Appeal No. 1999-1466
Application No. 08/371,486
junction,” while the base reference of Matsumura has junctions between two semiconductor
materials having different conductivity types.
The examiner responds (Answer, page 4) that LeComber shows silicon nitride to
be a useful gate insulator for a field-effect transistor, and it clearly would have been
obvious to have practiced a silicon nitride gate insulator in other insulated gate field-effect
transistor devices such as disclosed by Matsumura. The examiner’s position (Answer,
page 5) is that the LeComber device is not “entirely different” from that of Matsumura,
because the device of LeComber is a thin film field-effect transistor.
The abstract of LeComber discusses the characteristics of an insulated-gate field-
effect transistor made from amorphous silicon. The description of the structure shown in
Figure 1, at pages 179 and 180 of LeComber, is limited to discussion of an IGFET. We
find no suggestion that the silicon nitride film used in the IGFET is also recommended, or
even suitable, for a device having the type of junctions in the Matsumura device.
We agree with appellants that the teaching of LeComber would not have been
considered by the artisan as applicable to the type of device disclosed by Matsumura, and
thus would not have suggested modification of the device. While the obviousness may be
“clear” to the examiner, the references disclose different structures, and LeComber does
not discuss the reference’s teachings as applied to other environments. Nor has the
examiner supplied evidence (i.e., explanatory or supporting references) in support of the
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