Appeal No. 2002-1992
Application 09/206,170
Grieger discloses that after planarizing, preferably by
chemical mechanical polishing, a semiconductor device having a
doped silica surface, e.g., a borophosphosilicate (BPSG)
surface,3 silica-containing chemical mechanical polishing residue
can be completely removed from the doped silica surface, with a
tolerable level of doped silica removal, by immersing the device
in aqueous hydrofluoric acid (HF)/tetramethylammonium hydroxide
(TMAH) (abstract; col. 2, lines 15-20 and 31-38; col. 8,
lines 19-20; col. 10, lines 13-20; col. 12, lines 10-36).
Grieger teaches that “[w]hile the cleaning composition and
methods are very well-suited to removing residue from a device
surface, the same composition and methods may also result in some
removal of the atoms that form the surface of the device. Thus,
while in a preferred embodiment, the inventive method removes
only residue and not surface atoms, the inventive method may
remove surface atoms in addition to removing residue” (col. 11,
lines 43-50). Grieger also teaches that “[r]outine
experimentation may be needed in order to find a composition that
3
3 Chen’s dielectric material can be “[a]ny dielectric
material, whether presently known or yet to be discovered ...
including low dielectric materials such as carbon fluorinated
SiO2, organic polymers, etc.” (col. 5, line 66 - col. 6, line 2).
Chen’s dielectric materials, therefore, include Grieger’s doped
silica.
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