# US 12,225,720 B2 · Three-dimensional memory device with doped semiconductor bridge structures and methods for forming the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,225,720 B2 - Document ID: US12225720B2 - Status: Granted - Kind: B2 - Application number: 17/530,861 - Filed: 2021-11-19 - Published: 2023-02-23 - Granted: 2025-02-11 - Earliest claimed: 2021-08-19 - Assignees: SanDisk Technologies LLC - Applicants: Sandisk Technologies LLC - Inventors: Ryousuke Itou; Akihisa Sai; Kenzo Iizuka - Web page: https://patentgrep.com/patent/US12225720B2 ## CPC - H10B 41/27: the channels comprising vertical portions, e.g. U-shaped channels - H10B 41/10: characterised by the top-view layout - H10B 43/10: characterised by the top-view layout - H10B 43/27: the channels comprising vertical portions, e.g. U-shaped channels - H10P 50/667: {by liquid etching only} - H10W 20/056: {by filling conductive material into holes, grooves or trenches} - H10W 20/432: {comprising crossing interconnections} - H10W 20/4451: {Semiconductor materials, e.g. polysilicon} - H10B: ELECTRONIC MEMORY DEVICES - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 ## Abstract A vertically alternating sequence of continuous insulating layers and continuous sacrificial material layers is formed over a substrate, and memory opening fill structures including vertical stacks of memory elements are formed through the vertically alternating sequence. Backside trenches are formed to divide the vertically alternating sequence into a plurality of alternating stacks of insulating layers and sacrificial material layers. Bridge structures are formed within each of the backside trenches. The sacrificial material layers are replaced with electrically conductive layers while the bridge structure are present within the backside trenches. ## Claims ### Claim 1 A three-dimensional memory device, comprising: a pair of alternating stacks of insulating layers and electrically conductive layers laterally spaced apart from each other by a backside trench, wherein each of the pair of alternating stacks and the backside trench laterally extend along a first horizontal direction; arrays of memory openings vertically extending through a respective alternating stack among the pair of alternating stacks; arrays of memory openings fill structures located in the arrays of memory openings, wherein each of the memory opening fill structures comprises a respective vertical stack of memory elements; and a backside trench fill structure located within the backside trench and comprising a plurality of bridge structures; wherein each of the plurality of bridge structures includes a doped semiconductor material; and wherein each of the plurality of bridge structures is embedded within a respective dielectric semiconductor oxide liner which comprises a dielectric oxide of the doped semiconductor material. ### Claim 2 (depends on 1) The three-dimensional memory device of claim 1, wherein the plurality of bridge structures comprises: a first bridge structure located at a first vertical distance from a horizontal plane including a top surface of the substrate; and a second bridge structure located at a second vertical distance from the horizontal plane, wherein the second vertical distance is different from the first vertical distance. ### Claim 3 (depends on 2) The three-dimensional memory device of claim 2, wherein the second bridge structure is laterally offset from the first bridge structure along the first horizontal direction. ### Claim 4 (depends on 2) The three-dimensional memory device of claim 2, wherein the second bridge structure does not have any areal overlap with the first bridge structure in a plan view along a vertical direction that is perpendicular to a top surface of the substrate. ### Claim 5 (depends on 1) The three-dimensional memory device of claim 1, wherein: the first bridge structure is located above a horizontal plane including topmost surfaces of the pair of alternating stacks; and the second bridge structure is located below the horizontal plane including the topmost surfaces of the pair of alternating stacks. ### Claim 6 (depends on 5) The three-dimensional memory device of claim 5, further comprising a pair of contact-level dielectric material portions located above a respective alternating stack within the pair of alternating stacks, wherein the first bridge structure has a top surface located within a horizontal plane including top surfaces of the pair of contact-level dielectric material portions. ### Claim 7 (depends on 1) The three-dimensional memory device of claim 1, wherein the doped semiconductor material comprises boron doped silicon. ### Claim 8 (depends on 1) The three-dimensional memory device of claim 1, wherein the plurality of bridge structures comprises three bridge structures located at three different vertical distances from a horizontal plane including a top surface of the substrate. ### Claim 9 (depends on 1) The three-dimensional memory device of claim 1, wherein the backside trench fill structure comprises an insulating backside trench fill material portion embedding each bridge structure of the plurality of bridge structures. ### Claim 10 (depends on 9) The three-dimensional memory device of claim 9, wherein: the backside trench fill structure contacts a respective sidewall of each layer within the pair of alternating stacks; and sidewalls of the insulating backside trench fill material portion contacts a pair of lengthwise sidewalls of the backside trench that laterally extends along the first horizontal direction. ### Claim 11 (depends on 1) The three-dimensional memory device of claim 1, wherein the plurality of bridge structures comprises: a row of first bridge structures that are arranged along the first horizontal direction and located at a first vertical distance from a horizontal plane including a top surface of the substrate; and a row of second bridge structures that are arranged along the first horizontal direction and located at a second vertical distance from the horizontal plane, wherein the second vertical distance is different from the first vertical distance.