Appeal No. 2005-0287 Page 6
Application No. 09/216,214
the source/drain areas receive their final doping, which is
implanted (step 145) through the layer of metal to form regions
80. It is noted that the conformal metal on the sidewalls of the
gate acts to mask that portion of the substrate from receiving
this implant. An additional, optional implant (e.g., high-energy
boron for an NMOS device) can be performed at this point (step
150), to form the HALO implant, if desired.
The wafer is then annealed (step 155) to form a
silicide on the gate and to disperse the dopants. Note
that, since the source/drain areas are covered by an
oxide, a silicide will not form in these regions.
Unreacted metal will be stripped (step 160) from the
gate area, giving the structure shown in FIG. 2D.
The examiner (answer, page 7) acknowledges that “according
to Fig. 2C and page 8, lines 9-11 of the specification, it is
true that source/drains 80 are formed aligned with the metal
layer 50 before the formation of the metal silicide layer 60.”
However, the examiner (answer, page 8) maintains that:
a portion of the patterned polysilicon gate 20 and the
metal layer 50 must be converted to the silicon layer
60. A careful observation of Fig. 2C and Fig. 2D
clearly shows that the silicide layer 60 indeed
encroaches and consumes a portion of the patterned gate
20 and the gate sidewalls have moved.
Based on the assertions of the examiner concerning alleged
inward movement of the gate sidewall due to the silicide
formation, and the further opinion of the examiner concerning
alleged inward movement of the source/drain regions 80 under the
gate because of dopant dispersal involved in appellant’s
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