Thomas B. Richardson et al.Download PDFPatent Trials and Appeals BoardJul 24, 201913981974 - (D) (P.T.A.B. Jul. 24, 2019) Copy Citation 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. 13/981,974 01/08/2014 Thomas B. Richardson 31183-2403A 3264 159237 7590 07/24/2019 MacDermid Performance Solutions - Patents c/o Carmody Torrance Sandak & Hennessey LLP 195 Church Street P.O. Box 1950 New Haven, CT 06509-1950 EXAMINER SLUTSKER, JULIA ART UNIT PAPER NUMBER 2891 NOTIFICATION DATE DELIVERY MODE 07/24/2019 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): mpspatents@carmodylaw.com PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE ________________ BEFORE THE PATENT TRIAL AND APPEAL BOARD ________________ Ex parte THOMAS B. RICHARDSON, JOSEPH A. ABYS, WENBO SHAO, CHEN WANG, VINCENT PANECCASIO JR., CAI WANG, XUAN LIN, and THEODORE ANTONELLIS1 ________________ Appeal 2017-009107 Application 13/981,974 Technology Center 2800 ________________ Before BRADLEY W. BAUMEISTER, SHARON FENICK, and RUSSELL E. CASS, Administrative Patent Judges. CASS, Administrative Patent Judge. DECISION ON APPEAL Appellants appeal under 35 U.S.C. § 134(a) from the Examiner’s final rejection of claims 2, 4–11, 14–17, 19–22, 25, 28, and 30–34. Appeal Br. 7.2 We have jurisdiction under 35 U.S.C. § 6(b). An oral hearing was conducted on June 24, 2019. A transcript of the oral hearing will be made of record shortly. 1 Appellants list Enthone Inc. as the real party in interest. Appeal Brief filed March 27, 2017 (“Appeal Br.”) 3. 2 Rather than repeat the Examiner’s positions and Appellants’ arguments in their entirety, we refer to the above mentioned Appeal Brief, as well as the following documents for their respective details: the Final Action mailed November 17, 2016 (“Final Act.”); the Examiner’s Answer mailed May 18, 2017 (“Ans.”); and the Reply Brief (“Reply Br.”) mailed June 12, 2017. Appeal 2017-009107 Application 13/981,974 2 We reverse. THE INVENTION The present invention relates to a process for creating conductive paths in the manufacture of microelectronic devices, and more specifically for filling vias that are relatively deep and/or have a relatively small entry dimension. Spec. ¶ 1. The Specification explains that “[p]lating chemistry sufficient to copper[-]metallize small size via and trench features has been developed and finds use in the copper damascene method.” Id. ¶ 4. The Specification further explains that “[i]n another form, a wafer may be constructed to comprise one or more very deep via,” known as a “through silicon via” (TSV), which can “allow electrical interconnection between 2 or more wafers bonded to each other in a three-dimensional wafer stack.” Id. ¶ 5. The depth of a TSV, the Specification explains, “can vary from on the order of about 20 microns to about 500 microns.” Id. ¶ 7. The Specification explains that “[i]n filling deep via[s], and especially deep vias with relatively small entry dimensions, it has been found difficult to maintain satisfactory deposition rates throughout the filling process.” Id. ¶ 9. In the process according to the invention, an “electrodeposition circuit is established comprising an anode, the electrolytic composition, the aforesaid cathode, and a power source.” Id. ¶ 12. A potential is applied between the anode and the cathode during a via filling cycle to generate a cathodic electrodeposition current causing reduction of copper ions at the cathode, thereby plating copper onto the metallizing substrate at the bottom and sidewall of the via, the via preferentially plating on the bottom and lower sidewall to cause filling of the via from the bottom with copper. Id. Appeal 2017-009107 Application 13/981,974 3 “During the filling cycle, the polarity of [the] circuit is reversed for an interval to generate an anodic potential at the metalizing substrate and desorb [the] leveler from the copper surface within the via.” Id. “Copper deposition is resumed by re-establishing the surface of the copper within the via as the cathode in the circuit, thereby yielding a copper filled via feature.” Id. THE EXAMINER’S REJECTION Claims 2, 4–11, 14–17, 19–22, 25, 28, and 30–34 stand rejected as unpatentable over Mayer (US 6,946,065 B1; issued Sept. 20, 2005) in view of Ahrens (US 2005/0153546 A1; published July 14, 2005). ANALYSIS Appellants separately argue independent claims 25, 28, and 33. Each of these claims will be discussed in turn below. I. Claim 25 Claim 25 is reproduced below, with the key element at issue in italics: 25. A process for metalizing a through silicon via feature in a semiconductor integrated circuit device, said device comprising a surface having a via feature therein, said via feature comprising a sidewall extending from said surface and a bottom, said sidewall, said bottom and said surface having a metalizing substrate thereon for deposition of copper, said metalizing substrate comprising a seed layer, the process comprising: immersing said metalizing substrate in an electrolytic copper deposition composition, wherein the through silicon via feature has an entry dimension between 1 micrometers and 25 micrometers, a depth dimension between 50 micrometers and 300 micrometers, and an aspect ratio greater than 2:1, said Appeal 2017-009107 Application 13/981,974 4 metalizing substrate providing a cathode for electrolytic deposition of copper thereon, the electrolytic deposition composition comprising: a source of copper ions; an acid component selected from among an inorganic acid, an organic sulfonic acid, and mixtures thereof; an accelerator; a suppressor; a leveler; and chloride ions; establishing an electrodeposition circuit comprising an anode, the electrolytic deposition composition, the cathode, and a power source; applying a potential between the anode and the cathode during a via filling cycle to establish an anodic polarity at the anode and a cathodic polarity at the cathode to generate an electrodeposition current and cause reduction of copper ions at the cathode to plate copper onto the metalizing substrate at the bottom and sidewall of the via, the via preferentially plating on the bottom and lower sidewall to cause filling of the via from the bottom with copper; reversing a polarity of said electrodeposition circuit during the via filling cycle for at least one interval to generate an anodic potential at said metalizing substrate; resuming copper deposition by re-establishing the surface of the copper within the via as the cathode in the circuit, thereby yielding a copper filled via feature; wherein a ratio of cumulative charge transfer in said circuit during copper deposition within said filling cycle to Appeal 2017-009107 Application 13/981,974 5 cumulative charge transfer during a sum of all anodic potential intervals is at least 80:1. Appeal Br. 23–24 (Claims Appendix) (emphases added). The Examiner finds that Mayer teaches the limitations of claim 25 except for two limitations: (1) wherein the through silicon via feature has an entry dimension between 1 micrometers and 25 micrometers and a depth dimension between 50 micrometers and 300 micrometers; and (2) wherein a ratio of cumulative charge transfer in said circuit during copper deposition within said filling cycle to cumulative charge transfer during the sum of all anodic potential intervals is at least 80:1. Final Act. 5. As to element (1), the Examiner combines Mayer with Ahrens, which discloses a “through silicon via feature [having] an entry dimension between 1 micrometers and 25 micrometers, [and] a depth dimension between 50 micrometers and 300 micrometers for the purpose of fabrication [of] contact structures.” Id. (citing Ahrens ¶ 36). As to element (2), the Examiner finds that “Mayer discloses that a ratio of cumulative charge transfer in said circuit during copper deposition within said filling cycle to cumulative charge transfer during the sum of all anodic potential intervals should be greater than 1 to result in net plating.” Id. at 6 (citing Mayer col. 20, ll. 60–67; Fig. 11). The Examiner further determines that the “ratio of cumulative charge transfer in said circuit during copper deposition within said filling cycle to cumulative charge transfer during the sum of all anodic potential intervals therefore are art-recognized result-affecting variables/parameters,” and “therefore it would have been obvious to optimize (for example by routine experimentation) a ratio of cumulative charge transfer in said circuit during copper deposition within Appeal 2017-009107 Application 13/981,974 6 said filling cycle to cumulative charge transfer during the sum of all anodic potential intervals for the purpose of achieving net plating.” Id. (citing Mayer col. 20, ll. 60–67). The Examiner further states that this ratio is result affecting because it affects the degree of “net plating” achieved and avoids “seam and void formation.” Ans. 3 (citing Mayer col. 20, ll. 20–25, 60–67). Appellants acknowledge that “Mayer describes that ‘relation to charges carried in the forward and reverse pulses needs to be greater than 1 to result in net plating (not de-plating).’” Appeal Br. 10 (citing Mayer col. 20, ll. 64–67). Appellants argue, however, that there is no teaching or suggestion in the art “that would have led one skilled in the art to have adjusted or optimized this parameter to a ratio of at least 80:1 as described and claimed by Appellant[s].” Id. at 11. Appellants further argue that “one skilled in the art cannot ascertain from the teachings of Mayer that such values would be within the skill of one skilled in the art.” Id. Appellants assert that the “greater than 1” ratio in Mayer “is very different from” the 80:1 ratio in claim 25, and that that “the value of Mayer would have to be significantly modified or changed to achieve the desired result.” Id. We find that the Examiner has not made out a sufficient case of obviousness. The Examiner acknowledges that Mayer does not reasonably teach or suggest the claimed ratio of at least 80:1. Final Act. 5. The Examiner determines that one of skill would have achieved this ratio through optimization (id.), but we do not find a sufficient basis to conclude that optimization of the process taught in Mayer would have led to the invention of claim 25, particularly given the differences between Mayer’s process and the process of the claimed invention. Appeal 2017-009107 Application 13/981,974 7 More specifically, Mayer describes a damascene plating process used to create vias in interlayer dielectric trenches of “approximately 1 µm depth.” Mayer col. 2, ll. 63–67, col. 7, l. 13; Fig. 20. Claim 25, on the other hand, discloses a process for metallizing “through silicon vias” having “a depth dimension between 50 micrometers and 300 micrometers,” which is at least 50 times as large as the vias described in Mayer. Claim 25. The Examiner has not sufficiently shown that one of ordinary skill would have been motivated to use the interlayer-dielectric metallization process of Mayer for through silicon vias of the dimensions set forth in claim 25, much less that the routine optimization of such a process would have led to the claimed 80:1 ratio of cumulative charge transfer of copper deposition to anodic potential intervals. Additionally, the Examiner has not established that one of ordinary skill would have looked to Ahrens’s process, which is performed on a relatively thick silicon wafer, to optimize the process so as to achieve the claimed ratio specifically in Mayer’s relatively thin dielectric layer. The Examiner relies on Ahrens for teaching through silicon vias of the claimed dimensions. See Final Act. 5 (citing Ahrens ¶ 36). However, the Examiner does not point to sufficient disclosure in Ahrens that teaches or suggests a plating process for such through silicon vias using anodic potential intervals as set forth in the claim, much less the “at least 80:1 ratio” of cumulative charge transfer of copper deposition to such anodic potential intervals set forth in claim 25. Consequently, we are persuaded that the Examiner has failed to establish that it would have been obvious to one of ordinary skill to have optimized Mayer in the manner claimed. Appeal 2017-009107 Application 13/981,974 8 Accordingly, we reverse the Examiner’s rejection of claim 25. We also reverse the Examiner’s rejection of dependent claims 2, 4–11, 14–17, and 19–22, which are dependent on claim 25. II. Claim 28 Claim 28 is reproduced below, with the key elements at issue in italics: 28. A process for metalizing a through silicon via feature in a semiconductor integrated circuit device, said device comprising a surface having a via feature therein, said via feature comprising a sidewall extending from said surface and a bottom, said sidewall, said bottom and said surface having a metalizing substrate thereon for deposition of copper, said metalizing substrate comprising a seed layer, the process comprising: immersing said metalizing substrate in an electrolytic copper deposition composition, wherein the through silicon via feature has an entry dimension between 1 micrometers and 25 micrometers, a depth dimension between 50 micrometers and 300 micrometers, and an aspect ratio greater than 2:1, said metalizing substrate providing a cathode for electrolytic deposition of copper thereon, the deposition composition comprising: a source of copper ions; an acid component selected from among an inorganic acid, an organic sulfonic acid, and mixtures thereof; an accelerator; a suppressor; a leveler; and chloride ions; Appeal 2017-009107 Application 13/981,974 9 establishing an electrodeposition circuit comprising an anode, the electrolytic deposition composition, the cathode, and a power source; applying a potential between the anode and the cathode during a via filling cycle to establish a positive polarity at the anode and a negative polarity at the cathode to generate an electrodeposition current and cause reduction of copper ions at the cathode to plate copper onto the metalizing substrate at the bottom and sidewall of the via, the via preferentially plating on the bottom and lower sidewall to cause filling of the via from the bottom with copper; reversing a polarity of said electrodeposition circuit during the via filling cycle for at least one interval to generate an anodic potential at said metalizing substrate; resuming copper deposition by re-establishing the surface of the copper within the via as the cathode in the circuit, thereby yielding a copper filled via feature; wherein the via filling cycle comprises a plurality of faradaically material anodic potential intervals in each of which an average anodic charge transfer is at least 3 x 10·4 coulombs/cm2 integrated over a total electrodic surface area of said metalizing substrate, and wherein between successive faradaically material anodic potential intervals, an integrated average cathodic current charge transfer over the total electrodic surface area of said metalizing substrate is at least 1.5 x 10·2 coulombs/cm2. Appeal Br. 24–25 (Claims Appendix). The Examiner relies on Mayer for most of the features of claim 28, but finds that Mayer does not disclose: (1) wherein the through silicon via feature has an entry dimension between 1 micrometers and 25 micrometers and a depth dimension between 50 micrometers and 300 micrometers; and (2) “wherein between successive faradaically material anodic potential Appeal 2017-009107 Application 13/981,974 10 intervals, an integrated average cathodic current charge transfer over the total electrodic surface area of said metalizing substrate is at least 1.5 x 10·2 coulombs/cm2”; and (3) “wherein the via filling cycle comprises a plurality of faradaically material anodic potential intervals in each of which an average anodic charge transfer is at least 3 x 10·4 coulombs/cm2 integrated over a total electrodic surface area of said metalizing substrate.” Final Act. 7–8; Ans. 5–6. The Examiner finds that “Mayer discloses using an anodic potential for copper deposition (column 20, lines 46-50) and that some average charge transfer occurs during anodic potential interval (column 16, lines 10-20; column 20, lines 60-65; Fig. 11).” Ans. 5. The Examiner further states that “Mayer discloses that parameters of anodic and cathodic potentials as well as charge current density during these intervals can be optimized (column 16, lines 10-20) to achieve net plating (column 20, lines 60-67) without seam and void formation (column 20, lines 20-25).” Id. at 5–6. Consequently, the Examiner determines, these “are result- effective parameters” that would have been obvious to optimize. Id. at 6. Appellants respond that Mayer does not teach or suggest “any particular values of average anodic charge transfer or integrated average cathodic current charge transfer and thus it cannot be shown that the teachings of Mayer would have led one skilled in the art to have optimized” these values. Appeal Br. 12. Appellants also argue that the portion of Mayer cited by the Examiner does not disclose that the anodic and cathodic charge transfer values can be optimized, but rather “relates to the Initiation Phase of Mayer’s process, a phase that the Examiner has not used in the rejection of the remaining elements of the claims.” Reply Br. 4 (citing Mayer col. 16, ll. 10–20). “Moreover,” Appellants argue, “the cited passage Appeal 2017-009107 Application 13/981,974 11 only indicates a proposed range of current density for a superimposed cathodic-anodic waveform,” and “does not discuss optimization in general nor does it describe how variation of this variable [a]ffects properties or results of the method.” Id. Finally, Appellants argue that: Even taking the highest possible cathodic current density (255 mA/cm2) disclosed by Mayer in this passage and the highest possible time period (10ms), the result is still not the claimed invention. Using the conversion that lamp-second = 1 coulomb, the result of the conversion is 0.00255 coulombs/cm2, i.e., 0.255x10-2 coulombs/cm2, much less than the claimed range. Therefore, Mayer does not teach or render obvious the claimed invention. Id. We agree with Appellants that the Examiner has not sufficiently demonstrated obviousness of claim 28. The Examiner acknowledges that none of the prior art discloses the claimed ranges of average anodic charge transfer or integrated average cathodic current charge transfer set forth in claim 28. As Appellants point out, the range of Mayer relied on by the Examiner teaches a maximum charge transfer of 0.00255 coulombs/cm2, well below the claimed ranges. Reply Br. 4 (citing Mayer col. 16, ll. 10– 20). We also agree with Appellants that Mayer does not sufficiently disclose that average anodic charge transfer or integrated average cathodic current charge transfer are “result-oriented variables” that can be optimized to improve plating of for some other purposes. Moreover, as discussed above with respect to claim 25, Mayer differs from the process of claim 28 because Mayer describes a damascene plating process used to create vias in trenches of “approximately 1 µm depth,” while claim 28 recites a process for metallizing “through silicon vias” having “a depth dimension between 50 micrometers and 300 micrometers,” which is at Appeal 2017-009107 Application 13/981,974 12 least 50 times as large as the vias described in Mayer. Mayer col. 2, ll. 63– 67; col. 7, ll. 13; Fig. 20. The Examiner has not sufficiently shown that one of ordinary skill would have been motivated to use the metallization process of Mayer for through silicon vias of the dimensions set forth in claim 28, much less that the routine optimization of Mayer’s process would have led to the ranges of average anodic charge transfer or integrated average cathodic current charge transfer set forth in claim 28. Additionally, the Examiner has not established that one of ordinary skill would have looked to Ahrens to demonstrate that optimization of Mayer’s damascene process would have achieved the values set forth in claim 28. The Examiner does not point to sufficient disclosure in Ahrens that teaches or suggests a plating process for such through silicon vias using anodic potential intervals as set forth in the claim, much less the ranges of average anodic charge transfer or integrated average cathodic current charge transfer set forth in claim 28. Consequently, we are persuaded that the Examiner has failed to establish that it would have been obvious to one of ordinary skill to have optimized Mayer in the manner claimed. III. Claim 33 Claim 33 is reproduced below, with the key elements at issue in italics: 33. A process for metalizing a through silicon via feature in a semiconductor integrated circuit device, said device comprising a surface having a via feature therein, said via feature comprising a sidewall extending from said surface, and a bottom, said sidewall, said bottom and said surface having a metalizing substrate thereon for deposition of copper, said metalizing substrate comprising a seed layer, the process comprising: Appeal 2017-009107 Application 13/981,974 13 immersing said metalizing substrate with an electrolytic copper deposition composition, wherein the through silicon via feature has an entry dimension between 1 micrometers and 25 micrometers, a depth dimension between 50 micrometers and 300 micrometers, and an aspect ratio greater than 2:1, said metalizing substrate providing a cathode for electrolytic deposition of copper thereon, the deposition composition comprising: a source of copper ions; an acid component selected from among an inorganic acid, an organic sulfonic acid, and mixtures thereof; an accelerator; a suppressor; a leveler; and chloride ions; establishing an electrodeposition circuit comprising an anode, the electrolytic deposition composition the cathode, and a power source; applying a potential between the anode and the cathode during a via filling cycle to establish a positive polarity at the anode and a negative polarity at the cathode to generate an electrodeposition current and cause reduction of copper ions at the cathode to plate copper onto the metalizing substrate at the bottom and sidewall of the via, the via preferentially plating on the bottom and lower sidewall to cause filling of the via from the bottom with copper; reversing a polarity of said electrodeposition circuit during the via filling cycle for at least one interval to generate an anodic potential at said metalizing substrate; Appeal 2017-009107 Application 13/981,974 14 resuming copper deposition by re-establishing the surface of the copper within the via as the cathode in the circuit, thereby yielding a copper filled via feature; the method further comprising the steps of: reversing the polarity of the circuit to provide an anodic potential at said metalizing substrate in a plurality of intervals during the filling cycle; wherein a ratio of cumulative charge transfer in said circuit during copper deposition within said filling cycle to cumulative charge transfer during the sum of all intervals of anodic potential at said metalizing substrate is at least 50:1; wherein said filling cycle comprises a plurality of anodic potential intervals of material duration, and each of said anodic intervals of material duration extends for a period of at least 0.6 seconds, a period of cathodic current at said metalizing substrate between successive anodic potential intervals of material duration being at least 0.5 minutes; wherein a cumulative duration of all anodic potential intervals at said metalizing substrate during said filling cycle is not more than 50 seconds; wherein a cumulative extent of anodic charge transfer at said metalizing substrate in the sum of all said anodic potential intervals is not greater than an average of 1.8 coulombs/cm2 integrated over the total electrodic surface area of said metalizing substrate; wherein during each said anodic potential interval of material duration, a current density across an electrode surface of the metalizing substrate is maintained at an average of between 0.1 and 100 mA/cm2 integrated over a total electrodic surface area of said metalizing substrate; wherein each of said anodic potential intervals is effective to desorb leveler from the electrodic surface, whereby the average current density integrated over the total electrodic Appeal 2017-009107 Application 13/981,974 15 surface area of said metalizing substrate is increased upon resumption of cathodic current relative to a current density prior to said anodic potential interval; wherein said anodic potential intervals are effective to desorb suppressor from the surface of the copper within the via; wherein a ratio of cumulative duration of cathodic current during copper deposition within said filling cycle to cumulative duration of all anodic potential intervals at said metalizing substrate is at least 80:1; and wherein the copper filled via is at least one of substantially free of seams and voids or substantially free of mounds and protrusions. Appeal Br. 26–28 (Claims Appendix). The Examiner finds that Mayer does not disclose multiple limitations of claim 33, including: (1) wherein the through silicon via feature has an entry dimension between 1 micrometers and 25 micrometers, a depth dimension between 50 micrometers and 300 micrometers; (2) wherein a ratio of cumulative charge transfer in said circuit during copper deposition within said filling cycle to cumulative charge transfer during the sum of all anodic potential intervals is at least 50:1; (3) said anodic intervals of material duration extending for a period of at least 0.6 seconds, a period of cathodic current at said metalizing substrate between successive anodic potential intervals of material duration being at least 0.5 minutes; (4) wherein a cumulative duration of all anodic potential intervals at said metalizing substrate during said filling cycle is not more than 50 seconds; (5) during each said anodic potential interval of material duration, a current density across an electrode surface of the metalizing substrate is maintained at an average of between 0.1 and 100 mA/cm2 integrated over a total electrodic surface area of said metalizing substrate. Final Act. 19. Appeal 2017-009107 Application 13/981,974 16 As with the previous independent claims, the Examiner determines that it would have been obvious “to modify Mayer with Ahrens to have through silicon via feature has an entry dimension between 1 micrometers and 25 micrometers, a depth dimension between 50 micrometers and 300 micrometers for the purpose of fabrication contact structures.” Id. (citing Ahrens ¶ 36). As to the other limitations, the Examiner finds as follows: Regarding elements (2)-(5), Mayer discloses that a ratio of cumulative charge transfer in said circuit during copper deposition within said filling cycle to cumulative charge transfer during the sum of all anodic potential intervals should be greater than 1 to result in net plating (column 20, lines 60– 67; Fig.11 ). Mayer also discloses that anodic and cathodic charge transfer as wells as other parameters of deposition such as duration of anodic and cathode potential intervals, a period of cathodic and anodic current, a cumulative extend of anodic charge transfer, current densities affect filling of a via (column 20, lines 46-67). Parameters of electrodeposition therefore are art-recognized result-affecting variables/parameters. Final Act. 20. Accordingly, the Examiner finds that “it would have been obvious to optimize (for example by routine experimentation) the parameters of electrodeposition for the purpose of achieving net plating.” Id. (citing Mayer col. 20, ll. 60–67). Appellants argue that “there is no teaching or suggestion in Mayer that all of elements (2)-(8) are result effective variables that can be optimized.” Appeal Br. 15 (emphasis omitted). Appellants also argue that the 50:1 cumulative charge ratio in claim 33 is similar to the ratio in claim 25 and, thus, “is not obvious” “[f]or the same reasons as claim 25.” Reply Br. 4. As to the claim 33’s limitation that “requires each anodic interval to Appeal 2017-009107 Application 13/981,974 17 last at least 0.6 seconds and a cathodic interval of 0.5 minutes (30 seconds),” Appellants argue, “the largest time-period for even the cathodic interval discussed by Mayer is 200ms. (20:34).” Id. Moreover, Appellants assert, because “Mayer refers to the anodic period as a ‘pulse’ compared to the cathodic period, a person of ordinary skill in the art would understand that the anodic period would be even shorter.” Id. “In any event,” Appellants state, “the longest period described by Mayer is still much less than 0.6 seconds and 30 seconds.” Id. We agree with Appellants that the Examiner has not sufficiently demonstrated obviousness of claim 33. The Examiner acknowledges that none of the prior art discloses elements (2)–(8) of the claim referred to above. We also agree with Appellants that Mayer does not disclose that these are “result-oriented variables” that can be optimized to improve plating or for some other purposes. This is particularly true because, as discussed above with respect to claim 25, Mayer differs from the claimed process because Mayer describes a damascene plating process used to create vias in dielectric trenches of “approximately 1 µm depth,” whereas claim 33 recites a process for metallizing “through silicon vias” having “a depth dimension between 50 micrometers and 300 micrometers,” which depth is at least 50 times as large as the vias described in Mayer and in a different material. Mayer col. 2, ll. 63–67; col. 7, ll. 13; Fig. 20. As discussed above, the Examiner has not sufficiently shown that one of ordinary skill would have used the metallization process of Mayer for through silicon vias of the dimensions set forth in claim 33, much less that the optimization of Mayer’s process would have led to the ranges of average anodic charge transfer or integrated average cathodic current charge transfer set forth in claim 33. Appeal 2017-009107 Application 13/981,974 18 The Examiner also has not established that one of ordinary skill would have looked to Ahrens to demonstrate that optimization of Mayer’s damascene process would have achieved the values set forth in claim 33. Additionally, we determine that the Examiner has not established the obviousness of the 50:1 cumulative charge ratio in claim 33, for the same reasons discussed above with respect to the 80:1 range in claim 25. Finally, we agree with Appellants that the longest time period Mayer discloses for a charge transfer interval is 200 ms. Mayer col. 20, ll. 34; Reply Br. 4. This is significantly less than claim 33’s limitation requiring “each anodic interval to last at least 0.6 seconds and a cathodic interval of 0.5 minutes (30 seconds).” The Examiner has failed to sufficiently show that a routine optimization of Mayer would have resulted in the values set forth in the claim, which are much larger than the maximum length taught by Mayer, particularly given the differences in Mayer’s damascene process and the claimed invention’s focus on filling silicon vias, as discussed above. And, the Examiner fails to point to sufficient disclosure in Mayer that would support the conclusion that routine optimization of Mayer would have led one of ordinary skill to the claimed values. Consequently, we are persuaded that the Examiner has failed to establish that it would have been obvious to one of ordinary skill to have optimized Mayer in the manner claimed. IV. Conclusion We are persuaded that the Examiner erred in rejecting independent claims 25, 28, and 33 as obvious based on Mayer and Ahrens. We, therefore, reverse the Examiner’s rejection of those claims. We also reverse Appeal 2017-009107 Application 13/981,974 19 the rejections of claims 2, 4–11, 14–17, 19–22, 30–32, and 34, which are dependent on claims 25, 28, or 33. DECISION We reverse the Examiner’s rejection of claims 2, 4–11, 14–17, 19–22, 25, 28, and 30–34. REVERSED Copy with citationCopy as parenthetical citation