# US 10,871,708 B2 · Spatial-frequency matched wafer alignment marks, wafer alignment and overlay measurement and processing using multiple different mark designs on a single layer

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

- Number: US 10,871,708 B2
- Document ID: US10871708B2
- Status: Granted
- Kind: B2
- Application number: 15/879,286
- Filed: 2018-01-24
- Published: 2018-07-26
- Granted: 2020-12-22
- Earliest claimed: 2017-01-24
- Assignees: Nikon Corporation
- Applicants: Nikon Corporation
- Inventors: Steven Douglas Slonaker; Stephen P. Renwick
- Web page: https://patentgrep.com/patent/US10871708B2

## CPC

- G03F 1/42: Alignment or registration features, e.g. alignment marks on the mask substrates
- G03F 1/22: Masks or mask blanks for imaging by radiation of 100nm or shorter wavelength, e.g. X-ray masks, extreme ultraviolet [EUV] masks; Preparation thereof
- G03F 7/2004: {characterised by the use of a particular light source, e.g. fluorescent lamps or deep UV light}
- G03F 9/7076: {Mark details, e.g. phase grating mark, temporary mark}
- H10P 74/23: {characterised by multiple measurements, corrections, marking or sorting processes}
- H10P 74/27: {Structural arrangements therefor}
- H10P 76/2041: {Photolithographic processes}
- H10W 46/00: Marks applied to devices, e.g. for alignment or identification
- H10W 46/301: {for alignment}
- 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
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10

## Abstract

Alignment patterns that are selected based on device pattern spatial frequencies are defined on a reticle. The alignment patterns can include periodic arrays of lines, spaces, dots, of other pattern elements. Such patterns can be defined as sets associated with a common spatial frequency or frequency range, or some or all sets can include alignment marks having mark elements associated with different spatial frequencies.

## Claims

### Claim 1

A pattern mask, comprising:
a substrate;
a plurality of device pattern areas defined on the substrate; and
a set of alignment marks defined on the substrate and distributed along a first direction, wherein each alignment mark includes a periodic array of alignment mark elements along the first direction.

### Claim 2 (depends on 1)

The pattern mask of claim 1, wherein at least one of the alignment marks includes a plurality of segments distributed along a second axis that is different from the first axis.

### Claim 3 (depends on 2)

The pattern mask of claim 2, wherein the second axis is perpendicular to the first axis.

### Claim 4 (depends on 1)

The pattern mask of claim 1, wherein each of the alignment marks is associated with a different spatial frequency.

### Claim 5 (depends on 1)

The pattern mask of claim 1, wherein at least two of the alignment marks are associated with a common spatial frequency.

### Claim 6 (depends on 1)

The pattern mask of claim 1, wherein the alignment mark elements are lines and spaces.

### Claim 7 (depends on 6)

The pattern mask of claim 6, wherein the lines and spaces are periodically situated along the first axis, and the lines and spaces have a common width along the first axis.

### Claim 8 (depends on 7)

The pattern mask of claim 7, wherein the lines and spaces are periodically situated along the first axis, and a line width is different from a space width.

### Claim 9 (depends on 1)

The pattern mask of claim 1, wherein the alignment mark elements are dots, polygons, T-shapes, or cross-shapes.

### Claim 10 (depends on 1)

The pattern mask of claim 1, wherein each of the periodic arrays of alignment mark elements is associated with a different spatial frequency.

### Claim 11 (depends on 1)

The pattern mask of claim 1, further comprising a plurality of sets of alignment marks defined on the substrate, each alignment mark set extending along the first direction, wherein each alignment mark includes a periodic array of alignment mark elements along the first direction.

### Claim 12 (depends on 11)

The pattern mask of claim 11, wherein at least one of the alignment marks of each set includes a plurality of segments distributed along a second axis that is different from the first axis.

### Claim 13 (depends on 11)

The pattern mask of claim 11, wherein each of the sets of alignment marks is associated with a different spatial frequency.

### Claim 14 (depends on 6)

The pattern mask of claim 6, wherein the alignment mark elements are lines and spaces that are periodically situated along the first axis, and the lines and spaces have a common width along the first axis.

### Claim 15 (depends on 11)

The pattern mask of claim 11, wherein the alignment mark elements are dots, polygons, T-shapes, or cross-shapes.

### Claim 16 (depends on 1)

A method, comprising:
with the pattern mask of claim 1, defining a plurality of sets of alignment marks on a circuit substrate, each alignment mark set distributed along the first direction, wherein each alignment mark includes a periodic array of alignment mark elements along the first direction;
defining at least a first circuit pattern on the circuit substrate;
aligning a second circuit pattern with respect to the first circuit pattern based on detection of at least one of the plurality of sets of alignment marks.

### Claim 17 (depends on 16)

The method of claim 16, wherein the detection of at least one of the plurality of sets of alignment marks includes illuminating the at least one of the plurality of sets of alignment marks and obtaining an image of the at least one of the plurality of sets of alignment marks.

### Claim 18 (depends on 17)

The method of claim 17, wherein the alignment of the second circuit pattern is based on a spatial frequency defined by the at least one of the plurality of sets of alignment marks.

### Claim 19 (depends on 16)

The method of claim 16, further comprising defining the second circuit pattern on the circuit substrate after aligning the second circuit pattern.

### Claim 20

A method, comprising:
obtaining a spatial frequency spectrum associated with a circuit pattern;
based on the obtained spatial frequency spectrum, defining alignment mark set patterns that include a plurality of alignment marks distributed along a first direction, wherein each alignment mark includes a periodic array of alignment mark elements along the first direction; and
transferring the alignment mark set patterns to a mask.

### Claim 21 (depends on 20)

The method of claim 20, wherein the transferring comprises establishing the alignment mark set patterns in a metallic layer on a mask substrate.

### Claim 22 (depends on 20)

The method of claim 20, wherein the transferring comprises establishing the alignment mark set patterns at a plurality of locations in a metallic layer on a mask substrate.

### Claim 23

A method, comprising:
determining a spatial frequency spectrum associated with a pattern to be transferred from a reticle to a sensitized substrate; and
defining a periodic reticle pattern based on the spatial frequency spectrum.

### Claim 24 (depends on 23)

The method of claim 23, further comprising forming the pattern to be transferred and the periodic reticle pattern on a reticle.

### Claim 25 (depends on 24)

The method of claim 24, further comprising exposing a sensitized substrate to the pattern to be transferred and the periodic reticle pattern on a reticle.

### Claim 26

A pattern mask comprising:
a substrate;
first device patterns with a first pitch arranged on the substrate;
second device patterns with a second pitch different from the first pitch, arranged on the substrate; and
an alignment mark including first segments arranged with the first pitch and second segments arranged with the second pitch.

### Claim 27 (depends on 26)

The pattern mask of claim 26, wherein the alignment mark includes a plurality of lines, each of lines including first segments arranged with the first pitch and second segments arranged with the second pitch.

### Claim 28

A pattern mask comprising:
a substrate;
first device patterns arranged on the substrate, the first device patterns having a first pitch;
second device patterns arranged on the substrate, the second device patterns having a second pitch different from the first pitch; and
an alignment mark including a plurality of segments associated with a power spectral density corresponding to a weighted combination of the first pitch and the second pitch, wherein the plurality of segments includes first segments arranged with the first pitch and second segments arranged with the second pitch.

### Claim 29 (depends on 28)

The pattern mask of claim 28, wherein the alignment mark includes a plurality of lines, and wherein each of lines includes a plurality of segments.

### Claim 30 (depends on 26)

An exposure method comprising:
preparing the pattern mask of claim 26;
irradiating the pattern mask with an exposure beam to form a patterned exposure beam; and
exposing a workpiece with the patterned exposure beam.

### Claim 31 (depends on 30)

The exposure method of claim 30, further comprising:
detecting an alignment mark on the workpiece that is formed by the exposure of the workpiece with the patterned exposure beam;
positioning the substrate by based on the detection of the alignment mark; and
exposing the positioned workpiece.

### Claim 32 (depends on 28)

An exposure method comprising:
preparing the pattern mask of claim 28;
irradiating the pattern mask with an exposure beam to produce a patterned exposure beam; and
exposing a workpiece with the patterned exposure beam.

### Claim 33 (depends on 32)

The exposure method of claim 32, further comprising:
detecting an alignment mark on the substrate, wherein the alignment mark is formed by the exposure of the workpiece to the patterned exposure beam;
positioning the substrate by based on the detection of the alignment mark; and
exposing the positioned workpiece.

### Claim 34

A pattern mask comprising:
a substrate;
first device patterns arranged on the substrate, the first device patterns having a first pitch;
second device patterns arranged on the substrate, the second device patterns having a second pitch different from the first pitch; and
an alignment mark including a plurality of segments having a spatial frequency distribution that is a combination of the first pitch and the second pitch.

### Claim 35 (depends on 34)

The pattern mask of claim 34, wherein the spatial frequency distribution of the alignment marks is based on a weighted average of the first pitch and the second pitch.

### Claim 36 (depends on 34)

The pattern mask of claim 34, wherein the weighted average of the first pitch and the second pitch corresponds to the power spectral density associated with a combination of the first device patterns and the second device patterns.

### Claim 37 (depends on 1)

A method, comprising:
illuminating a set of marks on a workpiece, wherein the set of marks is transferred to the workpiece from the pattern mask of claim 1; and
detecting the set of marks on the workpiece.

### Claim 38

A method comprising:
illuminating a set of marks on a workpiece; and
detecting the set of marks, wherein the set of marks is distributed along a first direction, and each mark includes a periodic array of mark elements along the first direction.

### Claim 39 (depends on 38)

The method of claim 38, at least one of the marks includes a plurality of segments distributed along a second direction which is different from the first direction.

### Claim 40 (depends on 38)

The method of claim 38, wherein each of the marks is associated with a different spatial frequency.