Ex Parte IvanovDownload PDFBoard of Patent Appeals and InterferencesApr 27, 201211199620 (B.P.A.I. Apr. 27, 2012) 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. 11/199,620 08/09/2005 Igor C. Ivanov 5866-01701 2752 35617 7590 04/27/2012 DAFFER MCDANIEL LLP P.O. BOX 684908 AUSTIN, TX 78768 EXAMINER HORNING, JOEL G ART UNIT PAPER NUMBER 1712 MAIL DATE DELIVERY MODE 04/27/2012 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 BOARD OF PATENT APPEALS AND INTERFERENCES _________________ Ex parte IGOR C. IVANOV _________________ Appeal 2010-010657 Application 11/199,620 Technology Center 1700 _________________ Before CATHERINE Q. TIMM, KAREN M. HASTINGS, and DEBORAH KATZ, Administrative Patent Judges. KATZ, Administrative Patent Judge. DECISION ON APPEAL Appeal 2010-010657 Application 11/199,620 2 Appellants1 seek our review, under 35 U.S.C. § 134(a), of the Examiner’s decision to reject claims 1, 2, 4-7, 12-16, and 44-47. (App. Br. 2.) Appellants report that claims 17-43 have been cancelled and claims 3 and 8-11 have been withdrawn. (Id.) We have jurisdiction under 35 U.S.C. § 6(b). We affirm. The Examiner rejected claims 1, 2, 4-7, 12, 14, 15, 45-46, and 47 under 35 U.S.C. § 103(a) over Dubin2 and Danek.3 (Ans. 4-8.) Appellants present the same arguments against the rejection of independent claims 1 and 14 and do not argue for the separate patentability of the claims dependent on them. (See App. Br. 5 and 20.) We focus on claim 1 in our review. See 37 C.F.R. § 41.37(c)(1)(vii). Appellants’ claim 1 is directed to a microelectronic topography that includes a diffusion barrier, which inhibits metal features from diffusing to underlying or overlaying layers of the topography deposited. (Id. at 2.) Appellants’ claim 1 recites: A microelectronic topography, comprising: a metal structure having a bulk concentration of a first element disposed throughout the metal structure; and a diffusion barrier film formed in contact with the metal structure, wherein the diffusion barrier film is substantially absent of the first element and comprises a plurality of distinct metallic elements each different than the first element, wherein the diffusion barrier film has periodic successions of regions, 1 The real party in interest is said to be Lam Research Corp. (App. Br. 1.) 2 Dubin et al., U.S. Patent 5,695,810, issued December 9, 1997. 3 Danek and Levy, U.S. Patent 5,942,799, issued August 24, 1999. Appeal 2010-010657 Application 11/199,620 3 and wherein each of the periodic successions of regions comprises: at least one region with a concentration of a second element greater than a set amount, wherein the second element is one of the plurality of metallic elements of the diffusion barrier film; and at least one region with a concentration of the second element less than the set amount. (App. Br. 23, Claims App’x.) Appellants’ arguments raise the issue of whether those of ordinary skill in the art would have combined the teachings of Dubin and Danek. Specifically, Appellants argue that any modification of the barrier taught in Dubin by the teachings of Danek would create a multi-layer diffusion barrier of cobalt-tungsten-phosphorus (“CoWP”) with layers thinner than those taught in Dubin and that such thinner films of CoWP would not meet the requirements for the multilayer structure of Danek. (App. Br. 5.) According to Appellants, Dubin teaches a diffusion barrier with a single CoWP layer that is 150-200 nm thick, while Danek teaches a multilayer barrier with ultrathin layers of 10-50 angstroms. (App. Br. 6, citing Dubin, col. 6, ll. 20-23, and Danek, col. 2, ll. 28-35, col. 4, ll. 58-61, col. 5, ll. 46-49, and col. 6, ll. 21-24.) Appellants argue that these teachings would have prompted those of skill in the art to have formed a multilayer structure with sub-layers of 100-200 nm or greater, contrary to the interest in the art of reducing microelectronic topographies. (App. Br. 7-8.) Appeal 2010-010657 Application 11/199,620 4 Appellants read Dubin and Danek too narrowly. As the Examiner finds, although Danek provides certain examples of thicknesses of the sublayers as being between 10 and 50 angstroms, Danek also teaches that multilayer barriers can be engineered by selecting the compositions and thicknesses of barrier sublayers that are most advantageous. (Danek, col. 6, ll. 60-66; see Ans. 11.) Similarly, Dubin provides an example of a barrier of 150-200 nm, but also teaches that the specific details of the structures described are not absolutely necessary to making diffusion barriers. (Dubin, col. 3, l. 64, through col, 4, l. 3; see Ans. 11-12.) Appellants acknowledge that those of skill in the art would not necessarily be restricted to the thickness of layers taught in Danek and Dubin, but argue that the relative degree of thickness would be taken into account to create a multi-layer structure. (Reply. Br. 5.) We are not persuaded that the layers of different thicknesses exemplified in Dubin and Danek fail to suggest to the ordinary artisan the creation of the diffusion barrier of Appellants’ claimed microelectronic topography. The test for obviousness is not whether the features of a secondary reference may be bodily incorporated into the structure of the primary reference; nor is it that the claimed invention must be expressly suggested in any one or all of the references. Rather, the test is what the combined teachings of the references would have suggested to those of ordinary skill in the art. In re Keller, 642 F.2d 413, 425 (C.C.P.A. 1981). The regions of Appellants’ claimed diffusion barrier film are not restricted to specific thicknesses. Thus, we are not persuaded that any particular thickness is excluded from Appellants’ claimed topography. Danek teaches that multiple layer barriers Appeal 2010-010657 Application 11/199,620 5 have the advantage of superior diffusion barrier reliability due to suppression of grain boundary diffusion by the periodic structure. (See Danek, col. 2, l. 64, through col. 3, l. 3; Ans. 5).) Appellants’ argument that those in the art were continually seeking to reduce microelectronic topographies does not persuade us that those in the art would have been dissuaded from forming a diffusion barrier such as in Dubin with multiple layers. Even if the layers of Danek are thinner than what is discussed in Dubin, it would appear that the advantage of suppressing grain boundary diffusion by using the multilayer structure of Danek would be obtained. Appellants have not provided sufficient evidence to persuade us that the multiple layers taught in Danek would be incompatible with the diffusion barrier of Dubin.4 Accordingly, the preponderance of the evidence supports the Examiner’s conclusion that it would have been obvious to have used the multilayers of Danek in the barrier of Dubin. 4 Appellants cite two research articles Chang and Lu, “Thermal Stability and Interface Diffusion Behaviors of Electrolessly Deposited CoWP and Cu Films,” 155 J. Electrochemical Soc’y D234 (2008) and Tsai, et al., “Electroless CoWP as a Diffusion Barrier Between Electroless Copper and Silicon,” 36 J. Electronic Materials 1408 (2007), as evidence that those of skill in the art did not know the thermodynamic and kinetic stability of the interfaces between layers of CoWP and copper at the time the claimed subject matter was conceived. (App. Br. 12-13.) Even if these articles demonstrate the state of the art, the articles do not persuade us that it was expected that the multilayers of Danek would have been incompatible with the barrier of Dubin. . Appeal 2010-010657 Application 11/199,620 6 The Examiner also rejected dependent claims 13 and 16 under 35 U.S.C. § 103(a) over Dubin in view of Danek and Shacham-Diamond.5 (Ans. 8-9.) Claim 13 recites the microelectronic topography of claim 1, “wherein the plurality of metallic elements comprise cobalt, molybdenum, and at least one of chromium or boron.” (App. Br. 24, Claims App’x.) Appellants argue that though Shacham-Diamond teaches films of Co(MO,P), they are relatively thin and, according to Appellants, were not known to be suitable for the multilayer diffusion barrier layer of Danek. (See App. Br. 21.) For the reasons stated above, we are not persuaded that the thickness of the films in Shacham-Diamond indicates there would not have been a suggestion to use Co(Mo,P) in the diffusion barrier of Dubin. Appellants have not directed us to sufficient evidence that those of skill in the art would have considered the material of Shacham-Diamond to have been incompatible with a barrier of Dubin having multiple layers. The Examiner rejected dependent claim 44 over Dubin in view of Danek and Chopra6 (id. 9-10). Appellants rely on their arguments against the rejection of claim 1 over Dubin and Danek (see App. Br. 21), which we find unpersuasive, as discussed above. 5 Shacham-Diamon et al., “Electroless Co(MO,P) films for Cu interconnect application,” 64 Microelectronic Eng’g 315 (2002). 6 Chopra, U.S. Patent Application Publication 2002/0030274, published March 14, 2002. Appeal 2010-010657 Application 11/199,620 7 Decision Upon consideration of the record and for the reasons given, the rejections of claims is sustained. No time period for taking any subsequent action in connection with this appeal may be extended under 37 C.F.R. § 1.136. AFFIRMED tc Copy with citationCopy as parenthetical citation