Federal Circuit Vacates PTAB’s Decision to Uphold Enthone Patent

On Friday, October 26th, the U.S. Court of Appeals for the Federal Circuit issued a nonprecedential decision in BASF Corporation v. Enthone, Inc. which vacated an earlier decision stemming from an inter partes review (IPR) proceeding at the Patent Trial and Appeal Board (PTAB) which had upheld a patent owned by Enthone as valid over an obviousness challenge asserted by BASF. The Federal Circuit panel of Circuit Judges Timothy Dyk, Evan Wallach and Richard Taranto remanded the case to the PTAB after holding that certain findings made by the PTAB were inadequately supported or explained.

The patent-at-issue in this appeal is U.S. Patent No. 7303992, titled Copper Electrodeposition in Microelectronics. Issued to Enthone in December 2007, it covers a method for electroplating a copper deposit onto a semiconductor integrated circuit device substrate with electrical interconnect features including submicron-sized features having bottoms, sidewalls and top openings in such a way where the copper deposition in a vertical disposition from the bottoms to the top openings of the features is greater than the copper deposition on the sidewalls. The resulting invention enables the use of copper to substitute aluminum in semiconductor substrates while eliminating defects that can form during copper deposition.

BASF petitioned the PTAB to challenge the validity of the ‘992 on 35 U.S.C. § 103 grounds as obvious and the PTAB instituted the IPR on 24 challenged claims of the ‘992 patent. BASF argued that challenged claims were invalid as obvious based on two collections of asserted prior art. The first was U.S. Patent No. 6444110, Electrolytic Copper Plating Method (“Barstad”) in view of U.S. Patent Application No. 20020127847, Electrochemical Co-Deposition of Metals for Electronic Device Manufacture (“Alling”) and a 1989 BASF catalog for Pluronic and Tetronic block copolymer surfactants. The second was U.S. Patent Application No. 20020043467, Electrolyte (“Morrissey”) in view of Alling and the 1989 BASF catalog. The PTAB terminated the IPR finding that BASF did not prove the invalidity of the challenged claims by a preponderance of the evidence.

On appeal, BASF argued that the PTAB applied an overly stringent version of the motivation to combine test leading to the Board’s decision to uphold the ‘992 patent’s validity. The PTAB found that Alling didn’t provide the requisite motivation to combine the Tetronic copolymer in the BASF catalog with the superfilling method found in either Barstad or Morrissey. However, the Federal Circuit found that the PTAB adhered to the appellate court’s precedent in considering whether the level of unpredictability in the art demanded that BASF demonstrate a more definite motivation to combine the prior art in the manner alleged within BASF’s petition. Thus, the CAFC concluded that the PTAB didn’t apply an incorrect legal standard in its motivation to combine analysis.

BASF also argued that the PTAB’s nonobviousness findings either lacked support in the cited evidence or were inadequately explained, an argument with which the Federal Circuit agreed. The appellate court found that the PTAB failed to support its finding that a person having ordinary skill in the art wouldn’t have found Alling applicable to superfilling. The PTAB’s only support for this finding was a single passage cited from Enthone’s expert declaration and Enthone admitted in oral argument that the PTAB failed to support its finding.

The Federal Circuit also found that the PTAB acted arbitrarily and capriciously for reaching a conclusion regarding Barstad which was inconsistent with its findings in an IPR proceeding between the same parties on a different patent where BASF asserted the same combination of prior art. In the IPR on the ‘992 patent, the PTAB found that Barstad disclosed Tetronic copolymers as surfactants and thus they couldn’t be suppressors. In the other IPR, the PTAB found that Barstad disclosed the Tetronic copolymers as surfactant-type suppressor agents. The Federal Circuit panel found that these separate findings were plainly inconsistent. On remand, the Federal Circuit directed the PTAB to reconsider whether either the asserted combinations of prior art provide the requisite motivation to combine Alling with the other art, and to reevaluate whether Barstad discloses Tetronic copolymers as suppressors for use in superfilling.


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Join the Discussion

4 comments so far.

  • [Avatar for Ben]
    October 29, 2018 12:54 pm

    “If this case doesn’t illustrate that § 101 is out of control, nothing will.”

    Your post seems to illustrate that reactions to 101 are out of control. 😛

  • [Avatar for David Stein]
    David Stein
    October 29, 2018 03:17 am

    Here’s claim 1 of the ‘992 patent:

    1. A method for electroplating a copper deposit onto a semiconductor integrated circuit device substrate with electrical interconnect features including submicron-sized features having bottoms, sidewalls, and top openings, the method comprising:

    immersing the semiconductor integrated circuit device substrate including submicron-sized features having bottoms, sidewalls, and top openings wherein said submicron-sized features include high aspect ratio features having dimensions such that the high aspect ratio features have aspect ratios of at least about 3:1 into an electrolytic plating composition comprising a source of Cu ions in an amount sufficient to electrolytically deposit Cu onto the substrate and into the electrical interconnect features and a polyether suppressor compound comprising a combination of propylene oxide (PO) repeat units and ethylene oxide (EO) repeat units present in a PO:EO ratio between about 1:9 and about 9:1 and bonded to a nitrogen-containing species, wherein the molecular weight of the suppressor compound is between about 1000 and about 30,000; and

    supplying electrical current to the electrolytic composition to deposit Cu onto the substrate and superfill the submicron-sized features by rapid bottom-up deposition at a rate of growth in the vertical direction which is greater than a rate of growth in the horizontal direction.

    Who could have guessed that Supreme Court precedent about the patent-ineligibility of “fundamental economic practices,” “organizing human activities,” “mathematical relationships/formulas,” and “an idea in itself” would be cited against chemical processes for electroplating integrated circuits?

    If this case doesn’t illustrate that § 101 is out of control, nothing will.

  • [Avatar for Pro Say]
    Pro Say
    October 28, 2018 05:29 pm

    “All your patents are belong to us.”

    The CAFC

  • [Avatar for Bemused]
    October 28, 2018 02:53 pm

    Dyk, Wallach and Taranto: Dumber and Dumber and Dumbest.

    And so the cost, time and effort for the patent holder and the cloud on the title of the patent at issue all continue unabated. Because it wasn’t enough that the patent holder got past the PTAB killing fields. Not for these judges. They had to remand so the infringer can get yet another bite of the apple and so that another 18 or so months can be wiped off the life of the patent at issue.