Ex Parte Tang et al

Patent Trial and Appeal BoardSep 18, 2012

11393513 (P.T.A.B. Sep. 18, 2012)

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. 11/393,513 03/29/2006 Sanh D. Tang M22-3096 8491 21567 7590 09/18/2012 Wells St. John P.S. 601 West First Avenue Suite 1300 Spokane, WA 99201-3828 EXAMINER KUO, WENSING W ART UNIT PAPER NUMBER 2826 MAIL DATE DELIVERY MODE 09/18/2012 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 SANH D. TANG and VENKATESAN ANANTHAN ________________ Appeal 2010-003967 Application 11/393,513 Technology Center 2800 ________________ Before THOMAS S. HAHN, DENISE M. POTHIER, and JEREMY J. CURCURI, Administrative Patent Judges. CURCURI, Administrative Patent Judge. DECISION ON APPEAL Appeal 2010-003967 Application 11/393,513 2 SUMMARY Appellants appeal under 35 U.S.C. § 134(a) from the Examiner’s rejection of claims 53-58, 60, 64, 67, and 69. Claims 1-52, 59, 61-63, 65, 66, 68, and 70-72 have been canceled. App. Br. 3. We have jurisdiction under 35 U.S.C. § 6(b). Claims 53, 54, 60, 64, and 69 stand rejected under 35 U.S.C. § 103(a) as being obvious over Juengling (US 2006/0046407 A1; published Mar. 2, 2006) in view of Noble (US 6,552,435 B2; issued Apr. 22, 2003). Claims 55-58 stand rejected under 35 U.S.C. § 103(a) as being obvious over Juengling in view of Noble and Sugimoto (US 5,356,834; issued Oct. 18, 1994). Claims 67 stands rejected under 35 U.S.C. § 103(a) as being obvious over Juengling in view of Noble and Scheinberg (US 5,563,545; issued Oct. 8, 1996). We affirm. STATEMENT OF CASE Appellants’ invention relates to “floating body transistor constructions containing U-shaped semiconductor material slices.” (Abstract). Claim 53 is illustrative and reproduced below with the key disputed limitations emphasized: 53. A method of forming a semiconductor construction, comprising: providing a substrate comprising semiconductor material over an electrically insulative mass, the semiconductor material having a thickness; forming a plurality of first trenches extending into the semiconductor material, but not entirely through the thickness of the semiconductor Appeal 2010-003967 Application 11/393,513 3 material; the first trenches being U-shaped and extending primarily linearly along defined latitudinal directions; forming one or more second trenches which extend entirely through the semiconductor material and into the insulative mass; the forming of the second trenches leaving a plurality of spaced regions of the semiconductor material extending along and under the first trenches; the individual spaced regions of semiconductor material being trough-shaped with sidewalls of the troughs being along opposing sides of the first trenches, and bottoms of the troughs being under the first trenches; filling the second trenches with electrically insulative material; after filling the second trenches, forming a plurality of third trenches entirely through the semiconductor material and into the insulative mass extending primarily linearly along longitudinal directions substantially orthogonal to the latitudinal directions, the third trenches extending across the trough-shaped regions of the semiconductor material and across the electrically insulative material, and thus having peripheries comprising insulative material regions and semiconductor material regions; the third trenches dividing the trough-shaped semiconductor material into trough- shaped slices; lining the semiconductor material regions of the third trench peripheries with dielectric material; after the lining, forming conductive material within the third trenches; conductively doping at least portions of the sidewalls of the trough- shaped regions of the semiconductor material; and wherein the conductive material within the third trenches forms a plurality of front-gate/back-gate pairs, with each pair sandwiching a single of the trough-shaped slices therebetween; each sandwich of a front- gate/trough-shaped semiconductor material slice/back-gate being a floating body transistor unit cell. Appeal 2010-003967 Application 11/393,513 4 CONTENTIONS1 The Examiner finds that Juengling and Noble teach all recited limitations of representative claims 53 and 54, and specifically finds that Noble teaches that second and third trenches (trenches are formed in a grid pattern, and second and third trenches are trenches that are perpendicular to each other) extend entirely through the semiconductor material and into the insulative mass (column 5, lines 35-38) in order to form individual transistor components that are electrically insulated from one another (column 1, lines 26-28). (Ans. 5; see also Ans. 3-8, 11-12). Appellants argue that “Noble does not disclose . . . . the recited second and third trenches that extend into an insulative mass,” and that “Noble’s so called ‘second trenches’ . . . do not leave a plurality of spaced regions of semiconductor material extending along and under first trenches.” (App. Br. 10-12; Reply Br. 1-2). In response, the Examiner further states while . . . Noble’s trenches do not leave a plurality of spaced regions of semiconductor material extending along and under first trenches, Noble is not relied upon to teach these recited limitations. Juengling (e.g. Figures 25 and 26) teaches the claimed second 1200 and third 1800 trenches, wherein the forming of the second trenches 1200 leaves a plurality of spaced regions (2407, 2608) [0139] of semiconductor material extending along and under first trenches 800. (Ans. 11-12 (brackets in original)). The Examiner further states 1 Rather than repeat the Examiner’s positions and Appellants’ arguments in their entirety, we refer to the following documents for their respective details: the Appeal Brief (App. Br.) filed August 10, 2009; the Examiner’s Answer (Ans.) mailed October 28, 2009; and the Reply Brief (Reply Br.) filed December 28, 2009. Appeal 2010-003967 Application 11/393,513 5 Noble is relied upon to teach that it is well known in the semiconductor art to extend trenches entirely through semiconductor material and into an electrically insulative mass in order to electrically insulate individual transistor components from one another (column 5, lines 10-12). Noble (e.g. Figures 21-23) further teaches trenches that are perpendicular to each other, and while Noble does not explicitly state that the trenches in both directions extend into the insulative mass, it would [have been] obvious to one of ordinary skill to extend the trenches in both directions through the semiconductor material and into the insulative mass in order to effectively insulate individual devices from each other. (Ans. 12). ISSUES 1. Under 35 U.S.C. § 103(a), has the Examiner erred in rejecting claims 53 and 54 by finding that Juengling and Noble collectively teach: (a) the second and third trenches that extend into an insulative mass and (b) the second trenches leaving a plurality of spaced regions of the semiconductor material extending along and under the first trenches? ANALYSIS We agree with the Examiner’s position, with regard to claims 53 and 54, that Juengling and Noble collectively teach all claim limitations. The Examiner maps Juengling’s trenches 800, 1200, and 1800 to the recited first, second, and third trenches, respectively; and maps regions 2407, 2608 (in Figures 25 and 26) to the recited spaced regions of semiconductor material under the first trenches. The Examiner then cites to Noble to teach extending a trench into an insulative material and thus, when combining this Appeal 2010-003967 Application 11/393,513 6 teaching with Juengling, teaches or suggests extending trenches entirely through the semiconductor material and into an insulative mass. For support, the Examiner cites Noble, column 5, lines 35-38, which states the “etch [in Figure 2] stops short of substrate 12 and etches into a portion of insulative material 14,” and thus teaches extending a trench into an insulative mass as recited. The Examiner also cites Noble, Figures 21-23, as teaching trenches that are perpendicular to each other, such that one trench extends along a longitudinal direction as recited. The Examiner further discusses Noble, stating, “[i]ndividual transistors are often separated from one another by isolation regions which serve to electrically insulate transistor components from one another” (col. 1, ll. 26-28), and describing insulating material 20 and insulating material 14 (shown in Figure 1) constitute an isolation oxide grid 21 (shown in Figure 21), which effectively separates the individual islands and electrically insulates the same from one another (col. 5, ll. 10-12). These two passages in Noble teach and suggest applying the concept of extending trenches into an insulative mass to perpendicular trenches to isolate transistors/islands from one another. While not explicitly stating extending both trenches in Noble into the insulative mass, the Examiner reasons that it would have been obvious to one of ordinary skill to extend both trenches of Juengling through the semiconductor material and into the insulative mass, as taught and suggested by Noble as discussed above, in order to effectively insulate individual devices from each other by creating insulative islands. (See Ans. 5, 7, 12). We agree with the Examiner that by describing etching into insulative material 14, perpendicular trenches, and isolating transistors/islands from Appeal 2010-003967 Application 11/393,513 7 one another, Noble teaches and suggests the second and third trenches, when combined with Juengling, extend into an insulative mass as recited in claims 53 and 54. We also agree with the Examiner that Juengling and Noble collectively teach second trenches leaving a plurality of spaced regions of the semiconductor material extending along and under the first trenches as recited in claims 53 and 54. Appellants argue that Noble’s second trenches do not leave a plurality of spaced regions of semiconductor material extending along and under first trenches. (App. Br. 11-12). When addressing Juengling, the Examiner explains that the individual spaced regions of semiconductor material are trough-shaped with sidewalls of the troughs being along opposing sides of the first trenches, and bottoms of the troughs being under the first trenches. (Ans. 3-4, 6, 12). We see no error in the Examiner’s reliance on Juengling for teaching the argued limitations. Claim 54 recites the second and third trenches extend about half way through the insulative mass. We note that Appellants, for the first time in the Reply Brief, argue the Examiner indicates that the depth of the second and third trenches is merely a change in size relative to the prior art and is not patentably distinct since criticality has not been established (Reply Brief [sic]2 at page 8, paragraphs 2-4). Appellant[s] note[] that the depth of the trenches is not merely a difference in size relative to the prior art. In fact, the difference in depth results in a difference in both structure and function. . . . [E]xtension of the second and third trenches into the insulative mass is not merely a difference in size but affects the structure and function of the resulting device. 2 We assume Appellants are referring to page 8 of the Examiner’s Answer. Appeal 2010-003967 Application 11/393,513 8 (Reply Br. 1-2). Paragraphs 2-4 on page 8 of the Examiner’s Answer appear in the Final Office Action mailed February 27, 2009, on pages 9-10. Appellants’ arguments on these points are untimely and waived. See Ex parte Borden, 93 USPQ2d 1473, 1474 (BPAI 2010) (informative) (“[T]he reply brief [is not] an opportunity to make arguments that could have been made in the principal brief on appeal to rebut the Examiner’s rejections, but were not.”). Nevertheless, the Examiner finds that Noble, when combined with Juengling, teaches second and third trenches extending into the insulative mass (Ans. 12) and provides an explanation for extending the trench about half way through the insulative mass (Ans. 8). In response, Appellants have not established a criticality to this particularly recited depth. See Reply Br. 1-2. Appellants contend that there is a structural and functional difference to extending the trench into the insulative mass, which the combination of Juengling and Noble teaches, but provide no evidence as to the criticality of extending the trench half way through the insulative mass. Based on the evidence of record, we are not persuaded that the Examiner erred. We therefore sustain the Examiner’s rejection of claims 53 and 54, as well as claims 60, 64, and 69 which are not argued separately. We likewise sustain the Examiner’s obviousness rejections of (1) claims 55-58 over Juengling in view of Noble and Sugimoto and (2) claim 67 over Juengling in view of Noble and Scheinberg. Appellants have not particularly pointed out errors in the Examiner’s reasoning regarding the additional teachings of Sugimoto or Scheinberg, but merely reiterate the same arguments that are set forth in relation to independent claims 53 and 54 regarding the alleged Appeal 2010-003967 Application 11/393,513 9 deficiencies of Juengling and Noble. (App. Br. 12-13). We are not persuaded for the previously-stated reasons. DECISION The Examiner’s decision rejecting claims 53-58, 60, 64, 67, and 69 is affirmed. No time period for taking any subsequent action in connection with this appeal may be extended under 37 C.F.R. § 1.136(a)(1). See 37 C.F.R. § 1.136(a)(1)(iv) (2010). AFFIRMED babc