# US 12,218,008 B2 · Memory device including self-aligned conductive contacts

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- Number: US 12,218,008 B2
- Document ID: US12218008B2
- Status: Granted
- Kind: B2
- Application number: 18/200,852
- Filed: 2023-05-23
- Published: 2023-10-12
- Granted: 2025-02-04
- Earliest claimed: 2020-12-18
- Assignees: Micron Technology, Inc.
- Applicants: Micron Technology, Inc.
- Inventors: Kar Wui Thong; Harsh Narendrakumar Jain; John Hopkins
- Web page: https://patentgrep.com/patent/US12218008B2

## CPC

- H10B 43/10: characterised by the top-view layout
- H10W 20/069: {by forming self-aligned vias or self-aligned contact plugs}
- H10B 41/27: the channels comprising vertical portions, e.g. U-shaped channels
- H10B 43/27: the channels comprising vertical portions, e.g. U-shaped channels
- H10W 20/0698: {Local interconnections}
- H10W 20/076: {in via holes or trenches}
- H10W 20/083: {the openings being via holes penetrating underlying conductors}
- H10W 20/20: Interconnections within wafers or substrates, e.g. through-silicon vias [TSV]
- H10W 20/42: Vias, e.g. via plugs
- H10W 20/435: {Cross-sectional shapes or dispositions of interconnections}
- H10B: ELECTRONIC MEMORY DEVICES
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10

## Abstract

Some embodiments include apparatuses and methods of forming the apparatuses. One of the apparatuses includes levels of conductive materials interleaved with levels of dielectric materials; memory cell strings including respective pillars extending through the levels of conductive materials and the levels of dielectric materials; a dielectric structure formed in a slit, the slit extending through the levels of conductive materials and the levels of dielectric materials, the dielectric structure separating the levels of conductive materials and the levels of dielectric materials into a first portion and a second portion; first conductive structures located over and coupled to respective pillars of the first memory cell strings; second conductive structures located over and coupled to respective pillars of the second memory cell strings; and a conductive line contacting the dielectric structure, a conductive structure of the first conductive structures, and a conductive structure of the second conductive structures.

## Claims

### Claim 1

A method comprising:
forming levels of first materials interleaved with levels of second materials;
forming memory cell strings including forming respective pillars of the memory cell strings through the levels of first materials and the levels of second materials;
forming conductive structures over the pillars, respectively;
forming a slit after forming conductive structures, the slit dividing the conductive structures into a first portion of the conductive structures and a second portion of the conductive structures, the slit formed through the levels of first materials and the levels of second materials and dividing the levels of first materials and the levels of second materials into a first portion and a second portion, each of the first portion and the second portion including a respective portion of the memory cell strings;
forming a dielectric structure in the slit; and
forming a conductive line over and contacting the dielectric structure, a conductive structure of the first portion of the conductive structures, and a conductive structure of the second portion of the conductive structures.

### Claim 2 (depends on 1)

The method of claim 1, wherein forming the conductive structures includes:
forming a first conductive contact; and
forming a second conductive contact after forming the first conductive contact, the second conductive contact located between the first conductive contact and the conductive line.

### Claim 3 (depends on 2)

The method of claim 2, wherein the first and second conductive contacts include metal.

### Claim 4 (depends on 1)

The method of claim 1, wherein forming the dielectric structure includes:
forming a dielectric material on a first sidewall of the slit and on a second sidewall of the slit, the first and second sidewalls opposite from each other; and
forming an additional material between the dielectric material on the first sidewall of the slit and the dielectric material on the second sidewall of the slit.

### Claim 5 (depends on 1)

The method of claim 1, wherein the levels of first materials include respective levels of first dielectric materials, the levels of second materials include respective levels of second dielectric materials, and the method further comprises:
replacing the levels of first dielectric materials in the first portion and the second portion with respective levels of conductive materials before forming the dielectric structure in the slit, wherein,
the dielectric structure is formed after replacing the levels of first dielectric materials with respective levels of conductive materials, and
the dielectric structure electrically separates the levels of conductive materials in the first portion from the levels of conductive materials in the second portion.

### Claim 6 (depends on 5)

The method of claim 5, further comprising:
forming a staircase structure from a portion of the levels of conductive materials in the first portion;
forming conductive contacts at the staircase structure after forming the conductive structures, the conductive contacts coupled to the levels of conductive materials, respectively, in the first portion at the staircase structure, the conductive contacts having lengths extending in a direction from a first level of the levels of conductive materials in the first portion to a second level of the levels of conductive materials in the first portion; and
forming conductive lines contacting the conductive contacts, respectively.

### Claim 7 (depends on 1)

The method of claim 1, wherein the first materials have different dielectric materials from the second materials.

### Claim 8 (depends on 1)

The method of claim 1, wherein the first materials include silicon nitride.

### Claim 9 (depends on 1)

The method of claim 1, wherein the second materials include silicon dioxide.

### Claim 10

A method comprising:
forming levels of first dielectric materials interleaved with levels of second dielectric materials;
forming memory cell strings including forming respective pillars of the memory cell strings through the levels of first dielectric materials and the levels of second dielectric materials;
forming levels of first additional dielectric materials interleaved with levels of second additional dielectric materials after forming the pillars;
forming conductive structures over the pillars, respectively, and through the levels of first additional dielectric materials and the levels of second additional dielectric materials;
forming a slit after forming the conductive structures, the slit formed through the levels of first additional dielectric materials, the levels of second additional dielectric materials, the levels of first dielectric materials, and the levels of second dielectric materials,
the slit dividing the levels of first dielectric materials and the levels of second dielectric materials into a first portion and a second portion, each of the first portion and the second portion including a respective portion of the memory cell strings,
the slit dividing the levels of first additional dielectric materials and the levels of second additional dielectric materials into a first additional portion and a second additional portion, the first additional portion including a first portion of the conductive structures, the second additional portion including a second portion of the conductive structures;
replacing the levels of first dielectric materials in the first portion and the second portion and the levels of first additional dielectric materials in the first additional portion and the second additional portion with respective levels of conductive materials;
forming a dielectric structure in the slit, the dielectric structure electrically separating the levels of conductive materials in the first portion from the levels of conductive materials in the second portion, the dielectric structure electrically separating the levels of conductive materials in the first additional portion from the levels of conductive materials in the second additional portion; and
forming a conductive line over and contacting the dielectric structure, a conductive structure of the first portion of the conductive structures, and a conductive structure of the second portion of the conductive structures.

### Claim 11 (depends on 10)

The method of claim 10, wherein forming the conductive structures includes:
forming a conductive channel extending through the levels of first additional dielectric materials and the levels of second additional dielectric materials, the conductive channel coupled to a pillar of the pillars;
forming a first conductive contact over and coupled to the conductive channel; and
forming a second conductive contact after the first conductive contact is formed, the second conductive contact coupled between the first conductive contact and the conductive line.

### Claim 12 (depends on 11)

The method of claim 11, wherein the first and second conductive contacts include a same material.

### Claim 13 (depends on 11)

The method of claim 11, wherein the first and second conductive contacts include tungsten.

### Claim 14 (depends on 13)

The method of claim 13, wherein:
the first conductive structure is formed to have a first width; and
the first conductive structure is formed to have a second width, wherein the second width is less than the first width.

### Claim 15 (depends on 13)

The method of claim 13, further comprising:
forming an additional dielectric structure in the first additional portion after forming the dielectric structure in the slit, wherein,
the additional dielectric structure is formed through the levels of first additional dielectric materials in the first additional portion and the levels of conductive materials in the first additional portion, and
the dielectric structure electrically separates a first portion of the levels of conductive materials in the first additional portion from a second portion of the levels of conductive materials in the first additional portion.

### Claim 16 (depends on 10)

The method of claim 10, further comprising:
forming a staircase structure from a portion of the levels of conductive materials in the first portion; and
forming conductive contacts after forming the conductive structures, the conductive contacts coupled to the levels of conductive materials, respectively, of the staircase structure, the conductive contacts having lengths extending in a direction from a first level of the levels of conductive materials to a second level of the levels of conductive materials.

### Claim 17

A method comprising:
forming levels of first dielectric materials interleaved with levels of second dielectric materials;
forming memory cell strings including forming respective pillars of the memory cell strings through the levels of first dielectric materials and the levels of second dielectric materials;
forming conductive structures over the pillars, respectively, including forming respective first conductive contacts of the conductive structures;
forming first openings over the first conductive contacts, such that each of the first openings is vertically aligned with a respective conductive contact of the first conductive contacts;
forming a dielectric material in the first openings;
forming a slit after forming the dielectric material in the first openings, the slit formed through the levels of first dielectric materials and the levels of second dielectric materials, the slit dividing the levels of first dielectric materials and the levels of second dielectric materials into a first portion and a second portion, each of the first portion and the second portion including a respective portion of the memory cell strings,
the slit dividing the first conductive contacts into a first portion of the first conductive contacts and a second portion of the first conductive contacts;
replacing the levels of first dielectric materials in the first portion and the second portion with respective levels of conductive materials;
forming a dielectric structure in the slit, the dielectric structure electrically separating the levels of conductive materials in the first portion from the levels of conductive materials in the second portion;
forming second openings at respective locations of the dielectric material in the first openings to expose the first conductive contacts at the second openings, respectively;
forming second conductive contacts of the conductive structures in the second openings, respectively, the second conductive contacts contacting respective conductive contacts in the first and second portions of the first conductive contacts; and
forming a conductive line over and contacting the dielectric structure, contacting one of the second conductive contacts that contacts a conductive contact of the first portion of the first conductive contacts, and contacting one of the second conductive contacts that contacts a conductive contact of the second portion of the first conductive contacts.

### Claim 18 (depends on 17)

The method of claim 17, wherein forming the dielectric structure includes:
forming a first portion of the dielectric structure, such that the first portion of the dielectric structure includes a top surface at a level below a level of the dielectric material in the first openings; and
forming a second portion of the dielectric structure over the first portion of the dielectric structure, such that the second portion of the dielectric structure includes a top surface at a level above the level of the dielectric material in the first openings.

### Claim 19 (depends on 17)

The method of claim 17, further comprising:
forming a staircase structure from a portion of the levels of conductive materials in the first portion; and
forming additional conductive contacts before forming the second conductive contacts, the additional conductive contacts coupled to the levels of conductive materials in the first portion, respectively, of the staircase structure, the additional conductive contacts having lengths extending in the direction from a first level of the levels of conductive materials in the first portion to a second level of the levels of conductive materials in the first portion, and the additional conductive contacts including respective top surfaces above respective levels of the first conductive contacts.

### Claim 20 (depends on 19)

The method of claim 19, further comprising:
forming additional conductive lines contacting top surfaces, respectively, of the additional conductive contacts.