Interface formation and properties are the major research topics related to the advances in microelectronics. Since electronics and circuits are becoming smaller and faster, we are investigating the fundamental properties of semiconductor sandwich devices using surface science. These sandwich devices consist of three components: the copper metal layer, the thin film diffusion barrier layer, and the low-k dielectric substrate. We are investigating the surface chemistry of a copper precursor, commercially available copper(hexafluoroacetylacetone) vinyltrimethyl silane (Cu(hfac)VTMS), on a semiconductor substrate (Si(100)) covered with a thin barrier layer, titanium carbonitride (TiCN). Cu(hfac)VTMS is an excellent precursor molecule for copper deposition but its ligands present a significant danger of surface and interface contamination. For example, fluorine can easily penetrate the TiCN diffusion barrier which leads to a significant change in electrical properties of barrier material.  Fundamental surface chemistry is under investigation to remove the two ligands, VTMS and hfac, and to ultimately leave the clean copper layer on a diffusion thin film barrier layer by using nonthermal methods.  Another β-diketonate, other than hfacH, such as dipivaloylmethane (dpmH) is also under investigation as a potential fluorine-free ligand. In situ surface techniques that are used in our lab are multiple internal reflection-Fourier transform infrared spectroscopy (MIR-FTIR) and thermal programmed desorption (TPD).  Ex situ techniques used are X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (Tof-SIMS) at the Surface Analysis Facility at the University of Delaware. In situ XPS is done in a  collaboration with Professor Robert Opila at the Materials Science and Engineering department.   Transmission electron microscopy (TEM) is conducted at the W. M. Keck Electron Microscopy Facility (Department of Materials Sciences & Engineering, University of Delaware, Director Dr. C. Ni) and atomic force microscopy (AFM) for the project is done at the Delaware Biotechnology Institute (DBI).  We also use density functional theory computational modeling to verify structure, stability, infrared spectra, and the core level energy shifts to interpret XPS measurements.