# US 10,871,367 B2 · Substrate, metrology apparatus and associated methods for a lithographic process

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- Number: US 10,871,367 B2
- Document ID: US10871367B2
- Status: Granted
- Kind: B2
- Application number: 16/882,977
- Filed: 2020-05-26
- Published: 2020-09-10
- Granted: 2020-12-22
- Earliest claimed: 2017-08-28
- Assignees: ASML Netherlands B.V.
- Applicants: Asml Netherlands B.V.
- Inventors: Alok Verma; Hugo Augustinus Joseph Cramer; Thomas Theeuwes; Anagnostis Tsiatmas; Bert Verstraeten
- Web page: https://patentgrep.com/patent/US10871367B2

## CPC

- G01B 11/272: {using photoelectric detection means}
- G01N 21/55: Specular reflectivity
- G03F 7/70466: {Multiple exposures, e.g. combination of fine and coarse exposures, double patterning or multiple exposures for printing a single feature (stitching G03F7/70475)}
- G03F 7/70616: {Monitoring the printed patterns}
- G03F 7/70633: {Overlay, i.e. relative alignment between patterns printed by separate exposures in different layers, or in the same layer in multiple exposures or stitching}
- G03F 7/70683: {Mark designs}
- G06F 30/398: Design verification or optimisation, e.g. using design rule check [DRC], layout versus schematics [LVS] or finite element methods [FEM] (optical proximity correction [OPC] design processes G03F1/36)
- H10D 62/17: Semiconductor regions connected to electrodes not carrying current to be rectified, amplified or switched, e.g. channel regions
- H10W 42/00: Arrangements for protection of devices (arrangements for thermal protection H10W40/00)
- G01B 2210/56: Measuring geometric parameters of semiconductor structures, e.g. profile, critical dimensions or trench depth
- G06F 30/3308: using simulation
- G06F 30/367: Design verification, e.g. using simulation, simulation program with integrated circuit emphasis [SPICE], direct methods or relaxation methods
- G06F 2119/18: Manufacturability analysis or optimisation for manufacturability
- G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)
- 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)
- G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N)
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
- H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10

## Abstract

A substrate having a plurality of features for use in measuring a parameter of a device manufacturing process and associated methods and apparatus. The measurement is by illumination of the features with measurement radiation from an optical apparatus and detecting a signal arising from interaction between the measurement radiation and the features. The plurality of features include first features distributed in a periodic fashion at a first pitch, and second features distributed in a periodic fashion at a second pitch, wherein the first pitch and second pitch are such that a combined pitch of the first and second features is constant irrespective of the presence of pitch walk in the plurality of features.

## Claims

### Claim 1

A substrate comprising a plurality of features for use in measuring a parameter of a device manufacturing process by illumination of the features with measurement radiation from an optical apparatus and detecting a signal arising from interaction between the measurement radiation and the features,
wherein the plurality of features comprise first features distributed in a periodic fashion at a first pitch, and second features distributed in a periodic fashion at a second pitch, and
wherein the first pitch and second pitch are such that a combined pitch of the first and second features is essentially constant irrespective of the presence of pitch walk in the plurality of features.

### Claim 2 (depends on 1)

The substrate of claim 1, wherein the first features have been fabricated using a spacer patterning method and the combined pitch is a multiple of a width of a mandrel used in the spacer patterning method.

### Claim 3 (depends on 1)

The substrate of claim 1, wherein the first and second features are spatially coincident in x and y dimensions of the substrate.

### Claim 4 (depends on 1)

The substrate of claim 1, wherein the first and second features are fabricated on separate layers formed in or patterned on the substrate.

### Claim 5 (depends on 1)

The substrate of claim 1, wherein the first and second features are fabricated on a single layer formed in, or patterned on, the substrate.

### Claim 6 (depends on 5)

The substrate of claim 5, wherein one or more first features comprises a second feature, the height of which has been at least partially reduced.

### Claim 7 (depends on 6)

The substrate of claim 6, wherein the first features have a reduced height compared to the second features over at least part of a length and/or width of the first features in x and y dimensions of the substrate, the height of the features is defined along a corresponding z-axis, normal to the substrate.

### Claim 8 (depends on 6)

The substrate of claim 6, wherein a ratio of the height of the first features to the second features is 0.9 or less.

### Claim 9 (depends on 8)

The substrate of claim 8, wherein the ratio of the height of the first features to the second features is 0.1 or more.

### Claim 10 (depends on 6)

The substrate of claim 6, wherein the first features have been formed by:
removal of at least part of one or more of the second features to reduce their height, or
by depositing at least one layer on one or more of the second features to increase their height.

### Claim 11 (depends on 6)

The substrate of claim 6, wherein the first and second structures form a plurality of repeating periodic unit cell structures, each unit cell structure comprising at least one first feature and at least one second feature.

### Claim 12 (depends on 11)

The substrate of claim 11, wherein the distribution of the at least one first and second features in each unit cell structure is such that the unit cell structure is symmetric.

### Claim 13 (depends on 11)

The substrate of claim 11, wherein the unit cell structure has a width and/or length that is less than 150 nm.

### Claim 14 (depends on 1)

The substrate of claim 1, wherein the first and second features are arranged such that a signal comprising specular reflected radiation arising from interaction between the measurement radiation and the first and second features comprises 0th diffraction order and is measureable using the optical apparatus to determine the parameter of the device manufacturing process.

### Claim 15 (depends on 1)

The substrate of claim 1, wherein the first and second features are arranged such that a pitch walk error of the first and/or second features produces distinguishable pupil images in the pupil plane.

### Claim 16

A substrate comprising a plurality of features for use in measuring a parameter of a device manufacturing process by illumination of the features with measurement radiation from an optical apparatus and detecting a signal arising from interaction between the measurement radiation and the features,
wherein the plurality of features comprise first features distributed in a periodic fashion at a first pitch, and second features distributed in a periodic fashion at a second pitch different from the first pitch, the second features interspersed among first features, and
wherein a combined pitch of the first and second features is essentially constant irrespective of the presence of pitch walk in the plurality of features.

### Claim 17 (depends on 16)

The substrate of claim 16, wherein one or more first features comprises a second feature, the height of which has been at least partially reduced.

### Claim 18 (depends on 16)

The substrate of claim 16, wherein the first features have a reduced height compared to the second features over at least part of a length and/or width of the first features in x and y dimensions of the substrate, the height of the features is defined along a corresponding z-axis, normal to the substrate.

### Claim 19 (depends on 16)

The substrate of claim 16, wherein the first and second structures form a plurality of repeating periodic unit cell structures, each unit cell structure comprising at least one first feature and at least one second feature and the distribution of the at least one first and second features in each unit cell structure is such that the unit cell structure is symmetric.

### Claim 20 (depends on 19)

The substrate of claim 19, wherein the unit cell structure has a width and/or length that is less than 150 nm.