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The Specification May Be Dispositive of the Meaning of a Disputed Claim Term

April 06, 2006

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Last Month at the Federal Circuit - May 2006

Judges: Linn, Dyk, Prost (author)

In Semitool, Inc. v. Dynamic Micro Systems Semiconductor Equipment GmbH, No. 05-1299 (Fed. Cir. Apr. 6, 2006), the Federal Circuit affirmed the district court’s grant of SJ of noninfringement to Dynamic Micro Systems Semiconductor Equipment GmbH (“DMS”) and the denial of Semitool, Inc.’s (“Semitool”) motions to enforce a permanent injunction and settlement agreement. Semitool owns two patents, both directed to a machine that cleans semiconductor wafer carriers. Semitool’s cleaning machines use external air inlets and outlets to dry the air in a processing chamber. DMS also manufactures and sells a machine for cleaning semiconductor wafer carriers (“the Tornado”). DMS’s Tornado is a closed system that dries the air with condensing plates. Both machines wash the carriers and dry them by spinning at high speeds.

In a prior litigation, Semitool sued DMS for infringement, alleging that earlier versions of DMS’s cleaning machines infringed its patents. The district court issued a claim construction order and granted Semitool’s motion for SJ of infringement with regard to one of DMS’s two accused products.

The parties agreed to a settlement providing that in the event of a future infringement determination, the district court would retain jurisdiction and Semitool’s patents would be construed according to the claim construction order. The settlement agreement included a stipulation to entry of a permanent injunction barring DMS from infringing any claims of Semitool’s patents and specified that DMS’s accused products infringed, as would any device that is no more than a colorable variant.

DMS filed suit seeking a DJ that its Tornado did not infringe Semitool’s patents, but the parties agreed to dismiss the DJ complaint and the district court reopened the litigation. The district court noted that the parties disputed whether the Tornado’s condenser supplies drying gas to the process chamber and whether the condenser is part of that chamber. The district court never reached the second issue because it concluded, based on its previous claim construction, that the Tornado did not supply drying gas to the process chamber and, therefore, did not infringe.

On appeal, Semitool argued that the district court improperly limited the scope of its invention to cover only cleaning machines that supply drying gas from an external source. According to Semitool, the dried air that leaves a condenser within the Tornado supplies drying gas to a processing chamber, i.e., so long as the condenser is located outside the processing chamber, it can introduce drying gases into the processing chamber, even in a closed system.

The Federal Circuit found that it could only grant SJ of noninfringement if the condenser is inside the processing chamber and, because the district court did not reach that issue, it construed the claims to answer the question. Under Semitool’s construction, the processing chamber encompasses the central region of the processing vessel, where the carriers are loaded, cleaned, and dried. According to DMS, the processing chamber encompasses the entire interior of the processing vessel.

Some of the asserted claims had a limitation that the machine contain “a processing vessel defining a process[ing] chamber therewithin.” Based upon the claim language, the Federal Circuit found that the processing chamber covered by those claims encompassed the entire interior of the processing vessel, consistent with DMS’s interpretation. Another of the asserted claims, however, only specified “a processing chamber within the processing vessel,” leaving open to interpretation whether the processing chamber and the processing vessel are coextensive. The Court turned to the patent specification to make the determination. It noted that the specification treated the terms “processing chamber” and “processing vessel” synonymously. It also determined that because the specification described the bottom baffle separating an area where wafer carriers are cleaned and dried from the rest of the processing vessel as a false bottom, rather than an actual bottom, the area below the baffle was part of the processing chamber. Additionally, the specification referred to a port located below the bottom baffle as the “processing chamber outflow,” not the “processing vessel outflow,” port. Therefore, the Court concluded that the processing chamber and processing vessel were coextensive.

Accordingly, the Court construed Semitool’s claims to a machine that cleans semiconductor wafer carriers by supplying a drying gas to a processing chamber to exclude DMS’s Tornado because its condenser is located inside a processing chamber and the condenser cannot introduce gas into that chamber. Thus, the Tornado does not infringe the asserted claims, and the Court affirmed the district court’s denial of Semitool’s motions to enforce the settlement agreement.