AVS 53rd International Symposium
    Thin Film Thursday Sessions
       Session TF2-ThA

Paper TF2-ThA8
Laser Desorption from Polytetrafluoroethylene at 157 nm -- A Possible Reactant Source for Thin Film Growth

Thursday, November 16, 2006, 4:20 pm, Room 2022

Session: Pulsed Laser Deposition of Thin Films
Presenter: S. John, Washington State University
Authors: S. John, Washington State University
S.C. Langford, Washington State University
J.T. Dickinson, Washington State University
Correspondent: Click to Email
Thin film growth of a number of polymers, including polytetrafluoroethylene (PTFE -- Teflon), has been achieved using pulsed laser deposition (PLD). Past studies have also shown that 157 nm Excimer (nanosecond) pulsed laser irradiation is uniquely clean and efficient in etching PTFE. We characterize the resulting neutral and charged products accompanying this exposure using time resolved mass spectroscopy as a function of laser fluence. We find that photochemical release of neutral species of the form (CF@sub 2@)@sub n@, where n = 1,2,3, and possibly 4 occurs with non-thermal kinetic energies (~0.8 eV). A slow component is also observed attributed to an un-zipping reaction with a lifetime of 180 µs. We also observe both positive and negative ions with kinetic energies of a few eV. Mechanisms for the formation of these ions is under study; electrons emitted during the laser pulse are likely involved in the formation of negative ions. We examine possible scenerios to maximize PTFE film growth in light of our measurements.