Ex Parte Eshun et alDownload PDFPatent Trial and Appeal BoardApr 17, 201813654161 (P.T.A.B. Apr. 17, 2018) Copy Citation UNITED STA TES p A TENT AND TRADEMARK OFFICE APPLICATION NO. FILING DATE 13/654, 161 10/17/2012 23494 7590 04/19/2018 TEXAS INSTRUMENTS IN CORPORA TED P 0 BOX 655474, MIS 3999 DALLAS, TX 75265 FIRST NAMED INVENTOR Ebenezer Eshun 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 ATTORNEY DOCKET NO. CONFIRMATION NO. TI-71462 9557 EXAMINER TIJNGE, BRYAN R. ART UNIT PAPER NUMBER 2897 NOTIFICATION DATE DELIVERY MODE 04/19/2018 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): uspto@ti.com PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE BEFORE THE PATENT TRIAL AND APPEAL BOARD Ex parte EBENEZER ESHUN, HIMADRI SEKHAR PAL, and AMITABH JAIN Appeal2017-008024 Application 13/654,161 Technology Center 2800 Before TERRY J. OWENS, CHRISTOPHER C. KENNEDY, and SHELDON M. McGEE, Administrative Patent Judges. OWENS, Administrative Patent Judge. DECISION ON APPEAL STATEMENT OF THE CASE The Appellants appeal under 35 U.S.C. § 134(a) from the Examiner's rejection of claims 1-20. We have jurisdiction under 35 U.S.C. § 6(b). The Invention The Appellants claim a method for forming an integrated circuit. Claim 1 is illustrative: 1: A method of forming an integrated circuit, comprising the steps of: providing a substrate comprising a semiconductor; forming a lightly doped drain (LDD) implant masking layer; Appeal2017-008024 Application 13/654,161 using the LDD implant masking layer, implanting LDD dopants into said substrate to form LDD implanted regions adjacent to a gate in an area for a metal oxide semiconductor (MOS) transistor; using the LDD implant masking layer, implanting halo dopants at an angle into said substrate to form halo implanted regions adjacent to said gate and extending past said LDD implanted regions; using the LDD implant masking layer, performing an angled carbon implant which implants carbon ions at an angle into said substrate to form angled carbon implanted regions adjacent to said gate and extending past said LDD implanted regions at a surface of the substrate; using the LDD implant masking layer, performing a plurality of zero-degree carbon implants which implant carbon ions at different doses and/or energies substantially perpendicular to said top surface of the substrate into said substrate to form non-angled carbon implanted regions adjacent to said gate; and after performing the plurality of zero-degree carbon implants, removing the LDD implant masking layer. The References Hoentschel Lee (Lee '095) Momiyama Ohta US 2007 /0252205 Al US 7,573,095 B2 US 7 ,592,243 B2 US 2010/0003798 Al US 2010/0105185 Al US 2010/0279479 Al US 7 ,888,223 B2 Nov. 1, 2007 Aug. 11, 2009 Sept. 22, 2009 Jan. 7,2010 Apr. 29, 2010 Nov. 4, 2010 Feb. 15, 2011 Apr. 5, 2012 Ku Hat em Lee (Lee '223) Tsai US 2012/0083090 Al The Re} ections The claims stand rejected under 35 U.S.C. § 103 as follows: claims 1, 3---6, 9, and 10 over Lee '223 in view of Momiyama, Ku and Hatem, claim 2 over Lee '223 in view of Momiyama, Ku, Hatem and Ohta, claims 1 and 7 over Tsai in view of Momiyama, Ku and Hatem, claim 8 over Tsai in view 2 Appeal2017-008024 Application 13/654,161 of Momiyama, Ku, Hatem and Lee '095, claims 11 and 13-20 over Lee '095 in view of Hoentschel, Momiyama, Lee '223 and Hatem, and claim 12 over Lee '095 in view of Hoentschel, Momiyama, Lee '223, Hatem and Ohta. OPINION We reverse the rejections. We need address only the independent claims (1 and 11 ). Those claims require performing a plurality of zero-degree carbon implants substantially perpendicular to the top surface of a substrate using an LDD implant masking layer used to implant carbon ions at an angle into the substrate. To meet that claim requirement in the rejections of claim 1 over Lee '223 in view of Momiyama, Ku and Hatem and claim 11 over Lee '095 in view of Hoentschel, Momiyama, Lee '223 and Hatem, the Examiner relies upon the combined disclosures of Lee '223 and Momiyama (Final Act. 4--5, 11-14; Ans. 3--4, 7-8). Lee '223 co-implants carbon ions at an implantation angle of about 0- 30Q before forming a source/drain extension region (110), and co-implants carbon ions at an implantation angle of 0 degree before forming a source/drain region (120) (col. 6, 11. 24--58). Momiyama uses a resist mask (7) to form pocket regions (11 ), n-diffused regions (12) (having carbon ions implanted at a 0-30Q tilt angle) and extension regions (13) in an n-type element active region (3), removes the resist mask (7), uses a resist mask (8) to form pocket regions (14), n-diffused regions (15) (having carbon ions implanted at a 0-1 OQ tilt angle) and extension regions (16) in a p-type element active region ( 4 ), removes the resist mask (8), uses a resist mask (not shown) to expose only then-type element active region (3), implants n-type impurity ions into the n-type 3 Appeal2017-008024 Application 13/654,161 element active region (3) to form deep source/drain regions (17), removes the resist mask, uses a resist mask (not shown) to expose only the p-type element active region ( 4), and implants p-type impurity ions into the p-type element active region (4) to form deep source/drain regions (18) (col. 6, 11. 25-59; col. 7, 1. 38- col. 8, 1. 66; Figs. 1B-4C). Establishing a prima facie case of obviousness requires an apparent reason to modify the prior art as proposed by the Examiner. See KSR Int 'l Co. v. Teleflex Inc., 550 U.S. 398, 418 (2007). The Examiner finds that "Momiyama discloses using the LDD masking layer for the carbon implant, which Lee '223 discloses is a two part implant, one angled and one zero degrees. Therefore the combined teachings of Lee '223 and Momiyama clearly suggest performing an angled carbon implant and a zero degree carbon implant using the same LDD implant masking layer" (Ans. 3--4). Lee '223's zero-degree implant is used to form the source/drain region (120). The Examiner does not establish that Momiyama's use of resist layers other than the LDD masking layers (7, 8) to form the source/drain regions (17, 18) would have provided one of ordinary skill in the art with an apparent reason to use an LDD masking layer to form Lee '223 's source/drain regions (120). In the rejection of claim 1 over Tsai in view of Momiyama, Ku and Hatem, the Examiner relies upon the combined disclosures of Tsai and Momiyama to meet the Appellants' claim requirement of performing a plurality of zero-degree carbon implants substantially perpendicular to the top surface of a substrate using an LDD implant masking layer used to implant carbon ions at an angle into the substrate (Final Act. 7-8). 4 Appeal2017-008024 Application 13/654,161 Tsai forms an LDD region (24) by doping a silicon substrate (11) with a light concentration of an n-type dopant at each of two sides of a gate structure (18) using the gate structure (18) and an adjacent spacer (14) as a mask, then forms an SiC region (26) and a source/drain region (12) in the silicon substrate (11) at each of the two sides of the gate structure (18), the SiC region (26) having a second portion (28) with a higher SiC concentration than a first portion (27), by implanting carbon atoms at a normal angle and a tilt angle into a silicon substrate ( 11) and, after an n-type dopant for forming the source/drain region (12) is implanted into the silicon substrate (11) at each of the two sides of the gate structure (18), annealing to form crystalline SiC and simultaneously form the source/drain region (12) (i-f 22; Fig. 2). "Since the implantation angle is tilted, the carbon atoms can reach the position 44 under the LDD regions 24" (i-f 22; Fig. 7). The Examiner finds that 1) Momiyama's "LDD masking layer 7 is suitable for both angled and zero degree implants. Momiyama discloses using the LDD masking layer for the carbon implant, which Tsai discloses is a two part implant, one angled and one zero degrees. Therefore the combined teachings of Tsai and Momiyama clearly suggest performing an angled carbon implant and a zero degree carbon implant using the LDD implant masking layer" (Ans. 6), and 2) "the sequence disclosed by Tsai, implanting carbon before forming source/drain regions, enables one to use the same mask for the zero degree carbon implant as for the LDD, halo, and angled carbon implant previously carried out" (id.). The Examiner does not establish that Momiyama's use of different masks to form the carbon-implanted n-diffusion regions (12, 15) and the source/ drain regions ( 17, 18) would have provided one of ordinary skill in 5 Appeal2017-008024 Application 13/654,161 the art with an apparent reason to use Tsai's LDD (24)-forming mask (gate structure 18/first spacer 14) when implanting carbon atoms at a normal angle and a tilt angle into the SiC (26) and source/drain (12) regions. Accordingly, we reverse the rejections. DECISION/ORDER The rejections under 35 U.S.C. § 103 of claims 1, 3---6, 9, and 10 over Lee '223 in view of Momiyama, Ku and Hatem, claim 2 over Lee '223 in view of Momiyama, Ku, Hatem and Ohta, claims 1 and 7 over Tsai in view of Momiyama, Ku and Hatem, claim 8 over Tsai in view of Momiyama, Ku, Hatem and Lee '095, claims 11 and 13-20 over Lee '095 in view of Hoentschel, Momiyama, Lee '223 and Hatem, and claim 12 over Lee '095 in view of Hoentschel, Momiyama, Lee '223, Hatem and Ohta are reversed. It is ordered that the Examiner's decision is reversed. REVERSED 6 Copy with citationCopy as parenthetical citation