# US 12,765,408 B2 · Method of manufacturing an interconnect structure with a metal cap

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- Number: US 12,765,408 B2
- Document ID: US12765408B2
- Status: Granted
- Kind: B2
- Application number: 18/429,708
- Filed: 2024-02-01
- Published: 2024-05-23
- Granted: 2026-10-13
- Earliest claimed: 2021-03-12
- Assignees: Taiwan Semiconductor Manufacturing Company, Ltd.
- Applicants: Taiwan Semiconductor Manufacturing Company, Ltd.
- Inventors: Chun-Hsien Huang; Peng-Fu Hsu; Yu-Syuan Cai; Min-Hsiu Hung; Chen-Yuan Kao; Ken-Yu Chang; Chun-I Tsai; Chia-Han Lai; Chih-Wei Chang; Ming-Hsing Tsai
- Web page: https://patentgrep.com/patent/US12765408B2

## CPC

- H10W 70/685: comprising multiple insulating layers
- H10W 70/042: {Etching}
- H10W 70/65: Shapes or dispositions of interconnections
- H10W 72/352: {comprising metals or metalloids, e.g. solders}
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10

## Abstract

In some implementations, one or more semiconductor processing tools may form a metal cap on a metal gate. The one or more semiconductor processing tools may form one or more dielectric layers on the metal cap. The one or more semiconductor processing tools may form a recess to the metal cap within the one or more dielectric layers. The one or more semiconductor processing tools may perform a bottom-up deposition of metal material on the metal cap to form a metal plug within the recess and directly on the metal cap.

## Claims

### Claim 1

A method, comprising:
depositing a metal cap on a first conductive structure in a first dielectric layer, wherein an upper surface of the metal cap is coplanar with an upper surface of the first dielectric layer, and wherein an entire surface of sidewalls of the metal cap is surrounded by the first dielectric layer;
depositing one or more second dielectric layers on the metal cap;
partially removing a portion of the one or more second dielectric layers to form a recess; and
performing a bottom-up deposition of a metallic material of the metal cap to form a second conductive structure within the recess and directly on the metal cap, wherein a width of the second conductive structure is equal to a width of the first conductive structure.

### Claim 2 (depends on 1)

The method of claim 1,
wherein depositing the one or more second dielectric layers on the metal cap includes:
depositing an etch stop layer, and
wherein partially removing the portion of the one or more second dielectric layers comprises:
etching the one or more second dielectric layers until detecting the etch stop layer.

### Claim 3 (depends on 1)

The method of claim 1,
wherein performing the bottom-up deposition comprises:
selectively growing the metallic material of the metal cap.

### Claim 4 (depends on 3)

The method of claim 3,
wherein selectively growing the metallic material comprises one or more of:
performing a chemical vapor deposition, or
performing an atomic layer deposition.

### Claim 5 (depends on 3)

The method of claim 3,
wherein selectively growing the metallic material comprises:
selectively etching the metallic material, and depositing the metallic material, in an alternating sequence.

### Claim 6 (depends on 1)

The method of claim 1, further comprising:
depositing, before forming the second conductive structure, a hydrophobic material on the one or more second dielectric layers.

### Claim 7

A method, comprising:
depositing a first conductive structure in a recess of a first dielectric layer;
depositing a metal cap on the first conductive structure, wherein an upper surface of the metal cap is coplanar with an upper surface of the first dielectric layer, wherein the metal cap substantially overlaps an entire top surface of the first conductive structure, and wherein an entire surface of sidewalls of the metal cap is surrounded by the first dielectric layer;
depositing a second dielectric layer on the first dielectric layer and on the metal cap;
depositing a third dielectric layer on the second dielectric layer; and
forming a second conductive structure on the metal cap, wherein a width of the second conductive structure is equal to a width of the first conductive structure.

### Claim 8 (depends on 7)

The method of claim 7,
wherein the sidewalls of the metal cap are aligned with sidewalls of the first conductive structure.

### Claim 9 (depends on 8)

The method of claim 8,
wherein sidewalls of the second conductive structure are in direct contact and aligned with the sidewalls of the metal cap.

### Claim 10 (depends on 7)

The method of claim 7,
wherein forming the second dielectric layer on the first dielectric layer comprises:
depositing the second dielectric layer on the first dielectric layer and the metal cap, and
removing a portion of the second dielectric layer that resides on the metal cap,
wherein the second dielectric layer resides outside of the metal cap.

### Claim 11 (depends on 7)

The method of claim 7,
wherein the second conductive structure is formed within the third dielectric layer.

### Claim 12 (depends on 7)

The method of claim 7, further comprising:
depositing a hydrophobic material on the third dielectric layer.

### Claim 13

A method, comprising:
forming a recess in a first dielectric layer;
forming a first conductive structure in the recess;
depositing a metal cap on the first conductive structure and within the recess,
wherein an upper surface of the metal cap is coplanar with an upper surface of the first dielectric layer,
wherein sidewalls of the metal cap are aligned with sidewalls of the first conductive structure, and
wherein an entire surface of the sidewalls of the metal cap is surrounded by the first dielectric layer;
forming a second dielectric layer on the first dielectric layer and around the metal cap; and
forming a second conductive structure on the metal cap and in the second dielectric layer,
wherein sidewalls of the second conductive structure are in direct contact and aligned with the sidewalls of the metal cap,
wherein a width of the second conductive structure is equal to a width of the first conductive structure, and
wherein an upper surface of the second conductive structure resides above an upper surface the second dielectric layer.

### Claim 14 (depends on 13)

The method of claim 13,
wherein the second conductive structure is formed using a bottom-up metal-on-metal deposition.

### Claim 15 (depends on 14)

The method of claim 14,
wherein the bottom-up metal-on-metal deposition comprises selectively growing a metallic material of the metal cap to form the second conductive structure.

### Claim 16 (depends on 13)

The method of claim 13,
wherein the metal cap comprises one or more of: a titanium-based material, a cobalt-based material, a nickel-based material, a ruthenium-based material, a tantalum-based material, a tungsten-based material, and a platinum-based material.

### Claim 17 (depends on 13)

The method of claim 13,
wherein the second conductive structure has a width that is less than approximately 13 nanometers.

### Claim 18 (depends on 13)

The method of claim 13,
wherein the second conductive structure includes a tungsten-based structure.

### Claim 19 (depends on 18)

The method of claim 18,
wherein a concentration of tungsten at a lower portion of the tungsten-based structure is smaller than a concentration of tungsten at an upper portion of the tungsten-based structure.

### Claim 20 (depends on 13)

The method of claim 13, wherein forming the second dielectric layer comprises:
depositing the second dielectric layer on the first dielectric layer and the metal cap; and
removing a portion of the second dielectric layer on the metal cap.