the research of Professor Stephen Leone at the University of Colorado at Boulder. The goal of the work is to study fundamental aspects of kinetic energy enhanced neutral beam epitaxy of electronic materials at low substrate temperatures. Kinetic energy enhanced neutral atoms will be produced by pulsed laser vaporization of electron beam-deposited thin films of transparent substrates followed by velocity selection of the neutral atoms in the 1-10 eV range. Systems to be studied include cobalt, iron, platinum, tungsten, nickel, palladium, titanium and molybdenum atoms on silicon (100), cobalt silicide, and the heteroepitaxy of silicon/germanium. Film growth will be monitored by low energy electron diffraction, Auger spectroscopy and scanning electron microscopy. Time of flight ion scattering spectroscopy using He+ and Ne+ will be developed to determine lattice spacings of the films as a function of film thickness and growth mechanism. This research will address the fundamentals of metal film deposition on silicon substrates which are of fundamental importance to interconnects on semiconductors. Heteroepitaxy studies of the germanium/silicon system induces lattice-strain which offers the opportunity to control the effective bandgap structure of optoelectronic devices.
