# US 2021/0240091 A1 · Alignment Method and Apparatus

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- Number: US 2021/0240091 A1
- Document ID: US20210240091A1
- Status: Published application
- Kind: A1
- Application number: 17/049,597
- Filed: 2019-04-02
- Published: 2021-08-05
- Earliest claimed: 2018-04-26
- Assignees: ASML Netherlands B.V.
- Applicants: ASML Netherlands B.V.
- Inventors: Sebastianus Adrianus GOORDEN; Simon Reinald HUISMAN
- Web page: https://patentgrep.com/patent/US20210240091A1

## CPC

- G03F 9/7046: {Strategy, e.g. mark, sensor or wavelength selection}
- G03F 9/7073: {Alignment marks and their environment (marks specific to masks G03F1/42; marks specific to molds or stamps G03F7/0002; overlay marks G03F7/70633; marks applied to semiconductor devices H10W46/00)}
- G03F 9/7076: {Mark details, e.g. phase grating mark, temporary mark}
- G03F 9/7084: {Position of mark on substrate, i.e. position in (x, y, z) of mark, e.g. buried or resist covered mark, mark on rearside, at the substrate edge, in the circuit area, latent image mark, marks in plural levels}
- G03F 9/7088: {Alignment mark detection, e.g. TTR, TTL, off-axis detection, array detector, video detection}
- 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)

## Abstract

A method of determining a position of a feature (for example an alignment mark) on an object (for example a silicon wafer) is disclosed. The method comprises determining an offset parameter, determining the second position; and determining a first position from the second position and the offset parameter, the position of the mark being the first position. The offset parameter is a measure of a difference in: a first position that is indicative of the position of the feature; and a second position that is indicative of the position of the feature. The offset parameter may be determined using a first measurement apparatus and the second position may be determined using a second, different measurement apparatus.

## Claims

### Claim at position 1

-26. (canceled)

### Claim 27

A method of determining a position of a feature on an object, the method comprising:
determining an offset parameter, the offset parameter being a measure of a difference between:
a first position that is indicative of the position of the feature; and
a second position that is indicative of the position of the feature;
determining the second position; and
determining the first position from the second position and the offset parameter, the position of the mark being the first position.

### Claim 28 (depends on 27)

The method of claim 27, wherein the feature is disposed below a surface of the object and wherein at least a portion of the object between the feature and the surface is opaque, wherein the first position is a position of the feature and wherein the second position is a position of a residual topography formed by deposition of one or more process layers over the feature.

### Claim 29 (depends on 27)

The method of claim 27, wherein the offset parameter is determined using a first range of wavelengths and the second position is determined using a second range of wavelengths, the first range of wavelengths being greater than the second range of wavelengths.

### Claim 30 (depends on 27)

The method of claim 27, wherein the offset parameter is determined using a first illumination mode and the second position is determined using a second illumination mode.

### Claim 31 (depends on 27)

The method of claim 27, wherein the offset parameter is determined using a first illumination polarization state and the second position is determined using a second polarization state.

### Claim 32 (depends on 27)

The method of claim 27, wherein the first position is a position of the feature and wherein the second position is a position of a second feature.

### Claim 33 (depends on 27)

The method of claim 27, wherein the offset parameter is determined by first determining the first position and the second position, and subsequently determining the offset parameter from the first and second positions of the feature.

### Claim 34 (depends on 27)

The method of claim 27, wherein the offset parameter is at least partially calculated so as to correct for process variations.

### Claim 35 (depends on 27)

The method of claim 27, wherein the offset parameter is determined using a first spatial sampling and the second position is determined using a second spatial sampling.

### Claim 36 (depends on 27)

The method of claim 27, wherein determining the second position comprises irradiating the object in the vicinity of the feature with measurement radiation;
receiving at least a portion of the measurement radiation scattered from the object; and
determining the second position from at least a portion of the measurement radiation scattered from object.

### Claim 37

An apparatus comprising:
a substrate support for supporting an object having a feature; and
a measurement system operable to determine an offset parameter, the offset parameter being a measure of a difference between a first position that is indicative of the position of the feature and a second position that is indicative of the position of the feature.

### Claim 38 (depends on 37)

The apparatus of claim 37, further comprising:
a radiation system operable to irradiate the object with measurement radiation; and
wherein the measurement system is operable to receive at least a portion of the measurement radiation scattered from the object and further operable to determine the offset parameter at least partially from at least a portion of the measurement radiation scattered from the object.

### Claim 39 (depends on 38)

The apparatus of claim 38, wherein the radiation system is further operable to irradiate the object with pump radiation so as to produce a mechanical response in the object.

### Claim 40 (depends on 38)

The apparatus of claim 38, wherein the radiation system is operable to irradiate the object with measurement radiation having at least a first range of wavelengths or second range of wavelengths, and wherein the first position is a position of the feature that is determined using a first range of wavelengths and the second position is a position of the feature that is determined using a second range of wavelengths, the first range of wavelengths being greater than the second range of wavelengths.

### Claim 41 (depends on 38)

The apparatus of claim 38, wherein the radiation system is configured to irradiate the object with measurement radiation having at least a first illumination mode or a second illumination mode, and wherein the first position is a position of the feature that may be determined using a first illumination mode and the second position is a position of the feature that may be determined using a second illumination mode.

### Claim 42 (depends on 38)

The apparatus of claim 38, wherein the radiation system is configured to irradiate the object with measurement radiation having at least a first illumination polarization state or a second illumination polarization state, and wherein the first position is a position of the feature that may be determined using a first illumination polarization state and the second position is a position of the feature that may be determined using a second illumination polarization state.

### Claim 43

An apparatus comprising:
a substrate support for supporting an object having a feature with a position; and
a measurement system operable to determine:
a second position that is indicative of the position of the feature; and
a first position that is indicative of the position of the feature from the second position and an offset parameter;
wherein the offset parameter is a measure of a difference between a first position that is indicative of the position of the feature and a second position that is indicative of the position of the feature; and
wherein the radiation system is configured to irradiate the object with measurement radiation having at least a first range of wavelengths or second range of wavelengths, and wherein the first position is a position of the feature that is determined using a first range of wavelengths and the second position is a position of the feature that is determined using a second range of wavelengths, the first range of wavelengths being greater than the second range of wavelengths.