Parylene-n (Pa-n) and silver are being studied for ultralarge scale integrated circuits because of their favorable properties. These include low dielectric constant (2.65), negligible water take-up, chemical inertness, low temperature deposition, as well as compatibility with current integrated circuits manufacturing for Pa-n and the low resistivity (1.6 mu Omega cm), high electromigration resistance for silver. To meet integration requirements, Pa-n and Ag are studied to understand specific reliability issues, e.g., diffusion, delamination, or loss of adhesion, compatibility, etc. Initial measurements of silver and dielectric Pa-n were done using four-point probe. Thermal stability and texturing of Ag films on Pa-n? were confirmed using x-ray diffraction analysis. The change associated with resistivity of Ag films on Pa-l? sample supports the changes observed in x-ray spectra. Rutherford backscattering spectrometry and secondary ion mass spectroscopy analysis show insignificant diffusion of Ag in Pa-n. Adhesion analysis of Ag/Pa-n and Pa-n/Si was done using scratch and tape tests. Oxygen plasma surface treatment of Pa-n shows drastic improvement of adhesion between Ag and Pa-n without loss of thermal stability of the system. The improvement in adhesion is associated with increased roughness of Pa-n surface after plasma treatment.