# US 10,871,647 B2 · Apparatus and method for prevention of contamination on collector of extreme ultraviolet light source

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- Number: US 10,871,647 B2
- Document ID: US10871647B2
- Status: Granted
- Kind: B2
- Application number: 16/517,511
- Filed: 2019-07-19
- Published: 2020-02-06
- Granted: 2020-12-22
- Earliest claimed: 2018-07-31
- Assignees: Taiwan Semiconductor Manufacturing Company, Ltd.
- Applicants: Taiwan Semiconductor Manufacturing Co., Ltd.
- Inventors: Kuo-An Liu; Gwan-Sin Chang; Bharath Kumar Pulicherla; Li-Jui Chen; Sheng-Kang Yu; Chung-Cheng Wu; Zhiqiang Wu
- Web page: https://patentgrep.com/patent/US10871647B2

## CPC

- G02B 27/0006: {with means to keep optical surfaces clean, e.g. by preventing or removing dirt, stains, contamination, condensation (G02B1/18 takes precedence; cleaning in general B08B)}
- G03F 7/70033: {by plasma extreme ultraviolet [EUV] sources}
- G03F 7/70175: {Lamphouse reflector arrangements or collector mirrors, i.e. collecting light from solid angle upstream of the light source}
- G03F 7/70916: {Pollution mitigation, i.e. mitigating effect of contamination or debris, e.g. foil traps}
- G21K 1/06: using diffraction, refraction or reflection, e.g. monochromators (G21K1/10, G21K7/00 take precedence)
- H05G 2/009: {Auxiliary arrangements not involved in the plasma generation}
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- 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)
- G21K: HANDLING OF PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES
- H05G: X-RAY TECHNIQUE (investigating or analysing materials by the use of X-rays G01N23/00; apparatus for X-ray photography G03B42/02; X-ray tubes H01J35/00; TV systems having X-ray input H04N5/321)

## Abstract

An EUV collector mirror for an extreme ultra violet (EUV) radiation source apparatus includes an EUV collector mirror body on which a reflective layer as a reflective surface is disposed, a trajectory correcting device attached to or embedded in the EUV collector mirror body and a trajectory correcting device to adjust the trajectory of metal from the reflective surface of the EUV collector mirror body to an opposite side of the EUV collector mirror body.

## Claims

### Claim 1

An EUV vessel for an extreme ultra violet (EUV) radiation source apparatus, comprising:
an EUV collector mirror body on which a reflective layer as a reflective surface is disposed; and
a trajectory correcting device attached to or embedded in the EUV collector mirror body,
wherein the trajectory correcting device is configured to adjust a trajectory of metal ions towards an opposite side of the EUV vessel away from the EUV collector mirror body, and
wherein the trajectory correcting device includes a pulse timing module coupled to a first charging point at the EUV collector mirror body.

### Claim 2 (depends on 1)

The EUV vessel of claim 1, wherein a conduit connects the first charging point at the EUV collector mirror body and the pulse timing module.

### Claim 3 (depends on 1)

The EUV vessel of claim 1, wherein the first charging point is configured to positively bias the collector mirror body by applying a voltage in a range from 1 V to 50 V to the collector mirror body.

### Claim 4 (depends on 1)

The EUV vessel of claim 1, wherein the pulse timing module is configured to provide an amplitude modulation of the pulse.

### Claim 5 (depends on 1)

The EUV vessel of claim 1, wherein the pulse timing module is configured to provide a frequency modulation of the pulse.

### Claim 6 (depends on 1)

The EUV vessel of claim 1, wherein the pulse timing module is configured to provide an electric field to cause the metal ions to be redistributed in a direction away from the EUV collector mirror body.

### Claim 7 (depends on 1)

The EUV vessel of claim 1, wherein the trajectory correcting device includes a pulse timing module coupled to a second charging point at a lower cone of the EUV vessel, the lower cone being opposite from the collector and adjacent to exhaust ports.

### Claim 8

A method of preventing contamination of a collector of an extreme ultraviolet (EUV) radiation source, the method comprising:
providing an EUV collector mirror body on which a reflective layer as a reflective surface is disposed; and
providing a trajectory correcting device attached to or embedded in the EUV collector mirror body; and
applying an electric field to an EUV collector mirror body to adjust a trajectory of metal debris towards an opposite side of the EUV radiation source away from the EUV collector mirror body,
wherein the trajectory correcting device includes a pulse timing module coupled to a first charging point at a lower cone of an EUV vessel, the lower cone being opposite from the collector and adjacent to exhaust ports.

### Claim 9 (depends on 8)

The method of claim 8, wherein the first charging point at the EUV collector mirror body is connected to the pulse timing module by a conduit.

### Claim 10 (depends on 8)

The method of claim 8, further comprising positively biasing the collector mirror body by applying a voltage in a range from 1 V to 50 V to the EUV collector mirror body.

### Claim 11 (depends on 8)

The method of claim 8, further comprising modulating an amplitude of voltage pulses using the pulse timing module.

### Claim 12 (depends on 8)

The method of claim 8, further comprising modulating a frequency of voltage pulses using the pulse timing module.

### Claim 13 (depends on 8)

The method of claim 8, wherein the pulse timing module provides the electric field to the EUV collector mirror body.

### Claim 14 (depends on 8)

The method of claim 8, wherein the trajectory correcting device includes a pulse timing module coupled to a second charging point at the EUV collector mirror body.

### Claim 15

An extreme ultraviolet (EUV) radiation source, comprising:
a chamber enclosing an EUV vessel,
the EUV vessel comprising:
a collector mirror configured to reflect EUV radiation;
a debris collection mechanism disposed over the collector mirror;
a lower cone disposed over the debris collection mechanism;
at least one first charging point attached to the collector mirror;
a second charging point attached to the lower cone; and
a pulse timing module and a DC bias circuit coupled to the first charging point and the second charging point.

### Claim 16 (depends on 15)

The EUV radiation source of claim 15, wherein the pulse timing module, DC bias circuit, and the first charging point are configured to positively bias the collector mirror by applying a voltage in a range from 1 V to 50 V to the collector mirror.

### Claim 17 (depends on 16)

The EUV radiation source of claim 16, wherein the pulse timing module modulates a frequency and amplitude of the modulation of a DC pulse applied to the collector mirror.

### Claim 18 (depends on 16)

The EUV radiation source of claim 16, wherein the at least one first charging point is attached to the collector mirror adjacent to vanes of the debris collection mechanism.

### Claim 19 (depends on 16)

The EUV radiation source of claim 16, further comprising isolated electrode regions on a rear side of an EUV collector mirror.

### Claim 20 (depends on 19)

The EUV radiation source of claim 19, wherein the isolated electrode regions are separated by electrically insulating regions.