Copyright (2010) American Vacuum Society. This
article may be
downloaded for personal use only.
Any other use requires prior
permission of the author and the American Vacuum Society.
The following article appeared in J. Pak
et al., J. Vac. Sci. Technol. A 28(4), 536
(2010)
and may be found at https://avs.scitation.org/doi/abs/10.1116/1.3425805