# US 2022/0037205 A1 · Subtractive Line with Damascene Second Line Type

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- Number: US 2022/0037205 A1
- Document ID: US20220037205A1
- Status: Published application
- Kind: A1
- Application number: 16/941,860
- Filed: 2020-07-29
- Published: 2022-02-03
- Earliest claimed: 2020-07-29
- Assignees: International Business Machines Corporation
- Applicants: International Business Machines Corporation
- Inventors: Brent Anderson; Christopher J. Penny; Lawrence A. Clevenger; Nicholas Anthony Lanzillo; Kisik Choi; Robert ROBISON
- Web page: https://patentgrep.com/patent/US20220037205A1

## CPC

- H10W 20/063: {by forming conductive members before forming protective insulating material}
- H10W 20/056: {by filling conductive material into holes, grooves or trenches}
- H10W 20/0633: {using subtractive patterning of the conductive members}
- H10W 20/077: {on sidewalls or on top surfaces of conductors (H10W20/076 takes precedence)}
- H10W 20/089: {using processes for implementing desired shapes or dispositions of the openings, e.g. double patterning}
- H10W 20/435: {Cross-sectional shapes or dispositions of interconnections}
- H10W 20/438: {Interconnections with multiple fill metals, e.g. having different metals in wide and narrow interconnections, or having different metals in vias and in trenches}
- H10W 20/033: {in openings in dielectrics}
- H10W 20/038: {covering conductive structures (H10W20/037 takes precedence)}
- H10W 20/075: {of multilayered thin functional dielectric layers}
- H10W 20/4421: {the principal metal being copper}
- H10W 20/4441: {the principal metal being a refractory metal}
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10

## Abstract

Interconnect structures having subtractive line with damascene second line type are provided. In one aspect, an interconnect structure includes: first metal lines of a first line type disposed on a substrate; and at least one second metal line of a second line type disposed on the substrate between two of the first metal lines, wherein the first line type includes subtractive lines and the second line type includes damascene lines such that the first metal lines have a different metallization structure from the at least one second metal line. A method of forming an interconnect structure is also provided.

## Claims

### Claim 1

An interconnect structure, comprising:
first metal lines of a first line type disposed on a substrate; and
at least one second metal line of a second line type disposed on the substrate between two of the first metal lines, wherein the first line type comprises subtractive lines and the second line type comprises damascene lines such that the first metal lines have a different metallization structure from the at least one second metal line.

### Claim 2 (depends on 1)

The interconnect structure of claim 1, wherein the first metal lines comprise a metal selected from the group consisting of: cobalt (Co), ruthenium (Ru), tungsten (W), and combinations thereof, and wherein the at least one second metal line comprises a metal selected from the group consisting of: copper (Cu), Co, Ru, W, and combinations thereof.

### Claim 3 (depends on 1)

The interconnect structure of claim 1, wherein the different metallization structure comprises the first metal lines having at least one different metal from the at least one second metal line.

### Claim 4 (depends on 1)

The interconnect structure of claim 1, wherein the different metallization structure comprises a width W1′ of the first metal lines being different from a width W2′ of the at least one second metal line.

### Claim 5 (depends on 4)

The interconnect structure of claim 4, wherein W1′>W2′.

### Claim 6 (depends on 1)

The interconnect structure of claim 1, wherein the different metallization structure comprises the first metal lines having a different line height from the at least one second metal line.

### Claim 7 (depends on 1)

The interconnect structure of claim 1, further comprising:
spacers separating the first metal lines from the at least one second metal line.

### Claim 8 (depends on 7)

The interconnect structure of claim 7, wherein the spacers comprise a material selected from the group consisting of: silicon nitride (SiN), silicon oxynitride (SiON), silicon carbide nitride (SiCN), silicon oxide (SiOx), silicon carbide (SiC), silicon oxycarbide (SiCO), and combinations thereof.

### Claim 9 (depends on 7)

The interconnect structure of claim 7, wherein the spacers are bilayer spacers each comprising:
a first dielectric along a sidewall of the first metal lines; and
a second dielectric along a sidewall of the at least one second metal line.

### Claim 10 (depends on 1)

The interconnect structure of claim 1, wherein the different metallization structure comprises:
a barrier layer present only at a bottom of the first metal lines.

### Claim 11 (depends on 1)

The interconnect structure of claim 1, wherein the different metallization structure comprises:
a first barrier layer present only at a bottom of the first metal lines; and
a second barrier layer present at a bottom and along sidewalls of the at least one second metal line.

### Claim 12 (depends on 1)

The interconnect structure of claim 1, further comprising:
a capping layer disposed on the first metal lines.

### Claim 13 (depends on 12)

The interconnect structure of claim 12, wherein top surfaces of the at least one second metal line and the capping layer are coplanar.

### Claim 14 (depends on 1)

The interconnect structure of claim 1, wherein the different metallization structure comprises a bottom of the first metal lines being offset from a bottom of the at least one second metal line.

### Claim 15

A method of forming an interconnect structure, the method comprising:
depositing a metal layer onto a substrate;
subtractive patterning the metal layer into first metal lines; and
forming at least one second metal line between two of the first metal lines using a damascene process.

### Claim 16 (depends on 15)

The method of claim 15, further comprising:
forming spacers alongside the first metal lines with a first trench present between the spacers; and
forming the at least one second metal lines in the first trench such that the spacers separate the first metal lines from the at least one second metal line.

### Claim 17 (depends on 16)

The method of claim 16, wherein the spacers comprise sacrificial spacers, and wherein the method further comprises:
selectively removing the sacrificial spacers to form second trenches in between the first metal lines and the at least one second metal line; and
forming replacement spacers in the second trenches.

### Claim 18 (depends on 16)

The method of claim 16, further comprising:
depositing a first barrier layer onto the substrate such that the metal layer is deposited onto the substrate over the first barrier layer, wherein following the subtractive patterning of the metal layer into the first metal lines, the first barrier layer is present only at a bottom of the first metal lines.

### Claim 19 (depends on 18)

The method of claim 18, further comprising:
depositing a second barrier layer into and lining the first trenches, wherein, following the forming of the at least one second metal lines in the first trench, the second barrier layer present at a bottom and along sidewalls of the at least one second metal line.

### Claim 20 (depends on 15)

The method of claim 15, further comprising:
depositing a capping layer onto the metal layer, wherein following the subtractive patterning of the metal layer into the first metal lines, the capping layer is present on each of the first metal lines.