TOKYO ELECTRON LIMITED et al.

Patent Trials and Appeals BoardMar 2, 2021

2020002115 (P.T.A.B. Mar. 2, 2021)

UNITED STATES PATENT AND TRADEMARK OFFICE 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. 14/599,059 01/16/2015 Eiichi Nishimura 447650US41X DIV 9242 22850 7590 03/02/2021 OBLON, MCCLELLAND, MAIER & NEUSTADT, L.L.P. 1940 DUKE STREET ALEXANDRIA, VA 22314 EXAMINER KACKAR, RAM N ART UNIT PAPER NUMBER 1716 NOTIFICATION DATE DELIVERY MODE 03/02/2021 ELECTRONIC 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. Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the following e-mail address(es): OBLONPAT@OBLON.COM iahmadi@oblon.com patentdocket@oblon.com PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE BEFORE THE PATENT TRIAL AND APPEAL BOARD Ex parte EIICHI NISHIMURA, MASATO MORISHIMA, MORIHIRO TAKANASHI, AKITAKA SHIMIZU, and YUICHI SETSUHARA Appeal 2020-002115 Application 14/599,059 Technology Center 1700 Before BEVERLY A. FRANKLIN, LILAN REN, and MERRELL C. CASHION, JR., Administrative Patent Judges. FRANKLIN, Administrative Patent Judge. DECISION ON APPEAL STATEMENT OF THE CASE Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the Examiner’s decision to reject claims 1 and 3. We have jurisdiction under 35 U.S.C. § 6(b). We AFFIRM. 1 We use the word Appellant to refer to “applicant” as defined in 37 C.F.R. § 1.42(a). Appellant identifies the real party in interest as Tokyo Electron Limited. Appeal Br. 1. Appeal 2020-002115 Application 14/599,059 2 CLAIMED SUBJECT MATTER Claim 1 is illustrative of Appellant’s subject matter and is set forth below: 1. A substrate processing method executed by a substrate processing apparatus comprising an accommodating chamber in which a substrate is accommodated, a partition member that partitions the accommodating chamber into a plasma producing chamber and a substrate processing chamber, high-frequency antennas disposed in the plasma producing chamber, a process gas introducing unit that introduces a process gas into the plasma producing chamber, and a mounting stage that is disposed in the substrate processing chamber, and on which the substrate is mounted and to which a bias voltage is applied, the partition member comprising grounded conductors and insulating materials covering surfaces of the conductors, the substrate including an NiSi layer, a PMD layer, and a photoresist layer from which the PMD layer is partially exposed being laminated on the substrate in this order, the substrate processing method comprising: a contact hole formation step of etching the partially exposed PMD layer so as to form a contact hole in which the Nisi layer is partially exposed; an ashing step of removing the photoresist layer by ashing, a plasma producing step in which the process gas introducing unit introduces single gas of hydrogen gas into the plasma producing chamber, and the high-frequency antennas produce plasma from the hydrogen gas, wherein in said contact hole formation step and said ashing step, foreign matter is deposited on a surface of the NiSi layer partially exposed in the contact hole, and wherein in said plasma producing step, hydrogen radicals in the hydrogen plasma preferentially reach the substrate, and the foreign matter is removed by preferentially causing the foreign matter to chemically react with the hydrogen radicals Appeal 2020-002115 Application 14/599,059 3 without being sputtered by hydrogen ions in the hydrogen plasma. Appeal Br. 9 (Claims App.). REFERENCES The prior art relied upon by the Examiner is: Name Reference Date Ono US 4,450,031 May 22, 1984 Jaffe US 5,776,553 July 7, 1998 Savas (Savas ’022) US 5,811,022 Sept. 22, 1998 Li US 6,238,512 B1 May 29, 2001 Fukuda US 2004/0221815 A1 Nov. 11, 2004 Kobayashi US 2006/0254717 A1 Nov. 16, 2006 Honda US 2007/0221332 A1 Sept. 27, 2007 Savas (Savas ’975) US 2007/0269975 A1 Nov. 22, 2007 Morikawa US 2010/0133235 A1 June 3, 2010 THE REJECTIONS2,3 1. Claim 1 is rejected under 35 U.S.C. § 103(a) as being unpatentable over the combined teachings of Fukuda, Savas ’022, Ono, and Savas ’975. 2 We note that, Appellant states correctly on page 2 of the Appeal Brief that claims 1 and 3 are pending in this case. However, on pages 4 and 7 of the Appeal Brief, Appellant mistakenly refers to claims 11, 18, and 21 as rejected. We view this as an inadvertent error because the discussion that follows the first noted reference to these claims addresses appealed claim 1. Therefore, claims 11, 18, and 21, which were not expressly appealed, are not before us for review on appeal. 3 The Examiner maintains two sets of rejections based on different primary references (Fukuda and Savas ’975). Ans. 3; Final Act. 2, 6, 7, 10. The two sets of rejections are merely a reordering of the same cited art. Given that Appellant’s arguments focus on a single rejection (see generally Appeal Appeal 2020-002115 Application 14/599,059 4 2. Claim 3 is rejected under 35 U.S.C. § 103(a) as being unpatentable over the combined teachings of Fukuda,Savas ’022, Ono, and Savas ’975, as applied to claim 1 above, and further in view of Jaffe or Li and Morikawa or Honda or Kobayashi. OPINION For purposes of this appeal, we address separately argued claims, and the remaining claims stand or fall with the argued claims, consistent with 37 C.F.R. § 41.37(c)(1)(iv) (2017). We thus consider claim 1. We review the appealed rejections for error based upon the issues Appellant identifies, and in light of the arguments and evidence produced thereon. Ex parte Frye, 94 USPQ2d 1072, 1075 (BPAI 2010) (precedential) (cited with approval in In re Jung, 637 F.3d 1356, 1365 (Fed. Cir. 2011) (“[I]t has long been the Board’s practice to require an applicant to identify the alleged error in the examiner’s rejections.”). After considering the argued claims and each of Appellant’s arguments, we are not persuaded of reversible error in the appealed rejections. Rejection 1 We refer to the Examiner’s statement of the rejection for Rejection 1 as set forth on pages 2–6 of the Final Office Action. We refer to pages 4–7 of the Appeal Brief regarding Appellant’s position. Therein, Appellant primarily argues that the applied art does not teach or suggest (1) formation of foreign matter both during the process of contact formation and ashing Br.), we have consolidated the common rejections into a single statement of rejection for brevity purposes. Appeal 2020-002115 Application 14/599,059 5 and (2) that hydrogen radicals in plasma preferentially reach a substrate and foreign matter is preferentially caused to be reacted with hydrogen radicals chemically. Appeal Br. 5. We are unpersuaded by the aforementioned arguments for the reason provided by the Examiner on pages 3–6 of the Answer, with the following emphasis. With regard to prong (1) of Appellant’s argument pertaining to the formation of foreign matter (i.e., residue), the Examiner correctly finds that that the Abstract of Savas ‘975 discloses contact hole related residue. Ans. 5. Regarding residue due to ashing, the Examiner further notes that Savas ’975 discloses using oxygen as the gas for the ashing step for removing the photoresist layer and one of ordinary skill in the art would expect foreign matter to be deposited on a surface of the NiSi layer. Final Act. 13; Ans. 5; Savas ’975 ¶ 34; Spec. ¶ 59. Appellant contends that the Examiner’s reliance on Appellant’s own Specification in this manner is error. Appeal Br. 6; Reply Br. 2. However, on page 5 of the Answer, the Examiner states that this disclosure in the Specification represents a statement of fact and not a discovery by Appellant, and that it was relied upon in such manner. The Examiner further states that this well-known fact was corroborated by an EAST search when a search of “post oxygen ashing residue” gave 14 hits (dated 2006 and before), and the Examiner provided an attachment in support thereof. Ans. 5. Appellant argues that the EAST search is insufficient supporting evidence since no specific references are identified. Reply Br. 2. We agree with the Examiner’s position that ¶ 59 in the Specification indicates the known phenomena of residue formation associated with ashing Appeal 2020-002115 Application 14/599,059 6 using oxygen plasma. The Examiner’s cite to ¶ 59 of the Specification is appropriate because it is only to provide evidence in support of the Examiner’s Official Notice of what inherently occurs when ashing using oxygen plasma. This is further supported by the Examiner’s EAST search results. While Appellant believes the search results are inadequate, the search results cannot be ignored. With regard to prong (2) of Appellant’s argument that the applied art does not teach that hydrogen radicals in plasma preferentially reach a substrate, and foreign matter is preferentially caused to be reacted with hydrogen radicals chemically, we agree with the Examiner’s stated reply made on pages 5–6 of the Answer. Therein, the Examiner refers to ¶ 38 of Savas ‘975 which discloses: There may also be a separate fourth step, subsequent to the stop layer etch, in which the silicide surface exposed beneath the stop layer can be cleaned of remaining fluorine or carbon. This step may use pure hydrogen or hydrogen mixed with inert gas or gases. This is, an alternative to the usual sequence, avoids damage to the silicide material of the junctions by removing photoresist and residues. The Examiner further states that in light of the fact that the combination of applied references meets the apparatus described in Appellant’s Specification, the way hydrogen plasma behaves when operating the apparatus would not be expected to be different. We agree. Appellant then argues that the residues in Savas ‘975 and the present claims are different. Appeal Br. 7. We agree with the Examiner that Appellant makes this statement without explanation in support of this conclusion, and therefore we are unpersuaded. Ans. 6. We also agree with Appeal 2020-002115 Application 14/599,059 7 the Examiner that one would expect the residues would be the same because similar process and chemistries are used. Id. Appellant also argue that one skilled in the art would not have any rational reason to combine the references as done by the Examiner. Appeal Br. 6. For the reasons discussed by the Examiner in the record and as discussed supra, the rejection provides sufficient motivation for making the combination. On page 3 of the Reply Brief, Appellant argues that the rejection involves improper inferences. As discussed above, in light of the fact that the combination of applied references meets the apparatus as described in Appellant’s Specification, the Examiner correctly takes the position that operation of the apparatus, and in particular, ashing using oxygen, and using hydrogen radicals in plasma, would behave in the same way as claimed. In view of the above, we affirm Rejection 1. We also affirm Rejeciton 2 for the same reasons (Appellant does not separetly argue Rejection 2). CONCLUSION We affirm the Examiner’s decision. Appeal 2020-002115 Application 14/599,059 8 DECISION SUMMARY In summary: Claims Rejected 35 U.S.C. § Reference(s)/Basis Affirmed Reversed 1 103 Fukuda, Savas ’022, Ono, Savas ’975 1 3 103 Fukuda, Savas ’022, Ono, Savas ’975, Jaffe, Li, Morikawa, Honda, Kobayashi 3 Overall Outcome 1, 3 TIME PERIOD FOR RESPONSE No time period for taking any subsequent action in connection with this appeal may be extended under 37 C.F.R. § 1.136(a). See 37 C.F.R. § 1.136(a)(1) (iv). AFFIRMED