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 .
Election/Restrictions
Applicant’s election without traverse of Group II (claims 18-37) in the reply filed on 02/13/2026 is acknowledged.
Claim Rejections - 35 USC § 102
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claims 18, 29 are rejected under 35 U.S.C. 102(a)(2) as being anticipated by Baek et al. (US 2023/0343823 A1).
Regarding claim 18: Baek teaches in Fig. 1A -11B about a method of forming a device, comprising:
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forming a stack on a semiconductor substrate 105, wherein the stack comprises a first multi- layer stack 10L, a first sacrificial layer 115S and a second multi-layer stack 10U stacked on the semiconductor substrate in sequence, the first multi-layer stack comprises alternating stacked first semiconductor layers 110C and second sacrificial layers 110S, and the second multi-layer stack 10U comprises alternating stacked second semiconductor layers 120C and third sacrificial layers 120S (Fig. 1A);
forming a first epitaxial source/drain region 180S/180D and a second epitaxial source/drain region 170S/170D on the semiconductor substrate, wherein the first epitaxial source/drain region and the second epitaxial source/drain region are on opposite sidewalls of the stack (Fig. 6), respectively, and the first epitaxial source/drain region has a height greater than a height of the second epitaxial source/drain region (as shown in Fig. 6, 180S has higher height than 170S/170D);
replacing the second sacrificial layers with a first metal gate structure 220L (Fig. 10A); and
replacing the third sacrificial layers with a second metal gate structure 220U (Fig. 10A).
Regarding claim 29: Baek teaches in Fig. 1A -11B about a a method of forming a device, comprising:
forming a plurality of first semiconductor layers 110C arranged one above another over a substrate 105 (Fig. 1A);
forming a first metal gate structure 220L wrapping around the plurality of first semiconductor layers (Fig. 10A);
forming a plurality of second semiconductor layers 120C arranged one above another on the substrate; and
forming a second metal gate structure 220U wrapping around the plurality of second semiconductor layers (Fig. 10A), and spaced apart from the first metal gate structure (Fig. 11A), wherein when viewed from a cross-sectional view, the first metal gate structure has a first height, the second metal gate structure has a second height less than the first height (Fig. 11A, 220U around 3 of 10U and 220 L is around 2 of 10L), and wherein when viewed from a top view, the second metal gate structure has a top surface area different from a top surface area of the first metal gate structure (Fig. 10B).
Claim Rejections - 35 USC § 102
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale or otherwise available to the public before the effective filing date of the claimed invention.
Claim 21 is rejected under 35 U.S.C. 102(a)(1) as being anticipated by Cheng et al (US 2005/012367A1).
Regarding claim 21: Cheng teaches in Fig. 17A -17B, [0065] – [0066] about a method of forming a device, comprising:
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forming a first transistor 16 on a semiconductor substrate 12, wherein the first transistor comprises a first channel 30, a first source 38 and a first drain 38, the first source and the first drain are on opposite sides of the first channel;
forming a second transistor 14 over the first transistor, wherein the second transistor comprises a second channel 30, a second source 50 and a second drain 50, the second source and the second drain are on opposite sides of the second channel, and the first transistor is connected in series with the second transistor ([0066] left side of 16 and 14 are connected in series); and
depositing a first isolation structure 64 over the first drain 38.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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 of this title, 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 22 is rejected under 35 U.S.C. 103 as being obvious over Cheng et al (US 2005/012367A1) in view of Baek et al. (US 2023/0343823 A1).
Regarding claim 22: Cheng does not show wherein the first source and the second drain share a common epitaxial structure.
However Baek teaches in Fig. 11A bottom two transistors of 10L stack wherein the first source and the second drain share a common epitaxial structure.
Therefore it would have been obvious to a person of ordinary skill in the art at the time of Applicant's invention to combine Baek‘s teachings to Cheng's device to have the feature as claimed depending on transistors connectivity of series or parallel to reduce epitaxy step and thereby reducing cost.
Claims 30, 32 are rejected under 35 U.S.C. 103 as being obvious over Baek et al. (US 2023/0343823 A1) in view of Cheng et al (US 2005/012367A1).
Regarding claim 30: Baek does not show depositing first epitaxial structures disposed on opposite sides of the plurality of first semiconductor layers, and wherein the first epitaxial structures have top surfaces at different elevations.
Cheng shows in Fig. 17A depositing first epitaxial structures disposed on opposite sides of the plurality of first semiconductor layers, and wherein the first epitaxial structures have top surfaces at different elevations (38 on left is higher than 38 on right).
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Therefore it would have been obvious to a person of ordinary skill in the art at the time of Applicant's invention to combine Cheng‘s teachings to Baek's device to have the feature as claimed depending on transistors connectivity of series or parallel to reduce epitaxy step and thereby reducing cost.
Drawings and pictures can anticipate claims if they clearly show the structure which is claimed. In re Mraz, 455 F.2d 1069, 173 USPQ 25 (CCPA 1972). However, the picture must show all the claimed structural features and how they are put together. Jockmus v. Leviton, 28 F.2d 812 (2d Cir. 1928). The origin of the drawing is immaterial. For instance, drawings in a design patent can anticipate or make obvious the claimed invention as can drawings in utility patents. When the reference is a utility patent, it does not matter that the feature shown is unintended or unexplained in the specification. The drawings must be evaluated for what they reasonably disclose and suggest to one of ordinary skill in the art. In re Aslanian, 590 F.2d 911, 200 USPQ 500 (CCPA 1979). See MPEP § 2121.04 for more information on prior art drawings as “enabled disclosures
Regarding claim 32: Baek does not show growing second epitaxial structures from opposite sides of the plurality of second semiconductor layers, and wherein the second epitaxial structures have bottom surfaces at different elevations.
Cheng shows in Fig. 17A growing second epitaxial structures 50’s from opposite sides of the plurality of second semiconductor layers 30, and wherein the second epitaxial structures have bottom surfaces at different elevations.
Therefore it would have been obvious to a person of ordinary skill in the art at the time of Applicant's invention to combine Cheng‘s teachings to Baek's device to have the feature as claimed depending on transistors connectivity of series or parallel to reduce epitaxy step and thereby reducing cost.
Drawings and pictures can anticipate claims if they clearly show the structure which is claimed. In re Mraz, 455 F.2d 1069, 173 USPQ 25 (CCPA 1972). However, the picture must show all the claimed structural features and how they are put together. Jockmus v. Leviton, 28 F.2d 812 (2d Cir. 1928). The origin of the drawing is immaterial. For instance, drawings in a design patent can anticipate or make obvious the claimed invention as can drawings in utility patents. When the reference is a utility patent, it does not matter that the feature shown is unintended or unexplained in the specification. The drawings must be evaluated for what they reasonably disclose and suggest to one of ordinary skill in the art. In re Aslanian, 590 F.2d 911, 200 USPQ 500 (CCPA 1979). See MPEP § 2121.04 for more information on prior art drawings as “enabled disclosures
Claim 34 is rejected under 35 U.S.C. 103 as being obvious over Baek et al. (US 2023/0343823 A1) in view of Cheng et al (US 2005/012367A1) and further in view of Xie et al. (US Patent 11,1777,258 B2)
Regarding claim 34: Baek in view of Cheng does not teach forming a spacer material extending along sidewalls of the plurality of first semiconductor layers and a bottom surface of the second metal gate structure.
Xie teaches in Fig. 27 a spacer material (1502’ +702) extending along sidewalls of the plurality of first semiconductor layers 210’b, 214’b and a bottom surface of the second metal gate structure.
Therefore it would have been obvious to a person of ordinary skill in the art at the time of Applicant's invention to combine Xie‘s teachings to Baek's device to have the feature as claimed
to isolate the upper nanosheets from the lower nanosheets.
Allowable Subject Matter
Claim 19 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. The limitation allowable is “prior to replacing the third sacrificial layers with the second metal gate structure, etching sidewalls of the second semiconductor layers without etching the first semiconductor layers; and forming inner spacers on the etched sidewalls of the second semiconductor layers” in combination with other limitations as whole.
Claim 20 is also allowable being dependent on allowable claim 19.
Claim 23 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. The limitation allowable is “forming a third transistor over the second transistor, wherein the third transistor comprises a third channel, a third drain and a third source, the third drain and the third source are on opposite sides of the third channel, and the third drain and the second source share a common epitaxial structure” in combination with other limitations as whole.
24-28 are also allowable being dependent on allowable claim 23.
Claim 31 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. The limitation allowable is “forming a second isolation structure on a second one of the first epitaxial structures, wherein the first isolation structure and the second isolation structure have top surfaces at different elevations” in combination with other limitations as whole.
Claim 33 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. The limitation allowable is “wherein one of the second epitaxial structures interfaces a sidewall of a top one of the plurality of first semiconductor layers” in combination with other limitations as whole.
Claim 35 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. The limitation allowable is “an inner spacer spacing the first metal gate structure apart from the plurality of second semiconductor layers” in combination with other limitations as whole.
36-37 are also allowable being dependent on allowable claim 23.
Conclusion
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/Mohammed Shamsuzzaman/Primary Examiner, Art Unit 2897
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