Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Election/Restrictions
Claims 16-20 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 1/29/2026.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claim(s) 1-2, 9 and 11 is/are rejected under 35 U.S.C. 103 as being unpatentable over by Mayuzumi (US 20110042752 A1) in view of Liaw (US 20200135569 A1).
Regarding claim 1, Mayuzumi teaches, in FIG. 1A, a semiconductor device with “semiconductor substrate” 21, ”gate electrode” (gate structure) 31 over the substrate, “source/drain regions” 37 are described in paragraph 0110: “a stress applying film . . . is formed in the source/drain regions 37” (strained layers) are disposed aside the gate structure, paragraph 103 states that contact portions 103 are connected to the source/drain regions 37 (source/drain contact patterns), and FIG. 1A shows that the top surface of the source/drain contact patterns are coplanar with a top surface of the gate structure, “third contact portion” (gate contact via) 54 is disposed on and electrically connected to the gate structure 31, and “second contact potions” (source/drain contact vias) 53 are disposed on and connected to the source/drain contact patterns 43. FIG. 1B further teaches that the gate contact via has a bottom surface in physical contact with the gate structure and a top surface opposite the bottom surface.
Mayuzumi does not teach that the top surface of the gate contact via has a long-axis and a short-axis.
Liaw teaches, “drain vias” VD1, VD2, VD3 (bottom of paragraph 0044) “may each have a substantially elliptical top view profile, where the elliptical top view profile includes a long axis and a short axis. In some embodiments, a ratio of the long axis and the short axis is greater than 1:1 but less than 1.2:1” (bottom of paragraph 0044). The examiner notes that this discloses a completely elliptical contact, which has a long and short axis on both the top and the bottom. In this case, the bottom surface has a “diameter” (the short axis of the bottom surface) wherein the top surface has a short axis which is equal to the bottom diameter and a long axis that is longer that diameter. The examiner notes that the bottom surface having “a diameter” does not necessitate a perfectly circular bottom cross-section.
It would have been obvious to one having ordinary skill in the art at the effective filing date to modify the device taught by Mayuzumi such that the gate contact via is elliptical (and therefore such that the top surface has a long-axis and a short-axis, and such that the bottom surface has a diameter, wherein the short-axis of the upper surface is equal to the diameter, and the long-axis of the upper surface is greater than this diameter), as taught by the drain vias taught by Liaw. One having ordinary skill in the art is motivated to do so in order to, for example, tailor the profile of the via such that it is shorter in one direction (along the short-axis) while ensuring that the cross sectional surface area of the via is large enough to minimize resistance (with the addition of the long-axis and elliptical profile, as opposed to a simply circular profile).
Regarding claim 2, Mayuzumi further teaches in FIG. 1A that the height of the gate contact via is equal to a height of each of the source/drain contact vias.
Regarding claim 9, Mayuzumi teaches a semiconductor substrate, a gate structure over the substrate, strained layers aside the gate structure, source/drain patterns on and electrically connected to the strained layer, and a gate contact via disposed on and electrically connected to the gate structure (see above). Further, FIG. 1A and FIG. 1B show that the gate contact via is funnel shaped and that they have a bottom surface in physical contact with the gate structure and a top surface opposite to the bottom surface.
Mayuzumi does not teach that the top surface of the gate contact via has a long-axis and a short-axis.
Liaw teaches, “drain vias” VD1, VD2, VD3 (bottom of paragraph 0044) “may each have a substantially elliptical top view profile, where the elliptical top view profile includes a long axis and a short axis. In some embodiments, a ratio of the long axis and the short axis is greater than 1:1 but less than 1.2:1” (bottom of paragraph 0044). The examiner notes that this teaches a completely elliptical contact, which has a long and short axis on both the top and the bottom. In this case, the bottom surface has a diameter (the short axis of the bottom surface) wherein the top surface has a short axis which is equal to the bottom diameter and a long axis that is longer than the bottom surface.
Regarding claim 10 Mayuzumi teaches that a height of the gate contact via is equal to a height of each of the source/ drain vias, as shown above.
Regarding claim 11, Mayuzumi further teaches, in FIG. 1A and FIG. 1B, that each of the source/drain contact vias (53) has a funnel shape.
Claim(s) 3, 8 and 12 is/are rejected under 35 U.S.C. 103 as being unpatentable over by Mayuzumi (US 20110042752 A1) in view of Liaw (US 20200135569 A1) in further view of Chang (US 20220326301 A1).
Regarding claim 3, Mayuzumi teaches the limitations of claim 1 and further teaches, in paragraph 0129, that the opening in which the gate contact via is formed is “hole-shaped,” meaning the bottom surface of the gate contact via is circular in the top view.
However, Mayuzumi does not teach that the top surface of the gate contact via is elliptical.
Chang teaches, in paragraph 0075, “via contact” 130 in which “the upper surface of via contacts 130 may have an elliptical shape.”
However, Chang does not teach that a long-axis of a top surface of the top surface of the gate via is greater than a diameter of the bottom surface, and that the short-axis of the top surface of the gate via is equal to the diameter of the bottom surface.
Applicant has not disclosed that having a long-axis of an upper surface of a gate via that is greater than a diameter of a circular bottom surface, and a short axis of an upper surface of a gate via that is equal to a diameter of the circular bottom surface provides an advantage, is used for a particular purpose, or solves a stated problem other than the well-known and unsurprising function of a via. The examiner notes that the long-axis of the top surface being “greater than” a diameter of the bottom surface includes the long-axis being longer than the bottom diameter by even very small amounts (below even manufacturing tolerances), below that of which would garner meaningful benefits.
Therefore, before the effective filing date of the claimed invention it would have been obvious to one of ordinary skill in the art to modify the gate via of Mayuzumi such that a long-axis of the top surface is greater than a diameter of a circular bottom surface and such that the short axis of a top surface of the gate via is equal to the diameter of the circular bottom surface. This is because one of ordinary skill in the art would have expected this configuration to be one of several straightforward design variations of forming a via because of its equivalent performance with gate vias with circular cross sections on both top and bottom surfaces.
Regarding claim 8, Mayuzumi teaches, in FIG. 1A, that each of the source/drain contact vias has a bottom surface in physical contact with the corresponding source/drain contact pattern, and that these vias have a top surface opposite the bottom surface, and a circular bottom surface. Chang also teaches an elliptical top to a via, as shown above.
It would have been obvious to one having ordinary skill in the art to create the source/drain vias with a circular bottom and elliptical top in a top view, as taught by Mayuzumi and Chang, for the same reasons that one is motivated to create a gate contact via with a circular bottom and elliptical top in a top view, as shown above.
Claim(s) 4 is/are rejected under 35 U.S.C. 103 as being unpatentable over Mayuzumi (US 20110042752 A1) in view of Liaw (US 20200135569 A1) in further view of Smith (US 20220270979 A1).
Regarding claim 4, as shown above Mayuzumi and Chang teach the limitations of claim 1, however, they do not explicitly teach a ratio of area of the bottom surface to the top surface of the gate contact via between 1:1.2 and 1:2.
Smith teaches, in paragraph 0032, that the ratio of the area top surface of a via to the area of the bottom surface of a via is “greater than or about” 1.25:1, 1.5:1, 1.75:1, or 2:1.
It would have been obvious to one having ordinary skill in the art to construct the gate contact via taught by Mayuzumi and Chang with a bottom to top surface area ratio of between 1:1.2 and 1:2, as taught by Smith. One having ordinary skill in the art is motivated to do so in order to, for example, maximize area of contact on the top surface while maintaining a lower profile of the gate contact via as it passes through the rest of the device.
Claim(s) 6 is/are rejected under 35 U.S.C. 103 as being unpatentable over Mayuzumi (US 20110042752 A1) in view of Liaw (US 20200135569 A1) in view further of Tsai (US 20210280464 A1).
Regarding claim 6, Mayuzumi teaches a sidewall connecting the top and bottom surfaces of the via of FIG. 1A, but does not teach that a portion of the sidewall is curved.
Tsai teaches, in FIG. 19, contact vias 92, in which “the sidewalls of contact plugs 92 have substantially straight and slanted lower portions, and curved upper portions” (paragraph 0046).
It would have been obvious to one having ordinary skill in the art to modify the gate contact via taught by Mayuzumi and Chang such that the via has a portion of curved sidewall.
Claim(s) 12 is/are rejected under 35 U.S.C. 103 as being unpatentable over Mayuzumi (US 20110042752 A1) in view of Liaw (US 20200135569 A1) in further view of Chang (US 20220326301 A1).
Regarding claim 12, as explained above, Mayuzumi and Liaw teach the limitations of claim 9. Liaw further teaches an elliptical via profile (with a long and short axis, see above).
They do not teach that bottom surface of the gate contact via is circular in the top view.
Chang teaches, in paragraph 0075, “via contact” 130 in which “the upper surface of via contacts 130 may have an elliptical shape.”
However, Mayuzumi does not teach that the top surface of the gate contact via is elliptical.
Chang teaches, in paragraph 0075, “via contact” 130 in which “the upper surface of via contacts 130 may have an elliptical shape.”
However, Chang does not teach that a long-axis of a top surface of the top surface of the gate via is greater than a diameter of the bottom surface, and that the short-axis of the top surface of the gate via is equal to the diameter of the bottom surface.
Applicant has not disclosed that having a long-axis of an upper surface of a gate via that is greater than a diameter of a circular bottom surface, and a short axis of an upper surface of a gate via that is equal to a diameter of the circular bottom surface provides an advantage, is used for a particular purpose, or solves a stated problem other than the well-known and unsurprising function of a via. The examiner notes that the long-axis of the top surface being “greater than” a diameter of the bottom surface includes the long-axis being longer than the bottom diameter by even very small amounts (below even manufacturing tolerances), below that of which would garner meaningful benefits.
Therefore, before the effective filing date of the claimed invention it would have been obvious to one of ordinary skill in the art to modify the gate via of Mayuzumi such that a long-axis of the top surface is greater than a diameter of a circular bottom surface and such that the short axis of a top surface of the gate via is equal to the diameter of the circular bottom surface. This is because one of ordinary skill in the art would have expected this configuration to be one of several straightforward design variations of forming a via because of its equivalent performance with gate vias with circular cross sections on both top and bottom surfaces.
Claim(s) 13 is/are rejected under 35 U.S.C. 103 as being unpatentable over Mayuzumi (US 20110042752 A1) in view of Liaw (US 20200135569 A1) in further view of Smith (US 20220270979 A1).
Regarding claim 13, Chang teaches that a ratio of areas between the bottom and top surfaces of the gate contact via ranges from ‘about’ 1:1.25 to 1:2, as explained above.
It would have been obvious to one having ordinary skill in the art at the effective filing date to modify the device taught by Mayuzumi such that the ratio of the
It would have been obvious to one having ordinary skill in the art to construct the gate contact via taught by Mayuzumi with a bottom to top surface area ratio of between 1:1.2 and 1:2, as taught by Smith. One having ordinary skill in the art is motivated to do so in order to, for example, maximize area of contact on the top surface while maintaining a lower profile of the gate contact via as it passes through the rest of the device.
Claim(s) 7 and 15 is/are rejected under 35 U.S.C. 103 as being unpatentable over Mayuzumi (US 20110042752 A1) in view of Liaw (US 20200135569 A1) in further view of Tsai (US 20220270979 A1).
Regarding claim 7, as shown above, Mayuzumi, Liaw, and Tsai teach the limitations of claim 6. Tsai further teaches, in FIG. 19, an angle α between the bottom surface and sidewall of the gate contact via, and paragraph 0046 states that this angle may be “between about 80 degrees and about 90 degrees.” Additionally, the examiner notes that the sidewall depicted has an upper surface that curves to an angle of well over 45 degrees relative to the bottom surface (meaning that there exists a portion of the upper half of the sidewall, along its curve, which forms a 65 to 80 degree angle with the top surface of the via).
It would have been obvious to further modify the via taught by Mayuzumi such that the via includes an angle between 87 and 90 degrees between the sidewall and bottom surface, and an angle between 65 and 80 degrees between the top surface and a sidewall, as taught by Tsai. One having ordinary skill in the art is motivated to do so in order to achieve a desirable ratio of widths of the via between the top and bottom surfaces of the via, as this configuration is good for gap filling (Tsai, paragraph 0045).
Regarding claim 15, Mayuzumi, Chang, and Tsai teach a gate contact via with a sidewall connecting the top surface and bottom surface of the gate contact via, an inclined angle between a top surface and a side wall between 65 and 80 degrees, and an angle between the bottom surface and the sidewall of the gate contact via between 87 and 90 degrees, as shown above.
Claim(s) 21 is/are rejected under 35 U.S.C. 103 as being unpatentable over Mayuzumi (US 20110042752 A1) in view of Liaw (US 20200135569 A1) in further view of Tak (US 20170222014 A1).
Regarding claim 21, as explained above, Mayuzumi and Liaw teach the limitations of claim 1. Mayuzumi further teaches a sidewall of the gate contact via which connects the top surface to the bottom surface (see FIG. 1A).
They do not teach that the sidewall is curved convexly.
Tak teaches, in FIG. 2, a “contact plug” (via) wherein “Although FIG. 2 shows an example in which the contact plug 160 approximately has a cross-sectional shape of a circle and the second carbon-containing insulating layer 144A surrounding the contact plug 160 approximately has a cross-sectional shape of a circular ring, the inventive concept is not limited to the shapes shown in FIG. 2. For example, the contact plug 160 may have a cross-sectional shape of an ellipse . . . correspondingly, the second carbon-containing insulating layer 144A may have a cross-sectional shape of an elliptical . . . ring” ([0068]. In addition the bottom of [0068] states “In some embodiments, the second carbon-containing insulating layer 144A may have a varying thickness extending from an upper surface of the contact plug 160 towards the substrate 110 such that a first sidewall of the second carbon-containing insulating layer 144A with respect to a sidewall of the contact plug 160 may be concave and a second sidewall of the second carbon-containing insulating layer 144A with respect to the same sidewall of the contact plug 160 may be convex.” Also see FIG. 3a. The examiner notes that this teaches a convex contact plug, as the contact plug is directly in contact with the sidewall, and the sidewall is of uniform width (see FIGs. 1B, 1C, 3A). The examiner also notes that this via has a sidewall connecting the top and bottom surfaces.
It would have been obvious to one having ordinary skill in the art at the effective filing date to modify the device taught by Mayuzumi such that the sidewalls of the gate contact via are curved convexly, as taught by Tak. One having ordinary skill in the art is motivated to do so because, for example, this shape allows for the utilization of low-cost etching techniques (such as wet etching) to form the via hole (as opposed to more costly anisotropic etching techniques such as photoetching). See KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007).
Response to Arguments
The examiner acknowledges the removal of the term “substantially” in claims 2, 5, 10, and 14, as well as in the limitations of previously presented claim 5 (now integrated into claims 1 and 9). The rejections of claims 2, 4, 10, and 14 under 35 U.S.C. 112(b) are therefore withdrawn.
Applicant's arguments filed 6/11/2026 regarding claims 1 and 9 (page 9) have been fully considered but they are not persuasive. While previously presented claim 5 was indicated allowable in the previous office action, the scope of previously presented claim 5 was dependent on, and therefore included the limitations of, previously presented dependent claim 3. The limitations of previously presented claim 3 were not fully included in the scope of amended claims 1 and 9, therefore newly presented claims 1 and 9 have a claim scope that has was not indicated allowable, and arguments are moot; note the new grounds of rejection of amended claims 1 and 9 detailed above. See MPEP 1824 6.4 (b).
Applicant's arguments filed 6/11/2026 regarding claims 2, 4, 6-8, 10-15, and 21 have been fully considered but they are not persuasive. The limitations of independent claims 1 and 9 are rejected for the reasons stated above, therefore the claims dependent on this claim are not allowable for the same reasons as independent claims 1 and 9 are allowable, as independent claims 1 and 9 are not in condition for allowance (see rejections of amended independent claims 1 and 9 under 35 U.S.C. 103 above). See MPEP 1824 6.4 (b).
The examiner notes that previously presented claim 5 included the limitation “. . . a length of the long-axis is substantially equal to a diameter of the bottom surface . . .” In the rejection of claim 5 under 35 U.S.C. 112(b) in the non-final office action dated 3/11/2026, the examiner noted “For the purposes of this examination, ‘substantially equal to’ will be interpreted to be any values which are equal within rounding-range in as it appears in the prior art.” The applicant withdrew the indefinite “substantially equal to” language when including the rest of the limitations of claim 5 into amended claims 1 and 9 without incorporating language amounting to “any values which are equal within rounding range” in the limitations of amended claims 1 and 9; however, previously presented claim 5 was examined with these limitations. Therefore, presently presented claim 3 (which would otherwise contain the same limitations of previously presented claim 5, if not for the above stated reasons) contains a new, narrower set of limitations than previously presented claim 5, and requires further search and consideration. In light of this, a new rejection of amended claim 3 under 35 U.S.C. 103 is presented above and this action is final as necessitated by amendment. See MPEP 2143.03 (I).
As a courtesy to the applicant, the examiner notes that the inclusion of the limitations of amended claim 3 into amended claims 1 and 9, along with additional claim language that particularly points out a long-axis of meaningfully greater length than the short axis for the top-view elliptical profile of the top surface of the gate via (such as the language “wherein the length of the long-axis is greater than the diameter of the bottom surface by 2 nm to 6 nm” of claim 14) may overcome the rejections as currently presented, although more search and consideration may be required.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action. Any inquiry concerning this communication or earlier communications from the examiner should be directed to GABRIEL S MINNEY whose telephone number is (571)272-9688. The examiner can normally be reached Monday Friday, 8:30 a.m. 5 p.m. ET..
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Jacob Choi can be reached at (469) 295-9060. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/G.S.M./Examiner, Art Unit 2897
/JACOB Y CHOI/Supervisory Patent Examiner, Art Unit 2897
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