Ex Parte Manna et al

Patent Trial and Appeal BoardSep 25, 2012

11163349 (P.T.A.B. Sep. 25, 2012)

UNITED STATES PATENT AND TRADEMARKOFFICE 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. 11/163,349 10/15/2005 Indrajit Manna 1016-054 4348 22898 7590 09/26/2012 ISHIMARU & ASSOCIATES LLP 2055 GATEWAY PLACE SUITE 700 SAN JOSE, CA 95110 EXAMINER VIEIRA, DIANA C ART UNIT PAPER NUMBER 2814 MAIL DATE DELIVERY MODE 09/26/2012 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 PATENT TRIAL AND APPEAL BOARD ____________ Ex parte INDRAJIT MANNA, HIN KIONG YAP, KENG FOO LO, and JAE SOO PARK ____________ Appeal 2010-006307 Application 11/163,349 Technology Center 2800 ____________ Before MAHSHID D. SAADAT, JOHNNY A. KUMAR, and TREVOR M. JEFFERSON, Administrative Patent Judges. SAADAT, Administrative Patent Judge. DECISION ON APPEAL Appellants appeal under 35 U.S.C. § 134(a) from a non-final rejection of claims 1-20, which constitute all the claims pending in this application. We have jurisdiction under 35 U.S.C. § 6(b). We reverse. Appeal 2010-006307 Application 11/163,349 2 STATEMENT OF THE CASE Introduction Appellants’ invention relates to protection device systems for protecting integrated circuit devices from electrostatic discharge (ESD) events (see Spec. [Para 1]). Independent claim 6 is illustrative of the invention and reads as follows: 6. A tunable protection method comprising: forming a tunable trigger device having a trigger junction body overlapping a trigger active area to provide an overlap, the tunable trigger device providing an adjustable protection activation level by adjusting the overlap; forming a circuit protection device having a protection body overlapping a protection active area to provide an overlap, the circuit protection device providing an adjustable protection level for integrated circuits by adjusting the overlap; and connecting electrically the tunable trigger device and the circuit protection device to an input/output pad. The Examiner’s Rejections The Examiner relied on Russ (US 6,770,918 B2) and Stricker (US 7,136,268 B2), to reject claims 1-4, 6-14, and 16-20 under 35 U.S.C. § 103(a) (see Ans. 3-14), and further added Kawazoe (US 6,524,893 B2) to reject claims 5 and 15 (see Ans. 14-16). ANALYSIS Appellants contend that the Examiner erred in rejecting claims 1-4, 6- 14, and 16-20 under 35 U.S.C. § 103(a) as being unpatentable over the combination of Russ and Stricker because: Appeal 2010-006307 Application 11/163,349 3 Russ trigger diode 105 does not adjust the protection activation level by overlapping a trigger junction body and a trigger active area, but instead discloses forming an N-well region 507 in the N-epitaxial layer 508 to lower the trigger voltage as taught in Russ col. 12, line 62 through col. 13, line 08, which states: “In an alternative embodiment of FIGS. 5A and 5B, an N-well region 507 (drawn in phantom) is formed in the N-epitaxial layer 508 .... The N-well 507 is provided to further lower the trigger voltage by increasing the doping concentration (e.g., 10.sup.18 atoms/cm.sup.-3) at the N-side of the junction...” [deletions and underlining for clarity]. (App. Br. 11). The Examiner responds that the relied-on portions of Russ merely show that a trigger device may be adjusted by adjusting “the dopant concentration at the N-side of the junction to the desired trigger voltage” (Ans. 16-17). The Examiner further points out that “Stricker still teaches a trigger overlap between a trigger junction body and a trigger active area for the purpose of adjusting the protection activation level” (Ans. 17). The Examiner also finds Stricker adjusts the breakdown voltage “via an overlap of masked subcollector 245 with P-type base 220” (Ans. 18). The Examiner concludes that the teachings of the references show “the breakdown voltage is directly related to and adjustable via the overlap between masked subcollector regions 245 and P-type base 220” (id.). Appellants contend that the combination of Russ and Stricker is improper because the trigger device 105 of Russ is a heterojunction diode whereas Stricker discloses formation of heterojunction bipolar transistor structures (Reply Br. 4-5). Appellants conclude that the proposed combination does not teach or suggest the claimed trigger overlap, trigger Appeal 2010-006307 Application 11/163,349 4 junction body, and/or trigger active area for the purpose of adjusting the protection activation level (Reply Br. 6). With respect to the Examiner’s discussion of Figure 7B of Stricker and how the distance D between the base 220 and the subcollector 255 may be adjusted in order to adjust the breakdown voltage in the ESD trigger (Ans. 18), Appellants contend that the combination requires features of different devices to be combined (Reply Br. 7). In that regard, Appellants point out the differences between the different base and collector regions in Russ and Stricker and assert that the silicon controlled rectifier (SCR) device of Russ is formed from a lateral bipolar transistor and a vertical bipolar transistor, which would not benefit from the structure disclosed in Stricker (id.). We agree with Appellants’ contention above. As asserted by Appellants (Reply Br. 8), the proposed combination does not teach or suggest the trigger overlap to be formed by the trigger junction body overlapping the trigger device active area and the protection overlap to be formed by the protection body overlapping the protection active area. Further, we find that the Examiner’s position is based on the disclosure of Stricker describing adjusting the distances D and M between the base and collector masks, which actually relates to how the doping level of these regions may be controlled (see Stricker col. 4, ll. 36-48; col. 5, l. 57 – col. 6, l. 26). As such, the adjustment of the protection activation level would still be determined by the doping levels, the dopant out-diffusion, and the related depletion region (Stricker, col. 6, ll. 5-18). While Stricker refers to base and collector regions that are shown to be overlapped, the adjustment to the trigger device and the SCR protection Appeal 2010-006307 Application 11/163,349 5 device are disclosed to be based on controlling the doping in these regions, even in the lateral bipolar transistor. We also observe that Appellants’ Specification, in paragraphs 34 and 35, further describe the mechanism by which the protection activation level is based on the protection resistance which is adjusted by adjusting the overlap between a trigger junction body and a trigger active area as well as between the protection body and the protection active area of a circuit protection device. However, we do not find that the Examiner’s proposed rejection and the underlying analysis in any way establishes that adjusting the doping levels in the base and collector regions of Stricker would adjust the claimed overlap. Similarly, we do not find that the Examiner has clearly identified how the proposed combination would have resulted in the trigger overlap, trigger junction body, and/or trigger active area for the purpose of adjusting the protection activation level, as recited in claim 6 and similarly in other independent claims 1, 11, and 16. Therefore, we do not sustain the 35 U.S.C. § 103(a) rejection of independent claims 1, 6, 11, and 16, and of claims 2-5, 7-10, 12-15, and 17- 20 dependent thereon, respectively. DECISION The Examiner’s decision rejecting claims 1-20 is reversed. REVERSED tj