GROWTH OF ULTRATHIN CRYSTALLINE AL2O3 FILMS ORE RU(0001) AND RE(0001)SURFACES

Ultrathin aluminum oxide films (less than or equal to 20 Angstrom thic k) on Ru(0001) and Re(0001) surfaces have been grown by depositing alu minum in an oxygen ambient (0.5-1 x 10(-5) Ton), and have been charact erized by x-ray photoelectron spectroscopy (XPS), low energy ion scatt ering (LEIS), low energy electron diffraction (LEED), and high resolut ion electron energy loss spectroscopy. No LEED pattern is observed fro m the films of thickness > 5 Angstrom deposited on either surface at 3 00 K. Long range order of the films is achieved by depositing aluminum in ambient oxygen at elevated substrate temperatures (greater than or equal to 970 K). The LEIS results indicate three-dimensional growth f or the films on these substrates at 1170 K. Films on Ru(0001) show sha rper LEED patterns than those on Re(0001) substrates. Analysis of the XPS Al 2s/O 1s area ratios indicate that the films are stoichiometric. (C) 1996 American Vacuum Society.