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 I and Species K (Fig. 3K, claims 1-12) in the reply filed on 8/18/26 is acknowledged.
Drawings
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 rivet must be shown or the feature(s) canceled from the claim(s). It is unclear as to which element of the figures constitute a rivet (Cambridge Dictionary: a mechanical pin used to join two or more pieces together). No new matter should be entered.
Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
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 (i.e., changing from AIA to pre-AIA ) 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, 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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim(s) 1-3, 8-11 is/are rejected under 35 U.S.C. 103 as being unpatentable over U.S. Patent Application Publication No. 2024/0046966 (Lee ‘966) in view of U.S. Patent Application Publication No. 2019/0148506 (Kanakamedala) and U.S. Patent Application Publication No. 2014/0106574 (Kang).
Lee ‘966 discloses (Figs. 4A-4L)
1. (Original) A method, comprising:
forming a stack 400 comprising a set of levels, each level of the set of levels comprising a nitride layer 416 and an oxide layer 414;
removing a portion of the stack 400 to form a cavity 436 comprising a first sidewall (left) and a second sidewall (right);
removing, based at least in part on forming the cavity 436, a portion of the nitride layer 416 of each level of the set of levels to form a set of voids 442, wherein a first void of the set of voids 442 is formed at a first level based at least in part on removing the portion of the nitride layer 416 of the first level, and wherein a second void of the set of voids 442 is formed at a second level based at least in part on removing the portion of the nitride layer 416 of the second level;
conformally depositing, based at least in part on removing the portion of the portion of the nitride layer 416 of each level, an oxide material 444 on the first sidewall (left) and the second sidewall (right) of the cavity 436; and
forming a rivet 454 that couples a first word line 450 with a conductive pillar 456 based at least in part on conformally depositing the oxide material 444.
Lee ‘966 fails to disclose
depositing a nitride material on the stack to contact at least a portion of the nitride layer of one or more levels of the set of levels;
removing a portion of the nitride material, wherein a first void of the set of voids is formed at a first level based at least in part on removing the portion of the nitride material and the portion of the nitride layer of the first level, based at least in part on removing the portion of the nitride layer of the second level;
the oxide material filling a portion of the first void to form a third void that is smaller than the first void and filling the second void; and
wherein the first word line is associated with the first level that comprises the nitride material in contact with the portion of the nitride layer.
Kanakamedala teaches (Figs. 5, 6, 13A)
A method comprising:
depositing a nitride material 142 on the stack to contact at least a portion of the nitride layer 42 of one or more levels of the set of levels;
removing a portion of the nitride material 142 and a portion of the nitride layer 42 of each level to form a set of voids 43, wherein a first void of the set of voids is formed at a first level based at least in part on removing the portion of the nitride material 142 and the portion of the nitride layer 42 of the first level that is in contact with the portion of the nitride material 142 (enlarged/protruding cavity portion 143, t2 > t1).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to provide a nitride material in Lee ‘966. The motivation would be to increase the thickness of the contact region to increase the landing margin at the word line and reduce the likelihood of etching through the word line as taught by Kanakamedala ([0151], [0152], [0174], [0175], [0186], [0187]).
Kang teaches (Figs. 2-4).
A method comprising:
depositing an oxide material 210 filling a portion of the first void 204 to form a third void (unlabeled) that is smaller than the first void 204 and filling the second void 202.
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to form multiple voids in Lee ‘966. The motivation would be to simultaneously fill gaps of different sizes using a common deposition process to improve gap fill capability across variable-sized features as taught by Kang ([0004]).
Lee ‘966 in view of the nitride material of Kanakamedala teaches
2. (Original) The method of claim 1, further comprising:
forming, after conformally depositing the oxide material 444, a plurality of word lines 450 comprising at least the first word line and a second word line based at least in part on removing the nitride material 142 and the nitride layer 42 from each level of the set of levels to form a plurality of fourth voids 442 and depositing a first conductive material in the plurality of fourth voids (to form word lines 450), wherein forming the rivet 454 occurs after forming the plurality of word lines 450.
Kanakamedala teaches
3. (Original) The method of claim 2, wherein a first thickness t2 of the first word line 46 adjacent to the cavity 43 is greater than a second thickness t1of the second word line 46 adjacent to the cavity 143.
Kanakamedala teaches (Figs. 12, 13A)
8. (Original) The method of claim 1, further comprising:
performing a wet etching process to remove the nitride material 142 from sidewalls of the stack to expose a sidewall of the nitride layer 42 of the one or more levels of the set of levels that contacts the nitride material 142, wherein forming the cavity 79, 43, 143 is based at least in part on performing the wet etching process ([0132]-[0141]).
Lee ‘966 discloses
9. (Original) The method of claim 1, wherein forming the stack comprises: depositing each nitride layer 416 on each oxide layer 414 to form the stack 400 comprising a set of oxide layers 414 interleaving a set of nitride layers 416.
Lee ‘966 discloses
10. (Original) The method of claim 9, further comprising:
removing a portion of the set of nitride layers 416 and the set of oxide layers 414 to form each level of the set of levels, wherein the portion comprises a first subset of the set of oxide layers 414 and a first subset of the set of nitride layers 416, and
Kanakamedala teaches
wherein depositing the nitride material 142 occurs after forming each level of the set of levels.
Lee ‘966 discloses
11. (Original) The method of claim 1, wherein each level of the set of levels comprises a respective height and a respective width (421, 422, 423 have a vertical height defined by oxide layer 414 and nitride layer 416 and a horizontal width defined by the respective staircase tread/landing pad dimension).
Claim(s) 4, 6 is/are rejected under 35 U.S.C. 103 as being unpatentable over Lee ‘966 in view of Kanakamedala and Kang as applied to claim 2 above, and further in view of U.S. Patent No. 6,444,528 (Murphy).
Lee ‘966 discloses
4. (Original) The method of claim 2, further comprising:
removing, after forming the plurality of word lines 450, a portion of the oxide material 420 from the first sidewall (left) and the second sidewall (right) of the cavity 436, wherein removing the portion of the oxide material 420 from the third void 452 exposes sidewalls of the first word line 450, and
The combination of references fails to teach
wherein removing the portion of the oxide material from the second void decreases a thickness of a remaining portion of the oxide material in the second void that contacts the second word line.
Murphy teaches (Fig. 6)
A method comprising:
wherein removing the portion of the oxide material 42 from the second void decreases a thickness of a remaining portion of the oxide material 46 in the second void (that contacts the second word line).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to remove a portion of the oxide material in the modified method of Lee ‘966. The motivation would be so that a common oxide etch can completely remove a thinner oxide region while merely thinning a thicker oxide region, thereby preserving dielectric material where continued insulation is desired as taught by Murphy.
Lee ‘966 discloses
6. (Original) The method of claim 4, further comprising:
depositing, based at least in part on removing the portion of the oxide material 444, a second conductive material into the cavity 436 to form the conductive pillar 456 and the rivet 454, wherein the second conductive material contacts the first word line 450 and is electrically isolated from the second word line 450 by the remaining portion of the oxide material 444.
Claim(s) 5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Lee ‘966 in view of Kanakamedala, Kang, and Murphy as applied to claim 4 above, and further in view of U.S. Patent Application Publication No. 2004/0203217 (Lee ‘217).
The combination of references fails to teach
5. (Original) The method of claim 4, wherein removing the portion of the oxide material further comprises:
performing a wet etching process to conformally remove the portion of the oxide material from the first sidewall and the second sidewall of the cavity.
Lee ‘217 teaches (Fig. 2(d))
A method comprising:
wherein removing the portion of the oxide material 206 further comprises:
performing a wet etching process to conformally remove the portion of the oxide material 206 from the first sidewall (left) and the second sidewall (right) of the cavity 205.
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to perform a wet etching process in the modified method of Lee ‘966. The motivation would be wet etching is a well-known process for removing oxide material from sidewalls of a cavity as taught by Lee ‘217. See MPEP 2144.03.
Claim(s) 7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Lee ‘966 in view of Kanakamedala and Kang as applied to claim 1 above, and further in view of U.S. Patent No. 10,468,259 (Purayath).
The combination of references fails to teach
7. (Original) The method of claim 1, further comprising:
depositing a polysilicon material in the cavity after conformally depositing the oxide material, wherein forming the rivet occurs after depositing the polysilicon material in the cavity.
Purayath teaches
A method comprising:
depositing a polysilicon material 205 in the cavity 203 after conformally depositing the oxide material 204,
Lee ‘966 discloses
wherein forming the rivet 454 occurs after (later in the process in Fig. 4L) depositing the polysilicon material 205 in the cavity 203.
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to deposit polysilicon in the modified method of Lee ‘966. The motivation would be providing a conventional sequence of insulating the cavity surface with oxide before depositing polysilicon (a suitable material), thereby providing electrical isolation between the polysilicon and surrounding structures as taught by Purayath. See MPEP 2144.07.
Claim(s) 12 is/are rejected under 35 U.S.C. 103 as being unpatentable over Lee ‘966 in view of Kanakamedala and Kang as applied to claim 1 above, and further in view of U.S. Patent Application Publication No. 2022/0181141 (van Schravendijk).
The combination of references fails to teach
12. (Original) The method of claim 1, further comprising:
depositing a second nitride material over the stack after depositing the nitride material over the stack, wherein forming the cavity further comprises removing a portion of the second nitride material.
van Schravendijk
A method comprising:
depositing a second nitride material (SiN etch-stop over staircase) over the stack 111 / 112 after depositing the nitride material over the stack, wherein forming the cavity further comprises removing a portion of the second nitride material (removed and vias are formed to word line landing regions).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to form a second nitride material in the modified method of Lee ‘966. The motivation would be to provide a thicker landing pad at the word line contact region to prevent a contact via from punching through the word line during etching, thereby avoiding shorting between word lines and yield loss as taught by van Schravendijk ([0023], [0024], [0049], [0051].
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. U.S. Patent Nos. 9,530,781 (Miyamoto), 9,231,086 (Khoueir), U.S. Patent Application Publication No. 2023/0197507 (Xu) teach a staircase contact region where a word line is connected to a vertical conductive pillar through a lateral contact.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to TERESA M ARROYO whose telephone number is (703)756-1576. The examiner can normally be reached Monday - Friday (8:30 A.M. E.T. - 5:00 P.M. E.T.).
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/TERESA M. ARROYO/ Primary Examiner, Art Unit 2893
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