# US 10,312,098 B2 · Method of forming an interconnect structure

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,312,098 B2
- Document ID: US10312098B2
- Status: Granted
- Kind: B2
- Application number: 16/049,912
- Filed: 2018-07-31
- Published: 2018-11-22
- Granted: 2019-06-04
- Earliest claimed: 2014-02-07
- Assignees: Taiwan Semiconductor Manufacturing Company, Ltd.
- Applicants: Taiwan Semiconductor Manufacturing Company
- Inventors: Rueijer Lin; Ya-Lien Lee; Chun-Chieh Lin; Hung-Wen Su
- Web page: https://patentgrep.com/patent/US10312098B2

## CPC

- H10P 14/43: Chemical deposition, e.g. chemical vapour deposition [CVD]
- H10W 20/033: {in openings in dielectrics}
- H10W 20/036: {the barrier, adhesion or liner layers being within a main fill metal}
- H10W 20/425: {Barrier, adhesion or liner layers}
- 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

An interconnect structure and a method of forming an interconnect structure are disclosed. The interconnect structure includes a conductive plug over a substrate; a conductive feature over the conductive plug, wherein the conductive feature has a first sidewall, a second sidewall facing the first sidewall, and a bottom surface; and a carbon-containing barrier layer having a first portion along the first sidewall of the conductive feature, a second portion along the second sidewall of the conductive feature, and a third portion along the bottom surface of the conductive feature.

## Claims

### Claim 1

A method of forming an interconnect structure, the method comprising:
depositing a lower dielectric layer over a substrate;
forming a plug hole in the lower dielectric layer;
forming a conductive plug in the plug hole;
depositing an upper dielectric layer over the lower dielectric layer;
forming a trench in the upper dielectric layer and the lower dielectric layer over the conductive plug;
forming a carbon-containing barrier layer along inner surfaces of the trench, wherein the carbon-containing barrier layer extends below an uppermost surface of the conductive plug and seals a void in the conductive plug, wherein the carbon-containing barrier layer completely separates the void from the conductive plug; and
forming a conductive feature in the trench.

### Claim 2 (depends on 1)

The method of claim 1, wherein the forming the carbon-containing barrier layer is performed by atomic layer deposition (ALD), chemical vapor deposition (CVD), or combinations thereof.

### Claim 3 (depends on 1)

The method of claim 1, further comprising forming an etch stop layer over the lower dielectric layer, wherein the upper dielectric layer is formed over the etch stop layer.

### Claim 4 (depends on 1)

The method of claim 1, wherein forming the trench comprises etching the lower dielectric layer.

### Claim 5 (depends on 1)

The method of claim 1, wherein a ratio of a thickness of the carbon-containing barrier layer along a sidewall to a thickness of the carbon-containing barrier layer along a bottom is from 0.9 to 1.1.

### Claim 6 (depends on 1)

The method of claim 1, wherein a thickness of the carbon-containing barrier layer is from 4.5 Angstroms to 55 Angstroms.

### Claim 7

A method of forming an interconnect structure, the method comprising:
depositing a lower dielectric layer over a substrate;
forming a first recess in the lower dielectric layer;
forming a first conductive layer in the first recess, the first conductive layer having a void;
depositing an upper dielectric layer over the lower dielectric layer and the first conductive layer;
forming a second recess in the upper dielectric layer, wherein the second recess exposes the first conductive layer;
after forming the second recess, removing a portion of the first conductive layer to expose the void;
forming a carbon-containing layer along sidewalls of the void; and
forming a second conductive layer over the carbon-containing layer.

### Claim 8 (depends on 7)

The method of claim 7, wherein the carbon-containing layer seals the void.

### Claim 9 (depends on 7)

The method of claim 7, wherein the second conductive layer does not extend into the void.

### Claim 10 (depends on 7)

The method of claim 7, wherein a width of the first recess is less than a width of the second recess.

### Claim 11 (depends on 7)

The method of claim 7, wherein removing a portion of the first conductive layer removes a portion of the lower dielectric layer.

### Claim 12 (depends on 7)

The method of claim 7, wherein the carbon-containing layer completely separates the first conductive layer and the second conductive layer.

### Claim 13 (depends on 7)

The method of claim 7, wherein the void has an elliptical shape.

### Claim 14

A method of forming an interconnect structure, the method comprising:
forming a first dielectric layer;
forming a first recess in the first dielectric layer;
forming a first conductive layer in the first recess, an upper surface of the first conductive layer being level with an uppermost surface of the first dielectric layer, the first conductive layer having a void;
forming a second dielectric layer over the first dielectric layer;
after forming the second dielectric layer, forming a second recess through the second dielectric layer to the first conductive layer, wherein forming the second recess removes at least a portion of the first conductive layer to expose the void;
forming a carbon-containing layer along sidewalls of the second recess and sidewalls of the void; and
forming a second conductive layer over the carbon-containing layer, an upper surface of the second conductive layer and the second dielectric layer being level.

### Claim 15 (depends on 14)

The method of claim 14, wherein the carbon-containing layer comprises tantalum nitride (TaN), and wherein an atomic ratio of N divided by Ta is from about 2.3 to about 2.6.

### Claim 16 (depends on 14)

The method of claim 14, wherein the carbon-containing layer has a carbon concentration from about 0.1 atomic percent (at %) to about 5 atomic percent (at %).

### Claim 17 (depends on 14)

The method of claim 14, wherein the carbon-containing layer comprises a metal or a metal nitride.

### Claim 18 (depends on 14)

The method of claim 14, wherein the carbon-containing layer has a first portion along sidewall of the second recess, a second portion along a bottom of the second recess, and a third portion lining the void, wherein a ratio of a thickness of the first portion to a thickness of the second portion is from about 0.9 to about 1.1.

### Claim 19 (depends on 18)

The method of claim 18, wherein the thickness of the first portion is in a range from about 4.5 angstroms to about 55 angstroms.

### Claim 20 (depends on 18)

The method of claim 18, wherein the thickness of the second portion is in a range from about 5 angstroms to about 50 angstroms.