Ex Parte Birecki et alDownload PDFBoard of Patent Appeals and InterferencesMar 27, 200910932695 (B.P.A.I. Mar. 27, 2009) Copy Citation UNITED STATES PATENT AND TRADEMARK OFFICE ____________ BEFORE THE BOARD OF PATENT APPEALS AND INTERFERENCES ____________ Ex parte HENRYK BIRECKI, VU THIEN BINH, SI-TY LAM, HUEI PEI KUO, and STEVEN L. NABERHUIS ____________ Appeal 2009-1372 Application 10/932,695 Technology Center 2800 ____________ Decided:1 March 27, 2009 ____________ Before MAHSHID D. SAADAT, CARLA M. KRIVAK, and KARL D. EASTHOM, Administrative Patent Judges. SAADAT, Administrative Patent Judge. DECISION ON APPEAL Appellants appeal under 35 U.S.C. § 134(a) from the Examiner’s rejection of claims 9 and 12-14. Claims 1-8 and 15-31 have been canceled 1 The two-month time period for filing an appeal or commencing a civil action, as recited in 37 C.F.R. § 1.304, begins to run from the decided date shown on this page of the decision. The time period does not run from the Mail Date (paper delivery) or Notification Date (electronic delivery). Appeal 2009-1372 Application 10/932,695 2 and claims 10 and 11 have been objected to as being dependent upon rejected base claims, but otherwise indicated as allowable if rewritten in independent form. We have jurisdiction under 35 U.S.C. § 6(b). We reverse. STATEMENT OF THE CASE Appellants’ invention relates to a field emission device, which includes an emitter electrode, an extractor electrode, and a solid-state field controlled emitter that utilizes a Schottky metal-semiconductor junction or barrier. The Schottky metal-semiconductor barrier is formed on the emitter electrode and electrically coupled with the extractor electrode such that when an electric potential is placed between the emitter electrode and the extractor electrode, a field emission of electrons is generated from an exposed surface of the semiconductor layer. (Spec. 3:24-32). Independent Claim 9 is representative and reads as follows: 9. A process for fabricating electron emission devices, comprising: forming an emitter electrode layer; forming an extracting electrode layer proximate the conductive semiconductor layer; forming an aperture through a portion of the extracting electrode layer to expose a portion of the emitter electrode layer; forming a Schottky metal layer on the emitter electrode layer through the aperture; and forming a conductive semiconductor layer on the Schottky metal layer through the aperture to form a Schottky metal- Appeal 2009-1372 Application 10/932,695 3 semiconductor barrier between the metal layer and the conductive semiconductor layer, thereby forming a solid-state field controlled emitter. The Examiner relies on the following prior art in rejecting the claims: Christensen US 4,663,559 May 5, 1987 Birecki US 6,976,895 B2 Dec. 20, 2005 Claims 9 and 12-14 stand rejected under 35 U.S.C. § 102(b) as being anticipated by Christensen. Claims 9 and 12-14 stand rejected on the ground of non-statutory obviousness-type double patenting as being unpatentable over claims 1-7 of Birecki in view of Christensen. Rather than repeat the arguments here, we make reference to the Briefs (App. Br. filed Oct. 23, 2007; Reply Br. filed Mar. 26, 2008) and the Answer (mailed Jan. 8, 2008) for the respective positions of Appellants and the Examiner. ISSUE The issue is whether the Examiner erred in rejecting the claims under 35 U.S.C. § 102(b) and non-statutory obviousness-type double patenting. The issue specifically turns on whether Christensen discloses an electron emission device having a Schottky metal layer over the emitter electrode forming a Schottky metal-semiconductor barrier between the metal layer and a conductive semiconductor layer formed on the metal layer, as recited in claim 9. Appeal 2009-1372 Application 10/932,695 4 FINDINGS OF FACT 1. Christensen relates to a cold field emission device wherein insulator and conductor particles are deposited as a random mixture and form the tip of a conical structure having a base formed of a conductive material. The insulative and conductive materials forming the particles are chosen such that the work function of the insulator is greater than the work function of the conductor. That work function difference defines ohmic contact between the materials. (Abstract; col. 2, ll. 51-59). 2. Christensen discloses that emission of electrons is produced by imposing a field on a multiplicity of insulative particles in and of the surface of a cermet. The particles are arranged in a random distribution of insulative and conductive commingled particles. A cermet is particularly found at the exposed top surface or tip of a pyramid or conic structure. (Col. 4, ll. 13- 19). 3. Christensen teaches that the body of the conic structure is formed of conductive material while the last region forms the tip and is a mix of insulative and conductive particles, all in ohmic contact with adjacent particles. The work function of the insulative particles exceeds the work function of the conductive particles to define an ohmic contact therebetween. (Col. 4, ll. 24-35). 4. Christensen discloses that upon application of potential to the electrodes of the field emission device, assuming the field is sufficient, the electrons flow through the conductive particles and the ohmic contacts with the insulative particles to initiate electron flow in the conduction band of the insulative particles. The field acting upon the conductive particles undergoes Schottky barrier lowering to enable continual and constant Appeal 2009-1372 Application 10/932,695 5 tunneling and flow of electrons from the metal through the conductive band into vacuum. (Col. 4, l. 63 – col. 5, l. 4). 5. As shown in Figure 2 of Christensen, the bottom layer 41 of the conic structure is a conductor layer made of the same material as conductive particles 43 commingled in the cermet 42. (Col. 11, ll. 33-38). 6. Christensen further discloses that the conductive particles 43 are in ohmic contact with the insulative particles 44 having an initial deposit biased in favor of conductive particles in ohmic contact with the bottom or support layer 41. (Col. 11, ll. 49-56). 7. With further reference to Figure 2, Christensen discloses that the base of the conic structure 41 is in ohmic contact with a conductor 31, which is insulated from or formed upon an insulator substrate 28. (Col. 12, ll. 16-18). PRINCIPLES OF LAW In rejecting claims under 35 U.S.C. § 102, “[a] single prior art reference that discloses, either expressly or inherently, each limitation of a claim invalidates that claim by anticipation.” Perricone v. Medicis Pharm. Corp., 432 F.3d 1368, 1375 (Fed. Cir. 2005) (citing Minn. Mining & Mfg. Co. v. Johnson & Johnson Orthopaedics, Inc., 976 F.2d 1559, 1565 (Fed. Cir. 1992)). See also In re Paulsen, 30 F.3d 1475, 1478-79 (Fed. Cir. 1994). “Anticipation of a patent claim requires a finding that the claim at issue ‘reads on’ a prior art reference.” Atlas Powder Co. v. IRECO, Inc., 190 F.3d 1342, 1346 (Fed. Cir. 1999) (quoting Titanium Metals Corp. of Am. v. Banner, 778 F.2d 775, 781 (Fed. Cir. 1985)). Appeal 2009-1372 Application 10/932,695 6 ANALYSIS Appellants argue that Christensen does not disclose the claimed Schottky metal barrier between the metal layer formed on the emitter electrode layer and the conductive semiconductor layer formed on the metal layer (App. Br. 5). Appellants further assert that Christensen, in contrast with the claimed Schottky barrier, discloses an ohmic contact between cermet 42 and conductive layer 41 (App. Br. 5-6; Reply Br. 5). With respect to the reference made to the “‘Schottky barrier lowering’” in Christensen, Appellants argue that it is the barrier between the emitter and vacuum that is lowered, and not the barrier between the conductive base 41 and the cermet (App. Br. 6; Reply Br. 6). The Examiner relies on the only reference made to a Schottky barrier in Christensen, starting at column 4, line 63, and asserts (Ans. 6) that the same barrier lowering between the conductive particles and the insulative particles in the cermet layer must be between the cermet and base layer 41 (Ans. 7). The Examiner reasons that layer 41 is taught to be made of the same conductive material as the material forming conductive particles 43 in the cermet and therefore, a Schottky barrier is present between base layer 41 and insulative particles 44 in the cermet (id.). Upon a review of Christensen, we disagree with the Examiner’s characterization of the contact between base layer 41 and cermet layer 42 as a Schottky barrier. Christensen repeatedly teaches that the contact between the conductive conic structure 41 and the cermet layer 42 is an ohmic contact (FF 3 and 5-7). Christensen further describes the cermet layer formed over the tip of the conic structure as a random mixture of conductive and insulative particles in ohmic contact with each other (FF 1 and 2). Appeal 2009-1372 Application 10/932,695 7 Therefore, the contact between layers 41 and 42, as shown in Figure 2 of Christensen, is an ohmic contact. As argued by Appellants (App. Br. 6; Reply Br. 6), the only reference Christensen makes to a “Schottky barrier” is with respect to the behavior of the conductive and insulative particles in the presence of an electric field (FF 4). The described Schottky barrier lowering enables continual and constant tunneling and flow of electrons from the metal through the conductive band into vacuum (id.). While Christensen explains how the conduction within the cermet layer 42 takes place by tunneling between the conductive and insulative particles and the applied electric field has a Schottky barrier lowering effect (FF 4), the macroscopic nature of the contact between the cermet layer and the metal layer forming the conic structure 41 is identified as an ohmic contact. See also FF 6. CONCLUSION On the record before us, and in view of our analysis above, we find that Christensen does not disclose an electron emission device having a Schottky metal-semiconductor barrier between the metal layer formed on the emitter electrode and a conductive semiconductor layer formed on the metal layer, as recited in claim 9. Therefore, since Appellants have shown error in the Examiner’s position that Christensen anticipates claim 9, we do not sustain the 35 U.S.C. § 102 rejection of claims 9 and 12-14. Additionally, for the same reasons, we do not sustain the obviousness-type double patenting rejection of claims 9 and 12-14 as being unpatentable over claims 1-7 of Birecki in view of Christensen. Appeal 2009-1372 Application 10/932,695 8 ORDER The decision of the Examiner rejecting claims 9 and 12-14 is reversed. REVERSED KIS HEWLETT PACKARD COMPANY P. O. BOX 272400, 3404 E. HARMONY ROAD INTELLECTUAL PROPERTY ADMINISTRATION FORT COLLINS, CO 80527-2400 Copy with citationCopy as parenthetical citation