AVS 53rd International Symposium
    Plasma Science and Technology Tuesday Sessions
       Session PS1+MS+NM-TuM

Paper PS1+MS+NM-TuM6
Nickel Atom and Ion Density in an Inductively Coupled Plasma with an Internal Coil

Tuesday, November 14, 2006, 9:40 am, Room 2009

Session: Plasma Patterning
Presenter: L. Xu, University of Houston
Authors: L. Xu, University of Houston
N. Sadeghi, University Joseph Fourier-Grenoble & CNRS, France
M.K. Jain, University of Houston
S.C. Vemula, University of Houston
V.M. Donnelly, University of Houston
D.J. Economou, University of Houston
P. Ruchhoeft, University of Houston
Correspondent: Click to Email
Nanopantography uses monoenergetic ion beams to enable massively parallel patterning of nano-sized features (e.g. 10 nm dia., 100 nm deep holes etched into Si). Deposition of metal nanodots (e.g. Ni) can have applications such as catalysts for the growth of an orderly array of carbon nanotubes. For this purpose, we have developed an inductive plasma source containing a relatively large fraction of Ni@super +@. A two-turn Ni coil immersed in the plasma generates a Ni-containing Ar plasma. Ni was sputtered both from the negatively self-biased coil and from a Ni target powered by a separate rf power. By adding a trace amount of N@sub 2@, gas temperatures T@sub g@ (= rotational temperatures) were derived from N@sub 2@(C-B) spectra. At low powers (capacitively coupled), T@sub g@ derived from the 0-0 band was erroneously high. This was attributed to energy transfer from Ar metastable atoms to the N@sub 2@ C (@upsilon@=0). At high powers (inductively coupled), both the N@sub 2@ 0-0 and 4-4 bands provided the same reasonable T@sub g@ because electron-impact dominates excitation at high power. Optical emission of Ar at 419.8 nm was used to estimate the plasma density, and was in agreement with values predicted from a global model. Ni densities were determined by optical absorption (using a Ni hollow cathode lamp) and were found to increase with pressure and power. The Ni@super +@ densities also increase at higher pressures and powers. Model predictions of Ni@super +@ densities are consistent with metastable Ni@super +@ densities derived from optical absorption. Finally, 50nm dia. Ni islands have been deposited in preliminary nanopantography experiments with the Ni@super +@ beam.