AVS 51st International Symposium
    Plasma Science and Technology Tuesday Sessions
       Session PS2-TuA

Paper PS2-TuA5
Molecular Dynamics Study of Interactions Between Organic Polymer Surfaces and Hydrogen/Nitrogen Radical Beams

Tuesday, November 16, 2004, 2:40 pm, Room 213B

Session: Plasma and Polymers
Presenter: H.Y. Yamada, Kyoto University, Japan
Authors: H.Y. Yamada, Kyoto University, Japan
S.H. Hamaguchi, Osaka University, Japan
Correspondent: Click to Email
We have studied atomistic scale interactions between organic polymer surfaces and beams obtained from hydrogen/nitrogen plasmas, using classical molecular dynamics (MD) simulations. In typical etching processes of low-dielectric-constant (i.e. low-k) organic polymer layers for semiconductor interconnect applications, hydrogen and nitrogen based plasmas are often employed as their plasma etching sources. To carry out MD calculations of such systems, we have developed a classical interatomic potential model for systems consisting of H, C and N atoms, using interatomic potential data obtained from quantum mechanical calculations. One of the key factors that allow us to appropriately handle various covalent bonds formed among C and N atoms in numerical simulations is an algorithm that we have developed to determine the order of each covalent bond automatically based on local atomic arrangement. In this presentation, we shall discuss details of the newly developed potential model as well as sample MD simulations. As to MD simulations, we have focused on plasma etching of low-k organic polymer surfaces and simulated interactions of such polymer surfaces with energetic radical/cluster beams containing N and/or H atoms. The results obtained from these MD simulations are also compared with recent experimental observations as well as previously obtained MD simulation results for hydrocarbon beam injections into organic polymer surfaces [H. Yamada and S. Hamaguchi, J. Appl. Phys. (2004), submitted.]. We have observed that, as in the case of carbon beam injection simulations, injected N atoms strongly react with the polymer substrate and form bonding networks of C and N atoms on the substrate surface. On the other hand, at similar low injection energies, N2 molecules are less reactive due to their strong covalent bonds. At higher injection energies, however, we have observed that more N molecules can break into N atoms and form bonding networks on the polymer substrate.