IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Plasma Science Tuesday Sessions
       Session PS-TuP

Paper PS-TuP1
A Comparitive Study of PECVD of Fluorocarbon Films Using C@sub 3@F@sub 8@ and C@sub 4@F@sub 8@ Precursors

Tuesday, October 30, 2001, 5:30 pm, Room 134/135

Session: Plasma Deposition, Modeling, and Emerging Applications Poster Session
Presenter: I.T. Martin, Colorado State University
Authors: I.T. Martin, Colorado State University
G. Malkov, Colorado State University
E.R. Fisher, Colorado State University
Correspondent: Click to Email
Plasma polymerization of fluorocarbons has been studied extensively. Recently, greater control over film characteristics has been attained through manipulation of plasma parameters, such as the formation of highly ordered CF@sub 2@ rich films using downstream continuous wave (CW) and pulsed hexafluoropropylene oxide (HFPO) plasmas. Here, we explore films deposited from the fluorocarbon precursors, octafluoropropane (C@sub 3@F@sub 8@) and octafluorocyclobutane (C@sub 4@F@sub 8@). These compounds are used industrially as alternatives to CF@sub 4@ and C@sub 2@F@sub 6@ in PECVD chamber cleans. Here, we characterize film properties as a function of input power, distance from the glow, and pulsed vs. CW conditions. Data from FTIR and XPS show films deposited with downstream CW and pulsed plasma conditions have higher CF@sub 2@ content and lower cross-linking with both precursors. However, films deposited with C@sub 4@F@sub 8@ plasmas have a lower mechanical flexibility than those deposited with C@sub 3@F@sub 8@ plasmas. Comparison to the HFPO system suggests the oxygen present in the HFPO system may be integral to the deposition of highly ordered films. In addition to film characterization, we have used our imaging of radicals interacting with surfaces (IRIS) method to measure the surface interactions of CF@sub 2@ radicals during plasma processing. CF@sub 2@ surface loss coefficients determined for 5-150 W C@sub 3@F@sub 8@ and C@sub 4@F@sub 8@ plasmas indicate relatively high levels of scattering in these systems (S>1). Scatter values greater than unity indicate CF@sub 2@ radicals are produced at the surface. Substrate biasing and ion removal techniques will be used to determine the effects of ions on these measurements. These data can be correlated with mass spectral data collected with the IRIS apparatus. Collectively, the data presented provide a comprehensive picture of these fluorocarbon systems, from the gas-phase to the material to the plasma-surface interface.