Vapor Deposition Of Very Low K Polymer Films, Poly(Naphthalene), Poly(Fluorinated Naphthalene)

Abstract

AbstractSeveral novel processes have been developed in our lab to synthesize and deposit polymers that have extremely low dielectric constants (below 2.5) as thin films. These reactive intermediates are condensed onto wafers in a vacuum chamber and no chemical waste is produced. Furthermore, cold traps can be used to recover uncondensed monomers through the pumping system. Because of the extremely low dielectric constant, very low moisture uptake and high temperature stability of these vapor depositable materials, these environmentally friendly polymers are very attractive for future electronic applications as interlayer dielectrics. Examples are Parylene-F(fluorinated), poly(naphthalene) (PNT-N), poly(fluorinated naphthalene) (PNT-F), and Teflon AF 1600 (amorphous). These films were deposited at substrate temperatures between −20 and 350 °C and at deposition pressure was 10−4−2.5 Torr. The film thicknesses were between 0.1–10 μ. and dielectric constants were between 1.9–2.5. The thermal stabilities of these films were between 360–590 °C. Among them, poly(fluorinated naphthalene) dissociates at about 590 °C. Poly(naphthalene) and poly(fluorinated naphthalene) are obtained as films by vaporizing monomers in vacuo and transporting the vapor to a hot surface.