IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Plasma Science Monday Sessions
       Session PS1-MoA

Paper PS1-MoA7
Mechanisms for Surface Interactions of NH@sub x@ Radicals During NH@sub 3@ Plasma Processing of Metal and Polymer Substrates

Monday, October 29, 2001, 4:00 pm, Room 103

Session: Plasma-Surface Interactions I
Presenter: E.R. Fisher, Colorado State University
Authors: C.I. Butoi, Primax, Inc.
M.L. Steen, Colorado State University
E.R. Fisher, Colorado State University
Correspondent: Click to Email
The chemistry occurring at surfaces of substrates during plasma processing of polymers and metal surfaces is complex. For example, ammonia plasmas have been used to increase adhesion properties between metals and other materials and to create hydrophilic surfaces. We have examined interactions of NH and NH@sub 2@ radicals with different substrate materials during NH@sub 3@ plasma processing. NH@sub 2@ scatter coefficients, S, were obtained as a function of applied rf power (P) for polymer, silicon, and metal substrates. In most cases, S @>=@ 1, indicating NH@sub 2@ surface generation occurs at the plasma-substrate interface. Energy transfer between NH@sub 2@ and substrates was evaluated via translational temperatures for scattered NH@sub 2@ molecules, @THETA@@sub Tsc@. Translational temperatures for NH@sub 2@ molecules scattered from Pt, Cu, and Si substrates show little dependence on P, while NH@sub 2@ scattered from polymers have linear increases in @THETA@@sub Tsc@, changing by as much as ~120 K for P = 50-150 W. S and @THETA@@sub Tsc@ values measured using an ion-free molecular beam indicate ions increase both kinetic energy and amount of scattered NH@sub 2@. Examination of possible reaction pathways suggests that H atom abstraction by NH radicals may contribute to the observed surface generation of NH@sub 2@. Surface reactivity measurements for NH radicals on polymer surfaces show S < 1, consistent with this mechanism. The effects of P, substrate material and the presence of ions on NH surface interactions are presented, providing additional insight into the underlying mechanisms for NH@sub 3@ plasma processing of both polymer and metal surfaces. These surface interaction data will be presented along with mass spectral data and surface analysis, thereby providing a fairly comprehensive view of the ammonia plasma processing system.