Lithium addition during CVD diamond deposition using lithium tert.-butanolat as precursor

Abstract

Abstract Since doping of diamond is of great interest for electronic applications, the possibilities for the introduction of lithium into CVD diamond during the deposition process were examined. Lithium tert.-butanolat (C4H9OLi) is volatile enough to be transported by a small hydrogen flow 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 influences of diamond growth rates and the changes in diamond morphology show that Li influences the diamond deposition process. The diamond crystals of the coatings are well faceted, mainly showing a (111) morphology. SIMS depth profiles prove that lithium is present in the diamond films. The amount of lithium is constant within the film. It is significantly increased at the diamond/substrate interface.