# US 11,441,229 B2 · Method for selectively removing nickel platinum material

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- Number: US 11,441,229 B2
- Document ID: US11441229B2
- Status: Granted
- Kind: B2
- Application number: 16/444,262
- Filed: 2019-06-18
- Published: 2020-01-09
- Granted: 2022-09-13
- Earliest claimed: 2018-07-06
- Assignees: Entegris, Inc.
- Applicants: Entegris, Inc.
- Inventors: SeongJin Hong
- Web page: https://patentgrep.com/patent/US11441229B2

## CPC

- C23F 1/28: for etching iron group metals
- C23F 1/30: for etching other metallic material
- C23F 1/44: Compositions for etching metallic material from a metallic material substrate of different composition
- H10P 50/282: {of inorganic materials}
- H10P 50/642: {Chemical etching}
- H10P 50/644: {Anisotropic liquid etching (H10P50/61 takes precedence)}
- H10P 50/648: {Anisotropic liquid etching}
- H10P 50/667: {by liquid etching only}
- C23F: NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE (working metal by laser beams B23K26/00; desurfacing by applying flames B23K7/00; working of metal by electro-erosion B23H; producing decorative effects by removing surface material, e.g. by engraving, by etching, B44C1/22; electrolytic etching or polishing C25F); INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10

## Abstract

A method of selectively removing NiPt material from a microelectronic substrate, the method comprising contacting the NiPt material with an aqueous etching composition comprising: an oxidising agent; a strong acid; and a source of chloride.

## Claims

### Claim 1

A method of selectively removing NiPt material from a microelectronic substrate including NiPt and NiPt silicide, the method comprising;
i) contacting the NiPt material with an aqueous etching composition comprising:
from 0.1 to 5 wt %, based on the total weight of the composition, of an oxidizing agent component, wherein the oxidizing agent component is hydrogen peroxide (H2O2);
from 1 wt % to 20 wt %, based on the total weight of the composition, of a strong acid component selected from the group consisting of sulfuric acid, methanesulfonic acid, and combinations thereof;
from 1 wt % to 6 wt %, based on the total weight of the composition, of a source of chloride component selected from the group consisting of ammonium chloride, HCl, and combinations thereof; and
from 70 to 95 wt %, based on the total weight of the composition, of water,
wherein the strong acid component and the source of chloride component are present in a ratio of 5:1 to 1:5,
wherein the oxidizing agent component and strong acid component are present in a ratio of 5:1 to 1:5, and
wherein the oxidizing agent component and source of chloride component are present in a ratio of 5:1 to 1:5; and
ii) selectively removing the NiPt relative to the NiPt silicide with a NiPt etch rate of at least 100 Å/min, a NiPt silicide etch rate of at most 10 Å/min, and with a selectivity ratio of at least 40:1.

### Claim 2 (depends on 1)

The method of claim 1, wherein the amount of the oxidizing agent component in the composition is from 0.1 to 4 wt % based on the total weight of the composition.

### Claim 3 (depends on 1)

The method of claim 1, wherein the strong acid component is sulfuric acid.

### Claim 4 (depends on 1)

The method of claim 1, wherein the strong acid component is methanesulfonic acid.

### Claim 5 (depends on 1)

The method of claim 1, wherein the amount of the strong acid component in the composition is from 5 to 15 wt % based on the total weight of the composition.

### Claim 6 (depends on 1)

The method of claim 1, wherein the amount of the strong acid component in the composition is about 10 wt % or 11 wt %.

### Claim 7 (depends on 1)

The method of claim 1, wherein the source of chloride component is hydrogen chloride (HCl).

### Claim 8 (depends on 1)

The method of claim 1, wherein the source of chloride component is ammonium chloride.

### Claim 9 (depends on 1)

The method of claim 1, wherein the amount of the source of chloride component in the composition is in the range of from 1 to 5 wt % based on the total weight of the composition.

### Claim 10 (depends on 1)

The method of claim 1, wherein the microelectronic substrate further comprises TiN and wherein contacting the NiPt material with the aqueous etching composition further selectively removes the NiPt relative to the TiN with a selectivity ratio of at least 40:1.

### Claim 11 (depends on 1)

The method of claim 1, wherein the composition comprises less than 1 wt % nitric acid.