Ex Parte FreundDownload PDFBoard of Patent Appeals and InterferencesMar 23, 201011419592 (B.P.A.I. Mar. 23, 2010) Copy Citation UNITED STATES PATENT AND TRADEMARK OFFICE ____________ BEFORE THE BOARD OF PATENT APPEALS AND INTERFERENCES ____________ Ex parte JOSEPH MICHAEL FREUND ____________ Appeal 2009-014229 Application 11/419,5921 Technology Center 2800 ____________ Decided: March 23, 2010 ____________ Before JOSEPH F. RUGGIERO, SCOTT R. BOALICK, and BRADLEY W. BAUMEISTER, Administrative Patent Judges. BOALICK, Administrative Patent Judge. DECISION ON APPEAL 1 Application filed May 22, 2006. The real party in interest is LSI Corporation. Appeal 2009-014229 Application 11/419,592 2 This is an appeal under 35 U.S.C. § 134(a) from the rejection of claims 1-22, all the pending claims in the application. We have jurisdiction under 35 U.S.C. § 6(b). We reverse and enter new grounds of rejection pursuant to our authority under 37 C.F.R. § 41.50(b). STATEMENT OF THE CASE Appellant’s invention relates to a semiconductor device including an n-side waveguide layer, an active layer contacting the n-side waveguide layer and a p-side waveguide contacting the active layer. (Spec. Abstract.) An electron blocking layer contacts the p-side waveguide layer and a cladding layer contacts the electron blocking layer. (Spec. Abstract.) The cladding layer includes a cladding sublayer composed of two elements from group III of the periodic table (e.g., Al, Ga, In) and an element from group V of the periodic table (e.g., N, As). (Spec. Abstract.) In one example, the cladding sublayer is composed of InGaN. (Spec. 3:27-28.) Claim 1 is exemplary: 1. A semiconductor device comprising: an n-side waveguide layer; an active layer in contact with the n-side waveguide layer; a p-side waveguide layer in contact with the active layer; an electron blocking layer in contact with the p-side waveguide layer, the electron blocking layer comprising a first composition of two elements from group III of the periodic table and an element from group V of the periodic table; and a cladding layer, the cladding layer including a cladding sublayer in contact with the electron blocking layer, the cladding sublayer comprising a second composition of two elements from group III of the periodic table and an element from group V of the periodic table, the second composition being different from the first composition. Appeal 2009-014229 Application 11/419,592 3 The prior art relied upon by the Examiner in rejecting the claims on appeal is: Gaska 2004/0099869 A1 May 27, 2004 Belenky 5,448,585 Sept. 5, 1995 Takeharu Asano et al., 100-mW Kink-Free Blue-Violet Laser Diodes With Low Aspect Ratio, IEEE Journal of Quantum Electronics, Vol. 39, No. 1, Jan. 2003 (“Asano”). Claims 1-4 and 6-15 stand rejected under 35 U.S.C. § 102(b) as being anticipated by Asano. Claims 5, 16-20 and 22 stand rejected under 35 U.S.C. § 103(a) as being obvious over Asano and Belenky. Claim 21 stands rejected under 35 U.S.C. § 103(a) as being obvious over Asano and Gaska. ISSUES With respect to independent claim 1, Appellant argues that Asano does not teach “a cladding layer, the cladding layer including a cladding sublayer in contact with the electron blocking layer, the cladding sublayer comprising a second composition of two elements from group III of the periodic table [e.g., Al, Ga, In] and an element from group V of the periodic table [e.g., N, As]” because Asano teaches “a p-AlGaN electron blocking layer, followed by a first p-GaN sublayer of the [stressed layer superlattice] SLS cladding layer, followed by a first p-AlGaN sublayer of the SLS cladding layer.” (App. Br. 8.) Appellant presents similar arguments for independent claims 12, 15, 19 and 21. (App. Br. 12-13.) Appeal 2009-014229 Application 11/419,592 4 Appellant’s argument presents the following issue: Has the Examiner erred in finding that Asano teaches “a cladding layer, the cladding layer including a cladding sublayer in contact with the electron blocking layer, the cladding sublayer comprising a second composition of two elements from group III of the periodic table [e.g., Al, Ga, In] and an element from group V of the periodic table [e.g., N, As]”? FINDINGS OF FACT The record supports the following findings of fact (FF) by a preponderance of the evidence. Asano 1. Asano relates to a GaN-based laser diode. (Abstract.) Asano describes a laser diode including a GaN optical guiding layer, a multiple quantum well (MQW) active layer, a GaInN interlayer, a Mg-doped Al0.18Ga0.82N electron-blocking layer (p. 135, col. 2; fig. 1) and a p-Al0.12Ga0.88N-GaN superlattice cladding layer (p. 136, col. 1; fig. 1). Figure 1 illustrates that the Mg-doped Al0.18Ga0.82N electron- blocking layer contacts the p-Al0.12Ga0.88N-GaN superlattice cladding layer. 2. “A 0.5 μm-thick-modulation-doped p-Al0.12Ga0.88N-GaN superlattice cladding layer consisting of 100 pairs of 2.5 nm-thick undoped AlGaN and 2.5-nm-thick Mg-doped GaN layers was grown next to the AlGaN electron blocking layer . . . .” (P. 136, col. 1.) Appeal 2009-014229 Application 11/419,592 5 3. Figure 6(c) is a schematic diagram of conduction bands for a “new layer structure” corresponding to Figure 1. Figure 6(c) illustrates that the value of the conduction band (i.e., Ec) of the “p-(AlGaN/GaN) SLS cladding” layer in contact with the “p-AlGaN electron blocking” layer is about equal to the value of the “GaN guiding” layer. Appellant’s Specification 4. In reference to a prior art gallium nitride based semiconductor laser, Appellant describes that stress induced cracking in a MQW active layer 150 can occur for structures incorporating a p-AlGaN electron blocking layer 160 in a p-side waveguide layer 170 between the MQW active layer 150 and a cladding layer 180. (Spec. 2:13-15, 20-23; fig. 1B.) Appellant further describes that the present invention reduces excessive stress (Spec. 4:7-9) by alternatively placing the electron blocking layer 270 in contact with the p-side cladding layer 280 (Spec. 3:15-16, 7:14-17; figs. 2A, 2B), such that “the p-AlGaN electron blocking layer is adjacent to one of the p-AlGaN sublayers 282 within the SLS cladding layer 280” (Spec. 7:20-21; fig. 2B). “[A] progressive transition from higher aluminum content p-AlGaN to lower aluminum content p-AlGaN to p-GaN . . . is created near the interface of the electron blocking layer and the SLS cladding layer” that “reduces the severity of lattice mismatches between these adjacent layers and sublayers.” (Spec. 7:23-27.) Appeal 2009-014229 Application 11/419,592 6 PRINCIPLES OF LAW Anticipation is established when a single prior art reference discloses, expressly or under the principles of inherency, each and every limitation of the claimed invention. Atlas Powder Co. v. IRECO, Inc., 190 F.3d 1342, 1347 (Fed. Cir. 1999). “Section 103 forbids issuance of a patent when ‘the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art to which said subject matter pertains.’” KSR Int’l Co. v. Teleflex, Inc., 550 U.S. 398, 406 (2007) (citations omitted). In KSR, the Supreme Court emphasized “the need for caution in granting a patent based on the combination of elements found in the prior art,” id. at 415, and discussed circumstances in which a patent might be determined to be obvious. In particular, the Supreme Court emphasized that “[t]he combination of familiar elements according to known methods is likely to be obvious when it does no more than yield predictable results.” Id. at 416. The Court explained: When a work is available in one field of endeavor, design incentives and other market forces can prompt variations of it, either in the same field or a different one. If a person of ordinary skill can implement a predictable variation, § 103 likely bars its patentability. For the same reason, if a technique has been used to improve one device, and a person of ordinary skill in the art would recognize that it would improve similar devices in the same way, using the technique is obvious unless its actual application is beyond his or her skill. Id. at 417. Appeal 2009-014229 Application 11/419,592 7 During examination of a patent application, a claim is given its broadest reasonable construction consistent with the specification. In re Prater, 415 F.2d 1393, 1404-05 (CCPA 1969). “[T]he words of a claim ‘are generally given their ordinary and customary meaning.’” Phillips v. AWH Corp., 415 F.3d 1303, 1312 (Fed. Cir. 2005) (en banc) (internal citations omitted). The “ordinary and customary meaning of a claim term is the meaning that the term would have to a person of ordinary skill in the art in question at the time of the invention, i.e., as of the effective filing date of the patent application.” Id. at 1313. ANALYSIS We are convinced by Appellant’s argument (App. Br. 7-12; see also Reply Br. 2) that Asano does not teach “a cladding layer, the cladding layer including a cladding sublayer in contact with the electron blocking layer, the cladding sublayer comprising a second composition of two elements from group III of the periodic table [e.g., Al, Ga, In] and an element from group V of the periodic table [e.g., N, As],” as recited in claim 1. The Examiner found that Asano teaches all the features of claim 1. (Ans. 3-4, 7-8.) In particular, the Examiner found that the p-Al0.12Ga0.88N-GaN superlattice cladding layer of Asano corresponds to the claimed “cladding layer” and the Mg-doped Al0.18Ga0.82N electron-blocking layer corresponds to “the electron blocking layer.” (Ans. 4.) The Examiner reasoned that Asano teaches “a cladding sublayer in contact with the electron blocking layer, the cladding sublayer comprising a second composition of two elements from group III of the periodic table [e.g., Al, Ga, In] and an element from group V of the periodic table [e.g., N, As]” Appeal 2009-014229 Application 11/419,592 8 because “a cladding layer . . . is a plurality of sublayers comprising AlGaN/GaN” and “[t]he ordering of the layers is not in the claim.” (Ans. 7.) We understand, then, the Examiner’s position to be that the claim term “contact” may be interpreted broadly to mean “at least electrical contact” or “at least electrical communication.” That is, we understand the Examiner to be interpreting claim 1 as setting forth that the cladding sublayer of tertiary composition is “in at least electrical communication” with the electron blocking layer, but not necessarily in direct physical contact. We do not agree that this interpretation is reasonable. Under the broadest reasonable interpretation consistent with the Specification, we interpret “contact” as meaning direct physical contact between two adjacent layers. Appellant’s Specification describes reducing stresses between the p-AlGaN electron blocking layer 270 and the p-AlGaN sublayer 282 by reducing the severity of lattice mismatches between the two adjacent layers. (FF 4.) In other words, the p-AlGaN electron blocking layer 270 and the p-AlGaN sublayer 282 are in direct physical contact. (See FF 4.) If alternatively, “contact” could be reasonably interpreted as meaning “in at least electrical communication,” then both sublayers of a given SLS clad could be said to “contact” the electron blocking layer. In such a case, the claim could more simply recite, “a cladding layer contacting electron blocking layer . . . ” Instead though, the claim language specifically states that it is the clad’s tertiary sublayer, in particular, that is contacting the electron blocking layer. Specifying which sublayer of a superlattice contacts another structure only makes sense if “contact” means “direct physical contact.” Appeal 2009-014229 Application 11/419,592 9 Asano teaches that the Mg-doped Al0.18Ga0.82N electron-blocking layer (i.e., the claimed “electron blocking layer”) directly physically contacts the p-Al0.12Ga0.88 N-GaN superlattice cladding layer (i.e., the claimed “cladding layer”). (FF 1.) The superlattice cladding layer of Asano is composed of 100 pairs of AlGaN sublayers and Mg-doped GaN sublayers. (FF 2.) Figure 6(c) of Asano illustrates that a Mg-doped GaN sublayer directly physically contacts the electron-blocking layer, rather than a AlGaN sublayer. (FF 3.) Thus, Asano teaches that the Mg-doped GaN sublayer separates the electron-blocking layer from the AlGaN sublayer (i.e., “the cladding sublayer comprising . . . two elements from group III of the periodic table [i.e., in this case Al and Ga] and an element from group V of the periodic table [i.e., in this case N]”). (FF 3.) In other words, the AlGaN cladding sublayer is not in direct physical contact with the electron blocking layer, as required by the claim. Therefore, the Examiner has erred in finding that Asano teaches the limitation “a cladding layer, the cladding layer including a cladding sublayer in contact with the electron blocking layer, the cladding sublayer comprising a second composition of two elements from group III of the periodic table [e.g., Al, Ga, In] and an element from group V of the periodic table [e.g., N, As],” as recited in claim 1. We conclude that the Examiner has erred in rejecting claim 1 under 35 U.S.C. § 102(b). Claims 2-4 and 6-11 depend from independent claim 1, and we likewise conclude that the Examiner has erred in rejecting these claims for the reasons discussed with respect to independent claim 1. Independent claims 12 and 15 recite limitations similar to those discussed with respect to independent claim 1. We further conclude that the Appeal 2009-014229 Application 11/419,592 10 Examiner has erred in rejecting these claims, as well as claims 13 and 14, which depend from claim 12, for the reasons discussed with respect to claim 1. Claims 5 and 16-18 depend from independent claims 1 and 15 respectively, and the Examiner has erred in rejecting these claims under 35 U.S.C. § 103(a) for the reasons previously discussed with respect to claims 1 and 15. Belenky does not cure the above-noted deficiencies of Asano. Independent claim 19 recites limitations similar to those discussed with respect to independent claim 1, and the Examiner has erred in rejecting claim 19, as well as claim 20, which depends from claim 19, under 35 U.S.C. § 103(a) for the reasons previously discussed with respect to claim 1. Belenky does not cure the above-noted deficiencies of Asano. Independent claim 21 recites limitations similar to those discussed with respect to independent 1. Gaska does not cure the above-noted deficiencies of Asano. For the reasons previously discussed with respect to claim 1, the Examiner has erred in rejecting claim 21, as well as claim 22, which depends from claim 21, under 35 U.S.C. § 103(a). NEW GROUNDS OF REJECTION UNDER 37 C.F.R. § 41.50(b) The following additional prior art is relied upon: Kawaguchi WO 2005/034301 A1 Apr. 4, 2005 We enter the following new grounds of rejection: Claims 1, 12, 15 and 19 are rejected under 35 U.S.C. § 102(b) as being anticipated by Kawaguchi. Appeal 2009-014229 Application 11/419,592 11 Claim 21 is rejected under 35 U.S.C. § 103(a) as being obvious over Kawaguchi and Gaska. Claims 1, 12, 15 and 19 are rejected under 35 U.S.C. § 103(a) as being obvious over Asano and Kawaguchi. Claim 21 is rejected under 35 U.S.C. § 103(a) as being obvious over Asano, Kawaguchi, and Gaska. ADDITIONAL FINGINGS OF FACT Kawaguchi2 5. Kawaguchi relates to a nitride-based semiconductor light-emitting device. (¶ [0001].) Kawaguchi describes a third embodiment of a nitride semiconductor device including an n-GaN optical guide layer 404, a MQW active layer 405, a non-doped Ga0.98In0.02N intermediate layer 406, a non-doped GaN intermediate layer 407, a non-doped Al0.03Ga0.97N intermediate layer 408, a p-Al0.03Ga0.97N acceptor impurity doping start layer 409, a p-Al0.16Ga0.84N electron overflow suppression layer 410 and a SLS cladding layer 601. (¶ [0107]; fig. 7A.) The SLS cladding layer 601 is composed of p-Al0.08Ga0.92N/p-Al0.02Ga0.98N. (¶ [0107]; fig. 7C.) 6. Kawaguchi discloses that forming the quantum wells of the SLS p- cladding layer of tertiary p-Al0.02Ga0.98N (Fig. 7(c)) instead of binary p-GaN (e.g., Fig. 7(b)) reduces the unwanted memory effect so that the Mg concentration can be better controlled, and therefore, the 2 The Kawaguchi citations herein refer to EP 1 670 106 A1, an English-language translation of WO 2005/034301 A1. Appeal 2009-014229 Application 11/419,592 12 device’s operating voltage can be reduced in a more controlled manner. (¶¶ [020]-[021] and [108]-[109].) Also, in describing prior art reference, “Japanese Laid-Open Patent Publication No. 2000- 143396,” Kawaguchi further states that Al doping of a Mg-doped p- GaN crystal alleviates strain in the crystal associated with Mg. (¶ [0023].) Thus, a high hole concentration can be achieved because the Mg dopant occupies the Ga positions in the GaN crystal. (Id.) Gaska 7. Gaska relates to a “nitride-based light emitting heterostructure.” (¶ [0003].) In one embodiment for a light emitting heterostructure 110A (fig. 2), an n-type layer 120, a light generating structure 114, an electron blocking layer 122 and a Bragg reflector (DBR) structure 116 are formed above a substrate 112. (¶ [0026].) The electron blocking layer 122 is composed of AlGaN or AlGaInN. (¶ [0027].) ANALYSIS § 102 Rejection Kawaguchi teaches all the features of claim 1. (FF 5.) In particular: the n-GaN optical guide layer 404 of Kawaguchi corresponds to the claimed “n-side waveguide layer”; the MQW active layer 405 corresponds to the claimed “active layer”; the intermediate layers 406 to 408 and acceptor impurity doping start layer 409 collectively correspond to the claimed “p-side waveguide layer,” with at least the undoped intermediate layers 406- 408 constituting the functional sublayers of the compound-layer waveguide; Appeal 2009-014229 Application 11/419,592 13 the electron overflow suppression layer 410 corresponds to the claimed “electron blocking layer”; and the p-Al0.08Ga0.92N/p-Al0.02Ga0.98N SLS cladding layer 601 corresponds to the claimed “cladding layer.” (FF 5.) The intermediate layers 406 to 408 and acceptor impurity doping start layer 409 collectively function as a “p-side waveguide layer” because at least layers 406-408 have compositions that result in each having an index of refraction that is lower than the MQW active layer 405. See In re Bond, 910 F.2d 831, 832 (Fed. Cir. 1990) (there is no ipsissimis verbis test for determining whether a reference discloses a claim element). Independent claims 12, 15 and 19 recite limitations similar to those discussed with respect to independent claim 1. For at least the foregoing reasons, Kawaguchi anticipates claims 1, 12, 15 and 19. Because the Board of Patent Appeals and Interferences is a review body, rather than a place of initial examination, we have not reviewed dependent claims 2-11, 13, 14, 16-18 and 20 to the extent necessary to determine whether Kawaguchi renders any of these claims unpatentable as well. We leave it to the Examiner to determine the appropriateness of any further rejections of dependent claims 2-11, 13, 14, 16-18 and 20 under 35 U.S.C. §§ 102 and 103. § 103 Rejections Claim 21 – Kawaguchi/Gaska Kawaguchi teaches all the limitations of claim 21 except for “the electron blocking layer comprising a composition of three elements from group III of the periodic table [e.g., Al, Ga, In] and an element from group V of the periodic table [e.g., N, As].” (See FF 5.) Appeal 2009-014229 Application 11/419,592 14 Kawaguchi relates to a nitride-based semiconductor light-emitting device and teaches a p-Al0.16Ga0.84N electron overflow suppression layer 410 (i.e., corresponding to the claimed “electron blocking layer”). (FF 5.) Gaska relates to a nitride-based light emitting heterostructure and discloses an electron blocking layer 122 composed of AlGaN or AlGaInN. (FF 7.) It would have been obvious to one of ordinary skill in the art at the time of the invention to have alternatively composed Kawaguchi’s electron blocking layer from quaternary, AlGaInN as taught by Gaska. One of ordinary skill in the art would have recognized that substituting Gaska’s quaternary composition for Kawaguchi’s tertiary composition provides the benefit of increased control over the layer’s lattice constant and bandgap with a tradeoff of a possible decrease in the layer’s crystallinity. Combining Kawaguchi and Gaska is no more than the simple substitution of Gaska’s known AlGaInN electron blocking layer 122 for Kawaguchi’s known p- Al0.16Ga0.84N electron overflow suppression layer 410, with no unexpected results. See KSR, 550 U.S. at 417. For at least the foregoing reasons, claim 21 is obvious over the combination of Kawaguchi and Gaska. We leave it to the Examiner to determine the appropriateness of any further rejection of dependent claim 22 under 35 U.S.C. § 103. Claims 1, 12, 15 and 19 – Asano/Kawaguchi Asano teaches all the limitations of claim 1 (FF 1-2) except for “a cladding layer, the cladding layer including a cladding sublayer in contact with the electron blocking layer, the cladding sublayer comprising a second composition of two elements from group III of the periodic table [e.g., Al, Appeal 2009-014229 Application 11/419,592 15 Ga, In] and an element from group V of the periodic table [e.g., N, As]” (see FF 3). Kawaguchi relates to a nitride-based semiconductor light-emitting device and teaches a SLS cladding layer 601 composed of p-Al0.08Ga0.92N/p- Al0.02Ga0.98N. (FF 5.) Kawaguchi further teaches that Al doping of a Mg- doped p-GaN crystal produces a higher hole concentration. (FF 6.) It would have been obvious to one of ordinary skill in the art at the time of the invention to have modified Asano’s SLS cladding so as to alternatively compose the superlattice’s quantum wells from tertiary, AlGaN instead of binary GaN, as taught by Kawaguchi. One would have been motivated to do so for various purposes such as (1) to minimize the unwanted memory effect that is associated with GaN quantum wells, and (2) to produce a higher hole concentration than is achievable with Mg-doped p-GaN crystal. (FF 6). See KSR, 550 U.S. at 417. Independent claims 12, 15 and 19 recite limitations similar to those discussed with respect to independent claim 1. For at least the foregoing reasons, claims 1, 12, 15 and 19 are obvious over the combination of Asano and Kawaguchi. We leave it to the Examiner to determine the appropriateness of any further rejections of dependent claims 2-11, 13, 14, 16-18 and 20 under 35 U.S.C. § 103. Claim 21 – Asano/Kawaguchi/Gaska Asano and Kawaguchi teach all the limitations of claim 21 (FF 1, 2, 5) except for “the electron blocking layer comprising a composition of three elements from group III of the periodic table [e.g., Al, Ga, In] and an element from group V of the periodic table [e.g., N, As]” (see FF 3, 5). Appeal 2009-014229 Application 11/419,592 16 Similar to the previous discussion, combining Asano and Kawaguchi with Gaska is no more than the simple substitution of Gaska’s known AlGaInN electron blocking layer 122 for Asano’s known Mg-doped Al0.18Ga0.82N electron-blocking layer or Kawaguchi’s known p-Al0.16Ga0.84N electron overflow suppression layer 410, with no unexpected results. See KSR, 550 U.S. at 417. For at least the foregoing reasons, claim 21 is obvious over the combination of Asano, Kawaguchi and Gaska. We leave it to the Examiner to determine the appropriateness of any further rejection of dependent claim 22 under 35 U.S.C. § 103. This decision contains new grounds of rejection pursuant to 37 C.F.R. § 41.50(b). 37 C.F.R. § 41.50(b) provides that a “new ground of rejection pursuant to this paragraph shall not be considered final for judicial review.” 37 C.F.R. § 41.50(b) also provides that the Appellant, WITHIN TWO MONTHS FROM THE DATE OF THE DECISION, must exercise one of the following two options with respect to the new ground of rejection to avoid termination of proceedings (37 C.F.R. § 1.197 (b)) as to the rejected claims: (1) Reopen prosecution. Submit an appropriate amendment of the claims so rejected or new evidence relating to the claims so rejected, or both, and have the matter reconsidered by the examiner, in which event the proceeding will be remanded to the examiner …. (2) Request rehearing. Request that the proceeding be reheard under 37 C.F.R. § 41.52 by the Board upon the same record …. Appeal 2009-014229 Application 11/419,592 17 CONCLUSION Based on the findings of fact and analysis above, we conclude that the Examiner has erred in rejecting claims 1-22. We enter new grounds of rejection for claims 1, 12, 15 and 19 under 35 U.S.C. § 102(b) and for claims 1, 12, 15, 19 and 21 under 35 U.S.C. § 103(a). DECISION The rejection of claims 1-22 is reversed. Claims 1, 12, 15 and 19 are rejected as anticipated by Kawaguchi. Claim 21 is rejected as obvious over Kawaguchi and Gaska. Claims 1, 12, 15 and 19 are rejected as obvious over Asano and Kawaguchi. Claim 21 is rejected as obvious over Asano, Kawaguchi and Gaska. New grounds of rejection have been entered under 37 C.F.R. § 41.50(b). REVERSED 37 C.F.R. § 41.50(b) bim RYAN, MASON & LEWIS, LLP 90 FOREST AVENUE LOCUST VALLEY, NY 11560 Copy with citationCopy as parenthetical citation