CN-121999814-A - Single etching and buttress merging method for unit and comb-shaped features

Abstract

The present application relates to a single etch and buttress merge method for cell and comb features. One or more pillars and one or more piers of the memory array may be patterned, aligned, and formed in one processing step. For example, the one or more piers and the one or more pillars may be patterned and etched using pillar shapes to form a set of pillar cavities. The first subset of pillar cavities may be etched such that adjacent pairs of pillar cavities merge to form buttress cavities, the buttress cavities being filled with a first material and a liner to form the one or more buttresses. A second subset of the post cavities may be filled with the liner and the first material to form the one or more posts. Comb-like edge structures may be formed based on a third subset of the strut cavities.

Inventors

• F. M. Goodall
• T. J. Prested

Assignees

• 美光科技公司

Dates

Publication Date

20260508

Application Date

20251105

Priority Date

20251029

Claims (20)

1. 1. An apparatus, comprising: A substrate; A material stack comprising alternating layers of a first material and a second material; A plurality of buttresses extending through the stack of materials, wherein each buttress of the plurality of buttresses is positioned over a third material that extends into the substrate; A plurality of pillars extending through the stack of materials, wherein each pillar of the plurality of pillars is positioned over a fourth material extending into the substrate, and A plurality of comb edge structures extending through the stack of materials, wherein each comb edge structure of the plurality of comb edge structures is positioned above the third material, and wherein a portion of the first material extends at least partially into a respective buttress, a respective pillar, and a respective comb edge structure at each layer of the first material in the stack of materials.
2. 2. The apparatus of claim 1, wherein the plurality of comb edge structures comprises a first comb edge structure and a second comb edge structure, the plurality of struts and the plurality of buttresses being positioned between the first comb edge structure and the second comb edge structure.
3. 3. The apparatus of claim 1, wherein the plurality of comb edge structures form boundaries of one or more comb structures, the one or more comb structures corresponding to one or more word lines.
4. 4. The apparatus of claim 1, wherein a first leg and a second leg of the plurality of legs are separated by a leg of the plurality of legs.
5. 5. The apparatus of claim 1, wherein each of the plurality of struts comprises the first material and a liner.
6. 6. The apparatus of claim 5, wherein the liner comprises a silicon carbon nitride material.
7. 7. The apparatus of claim 1, wherein the first material comprises a nitride material and the second material comprises an oxide material.
8. 8. The apparatus of claim 1, wherein the third material comprises an alumina material or a tungsten material and the fourth material comprises a polysilicon material.
9. 9. A method, comprising: forming a plurality of post cavities through a material stack comprising alternating layers of a first material and a second material, the plurality of post cavities comprising a first set of post cavities associated with one or more comb-like edge structures, a second set of post cavities associated with one or more buttresses, and a third set of post cavities associated with one or more posts; Depositing a liner and the first material in each of the plurality of post cavities to form the one or more posts within the third set of post cavities, the liner comprising a third material; Applying a first masking material to the one or more struts; removing the liner and the first material in the first set of post cavities based at least in part on the first masking material; removing the liner and the first material in the second set of post cavities based at least in part on the first masking material; Depositing a fourth material in the first set of post cavities to form the one or more comb-like edge structures, and Depositing a fifth material in the second set of strut cavities to form the one or more piers.
10. 10. The method as recited in claim 9, further comprising: Applying a second masking material to the one or more buttresses, and The liner and the first material of the one or more struts are removed based at least in part on the second masking material, wherein the one or more struts are coupled with the one or more piers based at least in part on removing the liner and the first material of the one or more struts.
11. 11. The method as recited in claim 9, further comprising: Removing at least a portion of the second material in the first set of post cavities based at least in part on removing the liner and the first material in the first set of post cavities; removing at least a portion of the second material in the second set of post cavities based at least in part on removing the liner and the first material in the second set of post cavities; Merging two or more adjacent strut cavities in the first set of strut cavities based at least in part on removing the portion of the second material in the first set of strut cavities, wherein the one or more comb-like edge structures are formed based at least in part on merging the two or more adjacent strut cavities, and Adjacent strut cavities in the second set of strut cavities are merged based at least in part on removing the portion of the second material in the second set of strut cavities, wherein the one or more buttresses are formed based at least in part on merging the adjacent strut cavities.
12. 12. The method as recited in claim 11, further comprising: removing at least a portion of the first material in the second set of post cavities, wherein merging the adjacent post cavities is based at least in part on removing the portion of the first material.
13. 13. The method of claim 11, wherein the portion of the second material is removed via a buffered oxide etch process.
14. 14. The method of claim 9, wherein removing the liner and the first material comprises: removing the first material in the first set of post cavities and the second set of post cavities via a first etching process, and The liner is removed via a second etch process.
15. 15. The method according to claim 14, wherein: The first etching process is associated with a wet etching process or a vapor etching process, and The second etching process is associated with the vapor phase etching process.
16. 16. The method as recited in claim 9, further comprising: one or more comb structures are formed based at least in part on forming the one or more comb edge structures, wherein the one or more comb structures correspond to one or more word lines.
17. 17. The method of claim 9, wherein the first material in the first set of post cavities and the liner layer and the first material in the second set of post cavities are removed simultaneously.
18. 18. The method of claim 9, wherein the first material comprises a nitride material and the second material comprises an oxide material.
19. 19. The method of claim 9, wherein the third material comprises a silicon carbon nitride material and the fourth material comprises a dielectric material.
20. 20. An apparatus, comprising: One or more struts; one or more buttresses One or more comb edge structures, wherein the one or more buttresses, the one or more struts, and the one or more comb edge structures are formed by: Forming a plurality of post cavities through a material stack comprising alternating layers of a first material and a second material, the plurality of post cavities comprising a first set of post cavities associated with the one or more comb-like edge structures, a second set of post cavities associated with the one or more piers, and a third set of post cavities associated with the one or more posts; Depositing a liner and the first material in each of the plurality of post cavities to form the one or more posts within the third set of post cavities, the liner comprising a third material; Applying a first masking material to the one or more pillars, removing the liner and the first material in the first set of pillar cavities and the second set of pillar cavities based at least in part on the first masking material, and A fourth material is deposited in the first set of strut cavities to form the one or more comb-like edge structures and a fifth material is deposited in the second set of strut cavities to form the one or more piers.

Description

Single etching and buttress merging method for unit and comb-shaped features Cross reference to U.S. patent application Ser. No. 19/373,370 entitled "Single etching of Unit and comb features and buttress merging method (SINGLE ETCH AND PIER MERGE METHOD FOR CELL AND COMB FEATURES)" filed by Good et al at month 10 of 2025 and U.S. patent application Ser. No. 63/716,589 entitled "Single etching of Unit and comb features and buttress merging method (SINGLE ETCH AND PIER MERGE METHOD FOR CELL AND COMB FEATURES)" filed by Good et al at month 11 of 2024, each of which is assigned to its assignee and each of which is expressly incorporated herein by reference in its entirety. Technical Field The technical field relates to a single etching and buttress merging method for unit and comb-shaped features. Background Memory devices are widely used to store information in devices such as computers, user devices, wireless communication devices, cameras, digital displays, and others. Information is stored by programming memory cells within a memory device to various states. For example, a binary memory cell may be programmed to one of two support states, typically represented by a logic 1 or a logic 0. In some examples, a single memory cell may support more than two states, any of which may be stored. To access the stored information, the memory device may read (e.g., sense, detect, retrieve, determine) the state from the memory cells. To store information, the memory device may write (e.g., program, set, assign) a state to the memory cells. There are various types of memory devices including magnetic hard disks, random Access Memory (RAM), read Only Memory (ROM), dynamic RAM (DRAM), synchronous Dynamic RAM (SDRAM), static RAM (SRAM), ferroelectric RAM (FeRAM), magnetic RAM (MRAM), resistive RAM (RRAM), flash memory, phase Change Memory (PCM), self-selected memory, chalcogenide memory technology, NOR (NOR) and NAND (NAND) memory devices, and others. The memory cells may be described in terms of a volatile configuration or a non-volatile configuration. Memory cells configured in a non-volatile configuration can maintain a stored logic state for long periods of time even in the absence of an external power source. Memory cells configured in a volatile configuration may lose memory state when disconnected from an external power source. Disclosure of Invention An apparatus is described. The apparatus may include a substrate, a material stack including alternating layers of a first material and a second material, a plurality of buttresses extending through the material stack, wherein each buttress of the plurality of buttresses is positioned over a third material extending into the substrate, a plurality of posts extending through the material stack, wherein each post of the plurality of posts is positioned over a fourth material extending into the substrate, and a plurality of comb edge structures extending through the material stack, wherein each comb edge structure of the plurality of comb edge structures is positioned over the third material, and wherein a portion of the first material extends at least partially into a respective buttress, a respective post, and a respective comb edge structure at each layer of the first material in the material stack. A method is described. The method may include forming a plurality of post cavities through a material stack comprising alternating layers of a first material and a second material, the plurality of post cavities including a first set of post cavities associated with one or more comb-like edge structures, a second set of post cavities associated with one or more piers, and a third set of post cavities associated with one or more posts, depositing a liner and the first material in each of the plurality of post cavities to form the one or more posts within the third set of post cavities, the liner including a third material, applying a first masking material to the one or more posts, removing the liner and the first material in the first set of post cavities based at least in part on the first masking material, removing the liner and the first material in the second set of post cavities based at least in part on the first masking material, depositing a fourth material in the first set of post cavities to form the one or more comb-like edge structures, and depositing a fifth material in the second set of post cavities to form the one or more piers. An apparatus is described. The apparatus may include one or more struts, and one or more comb edge structures, wherein the one or more struts, and the one or more comb edge structures are formed by forming a plurality of strut cavities through a stack of material comprising alternating layers of a first material and a second material, the plurality of strut cavities including a first set of strut cavities associated with the one or more comb edge structures, a second set of strut cavities associated with the one or more struts, and a t