IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Organic Films and Devices Wednesday Sessions
       Session OF+TF+EL-WeA

Paper OF+TF+EL-WeA7
Chemisorption of Vinylacetic Acid on Si(001) and Its Subsequent Reaction with Iron Pentacarbonyl

Wednesday, October 31, 2001, 4:00 pm, Room 131

Session: Growth of Organic Thin Films
Presenter: Y. Kim, Korea Research Institute of Chemical Technology, South Korea
Authors: K. An, Korea Research Institute of Chemical Technology, South Korea
S.S. Lee, Korea Research Institute of Chemical Technology, South Korea
Y. Kim, Korea Research Institute of Chemical Technology, South Korea
Correspondent: Click to Email
Chemisorption of vinylacetic acid (VAA) on clean Si(001) substrate at room temperature and the change of its adsorption with temperature have been investigated by x-ray and ultraviolet photoelectron spectroscopy. It was hoped that the C=C double bond of the chemisorbed VAA may be utilized in the subsequent reaction with the second adsorbate, iron pentacarbonyl, Fe(CO)@sub 5@, in this study. VAA first adsorbs on Si(001) molecularly, and as the substrate temperature is increased to 350°C, loses the acidic hydrogen resulting in the configuration that has two equivalent oxygen atoms according to the change in the O 1s XPS peak. The curve-fitted Si 2p peak indicates formation of the Si@super 2+@ state on the surface. UPS also showed that the photoemission peak due to the OH group of VAA loses its intensity significantly. This surface species is stable up to about 350°C. As the temperature is raised even more to ~450°C, the adspecies are decomposed leaving a mixture of oxidized silicon and silicon carbide. At about 700°C, only tenacious oxygens remain on the carbided substrate surface. Iron pentacarbonyl was introduced into the XPS analysis chamber to 35000 L with the monolayer of the anionic species of VAA at 350°C. The surface, after the introduction of Fe(CO)@sub 5@, was found to consist of the acid anion and an iron species that shows metallic behavior according to XPS and UPS data. The Fe(CO)@sub 5@ molecules must have been completely dissociated since no accumulation of C or O adspecies has been detected. Also the surface iron atoms do not seem to have been oxidized judging from the shape of the Fe 2p level and the appearance of the Fermi level crossing. However, it is not yet clear whether the iron species have formed microscopic structures or not, while the change in the C 1s peak suggests that they may each have a chemical bond with the surface C=C double bond. At the moment a scanning tunneling microscopy experiment is in preparation to examine the surface structure of the iron species.