Accession Number : ADA302613
Title : Atomic Layer Epitaxy of Thin Diamond Films.
Descriptive Note : Final rept. Aug 92-Dec 94,
Corporate Author : AERODYNE PRODUCTS CORP NORTH BILLERICA MA
Personal Author(s) : Freedman, Andrew ; Robinson, Gary N. ; Neison, David D., Jr. ; Kebabian, Paul L. ; Zahniser, Mark S.
PDF Url : ADA302613
Report Date : NOV 1995
Pagination or Media Count : 93
Abstract : We are attempting to develop an atomic layer epitaxy scheme for the deposition of diamond thin films based on the use of halogenated reagents. To this end, we have been investigating the surface chemistry of diamond and graphite substrates with both fluorine and chlorine atoms. We have discovered, using ultrahigh vacuum surface analysis techniques (x-ray photoelectron spectroscopy (XPS) and low energy electron diffraction), that halogen beam dosing of diamond surfaces indicates that diamond is surprisingly unreactive towards both fluorine and chlorine atoms. Fluorine atoms efficiently adsorb as a carbon-monofluoride moiety at a saturation level of three-quarters of a monolayer at room temperature. The adlayer is ordered on the (111) surface but disordered on the (100) surface. Fluorine desorbs primarily as atomic fluorine over a broad temperature range (500-1200 K), indicating that diamond etching is not a major desorption process. Chlorine atoms bond much more weakly, saturating at a sub-monolayer coverage which is stable to a temperature of only 423 K. These results are ascribed to the severe steric crowding on the diamond surface and the inability of the diamond lattice to deform to accommodate the formation of multiple carbon-halogen bonds. jg p.2
Descriptors : *LAYERS, *THIN FILMS, *DIAMONDS, *EPITAXIAL GROWTH, *ATOMIC PROPERTIES, GRAPHITE, SUBSTRATES, ETCHING, ROOM TEMPERATURE, CHEMICAL BONDS, DEPOSITION, ELECTRON ENERGY, LOW ENERGY, X RAY PHOTOELECTRON SPECTROSCOPY, FLUORINE, BONDING, SURFACE CHEMISTRY, RANGE(EXTREMES), ELECTRON DIFFRACTION, DESORPTION, CHLORINE, HALOGENS, ULTRAHIGH VACUUM, ATOMIC BEAMS.
Subject Categories : Inorganic Chemistry
Laminates and Composite Materials
Atomic and Molecular Physics and Spectroscopy
Solid State Physics
Distribution Statement : APPROVED FOR PUBLIC RELEASE