# US 11,114,350 B2 · Method for removing photoresist from photomask substrate

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- Number: US 11,114,350 B2
- Document ID: US11114350B2
- Status: Granted
- Kind: B2
- Application number: 16/453,773
- Filed: 2019-06-26
- Published: 2020-10-15
- Granted: 2021-09-07
- Earliest claimed: 2019-04-12
- Assignees: Applied Materials, Inc.
- Applicants: Applied Materials, Inc.
- Inventors: Banqiu Wu; Khalid Makhamreh; Eli Dagan
- Web page: https://patentgrep.com/patent/US11114350B2

## CPC

- G03F 1/82: Auxiliary processes, e.g. cleaning or inspecting
- H10P 74/238: {comprising acting in response to an ongoing measurement without interruption of processing, e.g. endpoint detection or in-situ thickness measurement}
- H10P 50/287: {by chemical means}
- H10P 70/20: {Cleaning during device manufacture}
- G03F: PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR; (phototypographic composing devices B41B; photosensitive materials or processes for photographic purposes G03C; electrophotography, sensitive layers or processes therefor G03G)
- H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10

## Abstract

Methods and apparatus for removing a photoresist layer from a photomask substrate are provided. In one example, a method for removing a photoresist layer from a substrate in a chamber includes generating a first plasma including first radicals from a first gas mixture in a processing chamber, exposing a portion of a photoresist layer on a substrate to the first radicals to remove the portion of the photoresist layer from the substrate, generating a second plasma including second radicals from a second gas mixture, wherein the second radicals have a different composition than the first radicals, and exposing another portion of photoresist layer to the second radicals to remove the second portion of the photoresist layer.

## Claims

### Claim 1

A method for removing a photoresist from a substrate in a chamber, comprising:
generating a first plasma including first radicals from a first gas mixture supplied into a processing chamber;
exposing a first portion of the photoresist to the first radicals to remove the first portion of the photoresist from the substrate;
collecting a first signal at an OES detector, after exposing the first portion;
adjusting the first gas mixture supplied into the processing chamber based upon types of first radicals detected from the first signal;
generating a second plasma including second radicals from a second gas mixture supplied into the processing chamber, wherein the second radicals have a different composition than the first radicals;
exposing a second portion of the photoresist to the second radicals to remove the second portion of the photoresist from the substrate, wherein the second portion is a residual of the first portion;
collecting a second signal at the OES detector, after exposing the second portion;
adjusting the second gas mixture supplied into the processing chamber;
generating a first endpoint based upon an intensity of the first signal;
generating a second endpoint based upon an intensity of the second signal; and
removing the first portion based upon the first endpoint, and removing the second portion based upon the second endpoint.

### Claim 2 (depends on 1)

The method of claim 1, wherein the first gas mixture comprises at least one of H2, H2O2, H2O or O2 gas.

### Claim 3 (depends on 1)

The method claim 1, wherein the second gas mixture comprises O3 gas or O2 gas.

### Claim 4 (depends on 3)

The method of claim 3, wherein the second gas mixture comprises an oxidizing agent.

### Claim 5 (depends on 1)

The method of claim 1, wherein generating the first plasma further comprises:
collecting reflected signals at the OES detector, the reflected signals being reflected from a surface of the substrate.

### Claim 6 (depends on 5)

The method of claim 5, further comprising:
analyzing data from the reflected signals prior to removing the first portion or the second portion of the photoresist.

### Claim 7 (depends on 5)

The method of claim 5, further comprising:
adjusting a precursor gas supplied in the first gas mixture or the second gas mixture in response to analyzed data from the collected first or second signals.

### Claim 8 (depends on 5)

The method of claim 5, further comprising:
adjusting a process pressure when supplying the first gas mixture or the second gas mixture in response to analyzed data from the collected first or second signals.

### Claim 9 (depends on 5)

The method of claim 5, further comprising:
determining a photoresist removal recipe in response to analyzed data from the collected first or second signals.

### Claim 10 (depends on 1)

The method of claim 1, further comprising:
terminating the first gas mixture while supplying the second gas mixture.

### Claim 11

A computer-readable storage medium storing a program, which, when executed by a processor performs an operation for operating a processing chamber, the operation comprising:
collecting first signals at an OES detector, the first signals emitted from a surface of a photomask substrate during removal of a first portion of photoresist from the photomask substrate;
analyzing the collected first signals to determine a state of a first reactive species distributed across the surface of the photomask substrate;
determining a first photoresist removal recipe in response to the analysis of the collected first signals, wherein the first photoresist removal recipe includes adjusting a first gas mixture used to perform plasma etching of the first portion, and wherein the first photoresist removal recipe includes a first endpoint; and
collecting second signals at the OES detector, the second signals emitted during removal of a second portion of photoresist from the photomask substrate, wherein the second portion is a residual of the first portion;
analyzing the collected second signals to determine a state of a second reactive species distributed across the surface of the photomask substrate;
determining a second photoresist removal recipe in response to the analysis of the collected second signals, wherein the second photoresist removal recipe includes adjusting a second gas mixture used to perform etching of the second portion, and wherein the second photoresist removal recipe includes a second endpoint;
determining a first endpoint based upon an intensity of the first signals;
determining a second endpoint based upon an intensity of the signals; and
removing the first portion based upon the first endpoint and removing the second portion based upon the second endpoint.

### Claim 12 (depends on 11)

The computer-readable storage medium of claim 11, wherein the operation further comprises:
supplying more than one gas precursor to the surface of the photomask substrate after analyzing the first signals or the second signals.

### Claim 13 (depends on 12)

The computer-readable storage medium of claim 12, wherein the operation further comprises:
supplying a first gas precursor comprising H2O in the first gas mixture; and
supplying a second gas precursor comprising O2 in the second gas mixture.

### Claim 14 (depends on 13)

The computer-readable storage medium of claim 13, wherein the second gas precursor predominately reacts with residues from the first portion disposed on the photomask substrate.

### Claim 15 (depends on 11)

The computer-readable storage medium of claim 11, wherein the operation further comprises:
terminating the first gas mixture while supplying the second gas mixture.