2019003662 (P.T.A.B. May. 1, 2020)

Tokyo Electron Limited

Patent Trials and Appeals BoardMay 1, 2020

2019003662 (P.T.A.B. May. 1, 2020)

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. 14/537,652 11/10/2014 Ian J. Brown 448424US41YA 7828 133103 7590 05/01/2020 Oblon/TEH 1940 Duke Street Alexandria, VA 22314 EXAMINER MARKOFF, ALEXANDER ART UNIT PAPER NUMBER 1711 NOTIFICATION DATE DELIVERY MODE 05/01/2020 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): iahmadi@oblon.com oblonpat@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 IAN J. BROWN Appeal 2019-003662 Application 14/537,652 Technology Center 1700 Before BEVERLY A. FRANKLIN, JEFFREY B. ROBERTSON, and BRIAN D. RANGE, Administrative Patent Judges. ROBERTSON, Administrative Patent Judge. DECISION ON APPEAL1 STATEMENT OF THE CASE Pursuant to 35 U.S.C. § 134(a), Appellant2 appeals from the Examiner’s decision to reject claims 1–20. Appeal Br. 3. We have jurisdiction under 35 U.S.C. § 6(b). 1 This Decision includes citations to the following documents: Specification filed November 10, 2014 (“Spec.”); Final Office Action mailed June 30, 2017 (“Final Act.”); Appeal Brief filed July 31, 2018 (“Appeal Br.”); Examiner’s Answer mailed February 4, 2019 (“Ans.”); and Reply Brief filed April 4, 2019 (“Reply Br.”). 2 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 2019-003662 Application 14/537,652 2 We REVERSE. CLAIMED SUBJECT MATTER Appellant states the invention relates to semiconductor processing and particularly to substrate cleaning processes. Spec. ¶ 2. Claim 1, reproduced below, is illustrative of the claimed subject matter (Appeal Br. 9, Claims Appendix, disputed claim terms italicized for emphasis): 1. A method for cleaning a substrate, the method comprising: receiving a substrate in a cleaning system, the cleaning system including a wet clean system, a processing chamber, and a fluid delivery sub system, the substrate including a hardmask layer deposited on an underlying layer; spinning the substrate on a substrate holder in the processing chamber; depositing a hydrogen peroxide solution on a top surface of the substrate; irradiating the hydrogen peroxide solution on the substrate with ultraviolet (UV) electromagnetic radiation to create reactive oxygen species while the substrate is spinning, the UV electromagnetic radiation having a wavelength between approximately 185–400 nanometers, the hardmask being dissolved by irradiated hydrogen peroxide and being removed from the substrate by action of hydrogen peroxide flow and by action of spinning the substrate, wherein said irradiating comprises providing said UV at a radially non-uniform intensity to compensate for radially non-uniform thickness of the hydrogen peroxide solution on a top surface of the substrate. Appeal 2019-003662 Application 14/537,652 3 REFERENCES The prior art relied upon by the Examiner is: Name Reference Date Rastegar et al. hereinafter “Rastegar” US 2011/0132394 A1 June 9, 2011 Fitzsimmons et al. hereinafter “Fitzsimmons” US 2013/0200040 A1 August 8, 2013 REJECTION 1. The Examiner rejected claims 1–20 under 35 U.S.C. § 103 as unpatentable over Rastegar and Fitzsimmons. Final Act. 2–6. OPINION We limit our discussion to independent claim 1, which is sufficient for disposition of this rejection. The Examiner’s Rejection The Examiner found Rastegar discloses the method recited in claim 1, including “the use of wavelength as claimed and intensity as claimed and the distribution of energy as claimed.” Final Act. 3, citing Rastegar, Figs. 1A–4, ¶¶ 25–35. The Examiner found Rastegar fails to disclose the use of the method for removal of a hard mask comprising the compounds recited in the claims, but Fitzsimmons discloses that is was known to use solutions of hydrogen peroxide with additives to remove hard masks. Id., citing Fitzsimmons, ¶¶ 5, 6, 12–17, 35–41, 46, 50–73, 101–105, 113, and 114–121. Appeal 2019-003662 Application 14/537,652 4 The Examiner determined it would have been obvious to have extended the method of Rastegar on removal of hard masks or to have applied UV radiation to the hydrogen peroxide solution in the method of Fitzsimmons in order to enhance the action of hydrogen peroxide solutions. Id. at 4. Appellant’s Contentions Appellant argues, inter alia, Rastegar fails to disclose “providing said UV at a radially non-uniform intensity to compensate for radially non- uniform thickness of the hydrogen peroxide solution on a top surface of the substrate,” as recited in claim 1. Appeal Br. 5–6. In particular, Appellant acknowledges Rastegar discloses UV intensity values but argues Rastegar does not disclose non-uniform intensity and does not disclose intensity compensating for non-uniform hydrogen peroxide solution thickness on the top surface of the substrate. Id. Issue The dispositive issue is: Has Appellant identified reversible error in the Examiner’s determination that Rastegar discloses the recited method step in claim 1 of “said irradiating comprises providing said UV at a radially non-uniform intensity to compensate for radially non-uniform thickness of the hydrogen peroxide solution on a top surface of the substrate”? Discussion We are persuaded by Appellant’s arguments that Rastegar does not disclose providing a radially non-uniform UV intensity to compensate for Appeal 2019-003662 Application 14/537,652 5 radially non-uniform thickness of the hydrogen peroxide solution as recited in claim 1. Although the Examiner acknowledged claim 1 requires providing UV at a radially non-uniform intensity to compensate for radially non-uniform thickness of the hydrogen peroxide solution, the Examiner stated: “what is required by the claims is irradiating the hydrogen peroxide solution on the substrate with ultraviolet (UV) electromagnetic radiation at a radially non- uniform intensity.” In this regard, the Examiner stated the recited non-uniform intensity is met because “[s]uch is inherently presented in Rastegar et al due to the fact that the area of the substrate in center of the substrate is smaller than the area of the substrate and the periphery.” Ans. 7–8, (citing ¶ 27 of the Specification as “the only place wherein the application addresses the non-[un]iformed distribution of the solution” for support that non-uniformed distribution exists due to rotation of the substrate). Therefore, the Examiner’s position is that because the periphery of the substrate in Rastegar has a bigger surface area than the center of the substrate, and would be irradiated from the same length of the bar lamp applying UV radiation, the solution at the center would be provided with more radiation than the solution at the periphery. Id. at 8; see Rastegar, Fig. 2A. As to the intensity of UV light, Rastegar discloses the UV source may have “an intensity of about 1 mW/cm2 or higher, preferably higher than 5mW/cm2.” Rastegar, ¶ 25. Rastegar discloses also inert gas may be used in its process “to prevent from losing UV light intensity due to absorption by air and moisture.” Id. at ¶ 30. Rastegar discloses that in situations where the distance between the UV light source and the surface to be irradiated is Appeal 2019-003662 Application 14/537,652 6 minimal, “UV light with higher intensity may radiate the surface to create more ozone and other oxygen radicals within the liquid film.” Id. Rastegar does not disclose providing UV in a radially non-uniform intensity in order accomplish the goal of compensating for radially non-uniform distribution of the hydrogen peroxide solution, but rather only generally discloses ranges for intensities or general situations to either prevent loss of UV intensity or promote higher intensity. Rastegar, ¶¶ 25, 30. As to the Examiner’s reliance on the Specification in order to support the position that the non-uniform intensity is inherent in Rastegar, we observe that the Examiner is not correct that paragraph 27 is the only place in the Specification addressing the non-uniform distribution of hydrogen peroxide solution. See Ans. 7. The Specification discloses irradiating using a segmented or gradient UV exposure where a central portion of the substrate is irradiated at a first intensity and the edge portion of the substrate is irradiated at a second intensity, where the first intensity is greater than the second intensity due to thicker flow of hydrogen peroxide toward a center point of a substrate. Spec. ¶ 22. Thus, Appellant’s Specification describes situations where the UV radiation is itself provided in a non-uniform manner in order to address the non-uniform distribution of hydrogen peroxide solution on the substrate. Although it may be true that in certain situations, Rastegar may provide UV radiation in a non-uniform manner, we are not persuaded that it is necessarily the case that UV radiation is provided in a manner that would address the non-uniform distribution of hydrogen peroxide solution on a top surface of the substrate as recited in claim 1.3 3 While subjective intent of the performer of the method does not, by itself, affect claim scope or the obviousness analysis, claim 1 requires that Appeal 2019-003662 Application 14/537,652 7 Therefore, the Examiner does not provide sufficient rationale as to how the disclosures in Rastegar and Fitzsimmons would be modified in order to provide UV at a radially non-uniform intensity to compensate for radially non-uniform thickness of the hydrogen peroxide solution on a top surface of the substrate as recited in claim 1. Accordingly, we reverse the Examiner’s rejection of claim 1, and claims 2–20, dependent therefrom. CONCLUSION The Examiner’s rejection of claims 1–20 is reversed. DECISION SUMMARY In summary: Claims Rejected 35 U.S.C. § Reference(s)/Basis Affirmed Reversed 1–20 103 Rastegar, Fitzsimmons 1–20 REVERSED irradiating in a manner capable of compensating for radially non-uniform thickness of the hydrogen peroxide solution.