CHEMICAL VAPOR-DEPOSITION OF PLATINUM - NEW PRECURSORS AND THEIR PROPERTIES

The complexes cis-[PtMeRL2], where R = Me, CH2 = CH, CH2 = CHCH2, t-BuC = C and L = MeNC or L2 = 1,5-cyclooctadiene, are shown to be useful precursors for the chemical vapor deposition (CVD) of platinum films under mild conditions. Carbon impurities in the films and the temperature of CVD were both greatly reduced when CVD was carried out in the presence of hydrogen, but CVD was retarded in the presence of free MeNC. The sigma-allylplatinum or sigma-vinylplatinum complexes gave CVD at the lowest temperature. Thermolysis of cis-[PtMe2(MeNC)2] gives methane as a gaseous product, and this is shown to be formed by combination of a methylplatinum group with a hydrogen atom from H2, if present, or from the cell wall. The carbon impurities in the platinum films formed by CVD in the absence of hydrogen were shown to be derived at least partly from the methylplatinum groups.