Deposition of High Purity Parylene- F Using Low Pressure Low Temperature Chemical Vapor Deposition

Abstract

Parylene-F, poly(tetrafluoro-para-xylylene) (PA-F), has potential applications in microelectronics because of its high thermal stability and low dielectric constant. We found that a new precursor, 1,4-bis(trifluoromethyl) benzene (TFB) with a trace presence of α,α′-dibromo-α,α,α′,α′-tetrafluoro-p-xylene (DBX), can be used to produce PA-F films. PA-F films from this precursor are produced using a reaction line and a conventional deposition system. This process is simpler than previously reported processes and produces PA-F films with less impurities. The dielectric constant of the PA-F films produced by this process is 2.25 ± 0.05 at 1 MHz. The deposition process and the material properties of the PA-F films produced are presented.