DETAILED ACTION
Notice of Pre-AIA or AIA Status
1. The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
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.
Drawings
2. The drawings are objected to under 37 CFR 1.83(a). The drawings must show every feature of the invention specified in the claims. Therefore, the “less than” in “wherein a width of the middle portion is less than a width of the end portions” of claim 15 must be shown or the feature(s) canceled from the claim(s). No new matter should be entered.
Specifically, when “width” is used without “thickness”, “width” can be interpreted as a dimension opposed to length, and as such “width” can be understood as extending in any direction perpendicular to the direction that the length extends, as, for example, in claim 1 (“wherein a width of each channel region of the plurality of channel nanosheets varies across its length”). However, when “width” is used together with “thickness”, clarification is required as to which dimension is considered “width” and which is “thickness”.
A proposed drawing correction or corrected drawings are required in reply to the Office action to avoid abandonment of the application. The objection to the drawings will not be held in abeyance.
Claim Objections
3. Claims 4, 9, 11, 16 and 18 are objected to because of the following informalities:
Dependency of claim 9 (“claim 1”) should be changed to “claim 8” (without the change, claim 9 is identical to claim 2).
Dependency of claim 16 (“claim 1”) should be changed to “claim 15”
In each of claims 4, 11 and 18, “below” in “a source drain region immediately below and directly contacting the backside contact structure” should be changed to “above” for directional consistency.
Appropriate correction is required.
Claim Interpretations
4. Claim 15 recites “wherein each channel region of the plurality of channel nanosheets comprises a middle portion and end portions, wherein a thickness of the middle portion is less than a thickness of the end portions, and wherein a width of the middle portion is less than a width of the end portions” (emphasis added) wherein it is disclosed in the specification and in the drawings, paragraphs [0077], [0078], Figs. 23-25, that “embodiment illustrated in FIGS. 23-25,…”, “trimming the channel nanosheets 108 may have middle portions distinguishable from end portions. The middle portion of each channel nanosheet 108 is surrounded by the gate structure 136 and the end portions remain surrounded on top and bottom by the inner spacers 122. As such, according to embodiment of the present disclosure, a thickness and a width of the middle portion of each channel nanosheet 108 is smaller than a thickness and a width of the end portions of the channel nanosheet 108” (emphasis added). By the description alone, it appears that “thickness” and “width” are two different entities; However, when the statement and the claim are interpreted carefully together with the drawings, thickness and width are basically the same thing.
Claim Rejections - 35 USC § 102
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.
(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.
5. Claims 1, 8 and 15 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Liaw U.S. Patent Application Publication 2023/0035086 A1 (the ‘086 reference).
The reference discloses in Figs. 18A to 19H and related text a nanosheet semiconductor structure as claimed.
Referring to claim 1, the ‘086 reference discloses a nanosheet semiconductor structure comprising:
a plurality of channel nanosheets (208a, best seen in Fig. 18A, para [20, 80] (paragraph(s) [0020], [0080])) arranged one above another and each surrounded by a gate structure (244 (244n, 244p), para [80], best seen in Figs. 19A, 19C and 19F), wherein a width (in the vertical direction, as opposed to the length of the channel nanosheet 208a, which is in the horizontal direction) of each channel region (208a) of the plurality of channel nanosheets (208a) varies across its length (best seen in Figs. 18A and 19F).
Referring to claim 8 and using the same reference characters, interpretations, and citations as detailed above for claim 1 where applicable, the reference discloses a nanosheet semiconductor structure comprising:
a plurality of channel nanosheets (208a) arranged one above another and each surrounded by a gate structure (244 (244n, 244p)), wherein each channel region (208a) of the plurality of channel nanosheets comprises a first thickness (CT1) and a second thickness (CT2), and wherein the first thickness (CT1) is greater than the second thickness (CT2) (para [20, 77, 80]).
Referring to claim 15, as interpreted in the claim interpretations detailed above, and using the same reference characters, interpretations, and citations as detailed above for claims 1 and 8 where applicable, the reference discloses a nanosheet semiconductor structure comprising:
a plurality of channel nanosheets (208a) arranged one above another and each surrounded by a gate structure (244 (244n, 244p)), wherein each channel region (208a) of the plurality of channel nanosheets comprises a middle portion and end portions, wherein a thickness (CT2) of the middle portion is less than a thickness (CT1) of the end portions, and wherein a width (CT2, in the vertical direction, as opposed to the length of the channel nanosheet 208a, which is in the horizontal direction) of the middle portion is less than a width (CT1, in the vertical direction) of the end portions.
6. Claims 1-2, 8-9 and 15-16 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Frougier et al. U.S. Patent Application Publication 20210043727 A1 (the ‘727 reference).
The reference discloses in Figs. 1A-1D and related text a nanosheet semiconductor structure as claimed.
Referring to claim 1, the ‘727 reference discloses a nanosheet semiconductor structure comprising:
a plurality of channel nanosheets (110, para [46]) arranged one above another and each surrounded by a gate structure (164, para [41]), wherein a width (in the vertical direction, as opposed to the length of the channel nanosheet 110, which is in the horizontal direction) of each channel region (110) of the plurality of channel nanosheets (110) varies across its length (see Fig. 1A, para [46], and note that even though Frougier calls center region 111 of the channel region 110 a “channel region” and end portions 112 of the channel region 110 “source/drain extension regions” (para [48]), the nanosheet channel-region 110 can be termed a channel region because it is a region channeled between source/drain regions 115 (para [68])).
Referring to claim 8 and using the same reference characters, interpretations, and citations as detailed above for claim 1 where applicable, the reference discloses a nanosheet semiconductor structure comprising:
a plurality of channel nanosheets (110) arranged one above another and each surrounded by a gate structure (164), wherein each channel region (110) of the plurality of channel nanosheets comprises a first thickness (that of end portions 112, para [46]) and a second thickness (that of center portion 111), and wherein the first thickness is greater than the second thickness (para [46]).
Referring to claim 15, as interpreted in the claim interpretations detailed above, and using the same reference characters, interpretations, and citations as detailed above for claims 1 and 8 where applicable, the reference discloses a nanosheet semiconductor structure comprising:
a plurality of channel nanosheets (110) arranged one above another and each surrounded by a gate structure (164), wherein each channel region of the plurality of channel nanosheets comprises a middle portion (111) and end portions (112), wherein a thickness of the middle portion is less than a thickness of the end portions, and wherein a width (in the vertical direction, as opposed to the length of the channel nanosheet 110, which is in the horizontal direction) of the middle portion (111) is less than a width (in the vertical direction) of the end portions (112).
Referring to claims 2 and 9, the reference further discloses:
stack spacers (105, para [43]) below and vertically aligned with the plurality of channel nanosheets (110), wherein a width of the stack spacers (105) measured in a direction parallel to the gate structure (164) is greater than a width of the plurality of channel nanosheets (110) (as clearly depicted in Fig. 1B).
Referring to claim 16, the reference further discloses:
stack spacers (105, para [43]) below and vertically aligned with the plurality of channel nanosheets (110), wherein a width of the stack spacers (105) measured in a direction parallel to the gate structure (164) is greater than the width of the middle portions of the plurality of channel nanosheets (110) (see Fig. 1B).
7. Claims 1, 8 and 15 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Mehandru et al. U.S. Patent Application Publication 2023/0317786 A1 (the ‘786 reference).
The reference discloses in Figs. 1B, 1I and related text a nanosheet semiconductor structure as claimed.
Referring to claim 1, the ‘786 reference discloses a nanosheet semiconductor structure comprising:
a plurality of channel nanosheets (nanowires 158A, Figs. 1F, 1I, para [39]) arranged one above another and each surrounded by a gate structure (170, para [42]), wherein a width (in the vertical direction, as opposed to the length of the channel nanosheet 158A, which is in the horizontal direction) of each channel region (158A) of the plurality of channel nanosheets (158A) varies across its length (see Fig. 1B, para [32], para [41]: “each of the plurality of nanowires 158A has necked features where a relatively thinner channel region meets end portions, such as described in association with FIG. 1B”; and note that even though Mehandru calls center region 124A of the channel region 122 a “channel portion” and end portions 124B of the channel region 122 “end portions” (para [32]), the nanowire channel-region 122 can be termed a channel region because it is a region channeled between source/drain regions 132 (para [32])).
Referring to claim 8 and using the same reference characters, interpretations, and citations as detailed above for claim 1 where applicable, the reference discloses a nanosheet semiconductor structure comprising:
a plurality of channel nanosheets (158A) arranged one above another and each surrounded by a gate structure (170), wherein each channel region (158A) of the plurality of channel nanosheets comprises a first thickness (that of end portions 124B) and a second thickness (that of center portion 124A), and wherein the first thickness is greater than the second thickness (para [32, 41]).
Referring to claim 15, as interpreted in the claim interpretations detailed above, and using the same reference characters, interpretations, and citations as detailed above for claims 1 and 8 where applicable, the reference discloses a nanosheet semiconductor structure comprising:
a plurality of channel nanosheets (158A) arranged one above another and each surrounded by a gate structure (170), wherein each channel region (158A) of the plurality of channel nanosheets (158A) comprises a middle portion and end portions, wherein a thickness of the middle portion is less than a thickness of the end portions, and wherein a width (in the vertical direction, as opposed to the length of the channel nanosheet 158A, which is in the horizontal direction) of the middle portion is less than a width (in the vertical direction) of the end portions.
Allowable Subject Matter
8. Claims 3-7, 10-14 and 17-20, insofar as in compliance with the claim objections and the drawing objections detailed above, are 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 following is an examiner’s statement of reasons for the indication of allowable subject matter: The cited art, whether taken singularly or in combination, especially when all limitations are considered within the claimed specific combination, fails to teach or render obvious a nanosheet semiconductor structure with all exclusive limitations as recited in claims 3, 10 and 17, which may be characterized in that a backside contact structure is self-aligned to shallow trench isolation regions and partially extending beneath the gate structure.
Conclusion
9. Any inquiry concerning this communication or earlier communications from the examiner should be directed to TU TU V HO whose telephone number is (571)272-1778. The examiner can normally be reached on Monday to Thursday 6:30 - 15:00, Monday through Thursday.
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06-29-2026
/TU-TU V HO/Primary Examiner, Art Unit 2818
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