Appeal No. 2002-2225
Application 09/295,132
§ 103(a), the examiner must show that some objective teaching, suggestion or motivation in the
applied prior art taken as a whole and/or knowledge generally available to one of ordinary skill in
this art would have led that person to the claimed invention as a whole, including each and every
limitation of the claims arranged as required by the claims, without recourse to the teachings in
appellants’ disclosure. See generally, In re Rouffet, 149 F.3d 1350, 1358, 47 USPQ2d 1453,
1458 (Fed. Cir. 1998); Pro-Mold and Tool Co. v. Great Lakes Plastics, Inc., 75 F.3d 1568, 1573,
37 USPQ2d 1626, 1629-30 (Fed. Cir. 1996); In re Fritch, 972 F.2d 1260, 1265-66, 23 USPQ2d
1780, 1783-84 (Fed. Cir. 1992); In re Fine, 837 F.2d 1071, 1074-76, 5 USPQ2d 1596, 1598-
1600 (Fed. Cir. 1988); In re Dow Chem. Co., 837 F.2d 469, 473, 5 USPQ2d 1529, 1531-32
(Fed. Cir. 1988).. The requirement for objective factual underpinnings for a rejection under
§ 103(a) extends to the determination of whether the applied references can be combined. See In
re Lee, 277 F.3d 1338, 1343, 61 USPQ2d 1430, 1433-34 (Fed. Cir. 2002), and cases cited
therein.
The dispositive issue in this appeal is whether one of ordinary skill in this art would have
found in the combination of Vuillermoz and the knowledge in the prior art acknowledged by
appellants the reasonable suggestion to modify a MOS transistor having a silicon nitride layer as
an electrically conductive diffusion barrier between a tungsten electrical contact and a shallow
doped region formed on a semiconductor substrate taught by Vuillermoz (e.g., abstract and cols.
1-4) by forming the electrical contact using a doped polysilicon in place of tungsten because it
was known in the prior art that electrical contacts “are typically metal (i.e. tungsten) or a highly
doped polycrystalline silicon (polysilicon) material” as acknowledged by appellants
(specification, page 1, lines 21-23). We note that the conductive diffusion barrier shown in
Vuillermoz is termed a quantum conductive barrier layer in appealed claim 1.
While we agree with the examiner that appellants acknowledge that tungsten and a doped
polysilicon are art recognized to form electrical contacts, that fact alone does not establish that
these otherwise chemically dissimilar materials are interchangeable in every application where an
electrical contact is prepared by a particular process. The only process disclosed in the prior art
applied by the examiner to prepare a MOS transistor having an electrically conductive diffusion
barrier is shown in Vuillermoz and involves the formation of a silicon nitride layer from silicon
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