Ultrahigh vacuum chemical vapor deposition of rhodium thin films on clean and TiO2-covered Si(111)

Thin film deposition by thermal decomposition of dicarbonyl (2,4-pentanedionato)rhodium(I), Rh(Co)2(C5H7O2), has been studied under ultrahigh vacuum conditions. Thin films were deposited on clean Si(111)−(7 × 7) and TiO2-covered Si(111) substrates, and in situ analyzed by Auger electron spectroscopy. Rhodium films deposited in the temperature range 200–500 °C contain carbon and oxygen impurities. The carbon and oxygen incorporation is more severe in the initial deposition stage on a clean silicon surface than on a growing surface. The initial impurity incorporation is greatly reduced with a deposited TiO2 overlayer.