Ex Parte MENK et alDownload PDFPatent Trial and Appeal BoardJul 29, 201311839048 (P.T.A.B. Jul. 29, 2013) Copy Citation UNITED STATES PATENT AND TRADEMARKOFFICE UNITED STATES DEPARTMENT OF COMMERCE United States Patent and Trademark Office Address: COMMISSIONER FOR PATENTS P.O. Box 1450 Alexandria, Virginia 22313-1450 www.uspto.gov APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO. 11/839,048 08/15/2007 GREGORY E. MENK APPM/010849/PPC/CMP/CKIM 7795 44257 7590 07/29/2013 PATTERSON & SHERIDAN, LLP - - APPM/TX 3040 POST OAK BOULEVARD, SUITE 1500 HOUSTON, TX 77056 EXAMINER REMAVEGE, CHRISTOPHER ART UNIT PAPER NUMBER 1713 MAIL DATE DELIVERY MODE 07/29/2013 PAPER Please find below and/or attached an Office communication concerning this application or proceeding. The time period for reply, if any, is set in the attached communication. PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE ____________ BEFORE THE PATENT TRIAL AND APPEAL BOARD ____________ Ex parte GREGORY E. MENK, ROBERT L. JACKSON, GARLEN C. LEUNG, GOPALAKRISHNA B. PRABHU, PETER MCREYNOLDS, and ANAND N. IYER ____________ Appeal 2012-006360 Application 11/839,048 Technology Center 1700 ____________ Before CHUNG K. PAK, ROMULO H. DELMENDO, and BEVERLY A. FRANKLIN, Administrative Patent Judges. PAK, Administrative Patent Judge DECISION ON APPEAL The named inventors (hereinafter “Appellants”)1 appeal under 35 U.S.C. § 134 from the Examiner’s final rejection of claims 8 through 12, 21 through 25, and 27 through 31.2 We have jurisdiction pursuant to 35 U.S.C. § 6(b). 1 Appellants identify the real party in interest as Applied Materials, Inc., 3050 Bowers Avenue, Santa Clara, California 95054. (See Appeal Brief filed August 3, 2011 (“App. Br.”) at 3.) 2 Appellants do not appeal the objection to claim 26 set forth in the final Office action mailed November 9, 2010. (App. Br. 5-6.) Appeal 2012-006360 Application 11/839,048 2 STATEMENT OF THE CASE The subject matter on appeal is directed to “planarization of semiconductor devices and to methods…for material removal using polishing techniques.” (Spec. 1, ¶ [0001].) The purpose of the planarization is to remove a dielectric material, such as a silicon oxide layer, via chemical mechanical polishing with minimal dishing and loss of an underlying material, such as a silicon nitride layer, during the fabrication of the semiconductor devices, such as shallow trench isolation (STI) structures. (Spec. 3-5, ¶¶ [0006], [0007], and [0013].) Details of the appealed subject mattered are recited in illustrative claims 8, 21, and 27 reproduced below: 8. A method of selectively removing an oxide material disposed on a nitride material, comprising: positioning the substrate in proximity with a fixed abrasive chemical mechanical polishing pad; dispensing an abrasive free polishing composition having at least one organic compound selected from a group consisting of glycine, proline, arginine, histidine, and lysine, at least one fluorosurfactant, at least one basic pH adjusting agent, and deionized water, between the substrate and the polishing pad, wherein the pH of the polishing composition is between about 7 to about 11; and removing the oxide material and the nitride material at a removal rate ratio of the oxide material to the nitride material between about 10:1 or greater. 21. A method of selectively removing an oxide material disposed on a nitride material, comprising: positioning the substrate in proximity with a fixed abrasive chemical mechanical polishing pad; dispensing an abrasive free polishing composition between the substrate and the polishing pad, the abrasive free polishing composition consisting essentially of: Appeal 2012-006360 Application 11/839,048 3 at least one organic compound selected from the group consisting of glycine, proline, arginine, histidine, lysine, and combinations thereof; at least one fluorosurfactant; at least one basic pH adjusting agent in an amount sufficient to produce a pH of the polishing composition between about 7 to about 11; and deionized water; and selectively polishing the oxide material relative to the nitride material. 27. A method of selectively removing an oxide material disposed on a nitride material, comprising: positioning the substrate in proximity with a fixed abrasive chemical mechanical polishing pad; dispensing an abrasive free polishing composition between the substrate and the polishing pad, the abrasive free polishing composition consisting essentially of: between about 0.5 wt. % of and about 10 wt. % of proline; between about 0.0001 to about 1 wt. 5 of at least one fluorosurfactant; at least one basic pH adjusting agent in an amount sufficient to produce a pH of the polishing composition between about 10 to about 12; and deionized water; and selectively polishing the oxide material relative to the nitride material. (App. Br. 17-19 (Claims App’x)(emphasis added)). Appellants seek review of the following grounds of rejection maintained by the Examiner in the Answer mailed December 2, 2011 (“Ans.”): 1. Claims 8 and 21 under 35 U.S.C. § 103(a) as unpatentable over U.S. Patent Application Publication 2003/0176151 A1 published in the name of Tam et al. on September 18, 2003 (“Tam”) in view of U.S. Patent Appeal 2012-006360 Application 11/839,048 4 Application Publication 2005/0113000 A1published in the name of Belov et al. on May 26, 2005 (“Belov”); and 2. Claims 8 through 12, 21 through 25, and 27 through 31 under 35 U.S.C. § 103(a) as unpatentable over Tam in view of U.S. Patent Application Publication 2005/0031789 A1 published in the name of Liu et al. on February 10, 2005 (“Liu”). (App. Br. 9.) DISCUSSION I. Obviousness based on Tam and Belov Appellants acknowledge at page 10 of the Appeal Brief that: Tam teach[es] that STI polishing processes using conventional polishing pads and abrasive slurries have been observed to result in overpolishing of the deposited surface and formation of recesses in the STI features and other topographical defects, such as microscratches on the deposited surface. See Tam at ¶ [0010]. Tam teach[es] that this phenomenon of overpolishing and forming recesses in the STI features is referred to as dishing. See Tam at ¶ [0010]. Tam teach[es] that dishing is highly undesirable because dishing of substrate features may detrimentally affect device fabrication by causing failure of isolation of transistors and transistor components from one another resulting in short-circuits. See Tam at ¶ [0010]. Tam teach[es] that one solution to limit dishing of substrate features is to polish a substrate surface using a fixed abrasive polishing pad and a CMP composition or slurry that does not contain abrasive particles. See Tam at ¶ [0015]. Tam teach[es] a composition including at least one organic compound selected from a group of amino acids, at least on pH adjusting agent, and deionized water. See Tam at ¶ [0021]. [(Emphasis original.)] Consistent with this acknowledgement, the Examiner found that Tam teaches that the organic compound (amino acid) employed is selected from “glycine, proline, arginine, lysine and combinations thereof” in 1 to 6 Appeal 2012-006360 Application 11/839,048 5 percent by weight based on its CMP composition and the pH adjusting agent employed is selected from various inorganic and/organic bases, such as potassium hydroxide and ammonium hydroxide, in an amount sufficient to produce a pH of about 7 or more, preferably about 10 to about 12. (Compare, e.g., Ans. 4-6, 9, 10, and Tam, ¶¶ [0043]-[0045] with claims 8, 11, 12, 21, 22, 25, 27, 28.) The Examiner also found that Tam teaches selectively removing an oxide material, such as silicon oxide, disposed on a nitride material, such as silicon nitride, during the fabrication of shallow trench isolation (STI) structures at a removal ratio of 100:1 to 1200:1, preferably 935:1. (Compare Ans. 5, 7, and 10 and Tam, ¶¶ [0007], [0049] and [0059] with claims 8, 9, 10, 21, 23, 24, 27, 29, 30 and 31.) The presence of the amino acid is said to enhance the selective removal of silicon oxide with minimal dishing and loss of silicon nitride. (Tam, ¶ [0052].) Appellants only contend that one of ordinary skill in the art would not have been led to employ at least on fluorosurfactant in the CMP composition taught by Tam. (App. Br. 10-12 and Reply Brief filed January 3, 2012 (“Reply Br.”) at 3-5.) Thus, the dispositive question raised is: Did the Examiner err in finding that one of ordinary skill in the art, armed with the knowledge provided by the collective teachings of Tam and Belov, would have been led to employ at least one flourosurfactant in the CMP composition taught by Tam? On this record, we answer this question in the negative. As indicated supra, Tam discloses that it was known to employ a conventional CMP composition or slurry without abrasive articles in the context of chemical mechanical planarization that employs a polishing pad to minimize the phenomena of dishing and overpolishing observed when Appeal 2012-006360 Application 11/839,048 6 using such CMP composition or slurry that contains abrasive particles as acknowledged by Appellants. (See also App. Br. 10 and Tam, ¶¶ [0006], [0009], [0010], [0015] and [0016].) Tam also discloses that the use of a CMP composition in chemical mechanical planarization involves removing excess deposited materials, undesired surface topography and surface defects, such as rough surfaces, agglomerated materials, and contaminated layers or materials. (Tam, ¶¶ [0005 and [0006].) Thus, it can be inferred from these teachings of Tam that one of ordinary skill in the art not only would have looked to conventional CMP compositions with or without abrasive particles, including those taught by Belov, to improve its CMP composition, but also would have reasonably expected its CMP composition to retain removed unwanted deposited materials, e.g., silicon oxide, to form a slurry system during the chemical mechanical planarization of semiconductor devices. KSR Int’l. Co. v. Teleflex Inc., 550 U.S. 398, 418 (2007) (In making an obviousness determination one “can take account of the inferences and creative steps that a person of ordinary skill in the art would employ.”); In re Preda, 401 F.2d 825, 826 (CCPA 1968) (In evaluation the content of a prior art reference, “it is proper to take into account not only specific teachings of the [prior art] reference but also the inferences which one skilled in the art would reasonably be expected to draw therefrom.”) Although Tam does not expressly disclose using at least one flurosurfactant in its CMP composition, Belov teaches employing an optional surface active agent, such as a fluorosurfactant, to impart a desired viscosity and foam control to a CMP slurry composition containing pH adjusting constituents, such as potassium hydroxide and an ammonium, Appeal 2012-006360 Application 11/839,048 7 which has a pH in the range of from about 1.5 to about 8. (See Ans. 5 and Belov, ¶¶ [0061] and [0063].) In particular, Belov teaches that: Surface active agents can also be employed in the present invention. The surface active agents regulate the surface tension and control the foaming of the slurry system. Surfactants which contain a range of perfluoroalkyl groups (fluorosurfactants) are the preferred class of surface tension reducing agents. These surfactants are effective in small concentrations and stable in aqueous dispersions in the presence of acids and alkalis. Examples of these surface active agents include ZONYL®, fluorosurfactants manufactured by DuPont. [(Belov, ¶ [0064].) (Emphasis added.)] Given the above-discussed advantageous properties of fluorosurfactants even in the presence of alkalis and/or acids and in a CMP slurry system, we determine that one of ordinary skill in the art would have been led to employ at least one fluorosurfactant in the CMP composition taught by Tam, with a reasonable expectation of successfully regulating the surface tension and controlling the foaming of the slurry system resulting from removing and carrying unwanted deposited materials in the CMP composition taught by Tam during the chemical mechanical planarization of semiconductor devices. Accordingly, we affirm the Examiner’s decision rejecting claims 8 and 21 under 35 U.S.C. § 103(a) as unpatentable over the collective teachings of Tam and Belov. However, we denominate our affirmance as including a new ground of rejection pursuant to 37 C.F.R. § 41.50(b) (2010) because our reasons for the affirmance are materially different from those proffered by the Examiner. Appeal 2012-006360 Application 11/839,048 8 We also enter a new ground of rejection against claims 9 through 12, 22 through 25, and 27 through 31 under 35 U.S.C. § 103(a) as unpatentable over the collective teachings of Tam and Belov for the reasons indicated supra pursuant to 37 C.F.R. § 41.50(b) (2010). As indicated supra, the collective teachings of Tam and Belov would have suggested the subject matter recited in claims 8 through 11, 21, 23 through 25, and 29 through 31. Stated differently, the collective teachings of Tam and Belov would have led one of ordinary skill in the art to employ at least one fluorosurfactant taught by Belov in the abrasive free polishing composition taught by Tam used for selectively removing an oxide material disposed on a nitride material. Although Belov does not expressly disclose employing a specific amount of such fluorosurfactant as required by claims 12, 22, 27, and 28, it teaches that the amount of the fluorosurfactant affects the surface tension and the foaming of a CMP slurry system. (Belov, ¶ [0064].) In other words, Belov describes the amount of the fluorosurfactant used is a result effective variable. (Id.) It follows that the determination of the optimum or workable amount of at least one fluorosurfactant, such as the amounts of at least one fluorosurfactant recited in claims 12, 22, 27 and 28, for the CMP composition taught by Tam is well within the ambit of one of ordinary skill in the art. Pfizer, Inc. v. Apotex, Inc., 480 F.3d 1348, 1368 (Fed. Cir. 2007) (“[D]iscovery of an optimum value of a variable in a known process is usually obvious.”); In re Boesch, 617 F.2d 272, 276 (CCPA 1980)(“[D]iscovery of an optimum value of a result effective variable…is ordinarily within the skill of the art.”); Appeal 2012-006360 Application 11/839,048 9 II. Obviousness based on Tam and Liu The disclosure of Tam is discussed above. The dispositive question raised here is: Did the Examiner err in finding that one of ordinary skill in the art, armed with the knowledge provided by the collective teachings of Tam and Liu, would have been led to employ at least one flourosurfactant in the CMP composition taught by Tam? On this record, we answer this question in the affirmative. As correctly argued by Appellants, Liu teaches using surfactants, including flourosurfactants, as corrosion inhibitors in acidic polishing compositions that utilize oxidizers, such hydrogen peroxide, to minimize the removal rate of an interconnect metal. (App. Br. 13-15 and Liu, ¶¶ [0033- [0035].) However, nowhere did the Examiner demonstrate that there is an apparent reason to employ such corrosion inhibitors in the CMP composition taught by Tam. (Ans. 6-14.) In particular, the Examiner did not show that the CMP composition taught by Tam either causes corrosion or is acidic and contains oxidizers. (Id.) Accordingly, we reverse the Examiner’s decision rejecting claims 8 through 12, 21 through 25, and 27 through 31 under 35 U.S.C. § 103(a) as unpatentable over Tam in view of Liu. ORDER Upon consideration of the record, and for the reasons given above, it is ORDERED that the decision of the Examiner rejecting claims 8 and 21 under 35 U.S.C. § 103(a) as unpatentable over the collective teachings of Appeal 2012-006360 Application 11/839,048 10 Tam and Belov is AFFIRMED, but is denominated as including a new ground of rejection pursuant to 37 C.F.R. § 41.50(b) ; FURTHER ORDERED that a new ground of rejection against claims 9 through 12, 22 through 25, and 27 through 31 under 35 U.S.C. § 103(a) as unpatentable over the collective teachings of Tam and Belov is entered pursuant to 37 C.F.R. § 41.50(b); FURTHER ORDERED that the decision of the Examiner rejecting claims 8 through12, 21 through 25, and 27 through 31 under 35 U.S.C. § 103(a) as unpatentable over Tam in view of Liu is REVERSED; and FURTHER ORDERED that no time period for taking any subsequent action in connection with this appeal may be extended under 37 C.F.R. § 1.136(a) (2010). As indicated supra, this Decision contains a new ground of rejection pursuant to 37 C.F.R. § 41.50(b). 37 C.F.R. § 41.50(b) provides “[a] new ground of rejection pursuant to this paragraph shall not be considered final for judicial review.” 37 C.F.R. § 41.50(b) also provides that the Appellants, WITHIN TWO MONTHS FROM THE DATE OF THE DECISION, must exercise one of the following two options with respect to the new ground of rejection to avoid termination of the appeal as to the rejected claims: (1) Reopen Prosecution. Submit an appropriate amendment of the claims so rejected or new evidence relating to the claims so rejected, or both, and have the matter reconsidered by the Examiner, in which event the proceedings will be remanded to the Examiner. . . . Appeal 2012-006360 Application 11/839,048 11 (2) Request rehearing. Request that the proceedings be reheard under § 41.52 by the Board upon the same record. . . . AFFIRMED-IN-PART/37 C.F.R. § 41.50(b) kmm Copy with citationCopy as parenthetical citation