KR-102964798-B1 - Three-dimensional memory device including trench bridge structures having different volumes and methods for forming the same

KR102964798B1KR 102964798 B1KR102964798 B1KR 102964798B1KR-102964798-B1

Abstract

A three-dimensional memory device comprises: at least one alternating stack of insulating layers and electrically conductive layers; memory openings extending vertically through at least one alternating stack; memory opening filling structures located within the memory openings; and a laterally extending trench filling structure comprising a first type dielectric bridge structure having a first volume, a second type dielectric bridge structure having a second volume larger than the first volume, and a trench dielectric material portion, in contact with a first longitudinal sidewall of at least one alternating stack.

Inventors

위, 지신
마쓰노, 코이치
라시디, 세예드 에흐산 에스파하니
에스마일리, 에흐산
알스마이어, 요한

Assignees

샌디스크 테크놀로지스 아이엔씨.

Dates

Publication Date: 20260513
Application Date: 20240108
Priority Date: 20230815

Claims (20)

As a three-dimensional memory device, At least one alternating stack of insulating layers and electrically conductive layers having a first longitudinal sidewall and a second longitudinal sidewall extending laterally along a first horizontal direction; Memory openings extending vertically through at least one alternating stack; Memory opening filling structures located within the memory openings - each of the memory opening filling structures comprises a vertical semiconductor channel and a vertical stack of memory elements located at the levels of the electrically conductive layers -; and The first lateral extension trench filling structure in contact with the first longitudinal sidewall of the at least one alternating stack is included, and the first lateral extension trench filling structure is: A first type dielectric bridge structure having a first volume; A second type dielectric bridge structure having a second volume larger than the first volume; and It includes a first trench dielectric material portion, A three-dimensional memory device in which the first type dielectric bridge structure and the second type dielectric bridge structure are located on the first trench dielectric material portion.
A three-dimensional memory device according to claim 1, wherein the second type dielectric bridge structure has a greater vertical thickness than the first type dielectric bridge structure.
In paragraph 2, The above-described first type dielectric bridge structure has a first upper surface located within a first horizontal plane and a first lower surface vertically spaced from the first horizontal plane by a first vertical distance; The above-mentioned second type dielectric bridge structure has a second upper surface located within the first horizontal plane and a second lower surface vertically spaced from the first horizontal plane by a second vertical distance greater than the first vertical distance; A three-dimensional memory device comprising: a first trench dielectric material portion comprising an uppermost surface segment located within the first horizontal plane between the first type dielectric bridge structure and the second type dielectric bridge structure, a first recessed surface segment in contact with the first bottom surface, and a second recessed surface segment in contact with the second bottom surface.
In claim 1, the first lateral extension trench filling structure is: A plurality of first-type dielectric bridge structures having the first volume and the first pitch; and A three-dimensional memory device comprising a plurality of second-type dielectric bridge structures having a second volume larger than the first volume and a second pitch different from the first pitch.
A three-dimensional memory device according to claim 1, wherein the second type dielectric bridge structure has at least one of a larger horizontal length along the first horizontal direction or a larger horizontal width along the second horizontal direction perpendicular to the first horizontal direction than the first type dielectric bridge structure.
A three-dimensional memory device according to claim 1, further comprising at least one inverse-step dielectric material portion embedded within the at least one alternating stack and each comprising a dielectric material, wherein one of the at least one inverse-step dielectric material portion contacts each of the first type dielectric bridge structure, the second type dielectric bridge structure, and the first trench dielectric material portion.
In paragraph 6, The above at least one alternating stack includes a staircase having stepped surfaces; The above stepped surfaces are in contact with the stepped bottom surfaces of the at least one inversely stepped dielectric material portion; The above-mentioned step section includes respective longitudinal sidewalls in contact with the first lateral extension trench filling structure; The above memory opening filling structures are located within a first memory array region and within a second memory array region; The above-mentioned step portion is located between the first memory array region and the second memory array region; The electrically conductive layers are continuously extended from the first memory array region to the second memory array region; The above-mentioned first type dielectric bridge structure is positioned laterally adjacent to the upper part of the above-mentioned staircase; The above-described second type dielectric bridge structure is a three-dimensional memory device located laterally adjacent to the lower part of the above-described staircase.
A three-dimensional memory device according to claim 6, further comprising layer contact via structures that extend vertically through at least one inverse-stepped dielectric material portion and contact the top surface of each electrically conductive layer within at least one alternating stack.
In claim 6, the three-dimensional memory device wherein at least one inverse-step dielectric material portion is laterally spaced from the second longitudinal sidewall.
A three-dimensional memory device according to claim 6, wherein the first laterally extended trench filling structure further comprises an additional first type dielectric bridge structure that is laterally spaced from the first type dielectric bridge structure and the second type dielectric bridge structure and does not come into direct contact with any electrically conductive layer within the at least one alternating stack or the at least one inversely stepped dielectric material portion.
In claim 6, the at least one inverse-step dielectric material portion comprises two or more inverse-step dielectric material portions, and the two or more inverse-step dielectric material portions are: The lowest inverse-step dielectric material portion; and A three-dimensional memory device comprising a top inverted-stepped dielectric material portion that is placed on top of the bottom inverted-stepped dielectric material portion and contacts each of the first type dielectric bridge structure, the second type dielectric bridge structure, and the first trench dielectric material portion.
In Paragraph 11, The above-mentioned first-type dielectric bridge structure does not come into contact with any of the above-mentioned two or more inverse-stepped dielectric material parts; The above-mentioned second-type dielectric bridge structure is in contact with the above-mentioned uppermost inverse-stepped dielectric material portion; A three-dimensional memory device in which the first trench dielectric material portion contacts each of the two or more inverse-step dielectric material portions.
A three-dimensional memory device according to claim 1, wherein the first laterally extended trench filling structure further comprises a third type dielectric bridge structure having a third volume larger than the second volume.
In claim 1, the second lateral extension trench filling structure further comprises a second longitudinal sidewall in contact with the second longitudinal sidewall of the at least one alternating stack and including additional dielectric bridge structures, wherein each of the additional dielectric bridge structures within the second lateral extension trench filling structure has the first volume. Each of the above additional dielectric bridge structures has the same vertical thickness, horizontal length, and horizontal width as each of the above first type dielectric bridge structures; A three-dimensional memory device comprising a second laterally extended trench filling structure in contact with each of the additional dielectric bridge structures and a second trench dielectric material portion having the same material composition as the first trench dielectric material portion.
As a three-dimensional memory device, At least one alternating stack of insulating layers and electrically conductive layers having a first longitudinal sidewall and a second longitudinal sidewall extending laterally along a first horizontal direction; Memory openings extending vertically through at least one alternating stack; Memory opening filling structures located within the memory openings - each of the memory opening filling structures comprises a vertical semiconductor channel and a vertical stack of memory elements located at the levels of the electrically conductive layers -; and The first lateral extension trench filling structure in contact with the first longitudinal sidewall of the at least one alternating stack is included, and the first lateral extension trench filling structure is: First trench dielectric material portion; A plurality of first type dielectric bridge structures having a first volume and a first pitch; and It includes a plurality of second type dielectric bridge structures having a second volume larger than the first volume and a second pitch different from the first pitch, and A three-dimensional memory device in which the first type dielectric bridge structures and the second type dielectric bridge structures are located on the first trench dielectric material portion.
As a method for forming a three-dimensional memory device, A step of forming at least one vertical alternating sequence of insulating layers and sacrificial material layers on a substrate; A step of forming memory openings by passing through at least one vertical alternating sequence; Step of forming memory opening filling structures within the memory openings - each of the memory opening filling structures comprises a vertical semiconductor channel and a vertical stack of memory elements -; A step of forming lateral extension trenches by passing through at least one vertical alternating sequence above - the lateral extension trenches include a first lateral extension trench and a second lateral extension trench -; A step of forming a first sacrificial lateral extension trench filling structure and a second sacrificial lateral extension trench filling structure in the first lateral extension trench and the second lateral extension trench, respectively; A step of forming a first type recess cavity having a first volume and a second type recess cavity having a second volume by recessing portions of a first sacrificial lateral extension trench filling structure - said second volume is larger than said first volume -; A step of forming a first type dielectric bridge structure and a second type dielectric bridge structure in the first type recess cavity and the second type recess cavity, respectively; A step of removing the first sacrificial lateral extension trench filling structure and the second sacrificial lateral extension trench filling structure; and The method includes the step of replacing the remaining portions of the above sacrificial material layers with electrically conductive layers, A method in which the first type recess cavity has a first depth, and the second type recess cavity has a second depth greater than the first depth.
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In Paragraph 16, A step of forming additional recessed cavities by recessing portions of the second sacrificial lateral extension trench filling structure; and A method further comprising the step of forming additional dielectric bridge structures within the additional recess cavities, wherein each dielectric bridge structure formed within the second lateral extension trench has the same vertical range as the first depth.
In Paragraph 16, The lowest surface of the above-mentioned first-type dielectric bridge structure is formed on a horizontal plane including the upper surface of the uppermost sacrificial material layer of the above-mentioned sacrificial material layers; A method in which the lowest surface of the second type of dielectric bridge structure is formed below the horizontal plane including the upper surface of the uppermost sacrificial material layer.
In Paragraph 16, A step of forming a set of at least one stepped surface by patterning the above at least one vertical alternating sequence; and The method further includes the step of forming at least one inverse-step dielectric material portion on the set of at least one stepped surfaces, and The first lateral extension trench above cuts through at least one inverse-stepped dielectric material portion; The second lateral extension trench is laterally spaced from the at least one inverse-stepped dielectric material portion; The above-mentioned first-type dielectric bridge structure does not come into contact with any of the above-mentioned at least one inverse-step dielectric material portion; A method in which the second type dielectric bridge structure is formed directly above the sidewall of the at least one inverse-step dielectric material portion.

Description

Three-dimensional memory device including trench bridge structures having different volumes and methods for forming the same Cross-reference regarding related applications This application claims the benefit of the entire contents of U.S. Regular Application No. 18/450,150, filed with the U.S. Patent and Trademark Office on August 15, 2023, with the title of the invention “THREE-DIMENSIONAL MEMORY DEVICE INCLUDING TRENCH BRIDGE STRUCTURES HAVING DIFFERENT VOLUMES AND METHODS OF FORMING THE SAME,” which claims priority to U.S. Provisional Application No. 63/467,848 filed on May 19, 2023, and thereby incorporates them by reference for all purposes. Technology field The present disclosure generally relates to the field of semiconductor devices, and in particular, to a three-dimensional memory device comprising trench bridge structures having different volumes and a method of forming the same. Three-dimensional vertical NAND strings with 1 bit per cell are disclosed in the paper by T. Endoh et al. “Novel Ultra High Density Memory With A Stacked-Surrounding Gate Transistor (S-SGT) Structured Cell”, IEDM Proc. (2001) 33-36. According to one aspect of the present disclosure, a three-dimensional memory device comprises: at least one alternating stack of insulating layers and electrically conductive layers having a first longitudinal sidewall and a second longitudinal sidewall extending laterally along a first horizontal direction; memory openings extending vertically through at least one alternating stack; memory opening filling structures located within the memory openings—each of which includes a vertical stack of memory elements located at levels of a vertical semiconductor channel and electrically conductive layers—; and a first laterally extending trench filling structure in contact with the first longitudinal sidewall of at least one alternating stack, wherein the first laterally extending trench filling structure comprises: a first type dielectric bridge structure having a first volume; a second type dielectric bridge structure having a second volume larger than the first volume; and a first trench dielectric material portion. According to another aspect of the present disclosure, a three-dimensional memory device comprises: at least one alternating stack of insulating layers and electrically conductive layers having a first longitudinal sidewall and a second longitudinal sidewall extending laterally along a first horizontal direction; memory openings extending vertically through at least one alternating stack; memory opening filling structures located within the memory openings, each of which comprises a vertical stack of memory elements located at levels of a vertical semiconductor channel and electrically conductive layers; and a first laterally extending trench filling structure in contact with the first longitudinal sidewall of at least one alternating stack, wherein the first laterally extending trench filling structure comprises: a first trench dielectric material portion; a plurality of first type dielectric bridge structures having a first volume and a first pitch; and a plurality of second type dielectric bridge structures having a second volume larger than the first volume and a second pitch smaller than the first pitch. According to another aspect of the present disclosure, a method for forming a three-dimensional memory device comprises: forming at least one vertical alternating sequence of insulating layers and sacrificial material layers on a substrate; forming memory openings through at least one vertical alternating sequence; forming memory opening filling structures within the memory openings, wherein each memory opening filling structure comprises a vertical semiconductor channel and a vertical stack of memory elements; forming lateral extension trenches through at least one vertical alternating sequence, wherein the lateral extension trenches comprise a first lateral extension trench and a second lateral extension trench; and forming a first sacrificial lateral extension trench filling structure and a second sacrificial lateral extension trench filling structure in the first lateral extension trench and the second lateral extension trench, respectively. The method comprises the steps of: forming a first type recess cavity having a first volume and a second type recess cavity having a second volume by recessing portions of a first sacrificial lateral extension trench filling structure, wherein the second volume is larger than the first volume; forming a first type dielectric bridge structure and a second type dielectric bridge structure in the first type recess cavity and the second type recess cavity, respectively; removing the first sacrificial lateral extension trench filling structure and the second sacrificial lateral extension trench filling structure; and replacing the remaining portions of the sacrificial material layers with electrically conductive layers. FIG. 1 is a plan view of