Caroline Ann Kovac

Laser chemical vapor deposition of copper

The first laser‐induced deposition of copper has been demonstrated using a volatile copper coordination complex. The technique is characterized by reasonable rates and by the high quality of copper produced.

Photochemical generation and deposition of copper from a gas phase precursor

The photochemical generation and deposition of copper metal from a volatile copper coordination complex are described. Pulsed and cw ultraviolet light sources were used to induce deposition. The chemical compositions of the films are compared for all methods.

Polymer/metal interfaces studied by carbon near‐edge x‐ray absorption fine structure spectroscopy

Interaction of polyimide and two simple organic polymers with an evaporated chromium metal overlayer was studied by surface‐sensitive carbon 1s near‐edge x‐ray absorption fine structure (NEXAFS) spectroscopy. The technique was used to measure unoccupied electronic states in the polymers. Assignments of C1s→π* transitions in poly(pyromellitimido oxydianiline) (PMDA‐ODA polyimide) were based upon transitions measured for model polymers which contained structural subunits of the polyimide. Changes in the NEXAFS spectrum of each polymer were observed after sequential depositions of chromium. Abrupt changes in the carbonyl C1s→π* transition peaks show that the carbonyl groups on these polymers are sites for initial interaction with chromium. No evidence was seen for the formation of Cr–arene complexes on any of the polymer surfaces.

Metal Atom Reactions with Polymer Films

The chemical nature of the interface formed when an electropositive metal (chromium) is evaporated on the surface of oxygen-containing polymers has been investigated by synchrotron-radiation excited photoemission spectroscopy and by near-edge X-ray absorption fine stnrcture spectroscopy (NEXAFS). PMDA-ODA polyimide was studied along with two polymers intended to more simply model the complex chemical functionality of polyimide. Core-level spectra were resolved into distinct peaks, which were assigned to specific atoms in the polymer units, and changes in the spectra were monitored as chromium metal atoms were evaporated onto the surface. Similarly, NEXAFS spectra were taken as a function of chromium deposition. Results of these experiments show that chromium initially reacts very rapidly with surface carbonyl groups, but less strongly with ether oxygens or arene rings. In all polymers studied, formation of an electron-rich, carbide-like species was observed.