Chemical vapor deposition of metallic thin films using homonuclear and heteronuclear metal carbonyls

The purpose of this work has been to demonstrate a simple chemical vapor deposition (CVD) technique that employs easily handled solid metal carbonyls as precursors for the formation of metallic thin films. Co, Fe, Ru, and Os metallic thin films were deposited in a chemical vapor deposition (CVD) apparatus under a vacuum of 10(-5) Torr using Co-2(CO)(8), Fe-3(CO)(12), Ru-3(CO)(12), and Os-3(CO)(12) at 150, 200, 175, and 225 degrees C, respectively. FeCo3 and FeRu3 metal alloy films were deposited from HFeCo3(CO)(12) and H2FeRu3(CO)(13) at 150 and 200 degrees C, respectively. A Co/Ru/Co multilayer film was prepared by consecutively depositing each layer from the respective carbonyls at the aforementioned temperatures. The method employed differs from previously reported procedures in that a carrier gas is not used, but a dynamic vacuum of 10(-5) Torr is found sufficient to transport the precursor metal carbonyls to the heated substrate. The precursor carbonyls Co-2(CO)(8), Fe-3(CO)(12), and H2FeRu3(CO)(13), were sufficiently volatile that they could be maintained at room temperature. HFeCo3(CO)12 and Os-3(CO)(12) were maintained at 50 degrees C while Ru-3(CO)(12) was held at 75 degrees C. The films were characterized by Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM), and stylus profilometry.