Pacific Light Technologies Corp.

Patent Trials and Appeals Board

Jan 7, 2022

2021001109 (P.T.A.B. Jan. 7, 2022)

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. 15/156,242 05/16/2016 Weiwen Zhao 37621.635 4090 147546 7590 01/07/2022 Elliott Ostrander & Preston, P.C. 707 SW Washington St Suite 1500 Portland, OR 97205 EXAMINER NGUYEN, HAIDUNG D ART UNIT PAPER NUMBER 1761 NOTIFICATION DATE DELIVERY MODE 01/07/2022 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): eofficeaction@appcoll.com ipdocketing@eoplaw.com niel@eoplaw.com PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE BEFORE THE PATENT TRIAL AND APPEAL BOARD Ex parte WEIWEN ZHAO, KARI HALEY, and JUANITA N. KURTIN Appeal 2021-001109 Application 15/156,242 Technology Center 1700 Before MICHAEL P. COLAIANNI, DEBRA L. DENNETT, and SHELDON M. MCGEE, Administrative Patent Judges. COLAIANNI, Administrative Patent Judge. DECISION ON APPEAL Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the Examiner’s decision to reject claims 4 and 6-10. We have jurisdiction under 35 U.S.C. § 6(b). We AFFIRM. 1 “Appellant” refers to “applicant” as defined in 37 C.F.R. § 1.42. Appellant identifies the real party in interest as OSRAM Opto Semiconductors GmbH. Appeal Br. 3. Appeal 2021-001109 Application 15/156,242 2 CLAIMED SUBJECT MATTER The claims are directed to a method of fabricating a semiconductor structure (Spec. ¶ 3). The Specification describes that the semiconductor structure is fabricated by first forming a quantum dot, followed by encapsulation of the quantum dot by an insulator layer (id.). Quantum dots are beneficial in many products, such as LEDs or solar devices, but often cannot withstand thousands of hours of operation under the environmental and operating conditions encountered by these products (id. ¶5). According to the Specification, quantum dots are made robust by individually coating the quantum dots’ surfaces with an insulating layer of metal oxides, such as silica (id.). Independent claim 4, reproduced below, illustrates the claimed subject matter (italics added): 4. A method of fabricating a semiconductor structure, comprising: forming a nanocrystalline core from a first semiconductor material; forming at least one nanocrystalline shell from a second, different, semiconductor material that at least partially surrounds the nanocrystalline core, wherein the nanocrystalline core and the nanocrystalline shell form a quantum dot; and forming an insulator layer of silica bonded directly to the nanocrystalline shell individually and discretely encapsulating the quantum dot to create an individually and discretely coated quantum dot, using a reverse micelle sol-gel reaction, wherein the reverse micelle sol- gel reaction includes: dissolving the quantum dot in a first non-polar solvent to form a first solution; Appeal 2021-001109 Application 15/156,242 3 adding the first solution to a second solution having a surfactant dissolved in a second non-polar solvent; and, adding sodium silicate, potassium silicate, or lithium silicate to the second solution. REJECTION The Examiner maintains the rejection of claims 4 and 6-10 under 35 U.S.C. § 103 as unpatentable over Kurtin et al. (US 2013/0112941 A1, published May 9, 2013, “Kurtin”) in view of Brinker et al. (US 6,495,352 B1, issued Dec. 17, 2002, “Brinker”) (Final Act. 2-5). Appellant argues claims 4 and 6-10 as a group (see generally Appeal Br. 7-10; Reply Br. 2-5). We select claim 4 as representative. 37 C.F.R. § 41.37(c)(1)(iv). Accordingly, claims 4 and 6-10 will stand or fall with our analysis of independent claim 4. DISCUSSION After review of the respective positions provided by Appellant and the Examiner, we AFFIRM the Examiner’s prior art rejection under 35 U.S.C. § 103 for the reasons provided by the Examiner in the Final Action and the Answer. We add the following for emphasis. With respect to claim 4, the Examiner’s findings and conclusions regarding Kurtin and Brinker are located on pages 2 through 3 of the Final Office Action. The Examiner finds that Kurtin’s method of fabricating a semiconductor structure comprising a quantum dot teaches each step and limitation of the method recited in independent claim 4, except that Kurtin Appeal 2021-001109 Application 15/156,242 4 does not disclose adding a silicate of sodium, potassium, or lithium to coat the quantum dot with a silica insulator layer (Final Act. 2-3). The Examiner finds that Brinker teaches a method for encapsulating molecules by forming a silica sol using an alkali metal silicate precursor, such as sodium silicate or potassium silicate (id. at 3 (citing Brinker 1:11- 14; 3:20-31)). The Examiner determines that it would have been obvious to one of ordinary skill in the art at the time of the invention to encapsulate Kurtin’s quantum dot through Brinker’s step of forming a silica sol using sodium silicate or potassium silicate (Final Act. 3). According to the Examiner, one of ordinary skill in the art would have been motivated to form a silica sol using an alkali metal silicate precursor because Brinker discloses that doing so does not produce undesirable alcohols as a by-product (Final Act. 3 (citing Brinker 2:1-20)). Appellant argues that Brinker discourages using alkali metal silicates for bonding an insulator layer to the nanocrystalline shell of quantum dots because Brinker’s “molecules are embedded or entrapped in, but not bonded to, the [silica] thin film or gel” (Appeal Br. 8 (citing Brinker 4:33-36; 5:49- 59)). Appellant argues that the rejection of claim 4 improperly combines the cited references because Kurtin discloses first adding, inter alia, tetraethylorthosilicate (TEOS) to quantum dots and, thereafter, using reverse micelle reaction to form the insulator layer (Appeal Br. 8). Appellant contends that Brinker’s “first preparing a silica sol from alkali metal silicates, subsequently adding []organic molecules to the prepared silica sol and then aging the silica sol” (id.) actually “contradicts the sol formation in [Kurtin’s] reverse micelle process” (id. at 9). Appellant also argues that Brinker’s method requires “further preparation steps[,] including a cation Appeal 2021-001109 Application 15/156,242 5 exchange resin that needs to be removed by vacuum filtration” (id.). According to Appellant, these additional steps would have “discourage[d] a person skilled in the art from using alkali metal silicates in the method of Kurtin.” (id.; see Reply Br. 3). We are unpersuaded by Appellant’s arguments because they are premised on bodily incorporation and are not focused on the Examiner’s reason for combining the cited art. It is well established that the obviousness inquiry asks not “whether the references could be physically combined but whether the claimed inventions are rendered obvious by the teachings of the prior art as a whole.” In re Etter, 756 F.2d 852, 859 (Fed. Cir. 1985) (en banc); see also In re Keller, 642 F.2d 413, 425 (CCPA 1981) (“The test for obviousness is not whether the features of a secondary reference may be bodily incorporated into the structure of the primary reference.”). Moreover, to the extent Appellant alleges that Brinker requires additional steps that would have led a person skilled in the art from using alkali metal silicates, Appellant presents attorney argument unsupported by evidence. Appellant argues that “Brinker explicitly teaches that the generation of alcohol by using alkoxy silicates is detrimental when encapsulating biomolecules” (Appeal Br. 9; Reply Br. 4). Appellant argues that one of ordinary skill in the art would not have been motivated to use Brinker’s alkali metal silicates, instead of Kurtin’s alkoxy silicate, TEOS, because Kurtin’s “[q]uantum dots are clearly not biomolecules and thus are not affected by denaturing due to a generation of alcohol during encapsulation” (Appeal Br. 9; Reply Br. 4). In response, the Examiner determines that it would have been obvious to one of ordinary skill in the art to replace Kurtin’s TEOS precursor with Appeal 2021-001109 Application 15/156,242 6 another precursor, such as Brinker’s alkali metal silicates, because each precursor is known to form a silica coating (Ans. 7 (citing In re Ruff, 256 F.2d 590 (CCPA 1958)). We understand the Examiner’s citation of Ruff as providing support for the position that Kurtin’s alkoxy silicate and Brinker’s alkali metal silicates are known in the art as equivalent silicate precursors. In order to rely on equivalence as a rationale supporting an obviousness rejection, the equivalency must be recognized in the prior art, and cannot be based on applicant’s disclosure or the mere fact that the components at issue are functional or mechanical equivalents. Ruff, 256 F.2d at 590 (CCPA 1958); Smith v. Hayashi, 209 USPQ 754 (BPAI 1980); In re Fout, 675 F.2d 297, 301 (CCPA 1982) (holding that an “[e]xpress suggestion to substitute one equivalent component for another is not necessary to render such substitution obvious.”). In the instant case, Brinker recognizes that all of tetramethyl orthosilicate (TMOS), TEOS, sodium silicate, and potassium silicate are known to be used to encapsulate organic molecules in the formation of sol- gel matrices (Brinker 1:11-14; 1:66-2:3; 3:20-31). Brinker discloses that fluorescent dyes are a suitable organic molecule that may be encapsulated using alkali metal silicates (id. at 3:21). Kurtin teaches that semiconductor structures having quantum dots may be used as fluorescent labeled probes (Kurtin ¶ 41). In light of these disclosures, we find that the Examiner has established by a preponderance of the evidence that the prior art teaches sodium silicate and potassium silicate as known alternatives to using TEOS in encapsulating an organic molecule in a sol-gel matrix. Appeal 2021-001109 Application 15/156,242 7 Therefore, Appellant’s arguments are insufficient to convince us of reversible error in the Examiner’s rejection of claim 4. On this record, we sustain the Examiner’s § 103 rejection as to claims 6-10. CONCLUSION The Examiner’s decision is affirmed. DECISION SUMMARY In summary: Claim(s) Rejected 35 U.S.C. § Reference(s)/Basis Affirmed Reversed 4, 6-10 103 Kurtin, Brinker 4, 6-10 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