# US 12,765,406 B2 · Method of forming redistribution layer structure

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- Number: US 12,765,406 B2
- Document ID: US12765406B2
- Status: Granted
- Kind: B2
- Application number: 17/871,993
- Filed: 2022-07-25
- Published: 2022-11-10
- Granted: 2026-10-13
- Earliest claimed: 2019-10-16
- Assignees: Taiwan Semiconductor Manufacturing Company, Ltd.
- Applicants: Taiwan Semiconductor Manufacturing Company, Ltd.
- Inventors: Hung-Jui Kuo; Hui-Jung Tsai; Jyun-Siang Peng; Chia-Wei Wang
- Web page: https://patentgrep.com/patent/US12765406B2

## CPC

- H10W 70/685: comprising multiple insulating layers
- H10W 70/05: of insulating or insulated package substrates, or of interposers, or of redistribution layers (manufacture or treatment of leadframes H10W70/04)
- H10W 70/611: {for connecting multiple chips together}
- H10W 74/117: {the substrate having spherical bumps for external connection}
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10

## Abstract

A conductive structure, a semiconductor package and methods of forming the same are disclosed. A conductive structure includes a metal feature, an insulating layer and a nitridized metal layer. The metal feature is disposed over a substrate and includes a lower metal pattern and an upper metal pattern over the lower metal pattern. The insulating layer surrounds the metal feature. The nitridized metal layer is disposed between the lower metal pattern and the upper metal pattern.

## Claims

### Claim 1

A method of forming a redistribution layer structure, comprising:
forming a first metal via over a die and forming a first polymer layer around the first metal via;
forming a seed layer over the first metal via and the first polymer layer;
forming a bottom anti-reflection coating layer over the seed layer;
forming a first photoresist layer over the bottom anti-reflection coating layer, wherein the first photoresist layer has a trench pattern that exposes a portion of the bottom anti-reflection coating layer;
removing the exposed portion of the bottom anti-reflection coating layer, so that the trench pattern of the first photoresist layer exposes a portion of the seed layer;
forming a first metal line in the trench pattern of the first photoresist layer by using the exposed seed layer as a seed;
removing the first photoresist layer; and
forming a first nitridized metal layer from a surface portion of the first metal line.

### Claim 2 (depends on 1)

The method of claim 1, wherein forming the first nitridized metal layer comprises performing a nitrogen-containing plasma to the first metal line and the bottom anti-reflection coating layer aside the first metal line.

### Claim 3 (depends on 2)

The method of claim 2, wherein the nitrogen-containing plasma comprises N2, NH3, NH4, NHx, or a combination thereof.

### Claim 4 (depends on 1)

The method of claim 1, further comprising performing an oxygen-containing plasma to remove the bottom anti-reflection coating layer aside the first metal line and therefore expose the underlying seed layer.

### Claim 5 (depends on 4)

The method of claim 4, wherein the oxygen-containing plasma includes oxygen (O2), ozone (O3), nitrous oxide (N2O), or a combination thereof.

### Claim 6 (depends on 4)

The method of claim 4, further comprising, after performing the oxygen-containing plasma,
performing a nitrogen-containing plasma to the seed layer aside the first metal line, so as to form a second nitridized metal layer from a surface portion of the seed layer, wherein the first nitridized metal layer and the second nitridized metal layer are in contact with each other;
forming a second photoresist layer over the first and second nitridized metal layers, wherein the second photoresist layer has an opening pattern that exposes a portion of the first nitridized metal layer;
forming a second metal via in the opening pattern of the second photoresist layer by using the exposed first nitridized metal layer as a seed; and
removing the second photoresist layer.

### Claim 7 (depends on 6)

The method of claim 6, further comprising removing a portion of the first nitridized metal layer, the second nitridized metal layer, and a portion of the seed layer below the second photoresist layer.

### Claim 8 (depends on 7)

The method of claim 7, wherein an edge of the remaining first nitridized metal layer is aligned with an edge of the second metal via.

### Claim 9 (depends on 6)

The method of claim 6, further comprising forming a second polymer layer around the first metal line and the second metal via.

### Claim 10

A method of forming a redistribution layer, comprising:
forming a seed layer over a die;
forming a bottom anti-reflection coating layer over the seed layer;
forming a first photoresist layer over the bottom anti-reflection coating layer, wherein the first photoresist layer has a trench pattern that exposes a portion of the bottom anti-reflection coating layer;
removing the exposed portion of the bottom anti-reflection coating layer, so that the trench pattern of the first photoresist layer exposes a portion of the seed layer;
forming a metal line in the trench pattern of the first photoresist layer by using the exposed seed layer as a seed;
removing the first photoresist layer; and
performing a nitrogen-containing plasma to the metal line and the bottom anti-reflection coating layer aside the metal line, so as to form a nitridized metal layer from a surface portion of the metal line.

### Claim 11 (depends on 10)

The method of claim 10, further comprising, after performing the nitrogen-containing plasma,
performing a descum process to remove the bottom anti-reflection coating layer aside the metal layer and therefore expose the underlying seed layer.

### Claim 12 (depends on 11)

The method of claim 11, further comprising performing another nitrogen-containing plasma to the metal line and the exposed seed layer.

### Claim 13 (depends on 11)

The method of claim 11, further comprising forming a metal via on the metal line by using the nitridized metal layer as a seed.

### Claim 14

A method of forming a redistribution layer, comprising:
forming a seed layer over a die;
forming a metal line by using the seed layer as a seed;
performing a nitrogen-containing plasma to an entire top surface and entire sidewalls of the metal line, so as to form a metal protection layer from the entire top surface and the entire sidewalls of the metal line; and
forming a metal via by using the metal protection layer as a seed.

### Claim 15 (depends on 14)

The method of claim 14, wherein a method of forming the metal line comprises:
forming a bottom anti-reflection coating layer over the seed layer;
forming a first photoresist layer over the bottom anti-reflection coating layer, wherein the first photoresist layer has a trench pattern that exposes a portion of the bottom anti-reflection coating layer;
removing the exposed portion of the bottom anti-reflection coating layer, so that the trench pattern of the first photoresist layer exposes a portion of the seed layer;
forming the metal line in the trench pattern of the first photoresist layer by using the portion of the seed layer as a seed;
removing the first photoresist layer; and
removing the bottom anti-reflection coating layer.

### Claim 16 (depends on 15)

The method of claim 15, wherein the nitrogen-containing plasma is performed after removing the first photoresist layer and before removing the bottom anti-reflection coating layer.

### Claim 17 (depends on 16)

The method of claim 16, wherein removing the bottom anti-reflection coating layer comprises performing an oxygen-containing plasma to remove the bottom anti-reflection coating layer aside the metal line.

### Claim 18 (depends on 17)

The method of claim 17, further comprising performing another nitrogen-containing plasma after the oxygen-containing plasma.

### Claim 19 (depends on 18)

The method of claim 18, wherein the another nitrogen-containing plasma comprises N2, NH3, NH4, NHx, or a combination thereof.

### Claim 20 (depends on 17)

The method of claim 17, wherein the oxygen-containing plasma includes oxygen (O2), ozone (O3), nitrous oxide (N2O), or a combination thereof.