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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on January 7, 2026 has been entered.
Election/Restrictions
Applicant election without traverse of Group I, claims 1-11 and 20-28 in the reply filed on April 25, 2025 is acknowledged.
Previously elected claims 5 and 28 were previously cancelled claims 29 and 30 were added. Claims 21-24 are newly cancelled and claims 31-34 are newly added.
The examiner notes that claims 1-4, 6-11, 20, 25-27, and 29-34 are examined.
Response to Amendment
This Office Action is in response to Applicant’s Amendment filed January 7, 2026. Claims 1, 7, 8, and 20 are amended. Claims 21-24 are cancelled. Claims 31-34 are newly added. The Examiner notes that claims 1-4, 6-11, 20, 25-27, and 29-34 are examined.
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.
Claims 1-4, 6-11, 20, 25-27, and 29-34 are rejected under 35 U.S.C. 103 as being unpatentable over Hopkins (US 2021/0358805 A1) in view of Larsen (US 2022/0285378 A1).
With respect to claim 1, Hopkins teaches in Fig. 19:
A semiconductor device (integrated assembly 10) comprising:
a memory stack of gate layers (stack 20 including levels 22 that comprise conductive materials 26) and insulating layers (levels 24 that include insulative material 28),
the gate layers (22) and the insulating layers (24) being stacked alternatingly and being formed into stair steps in a staircase region (“staircase (14)”) (Fig. 19);
a landing stack (liner material 70 and etch stop material 72 that forms etch stop structure 74) formed on the stair steps in the staircase region,
the landing stack comprising an upper layer (74) that is etch selective to a contact isolation layer (fill material 76) that covers the staircase region;
and a first contact structure (interconnects 42 made from conductive material 96) on a first stair step (one of the stair steps corresponding to the first contact structure) of the stair steps,
the first contact structure (42/96) extending through a first contact hole in the contact isolation layer (openings 78) and the landing stack (74 and 70) and being connected with a first gate layer (each contact extends to a layer 22) of the first stair step.
a spacer isolation structure (contact spacer 195) disposed between the upper layer (165) and the first contact structure (one of 197),
the spacer isolation structure isolating the upper layer from the first contact structure (para. 66 “The second etch-stop layer pattern 165 and the contact 197 may be insulated from each other by the contact spacer 195”),
the spacer isolation structure (spacer 102) completely surrounded by the upper layer (74) in a horizontal plane perpendicular to the first contact structure (42/96).
wherein the landing stack (74 and 70) further comprises an isolation layer (70) that extends over the stair steps
and includes a first portion disposed below the upper layer (horizontal portions of 70 and portions on step sidewalls are below 74)
and a second portion (see annotated Fig. 19 below)
Hopkins fails to teach:
and a second portion disposed above an entirety of the upper layer.
Larsen teaches a similar structure in which a dielectric structure 122 analogous to the upper layer is formed over a liner layer 120 analogous to the isolation layer employed to form contact openings filled with contact structures 146. Larsen teaches in para. 47 that “dielectric structures 122 may be formed to discontinuously extend on or over portions of the dielectric liner material 120 within horizontal boundaries of the stadium structures 110.”
Combining the teaching of Hopkins with the teaching of Larsen that the upper layer is only needed in areas where contacts are formed, it would be obvious to remove the portion of 74 in Hopkins along the second portion of the isolation structure as defined in annotated Fig. 19 below because that portion of the layer does not include any areas in which contact holes are defined, meeting the limitation:
and a second portion disposed above an entirety of the upper layer.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Hopkins to remove an unnecessary portion of the upper layer as described by Larsen in order to reduce the materials needed for the final product and reduce the risk of shorting the gate layers on the side of the stack. See MPEP 2144.
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With respect to claim 2, Hopkins further teaches:
wherein: the landing stack (74 and 70) with the upper layer (74) extends over the stair steps (see Fig. 19).
With respect to claim 3, Hopkins further teaches:
wherein the upper layer (74) is formed of a conductive material (para. 58 “The etch-stop material 72 may comprise any suitable composition(s), and may be insulative, semiconductive or conductive. In some embodiments, the etch-stop material may comprise, consist essentially of, or consist of one or more of aluminum oxide, carbon-doped silicon nitride, silicon and tungsten.”)
With respect to claim 4, Hopkins further teaches:
wherein the upper layer (74) is formed of a same material as the gate layers (22 made of material 26) (para. 58 teaches that 74 may be tungsten, para. 72 teaches that 26 may be tungsten)
With respect to claim 6, Hopkins further teaches:
the spacer isolation structure (102) is disposed in a recessed space (cavities 99) of the upper layer (74) from a sidewall (disposed along all sidewalls) of the first contact hole (78) (see Fig. 16).
With respect to claim 7, Hopkins further teaches:
Wherein the first portion of the isolation layer (70) is at least partially disposed on a riser sidewall (disposed on sidewalls of steps 66) from the first stair step (step furthest to the right) to a second stair step (step second from the right),
the first portion isolating the upper layer from a second gate layer of the second stair step (70 is between the gate 22 and 74)
With respect to claim 8, Hopkins further teaches:
the second portion of the isolation layer (see annotated Fig. 19 above) is disposed on a sidewall of multiple gate layers and insulating layers (second portion is on sidewall in part on the left where there are no stairs).
With respect to claim 9, Hopkins further teaches:
wherein the isolation layer (70 and 74) extends over the stair steps (steps 66 in staircase) (Fig. 19).
With respect to claim 10, Hopkins further teaches:
wherein the isolation layer (70 and 74) is formed on an insulating layer (24 made of material 28) above the first gate layer (bottommost 22).
With respect to claim 11, Hopkins further teaches:
wherein a material of the upper layer (74) is tungsten (para. 58 “The etch-stop material 72 may comprise any suitable composition(s), and may be insulative, semiconductive or conductive. In some embodiments, the etch-stop material may comprise, consist essentially of, or consist of one or more of aluminum oxide, carbon-doped silicon nitride, silicon and tungsten.”)
With respect to claim 25, Hopkins further teaches:
wherein a material of the upper layer (74) is tungsten (para. 58 “The etch-stop material 72 may comprise any suitable composition(s), and may be insulative, semiconductive or conductive. In some embodiments, the etch-stop material may comprise, consist essentially of, or consist of one or more of aluminum oxide, carbon-doped silicon nitride, silicon and tungsten.”)
With respect to claim 29, Hopkins further teaches:
further comprising: contact structures (interconnects 42 made from conductive material 96),
wherein each contact structure of the contact structures (42/96) is formed on a respective stair step of the stair steps (see Fig. 19),
extends through a respective contact hole (openings 78 as shown in Fig. 18) in the contact isolation layer (76) and the landing stack (74 and 70) and is connected with a respective gate layer (22 made from material 26) of the first stair step:
and spacer isolation structures (spacers 102),
wherein each spacer isolation structure of the spacer isolation structures surrounds exactly one respective contact structure (one spacer 102 surrounds each contact, see Fig. 19).
With respect to claim 30, Hopkins further teaches:
further comprising: contact structures (interconnects 42 made from conductive material 96),
wherein each contact structure of the contact structures (42/96) is formed on a respective stair step of the stair steps (see Fig. 19),
extends through a respective contact hole (openings 78 as shown in Fig. 18) in the contact isolation layer (76) and the landing stack (74 and 70) and is connected with a respective gate layer (22 made from material 26) of the first stair step:
and spacer isolation structures (spacers 102),
wherein each spacer isolation (102) structure of the spacer isolation structures is disposed between the upper layer (74) and exactly one respective contact structure (42/96), and isolates the upper layer from the exactly one respective contact structure.
With respect to claim 31, Hopkins further teaches:
wherein a width of the spacer isolation structure in the horizontal plane increases before decreasing along a longitudinal direction of the first contact structure. (see Fig. 19, 102 is rounded and is thinnest at the top and bottom, increasing and then decreasing while moving up through the structure)
With respect to claim 32, Hopkins further teaches:
wherein the spacer isolation structure has a middle portion sandwiched by a top portion and a bottom portion, and the middle portion is wider than the top portion and the bottom portion along a longitudinal direction of the first contact structure. (see Fig. 19, 102 is rounded and is thinnest at the top and bottom, increasing and then decreasing while moving up through the structure)
With respect to claim 20, Hopkins teaches in Fig. 19:
A memory system device, comprising: a controller (para. 91 “The conductive interconnects 42 of FIG. 19 may be coupled with driver circuitry 62 analogous to that shown in FIG. 6.”) coupled to a semiconductor memory device (integrated assembly 10) to control data storage operation on the semiconductor memory device; and
the semiconductor memory device (10) comprising:
a memory stack of gate layers (stack 20 including levels 22 that comprise conductive materials 26) and insulating layers (levels 24 that include insulative material 28),
the gate layers (22) and the insulating layers (24) being stacked alternatingly and being formed into stair steps in a staircase region (“staircase (14)”) (Fig. 19);
a landing stack (liner material 70 and etch stop material 72 that forms etch stop structure 74) formed on the stair steps in the staircase region,
the landing stack comprising an upper layer (74) that is etch selective to a contact isolation layer (fill material 76) that covers the staircase region;
and a first contact structure (interconnects 42 made from conductive material 96) on a first stair step (one of the stair steps corresponding to the first contact structure) of the stair steps,
the first contact structure (42/96) extending through a first contact hole in the contact isolation layer (openings 78) and the landing stack (74 and 70) and being connected with a first gate layer (each contact extends to a layer 22) of the first stair step.
a spacer isolation structure (contact spacer 195) disposed between the upper layer (165) and the first contact structure (one of 197),
the spacer isolation structure isolating the upper layer from the first contact structure (para. 66 “The second etch-stop layer pattern 165 and the contact 197 may be insulated from each other by the contact spacer 195”),
the spacer isolation structure (spacer 102) completely surrounded by the upper layer (74) in a horizontal plane perpendicular to the first contact structure (42/96).
wherein the landing stack (74 and 70) further comprises an isolation layer (70) that extends over the stair steps
and includes a first portion disposed below the upper layer (horizontal portions of 70 and portions on step sidewalls are below 74)
and a second portion (see annotated Fig. 19 below)
Hopkins fails to teach:
and a second portion disposed above an entirety of the upper layer.
Larsen teaches a similar structure in which a dielectric structure 122 analogous to the upper layer is formed over a liner layer 120 analogous to the isolation layer employed to form contact openings filled with contact structures 146. Larsen teaches in para. 47 that “dielectric structures 122 may be formed to discontinuously extend on or over portions of the dielectric liner material 120 within horizontal boundaries of the stadium structures 110.”
Combining the teaching of Hopkins with the teaching of Larsen that the upper layer is only needed in areas where contacts are formed, it would be obvious to remove the portion of 74 in Hopkins along the second portion of the isolation structure as defined in annotated Fig. 19 below because that portion of the layer does not include any areas in which contact holes are defined, meeting the limitation:
and a second portion disposed above an entirety of the upper layer.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify Hopkins to remove an unnecessary portion of the upper layer as described by Larsen in order to reduce the materials needed for the final product and reduce the risk of shorting the gate layers on the side of the stack. See MPEP 2144.
With respect to claim 26, Hopkins further teaches:
wherein: the landing stack (74 and 70) with the upper layer (74) extends over the stair steps (see Fig. 19).
With respect to claim 27, Hopkins further teaches:
wherein the upper layer (74) is formed of a conductive material (para. 58 “The etch-stop material 72 may comprise any suitable composition(s), and may be insulative, semiconductive or conductive. In some embodiments, the etch-stop material may comprise, consist essentially of, or consist of one or more of aluminum oxide, carbon-doped silicon nitride, silicon and tungsten.”)
With respect to claim 33, Hopkins further teaches:
wherein a width of the spacer isolation structure in the horizontal plane increases before decreasing along a longitudinal direction of the first contact structure. (see Fig. 19, 102 is rounded and is thinnest at the top and bottom, increasing and then decreasing while moving up through the structure)
With respect to claim 34, Hopkins further teaches:
wherein the spacer isolation structure has a middle portion sandwiched by a top portion and a bottom portion, and the middle portion is wider than the top portion and the bottom portion along a longitudinal direction of the first contact structure. (see Fig. 19, 102 is rounded and is thinnest at the top and bottom, increasing and then decreasing while moving up through the structure)
Response to Arguments
Applicant’s arguments with respect to claims 1 and 20 and their dependents have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to AARON MICHAEL WEGNER whose telephone number is (571)270-7647. The examiner can normally be reached Mon-Fri 8:30 AM - 5 PM.
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/A.M.W./Examiner, Art Unit 2897
/JACOB Y CHOI/Supervisory Patent Examiner, Art Unit 2897