DETAILED ACTION
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 .
Response to Arguments
Applicant's arguments filed 10 December 2025 have been fully considered and the responses are respectfully set forth below.
Regarding the 35 USC 112 rejections of claims 21-24 in the previous Office action (Remarks; page 8). Applicant has cancelled the limitations at issue (as noted in the previous rejection). Therefore the 35 USC 112 rejection of claims 21-24 are withdrawn.
Regarding the amendment to claim 1 (Remarks; page 9), Applicant has amended previously indicated allowable dependent claim 5 into independent claim 1. Therefore the rejection of claim 1 in view of the applied prior art in the previous Office action is withdrawn.
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Regarding the amendment to claim 10 (Remarks; page 9-10), Applicant has amended claim 10 to include additional features including:
“a dielectric fin disposed between the first source/drain feature and the second source/drain feature along a first direction…. And wherein the dielectric liner comprises a first part laterally adjacent to the dielectric filler along the first direction and a second part laterally adjacent to the dielectric filler along a second direction different from the first direction … in a top view, the etching process further removes the first part of the dielectric liner without removing the second part of the dielectric liner”.
The ”first part” and “second part” of the dielectric liner has not been detailed in the claim with sufficient specificity to overcome the prior art of record Xie, and still reads on Xie.
The prior art of record Chan as modified by Xie teaches these limitations. Xie teaches these limitations as mapped with the accompanying drawing “Xie mapped figures” provided above for ease of reference.
Xie teaches the dielectric feature (162/165) disposed between the first source/drain feature (130) and the second source/drain feature (135) along a first direction (Y direction according to Xie mapped figures, wherein figures 1A, 6A, and 7A correspond to the cross section/arrow “1A-1A” in Fig. 1)…. And wherein the dielectric liner (162) comprises a first part (Xie mapped figures 6A; 1st part) laterally adjacent to the dielectric filler (165) along the first direction (Y) and a second part (Xie mapped figures 6B; 2nd part) laterally adjacent to the dielectric filler (165) along a second direction (X direction according to Xie mapped figures, wherein figures 1B, 6B, and 7B correspond to the cross section/arrow “1B-1B” in Fig. 1) different from the first direction (Y) … in a top view (cross sections in Y and X directions in view of Fig. 1), the etching process further removes the first part of the dielectric liner (1st part of 162) without removing the second part (2nd part of 162) of the dielectric liner (as shown in the provided Xie mapped figures). The rejection has been updated in view of the “Xie mapped figures” provided above.
Furthermore, the amendment to independent claim 10 introduces 35 USC 112 issues into dependent claim 25, and claim 25 is therefore rejected as detailed below.
Regarding the amendment to claim 21 (Remarks; page 11), the limitations relating to the previous 112 rejection have been removed. Upon further search and consideration, the prior art of record does not appear to teach or render obvious the limitations of “in a cross sectional view cut through the source/drain feature without cutting through the gate structure, a top surface of the source/drain contact is above the topmost surface of the second insulation layer”.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claim 25 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Regarding Claim 25, it recites “a top view”, “a first part” “a first direction, “a second part” and “a second direction” in lines 2, 2, 2-3, 3, and 3-4 respectively. These are duplicate limitations from newly amended claim 10, and it is unclear if the “a top view”, “a first part” “a first direction, “a second part”, and “a second direction” recited in claim 25 are intended to refer to the same “a top view”, “a first part” “a first direction, “a second part”, and “a second direction” as recited in claim 1.
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) 10-15 are rejected under 35 U.S.C. 103 as being unpatentable over Boon Teik Chan et al (US 2022/0122895 A1; hereinafter Chan) in view of Ruilong Xie et al (US 20190295898 A1; hereinafter Xie).
Regarding Claim 10, Chan teaches a method, comprising:
receiving a workpiece comprising:
a first source/drain feature (Fig. 3a; 122; ¶0090) and a second source/drain feature (Fig. 3a; 124; ¶0090),
a dielectric fin (Fig. 3a; 120+132; ¶0085 and ¶0092; wherein 132 is on upper portions of the sidewalls of 120) disposed between the first source/drain feature (122) and the second source/drain feature (124) along a first direction (Y direction which is between the source/drain features), wherein a top surface of the dielectric fin (120+132) is above a top surface of the first source/drain feature (122) (as shown in Fig. 3a), and
a dielectric layer (Fig. 3b; 134; ¶0100) over the first source/drain feature (122), the second source/drain feature (124), and the dielectric fin (120+132) (as shown in Fig. 3b);
selectively removing a portion of the dielectric layer (134) disposed directly over the dielectric fin (120+132) to form an opening (as shown in Fig. 3c; opening 140);
forming a dielectric feature (Fig. 3d; 142; ¶0099) to fill the opening (140; as shown in Fig. 3d),
performing an etching process to selectively remove a first portion and a second portion of the dielectric layer (134) to form a first trench (Fig. 3f; 148a) exposing the first source/drain feature (122) and a second trench (Fig. 3f; 148d) exposing the second source/drain feature (124) (as shown in Fig. 3f; wherein liner 133 is optional and therefore the source/drain features are exposed; ¶0097), respectively; and
forming a first contact feature (Fig. 3g; 150a; ¶0113) in the first trench (148a) and a second contact feature (Fig. 3g; 150d; ¶0113) in the second trench (148d), the first contact feature (150a) and the second contact (150d) feature being spaced apart by the dielectric feature (142) (as shown in Fig. 3g).
Chan does not expressly disclose wherein the dielectric feature (142) comprises a dielectric filler and a dielectric liner extending along a sidewall surface of the dielectric filler, wherein the dielectric filler has a different composition than the dielectric liner; and wherein the dielectric liner comprises a first part laterally adjacent to the dielectric filler along the first direction and a second part laterally adjacent to the dielectric filler along a second direction different from the first direction, wherein in a top view, the etching process further removes the first part of the dielectric liner without removing the second part of the dielectric liner
In the same field of endeavor, Xie teaches a similar method of forming a dielectric feature in Fig. 6A and Fig. 7A. Xie teaches conformally depositing a dielectric liner (Xie; Fig. 6A; 162; ¶0019) over a trench and a dielectric filler (Xie; Fig. 5A/6A; 160/165; ¶0018-0019; hereinafter 165) to form a dielectric feature (162+165) to separate adjacent source drains (Fig. 6a; 130/135; ¶0016) in a first direction (Y direction according to Xie mapped figures, wherein figures 1A, 6A, and 7A correspond to the cross section/arrow “1A-1A” in Fig. 1), wherein the dielectric liner (162) extends along a sidewall of the dielectric filler (165) (as shown in Fig. 6A); and wherein (162) and (165) have different compositions (Xie; ¶0019); wherein the dielectric liner (162) comprises a first part (Xie mapped figures 6A; 1st part) laterally adjacent to the dielectric filler (165) along the first direction (Y) and a second part (Xie mapped figures 6B; 2nd part) laterally adjacent to the dielectric filler (165) along a second direction (X direction according to Xie mapped figures, wherein figures 1B, 6B, and 7B correspond to the cross section/arrow “1B-1B” in Fig. 1) different from the first direction (Y).
This is followed by an etching process to form trenches on either side of the dielectric feature (162+165) to expose the respective source/drains (130/135), wherein, in a top view (as shown by cross sections in Y and X directions in view of Fig. 1), the etching process further removes the first part of the dielectric liner (1st part of 162) without removing the second part (2nd part of 162) of the dielectric liner (as shown in the provided Xie mapped figures above).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have the two-layered dielectric features of Xie (162+165) as the dielectric feature of Chan (142) in order to provide the dielectric feature with resistance to certain etchants and/or provide a stop layer for CMP processes (Xie; ¶0020).
Regarding Claim 11, Chan modified by Xie teaches the method of claim 10, wherein the forming of the first contact feature (150a) and the second contact feature (150d) comprises:
depositing a contact feature layer over the workpiece (Chan; ¶0114); and
performing a planarization process (Chan; ¶0116) to the workpiece to expose a top surface of the dielectric feature such that the contact feature layer is divided by the dielectric feature into the first contact feature and the second contact feature (as shown in Chan Fig. 3g).
Regarding Claim 12, Chan modified by Xie teaches the method of claim 10, wherein the forming of the dielectric feature (162+165 as modified by Xie to replace 142 of Chan) comprises:
conformally depositing the dielectric liner (Xie; 162) over the opening such that the dielectric liner is disposed directly over the dielectric fin (Chan; 120+132); and
depositing the dielectric filler (Xie; 165) over the dielectric liner (Xie; 162) (as shown in Xie Fig. 5A/6A),
wherein the composition of the dielectric filler (Xie; 165) is more etch-resistant than the dielectric liner (Xie; 162) with respect to the etching process (as shown in Fig. 7A of Xie; when the etching process is performed to form the contact openings exposing the source/drain 130/135; the dielectric filler 165 is more etch resistant than the dielectric liner 162 because 162 is partially etched at an upper surface of the dielectric feature 162+165).
Regarding Claim 13, Chan modified by Xie teaches the method of claim 12, but does not expressly disclose wherein the dielectric liner (162) comprises silicon oxide,
wherein the dielectric filler (160/165) comprises silicon, silicon nitride, silicon carbonitride, silicon oxycarbonitride, silicon oxynitride, or aluminum oxide.
However, Xie teaches in ¶0019 the opposite, wherein (162) comprises a nitride of silicon and (160/165) comprises an oxide of silicon.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to try one of two configurations of the dielectric materials for the dielectric feature, with a reasonable expectation of success at providing the appropriate etch selectivity for forming the contact openings of the device. MPEP 2143 I (E).
Regarding Claim 14, Chan modified by Xie teaches the method of claim 12, but does not expressly disclose wherein a composition of the dielectric liner (Xie; 162; SiN) is the same as a composition of the dielectric layer (Chan; 134; ¶0100 silicon oxide or other dielectric material).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to substitute the dielectric material of Chan (SiO2 or other suitable dielectric; ¶0100) with SiN because the substitution of a known equivalent for another known equivalent is prima facie case of obviousness. The selection of a known material based on its suitability for its intended use supported a prima facie obviousness determination in Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945).
Regarding Claim 15, Chan modified by Xie teaches the method of claim 12,
wherein, before the performing of the etching process, the dielectric liner (Xie 162) has a third width along a first direction substantially perpendicular to a lengthwise direction of the dielectric fin, and the dielectric filler (165) has a fourth width along the first direction,
wherein a ratio of the fourth width to the third width is between about 0.2 and about 10 (as shown in Xie Fig. 7A).
Regarding Claim 26, Chan modified by Xie teaches the method of claim 10, wherein the dielectric liner (Xie; 162) comprises a third part (Xie mapped figures, 3rd part) disposed under the dielectric filler (Xie; 165), and the performing of the etching process removes the first part (1st part) of the dielectric liner (162) without removing the third part (3rd part) of the dielectric liner.
Allowable Subject Matter
Claims 1-4, 6-9, and 21-24 are allowed.
The following is an examiner’s statement of reasons for allowance:
Regarding Claim 1, the prior art of record teaches many limitations of claim 1 (see previous Office action). However, none of the references of record teaches or suggests the claimed method of forming a semiconductor device (in combination(s) as set forth in the claim(s)) comprising all limitations of claim 1 and wherein the workpiece further comprises an etch stop layer on the first source/drain feature and the second source/drain feature, wherein, after the selectively removing, the dielectric liner is vertically sandwiched between the etch stop layer and the dielectric filler.
For at least this reason, claims 2-4 and 6-9 are also allowed based on their dependency from claim 1.
Regarding Claim 21, the prior art of record teaches many limitations of claim 21. However, none of the references of record teaches or suggests the claimed method of forming a semiconductor device (in combination(s) as set forth in the claim(s)) comprising all limitations of claim 21 and further wherein in a cross sectional view cut through the source/drain feature without cutting through the gate structure, a top surface of the source/drain contact is above the topmost surface of the second insulation layer.
For at least this reason, claims 22-24 are also allowed based on their dependency from claim 21.
Any comments considered necessary by applicant must be submitted no later than the payment of the issue fee and, to avoid processing delays, should preferably accompany the issue fee. Such submissions should be clearly labeled “Comments on Statement of Reasons for Allowance.”
Conclusion
Applicant's amendment necessitated the 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 NATHAN PRIDEMORE whose telephone number is (703)756-4640. The examiner can normally be reached Monday - Friday 8:00am - 4:00pm EST.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, JULIO MALDONADO can be reached at (571) 272-1864. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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NATHAN PRIDEMORE
Examiner
Art Unit 2898
/NATHAN PRIDEMORE/Examiner, Art Unit 2898 /JULIO J MALDONADO/Supervisory Patent Examiner, Art Unit 2898
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