IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Surface Engineering Monday Sessions
       Session SE-MoP

Paper SE-MoP4
Effect of Pre and Post Surface Modification on Copper (II) Fluoride Formation in the Cu/PTFE System

Monday, October 29, 2001, 5:30 pm, Room 134/135

Session: Poster Session
Presenter: J. Torres, Johns Hopkins University
Authors: J. Torres, Johns Hopkins University
C.C. Perry, Johns Hopkins University
S.R. Carlo, Johns Hopkins University
D.H. Fairbrother, Johns Hopkins University
Correspondent: Click to Email
Fluoropolymers are attractive materials for devices in the microelectronics industry because of their desirable physical, chemical, and dielectric properties. Copper is best suited for interconnect wiring because of its low resistivity and electro-migration; unfortunately, its adhesion to fluoropolymers is generally poor. In this study we present results of the effect of Ar@super +@ and X-ray pre and post treatment of PTFE surface in terms of CuF@sub 2@ formation. There seems to be correlation between adhesion and chemical reactivity with the surface, thus, any pre or post processes that initiate the formation of Cu-F bonds will enhance adhesion. Although there are studies in the literature that characterize the Cu/PTFE interface, few studies have concentrated specifically on pre- and post surface modification with respect to compound formation. Copper thermally evaporated on unmodified PTFE is chemically inert, forming a metallic overlayer; no Cu-F bond formation in either the F(1s) or C(2p) XPS regions was observed. Pretreatment of PTFE with either Ar@super +@ or X-ray irradiation was found to be ineffective in activating the surface towards Cu-F bond formation during physical vapor deposition of Cu. In contrast, post-surface modification of the Cu/PTFE interface with either Ar@super +@ or X-ray irradiation resulted in the production of CuF@sub 2@. The extent of CuF@sub 2@ production was found to be similar for both Ar@super +@ and X-ray irradiation post-treatment strategies for comparable initial Cu coverages, suggesting a common reaction mechanism for the formation of CuF@sub 2@. AFM images of virgin PTFE show an amorphous surface, composed of globular features, while after Ar@super +@ treatment the surface becomes fibrous. When Cu is deposited on PTFE the surfaces appearance is smooth as a result of the metallic overlayer.