Representing To PTO That A Product-By-Process Claim Limitation Is Structurally Distinct From The Prior Art Prevents Recapture In Reissue

In Greenliant Systems, Inc. v. Xicor LLC, No. 11-1514 (Fed. Cir. Aug. 22, 2012), the Federal Circuit affirmed the district court's grant of SJ of invalidity relating to claims of reissued U.S. Patent No. RE38,370 ("the RE'370 patent") for violation of the rule against recapture.

The RE'370 patent was a broadening reissue of U.S. Patent No. 5,977,585 ("the '585 patent"). The specifications of both the '585 patent and the RE'370 patent disclose improvements to electronic memory devices, such as EEPROM circuits. In an EEPROM, charge is transferred to and from a floating gate electrode through a tunneling oxide layer that acts as an insulator when not actively tunneling. The improved tunneling oxide layer disclosed in the '585 and RE'370 patents reduces pin-hole defects and stress present in traditional tunneling oxide layers.

During examination of the '585 patent, the examiner rejected claims 13 and 14 as obvious. In response, Xicor LLC ("Xicor") amended claim 13 to include "said silicon dioxide layer being formed by low pressure chemical vapor deposition comprising the use of [tetraethylorthosilicate ('TEOS')]." Slip op. at 6. The examiner stated that the process limitations of the device claims (i.e., how the tunneling layer is formed by a low-pressure chemical vapor deposition comprising the use of TEOS) would not be given patentable weight over the prior art of record unless Xicor established that those process limits imparted "structural limitations" that distinguished the claimed device from prior art devices. Xicor responded that deposited TEOS oxide did in fact have significant structural benefits over the prior art. The examiner maintained the rejections, but the Board reversed the examiner's rejections and the '585 patent issued.

Xicor filed a reissue application based on the '585 patent adding new claims 12 and 13. Claims 12 and 13 omitted the "comprising the use of [TEOS]" limitation, but otherwise duplicated claims 1 and 4 of the '585 patent. The reissue examiner ultimately found that claims 12 and 13 were not barred by the recapture rule and the '585 patent reissued as the RE'370 patent.

Greenliant Systems, Inc. ("Greenliant") filed a DJ action against Xicor, seeking a declaration that it did not infringe any claims of the RE'370 patent and that all claims of the RE'370 patent were invalid. The parties agreed that an SJ order in another case involving Silicon Storage Technology, Inc. ("SST"), determining that claims 12 and 13...