In this letter, we describe a unique method of producing hyperthermal
neutrals for material processing. The hyperthermal neutrals are produc
ed by accelerating inns across a sheath from a plasma onto a surface,
On impact, the ions are neutralized and reflected with similar to 50%
of their incident energy, These neutrals then bounce off of additional
surfaces prior to impacting the target, This unique multiple bounce s
ystem was developed for the following reasons: to reduce contamination
from sputtered surface material, improve beam uniformity, and reduce
UV radiation in the hc atn path. As a test of this method, we built a
prototype beam source and used it to ash photoresist at rates up to 0.
022 mu m/min. These rates are consistent with a predicted neutral beam
flux, 2 x 10(14) cm(-2) s(-1). In addition, a simple model is used to
indicate that this method is capable of producing economically accept
able ash rates. Comparisons with other neutral-beam production methods
are made. (C) 1997 American Institute of Physics.