# US 12,014,933 B2 · Semiconductor device fabrication with removal of accumulation of material from sidewall

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

- Number: US 12,014,933 B2
- Document ID: US12014933B2
- Status: Granted
- Kind: B2
- Application number: 17/562,093
- Filed: 2021-12-27
- Published: 2022-04-21
- Granted: 2024-06-18
- Earliest claimed: 2018-08-31
- Assignees: Taiwan Semiconductor Manufacturing Company, Ltd.
- Applicants: Taiwan Semiconductor Manufacturing Company Limited
- Inventors: Yan-Hong Liu; Yeh-Chien Lin; Jin-Huai Chang
- Web page: https://patentgrep.com/patent/US12014933B2

## CPC

- H10P 50/266: {by vapour etching only}
- H10D 1/47: Resistors having no potential barriers
- H10D 1/692: {Electrodes}
- H10D 1/696: {comprising multiple layers, e.g. comprising a barrier layer and a metal layer (barrier layers to prevent diffusion of hydrogen or oxygen in perovskite based capacitors H10D1/688)}
- H10D 86/85: characterised by only passive components
- H10P 50/71: {using masks for conductive or resistive materials}
- H10P 70/273: {the processing being a delineation of conductive layers, e.g. by RIE}
- H10P 76/204: {of organic photoresist masks}
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES

## Abstract

A method of fabricating a semiconductor device is provided. The method includes forming a first metal layer over a semiconductor substrate, and forming a first layer over the first metal layer. The first layer and first metal layer are etched to expose a sidewall of the first layer and a sidewall of the first metal layer, wherein the etching disburses a portion of the first metal layer to create an accumulation of material on at least one of the sidewall of the first layer or the sidewall of the first metal layer. At least some of the accumulation is etched away using an etchant comprising fluorine.

## Claims

### Claim 1

A method for fabricating a semiconductor device, comprising:
forming a first metal layer over a semiconductor substrate;
forming a first layer over the first metal layer and contacting the first metal layer;
forming a second metal layer over the first layer and contacting the first layer;
etching the first layer and the first metal layer to expose a sidewall of the first layer and a sidewall of the first metal layer, wherein the etching disburses a portion of the first metal layer to create an accumulation of material on at least one of the sidewall of the first layer or the sidewall of the first metal layer; and
etching the accumulation using an etchant comprising fluorine to remove at least some of the accumulation.

### Claim 2 (depends on 1)

The method of claim 1, wherein the first metal layer comprises at least one of tantalum nitride or titanium nitride.

### Claim 3 (depends on 1)

The method of claim 1, wherein forming the first metal layer comprises forming the first metal layer over an etch stop layer.

### Claim 4 (depends on 1)

The method of claim 1, comprising:
forming a dielectric layer over the second metal layer, and
forming a third metal layer over the dielectric layer.

### Claim 5 (depends on 4)

The method of claim 4, wherein the first metal layer, the second metal layer, and the third metal layer have a same composition.

### Claim 6 (depends on 5)

The method of claim 5, wherein the first layer has a composition that is different than the composition of the first metal layer, the second metal layer, and the third metal layer.

### Claim 7 (depends on 1)

The method of claim 1, wherein the etchant comprises at least one of CF4, SF6, NF3, or CHF3.

### Claim 8

A method for fabricating a semiconductor device, comprising:
forming a plurality of layers over a semiconductor substrate, comprising:
forming a first metal layer over a semiconductor substrate;
forming a first layer over the first metal layer and contacting the first metal layer;
forming a second metal layer over the first layer and contacting the first layer;
etching the plurality of layers to expose a sidewall of the first metal layer, a sidewall of the first layer, and a sidewall of the second metal layer, wherein the etching creates an accumulation of material on the sidewall of the first metal layer, the sidewall of the first layer, and the sidewall of the second metal layer; and
etching the accumulation using a first etchant comprising fluorine to remove at least some of the accumulation.

### Claim 9 (depends on 8)

The method of claim 8, wherein the accumulation comprises metal atoms from at least one of the plurality of layers.

### Claim 10 (depends on 8)

The method of claim 8, wherein the first etchant comprises at least one of CF4, SF6, NF3, or CHF3.

### Claim 11 (depends on 8)

The method of claim 8, wherein:
the plurality of layers comprises a first dielectric layer over the second metal layer,
and
the accumulation is present on a sidewall of the first dielectric layer.

### Claim 12 (depends on 8)

The method of claim 8, wherein etching the plurality of layers comprises etching the plurality of layers using a second etchant different than the first etchant.

### Claim 13 (depends on 12)

The method of claim 12, wherein the second etchant comprises carbon.

### Claim 14 (depends on 13)

The method of claim 13, wherein the accumulation comprises metal atoms from at least one of the plurality of layers and carbon atoms from the second etchant.

### Claim 15 (depends on 8)

The method of claim 8, wherein:
forming the plurality of layers comprises forming an etch stop layer over the semiconductor substrate prior to forming the first metal layer, wherein etching the plurality of layers exposes the etch stop layer.

### Claim 16

A method for fabricating a semiconductor device, comprising:
forming a first metal layer over a semiconductor substrate;
forming a first dielectric layer over the first metal layer;
etching the first dielectric layer and the first metal layer to expose a sidewall of the first dielectric layer and a sidewall of the first metal layer, wherein the etching disburses a portion of the first metal layer to create an accumulation of material on at least one of the sidewall of the first dielectric layer or the sidewall of the first metal layer;
etching the accumulation using an etchant comprising fluorine to remove at least some of the accumulation; and
forming a second dielectric layer adjacent the sidewall of the first dielectric layer after etching the accumulation.

### Claim 17 (depends on 16)

The method of claim 16, wherein forming the second dielectric layer comprises forming the second dielectric layer adjacent the sidewall of the first metal layer after etching the accumulation.

### Claim 18 (depends on 16)

The method of claim 16, wherein the etchant comprises at least one of CF4, SF6, NF3, or CHF3.

### Claim 19 (depends on 16)

The method of claim 16, wherein:
forming the first metal layer comprises forming the first metal layer over an etch stop layer, and
the accumulation of material contacts the etch stop layer.

### Claim 20 (depends on 16)

The method of claim 16, wherein etching the first dielectric layer and the first metal layer comprises etching the first dielectric layer and the first metal layer using a second etchant different than the etchant.