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.  This part of our research deals mostly with the ways chemical interaction of organometallic precursor molecules with silicon substrate can either be blocked or promoted. A semiconductor substrate Si(100) is reacted with a TiCN deposition precursor, tetrakis-(dimethylamino)-titanium (TDMAT) at various conditions, the surface of the substrate can be precovered with N-, O-, or C-containing compounds to alter the deposition chemistry. Ammonia-precovered surface promodes the deposition chemistry of TDMAT. 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). Density functional theory computational modeling is a very substantial part opf this project. It is used to verify structure, stability, reaction pathways, infrared spectra, and the core level energy shifts to interpret XPS measurements.