# US 12,009,293 B2 · Barrier-free interconnect structure and manufacturing method thereof

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- Number: US 12,009,293 B2
- Document ID: US12009293B2
- Status: Granted
- Kind: B2
- Application number: 17/693,925
- Filed: 2022-03-14
- Published: 2022-06-23
- Granted: 2024-06-11
- Earliest claimed: 2019-09-17
- Assignees: Taiwan Semiconductor Manufacturing Company, Ltd.
- Applicants: Taiwan Semiconductor Manufacturing Co., Ltd.
- Inventors: Pei-Yu Wang; Cheng-Ting Chung; Wei Ju Lee
- Web page: https://patentgrep.com/patent/US12009293B2

## CPC

- H10W 20/039: {also covering sidewalls of the conductive structures}
- H10W 20/42: Vias, e.g. via plugs
- H10W 20/034: {bottomless barrier, adhesion or liner layers}
- H10W 20/038: {covering conductive structures (H10W20/037 takes precedence)}
- H10W 20/056: {by filling conductive material into holes, grooves or trenches}
- H10W 20/057: {by selectively depositing, e.g. by using selective CVD or plating}
- H10W 20/074: {of dielectric parts comprising thin functional dielectric layers, e.g. dielectric etch-stop, barrier, capping or liner layers}
- H10W 20/081: {by forming openings in the dielectric parts}
- H10W 20/063: {by forming conductive members before forming protective insulating material}
- H10W 20/077: {on sidewalls or on top surfaces of conductors (H10W20/076 takes precedence)}
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10

## Abstract

Semiconductor devices and method of forming the same are disclosed herein. A semiconductor device according to the present disclosure includes a first dielectric layer having a first top surface and a contact via extending through the first dielectric layer and rising above the first top surface of the first dielectric layer.

## Claims

### Claim 1

A method, comprising:
forming a first dielectric layer over a contact feature using flowable chemical vapor deposition (FCVD) or spin-on coating, the first dielectric layer comprising a first top surface;
forming a contact via extending through the first dielectric layer and having a second top surface above the first top surface of the first dielectric layer;
depositing a barrier layer over the first dielectric layer and the contact via;
planarizing the barrier layer by chemical mechanical polishing to expose the first top surface of the contact via while the first dielectric layer remains covered by the barrier layer; and
after the planarizing, patterning the barrier layer to form a patterned barrier layer and expose a portion of the first dielectric layer.

### Claim 2 (depends on 1)

The method of claim 1, further comprising:
depositing an etch stop layer over the patterned barrier layer and the portion of the first dielectric layer;
depositing a second dielectric layer over the etch stop layer; and
forming a trench through the second dielectric layer and the etch stop layer to expose the first top surface of the contact via.

### Claim 3 (depends on 2)

The method of claim 2, further comprising:
depositing a barrier spacer layer over the trench, including over the second top surface of the contact via; and
removing the barrier spacer layer over the second top surface of the contact via to form a barrier spacer,
wherein the barrier spacer is in contact with the barrier layer.

### Claim 4 (depends on 2)

The method of claim 2, wherein the patterned barrier layer has a first width and the trench has a second width smaller than the first width.

### Claim 5 (depends on 1)

The method of claim 1, where the forming of the contact via comprises:
forming a via opening through the first dielectric layer;
depositing a conductive material in the via opening to form the contact via;
planarizing the contact via and the first dielectric layer; and
selectively etching back the first dielectric layer.

### Claim 6 (depends on 1)

The method of claim 1, wherein the forming of the contact via comprises:
depositing a sacrificial layer over the first dielectric layer;
forming a via opening through the first dielectric layer and the sacrificial layer;
depositing a conductive material in the via opening to form the contact via;
planarizing the contact via and the sacrificial layer; and
removing the sacrificial layer.

### Claim 7 (depends on 6)

The method of claim 6, wherein a composition of the sacrificial layer is different from a composition of the first dielectric layer.

### Claim 8 (depends on 6)

The method of claim 6, wherein the second top surface comprises a convex top surface.

### Claim 9 (depends on 1)

The method of claim 1, wherein the forming of the contact via comprises:
forming a via opening through the first dielectric layer to expose the contact feature; and
selectively depositing a conductive material over the exposed contact feature to form the contact via,
wherein the selectively depositing of the conductive material does not substantially deposit the conductive material over the first top surface of the first dielectric layer.

### Claim 10

A method, comprising:
forming a metal etch stop layer over a contact feature;
forming a first dielectric layer over the metal etch stop layer;
forming a contact via extending through the metal etch stop layer and the first dielectric layer and having a first top surface above a second top surface of the first dielectric layer;
depositing a barrier layer over the first dielectric layer and the contact via;
planarizing the barrier layer to expose the first top surface of the contact via;
depositing an etch stop layer over the barrier layer;
depositing a second dielectric layer over the etch stop layer;
forming a trench through the etch stop layer and the second dielectric layer to expose the first top surface of the contact via; and
depositing a conductive feature in the trench.

### Claim 11 (depends on 10)

The method of claim 10, further comprising:
before the depositing of the conductive feature, depositing a barrier spacer layer over the second dielectric layer and the trench; and
etching back the barrier spacer layer to form a barrier spacer and to expose the first top surface of the contact via.

### Claim 12 (depends on 11)

The method of claim 11,
wherein the contact via comprises tungsten or ruthenium,
wherein the conductive feature comprises copper,
wherein the barrier layer and the barrier spacer comprise tantalum nitride.

### Claim 13 (depends on 10)

The method of claim 10, further comprising:
before the depositing of the etch stop layer, patterning the barrier layer to expose a portion of the first dielectric layer.

### Claim 14 (depends on 13)

The method of claim 13, wherein the etch stop layer is in direct contact with sidewalls of the patterned barrier layer.

### Claim 15 (depends on 10)

The method of claim 10, wherein the forming of the contact via comprises:
forming a via opening through the metal etch stop layer and the first dielectric layer to expose the contact feature; and
selectively depositing a conductive material over the exposed contact feature to form the contact via,
wherein the selectively depositing of the conductive material does not substantially deposit the conductive material over the second top surface of the first dielectric layer.

### Claim 16 (depends on 10)

The method of claim 10, where the forming of the contact via comprises:
forming a via opening through the metal etch stop layer and the first dielectric layer;
depositing a conductive material in the via opening to form the contact via;
planarizing the contact via and the first dielectric layer; and
selectively etching back the first dielectric layer.

### Claim 17

A method, comprising:
receiving a workpiece comprising:
a first etch stop layer, and
a first dielectric layer over the first etch stop layer;
forming a via opening through the first etch stop layer and the first dielectric layer along a vertical direction;
forming a contact via in the via opening such that a top surface of the contact via rises above a top surface of the first dielectric layer;
depositing a barrier layer over the first dielectric layer and the contact via;
planarizing the barrier layer to expose the top surface of the contact via;
patterning the planarized barrier layer such that the patterned barrier layer comprises a circular shape when viewed along the vertical direction;
depositing a second etch stop layer over the patterned barrier layer;
depositing a second dielectric layer over the second etch stop layer;
forming a trench through the etch stop layer and the second dielectric layer to expose the top surface of the contact via and a portion of the second etch stop layer; and
depositing a conductive feature in the trench.

### Claim 18 (depends on 17)

The method of claim 17, wherein the conductive feature spans over the second etch stop layer, the barrier layer, and the top surface of the contact via.

### Claim 19 (depends on 17)

The method of claim 17, further comprising:
before the depositing of the conductive feature, depositing a barrier spacer layer over the trench, including over the second dielectric layer; and
etching back the barrier spacer layer to expose the top surface of the contact via and to form a barrier spacer in contact with the second etch stop layer and the second dielectric layer.

### Claim 20 (depends on 19)

The method of claim 19, wherein, after the etching back, a portion of the barrier layer is exposed in the trench.