LITHIUM ADDITION DURING CVD DIAMOND DEPOSITION USING LITHIUM TERT-BUTANOLAT AS PRECURSOR

Since doping of diamond is of great interest for electronic applicatio ns, the possibilities for the introduction of. lithium into CVD diamon d during the deposition process were examined. Lithium tert-bulanolat (C4H9OLi) is volatile enough to be transported by a small hydrogen flo w to the reactor. Diamond films were grown by the hot-filament method under various deposition conditions (Li-precursor concentrations, CH4 concentrations, filament temperature, substrate temperature). The infl uences of diamond growth rates and the changes in diamond morphology s how that Li influences the diamond deposition process. The diamond cry stals of the coatings are well faceted, mainly showing a (111) morphol ogy. SIMS depth profiles prove that lithium is present in the diamond films. The amount of lithium is constant within the film. It is signif icantly increased at the diamond/substrate interface. (C) 1997 Elsevie r Science S.A.