11307956 (B.P.A.I. Aug. 18, 2010)

Ex Parte SHIMA et al

Board of Patent Appeals and InterferencesAug 18, 2010

11307956 (B.P.A.I. Aug. 18, 2010)

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. 11/307,956 02/28/2006 Masaki SHIMA FUK.006.0002.NP 2955 58789 7590 08/19/2010 NDQ&M WATCHSTONE LLP 300 NEW JERSEY AVENUE, NW FIFTH FLOOR WASHINGTON, DC 20001 EXAMINER TRINH, THANH TRUC ART UNIT PAPER NUMBER 1795 MAIL DATE DELIVERY MODE 08/19/2010 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 MASAKI SHIMA and KUNIMOTO NINOMIYA ____________ Appeal 2010-000714 Application 11/307,956 Technology Center 1700 ____________ Before EDWARD C. KIMLIN, PETER F. KRATZ, and FRANCISCO C. PRATS, Administrative Patent Judges. KIMLIN, Administrative Patent Judge. DECISION ON APPEAL1 This is an appeal from the final rejection of claims 1-10. Claim 1 is illustrative: 1 The two-month time period for filing an appeal or commencing a civil action, as recited in 37 C.F.R. § 1.304, or for filing a request for rehearing, as recited in 37 C.F.R. § 41.52, begins to run from the “MAIL DATE” (paper delivery mode) or the “NOTIFICATION DATE” (electronic delivery mode) shown on the PTOL-90A cover letter attached to this decision. Appeal 2010-000714 Application 11/307,956 2 1. A stacked photovoltaic device having a light incidence surface, comprising a plurality of photovoltaic cells stacked and each including a photoelectric conversion layer composed of a substantially intrinsic semiconductor, said plurality of photovoltaic cells including a first photovoltaic cell closest to the light incidence surface and at least a second photovoltaic cell, the photoelectric conversion layer in the first photovoltaic cell closest to the light incidence surface including an amorphous semiconductor, and the photoelectric conversion layer in said second photovoltaic cell including a non-single crystalline semiconductor containing crystal grains, and the concentration of impurities contained in the photoelectric conversion layer in said second photovoltaic cell being higher than the concentration of impurities contained in the photoelectric conversion layer in said first photovoltaic cell. The Examiner relies upon the following references in the rejection of the appealed claims: Yamazaki 4,591,892 May 27, 1986 Saito 2002/011264 A1 Jan. 31, 2002 Kondo 6,858,308 B2 Feb. 22, 2005 Appellants’ claimed invention is directed to a stacked photovoltaic device comprising a plurality of photovoltaic cells which each include a photoelectric conversion layer. The conversion layer in the cell closest to the light incidence surface, or the top layer, includes an amorphous semiconductor. The conversion layer in the second cell, the bottom layer, includes a non-single crystalline semiconductor containing crystal grains. The concentration of impurities in the conversion layer of the second or Appeal 2010-000714 Application 11/307,956 3 bottom cell is higher than the concentration of impurities in the conversion layer in the first or top cell. Appealed claims 1-10 stand rejected under 35 U.S.C. § 102(b) as being anticipated by Kondo. The appealed claims also stand rejected under 35 U.S.C. § 103(a) as being unpatentable over Saito in view of either Yamazaki or Kondo. We have thoroughly reviewed the respective positions advanced by Appellants and the Examiner. In so doing, we agree with Appellants that the Examiner’s rejections are not supported by the prior art evidence relied upon. Accordingly, we will not sustain the Examiner’s rejections. We consider first the rejection of the appealed claims under § 102 over Kondo. Kondo, like Appellants, discloses a stacked photovoltaic device comprising first and second photovoltaic cells, each comprising a photoelectric conversion layer, with the conversion layer of the first cell including an amorphous semiconductor and the conversion layer of the second cell including a non-single crystalline semiconductor containing crystal grains. Kondo’s conversion layer in the second cell comprises impurities. However, as acknowledged by the Examiner, Kondo does not disclose any relationship between the concentration of impurities in the two conversion layers, i.e., Kondo does not teach the claim requirement that the concentration of impurities in the second conversion layer is higher than the concentration of impurities in the first conversion layer. The Examiner reasons that Kondo’s teaching of adding impurities to the second conversion layer, and not teaching adding impurities to the first conversion layer, necessarily results in a higher concentration of impurities in the second conversion layer. However, we agree with Appellants that Appeal 2010-000714 Application 11/307,956 4 Kondo’s inclusion of specific impurities in the second conversion layer, and silence with respect to the concentration of impurities in the first conversion layer, does not establish that the concentration of impurities in the second conversion layer is necessarily higher than the concentration of impurities in the first conversion layer. As stated by Appellants “Kondo does not describe any attempt or effort to exclude impurities” in the first conversion layer, and Kondo’s failure to describe impurities in the first conversion layer could mean that Kondo is indifferent to the concentration of impurities in the first conversion layer (Prin. Br. 6, first para.). Also, Appellants’ Specification sets forth that the reaction pressure and high-frequency power used during formation of the conversion layer are factors which determine the concentration of impurities in the layer. The higher the reaction pressure and high-frequency power during layer formation, the higher concentration of impurities in the conversion layer. Appellants also submit that the comparative data in the Specification demonstrates that “[i]mpurities are more likely to be incorporated into an amorphous semiconductor than a microcrystalline semiconductor” (Reply Br. 4, 3rd para.). The Examiner points to Table 14 of Kondo for the conditions for forming the first or top conversion layer and the Examiner states that Table 14 discloses no impurities, such as oxygen, nitrogen or carbon, introduced anywhere in the vacuum vessel 217 which forms the amorphous conversion layer (Ans. 10, penultimate sent.). The Examiner has not rebutted, however, Appellants’ argument that the pressure in a vacuum vessel 213 for forming the crystalline second conversion layer is 200 Pa (Table 1) while the pressure in a vacuum vessel 217 for forming the amorphous conversion layer Appeal 2010-000714 Application 11/307,956 5 is 1500 Pa (Table 14) (Reply Br., sent. bridging pp. 4-5; see also Prin. Br. 6). Since a higher pressure introduces a higher concentration of impurities during the formation of the conversion layer, it cannot be presumed that a conversion layer formed under a pressure of 1500 Pa has a concentration of impurities less than a conversion layer formed under a pressure of 200 Pa. Manifestly, since the Examiner has not addressed this argument, or other relevant arguments advanced by Appellants, the Examiner has not carried the burden of demonstrating that the process of Kondo necessarily or inherently produces a second conversion layer having a higher concentration of impurities than the first conversion layer. It is well settled that a finding of inherency requires inevitability not possibility. Regarding the § 103 rejection, the Examiner points to no teaching in either of the cited references for forming a crystalline conversion layer having a higher concentration of impurities than the level of impurities in the amorphous conversion layer. Simply because the prior art teaches that the concentration of impurities in the conversion layers can be controlled does not establish the obviousness of having a greater concentration of impurities in the crystalline conversion layer. The mere fact that the prior art could be modified does not make the modification obvious under § 103 unless the prior art suggested the desirability of the modification. In re Gordon, 733 F.2d 900, 902 (Fed. Cir. 1984). Appeal 2010-000714 Application 11/307,956 6 In conclusion, based on the foregoing, we are constrained to reverse the Examiner’s rejections. REVERSED kmm NDQ&M WATCHSTONE LLP 300 NEW JERSEY AVENUE, NW FIFTH FLOOR WASHINGTON, DC 20001