TWI612851B - System for an extreme ultraviolet light source, method of aligning an irradiating amplified light beam generated from an extreme ultraviolet light system relative to a target material, and extreme ultraviolet light system - Google Patents

Abstract

A system for a very ultraviolet light source includes one or more optical elements positioned to receive a reflected amplified beam and to direct the reflected amplified beam into first, second, and third channels, the reflected amplified beam comprising a target material interacting with at least a portion of the reflected light beam; a first sensor that senses light from the first channel; a sensing originating from the second channel and the third channel a second sensor of light having a lower acquisition rate than the first sensor; and an electronic processor coupled to a computer readable storage medium, the media storage instructions, when executed And causing the processor to: receive data from the first sensor and the second sensor, and determine, according to the received data, a location of the illuminated amplified beam in one or more dimensions relative to the target material.

Description

A system for an extreme ultraviolet light source that amplifies a beam of light generated by an extreme ultraviolet light system Method for alignment of target materials and extreme ultraviolet light system Cross-reference to related applications

U.S. Provisional Patent Application Serial No. 61/787,228, filed on Mar. U.S. Patent Application Serial No. 14/035,847, entitled,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, No. 184,777, entitled The Role of Beam Positioning Control for Extremely Ultraviolet Light Sources, the entire contents of which is incorporated herein by reference.

Field of invention

The subject matter of the present disclosure relates to beam positioning control for extreme ultraviolet (EUV) sources.

Background of the invention

Extreme ultraviolet (EUV) light, for example, having electromagnetic radiation of about 50 nanometers or less (often also referred to as soft x-rays) and including light at a wavelength of about 13 nm, capable of Used in photolithographic etching processes to produce extremely small features in a substrate, for example, germanium wafers.

The method of producing EUV light includes, but is not necessarily limited to, converting a material having a composition, for example, yttrium, lithium or tin, in the EUV range to a plasma state. In this method, commonly referred to as laser-excited plasma (LPP), the plasma can illuminate a target material, such as a droplet, stream, or mass, by utilizing an amplified beam that can be considered to drive a laser. Produced in the form of a cluster of materials. For this process, the plasma is typically produced in a sealed container, such as a vacuum chamber, and monitored using different types of measuring equipment.

Summary of invention

In one general aspect, a system for an extreme ultraviolet light source includes one or more optical elements positioned to receive a reflected amplified beam and to direct the reflected amplified beam into the first, second, and third a channel, the reflected amplified beam comprising a reflection of at least a portion of an illuminated amplified beam that interacts with a target material; a first sensor that senses light from the first channel; a sensed source a second sensor for the light of the second channel and the third channel, the second sensor having a lower acquisition rate than the first sensor; and an electronic processing coupled to a computer readable storage medium The media storage instruction, when executed, causes the processor to: receive data from the first sensor and the second sensor, and determine, according to the received data, the illuminated amplified beam relative to the target material One of more than one dimension.

Implementations may include one or more of the following characteristics.

The medium can further store instructions that, when executed, cause the location The processor determines an adjustment to the illuminated amplified beam based on the determined position. The determined adjustment can include a distance, in more than one dimension, to move the illumination to amplify the beam.

The instructions causing the processor to determine the position of one of the illumination amplified beams may include, when executed, causing the processor to determine a direction parallel to a direction of propagation of the illumination amplified beam, the illumination amplification beam being relative to One of a focus position of the target material, and one of the focus positions of the illumination magnified beam relative to the target material in a first transverse direction determined to be perpendicular to a direction of propagation of the illumination amplified beam Instructions. The instructions can further include, when executed, causing the processor to determine the focus of the illumination amplified beam in a second transverse direction that is perpendicular to the first lateral direction and perpendicular to the direction of propagation of the illumination amplified beam The instruction of one of the locations.

The system also includes an astigmatism optical element positioned in the third channel to modify the wavefront of the reflected amplified beam.

The system also includes multiple partially reflective non-diffusing optical elements positioned at a different location in the third channel and respectively receiving at least a portion of the reflected amplified beam, each of the multiple partially reflective optical elements forming a beam of light A path of a different length between the target material and the second detector is followed.

The first, second, and third channels can be three separate paths defined by one or more refractive or reflective optical elements that direct a portion of the reflected amplified beam.

The reflected amplified beam may include a pre-pulse beam and a drive a reflection of the beam of light that is an amplified beam that converts the target material into a plasma upon interaction, and the pre-pulse and drive beam can comprise different wavelengths, and the system can further include one or more The spectral filter is only permeable to one of the pre-pulsed beam and the driven beam.

The first sensor is capable of sensing a light ray originating from the first channel at a high acquisition rate; the second sensor can include a two-dimensional imaging sensor sensing the second channel and the a third channel of light and measuring an intensity distribution of the light; and, when executed, causing the processor to determine, based on the received data, the instructions of the one of the illuminated amplified beams to cause the processor to determine the illumination Amplifying the beam in more than one dimension relative to a focus position of the target material.

In another general aspect, aligning an illumination amplified beam with respect to a target material includes accessing a first, second, and third measurements of a reflected amplified beam, the first obtained by a first sensor a second, third measurement obtained by a second sensor having a lower acquisition rate than the first sensor, and the reflected amplified beam is one of the illumination amplified beams derived from a target material Determining, according to the first measurement, a first position of the amplified beam relative to the target material in a direction perpendicular to a direction of propagation of the illumination amplified beam; determining, according to the second measurement, a direction in which the direction of propagation of the amplified light beam is perpendicular, a second position of the amplified light beam relative to the target material; determining, according to the third measurement, in a direction parallel to a direction of propagation of the amplified light beam One of the focus positions of the magnifying beam relative to the target material And reorienting the illumination amplified beam relative to the target material to align the illumination amplified beam with respect to the target material depending on the first location, the second location, or the focus location.

Implementations may include one or more of the following characteristics.

Adjusting the location of the focus position of the magnified beam can be determined based on the determined location of the focus position, and repositioning the illumination magnifying beam can include moving in accordance with the determined adjustment of the location for the focus position This illumination amplifies the focus position of the beam.

The adjustment to the amplified beam can be determined based on one or more of the determined first location or the determined second location.

The amplified beam can be a pulsed light, and the determined first location can be a location of the amplified beam in a direction parallel to a direction in which the target material travels relative to the target material, and for the amplification The determined adjustment of the beam alignment may be a distance between the magnifying beam and the target material in a direction parallel to a direction in which the target material travels, and repositioning the illuminated magnifying beam pulse A delay may be generated in the magnified beam that cooperates with the distance between the magnified beam and the target material such that a subsequent pulsed light intersects a target material.

The determined second location may include the amplified beam in a direction that is perpendicular to a direction of travel of the target material and perpendicular to a direction in which the amplified beam propagates, and the determined adjustment for alignment of the amplified beam may be Included between the magnifying beam and the location of the target material, and repositioning the illumination beam may include The determined adjustment produces an output sufficient to cause repositioning of an optical assembly that manipulates the amplified beam; and providing an output to the optical assembly.

Relocating the illumination amplified beam may include generating an output based on the determined adjustment of the location of the focus position, the output being sufficient to cause repositioning of an optical component that focuses the amplified beam; and for including the optical component An optical assembly provides an output.

The third measurement can include an image of the reflected amplified beam and an operation of determining a location of the focus of the amplified beam can include analyzing the image to determine a shape of the reflected amplified beam. The act of analyzing the shape of one of the reflected amplified beams may include the act of determining the ellipticity of the reflected amplified beam.

The third measurement can include an image of the reflected amplified beam sampled at the plurality of locations, and an operation of determining a location of the focus position of the amplified beam can include comparing the reflected amplified beam at two or more locations in the plurality of locations The width.

In another general aspect, a polar ultraviolet light system includes a source that produces an illumination amplified beam; a steering system that manipulates the illumination amplified light beam toward a target material in a vacuum chamber and focuses; a beam positioning system that includes One or more optical elements positioned to receive a reflected amplified beam reflected from the target material and configured to direct the reflected amplified beam into the first, second, and third channels; a sensing source a first sensor from the light of the first channel; a second sense of sensing light from the second channel and the third channel, including a two-dimensional imaging sensor The second sensor has a lower acquisition rate than the first sensor; and an electronic processor coupled to a computer readable storage medium, the media storage instruction, when executed, causes the processor Receiving data from the first sensor and the second sensor, and determining, according to the received data, a location of the illuminated amplified beam above a dimension relative to the target material.

Implementations may include one or more of the following characteristics. The medium can further store instructions that, when executed, cause the processor to determine an adjustment of the location of the amplified light beam for the illumination based on the determined location. The determined adjustment may include an adjustment above one dimension.

Having the processor determine that the instructions to illuminate the amplified light beam relative to the target material can include, when executed, causing the processor to determine one direction parallel to a direction of propagation of the illumination amplified beam, the illumination amplification a position of the light beam relative to a focus of the target material, and determined in a first and second transverse directions, each of which is perpendicular to a direction of propagation of the illumination amplified beam, the focus position of the illumination amplified beam being relative to The instruction of a location of the target material.

The instructions can further include, when executed, causing the processor to determine an adjustment of the amplified beam in accordance with the determined location of the amplified beam and to provide the generated output to the steering system.

Implementations of any of the techniques described above may include a method, process, apparatus, kit, or pre-assembled system for retrofitting an existing EUV source, except that there is an executable instruction or device on a computer readable medium. The details of one or more of the implementations are tied to the accompanying drawings and below. Presented in the Ming Dynasty. Other features will be apparent from the description and drawings, and claims.

100‧‧‧LPP EUV light source

105‧‧‧ Target premises

107‧‧‧Internal

110‧‧‧Amplified beam

114‧‧‧Target mixture

115‧‧‧Drive laser system

120‧‧‧beam transport system

122‧‧‧ Focus assembly

124‧‧‧Metrics and Weights System

125‧‧‧Target material conveying system

126‧‧‧Target material conveying control system

127‧‧‧Target material supply device

130‧‧‧vacuum room

135‧‧‧Collector mirror

140‧‧‧孔口

145‧‧‧ middle premises

150‧‧‧Shield

155‧‧‧Master controller

15‧‧‧Drop Detection and Feedback System

157‧‧‧Laser Control System

158‧‧‧ Beam Control System

165‧‧‧Light source detector

175‧‧‧Guided laser

180‧‧‧Drive laser system

181,182,183‧‧‧Power Amplifier

184‧‧‧Light

185‧‧‧ Output window

186‧‧‧ curved mirror

187‧‧‧ Spatial Filter

188‧‧‧ curved mirror

189‧‧‧ input window

190‧‧‧ Output window

191‧‧‧Light

192‧‧‧Folding mirror

193‧‧‧ input window

194‧‧‧ Output window

195‧‧‧Output beam

196‧‧‧Folding mirror

197‧‧‧孔口

200‧‧‧ Optical Imaging System

205‧‧‧LPP EUV light source

210‧‧‧ lithography tools

215‧‧‧Drive laser system

216‧‧‧Amplified magnifying beam

217‧‧‧Reflected amplified beam

217a, 217b‧‧‧ return beam

220‧‧‧Control system

222,224‧‧‧Optical components

226‧‧‧ Focus System

227,228‧‧‧ actuation system

240‧‧‧vacuum room

242‧‧‧ Target premises

244‧‧ ‧ focal plane

246‧‧‧ Target materials

247‧‧‧Target material supply device

248‧‧‧Target material flow

260‧‧‧beam positioning system

262‧‧‧ interface

263‧‧‧ interface

280‧‧‧ Controller

282‧‧‧Electronic processor

284‧‧‧Electronic storage device

300‧‧‧ imaging system

305‧‧‧Light source

316,317‧‧‧ channel

335‧‧‧ window

340‧‧‧Optical components

405‧‧‧Folding mirror

410a, 410b‧‧‧Partial reflective optical components

411,412,413‧‧‧beam

415-417‧‧‧ channel

420,421‧‧‧ sensor

422a-422d‧‧‧Sensor components

424,425‧‧ images

426,428,430‧‧‧Reproduction

432,434,436‧‧‧Optical components

442‧‧‧Optical components/spectral filters

505‧‧‧ spots

700‧‧‧ Beam Positioning System

705‧‧‧Folding mirror

710a, 710b‧‧‧Partial reflective optical components

711,712,713‧‧‧beam

715,716,717‧‧ channels

720,721‧‧‧ sensor

732‧‧‧Optical components

734‧‧‧Optical assembly

736‧‧‧Optical components

740‧‧‧flat reflective elements

741‧‧‧ Spatial Filter

742,743‧‧ lens

744‧‧‧孔口

745‧‧‧ openings

746‧‧‧Astigmatism optics

748‧‧‧ lens

750,750A-750C‧‧ images

751‧‧‧ sensor

752, 754 ‧ ‧ spots

752A, 754A‧‧‧Reproduction

752B, 754B‧‧‧Reproduction

752C, 754C‧‧‧Reproduction

1100‧‧‧beam positioning system

1110a, 1110b‧‧‧Partial reflective optics

1111,1112,1113‧‧·beam

1115, 1116, 1117‧‧ channels

1120, 1121‧‧‧ sensor

1132, 1134‧‧‧ Optical components

1140‧‧‧ polarizer

1142‧‧‧Spectral filter

1144‧‧‧Filter controller

1146‧‧‧flat reflective elements

1148‧‧‧ lens

1150‧‧‧Astigmatism optics

1152‧‧‧ sensor

1200‧‧‧Optical assembly

1202‧‧‧ lens

1204‧‧‧Light source

1205a, 1205b‧‧‧Partial reflective optical components

1210, 1211, 1212, 1213‧‧ spot

1210A, 1211A‧‧ spot

1210B, 1211B‧‧ spot

1210C‧‧ spot

1218a, 1218b‧‧‧ Beam

1221‧‧‧ sensor

1225, 1226‧‧ points

1250‧‧ images

1400‧‧‧Optical assembly

1400B‧‧‧ Process

1402‧‧ lens

1405a-1405e‧‧‧Partial reflective optical components

1410-1414‧‧ spot

1450, 1460, 1470, 1480 ‧ steps

1505A-1505C‧‧‧Image

1520A-1520C‧‧ spot

1600‧‧‧ Process

1610-1650‧‧ steps

Figure 1A is a block diagram of a laser-excited plasma extreme ultraviolet light source.

Figure 1B is a block diagram of an example of a drive laser system that can be used in the light source of Figure 1A.

2A is a top plan view of an example of an imaging system including a light source and a lithography tool.

Figure 2B is a partial side perspective view of the light source of Figure 2A.

2C is a cross-sectional top view of the light source of FIG. 2A taken along line 2C-2C.

3A is a top plan view of another example of an imaging system including a light source and a lithography tool.

Figure 3B is a partial side perspective view of the light source of Figure 3A.

Figure 3C is a cross-sectional top view of the light source of Figure 3A taken along line 3C-3C.

Figure 4 is an exemplary beam positioning system.

5A-5C are exemplary images of a reflected beam forming a spot on a quadrant sensor.

Figure 6 is an exemplary graph of the reaction of a quadrant sensor as a function of distance between an illumination beam and a target material.

Figure 7 shows a block diagram of another exemplary beam positioning system.

Figures 8A-8C show side views of an illumination amplified beam relative to a target material.

Figures 9A-9C are examples of images derived from an inductor that images a two reflected beam.

10A and 10B are exemplary graphs of sensor responses as a function of distance between a source of illumination and a target material.

Figure 11 shows a block diagram of another exemplary beam positioning system.

Figures 12 and 14 show block diagrams of exemplary optical assemblies.

Figures 13A-13C show side views of an illumination amplified beam relative to a target material.

Figure 14B is a flow diagram of an exemplary process for adjusting a focus position relative to a target material.

15A-15C are examples of images derived from an inductor that images a two reflected beam.

Figure 16 is a flow diagram of an exemplary process for aligning an illumination amplified beam with respect to a target material.

Detailed description of the preferred embodiment

The present invention discloses techniques for controlling the magnification of a laser-excited plasma (LPP) extreme ultraviolet (EUV) source based on the measurement alignment of the reflected amplified beam or otherwise. The LPP EUV source produces EUV light by directing an amplified beam (either an amplified beam or a forward beam) toward a target location that receives a target material. The target material includes when converted into A material that emits EUV light when it is plasma. When the illumination amplification beam strikes the target material, the target material can absorb the amplified beam and convert it into a plasma and/or the target material can reflect the illumination amplified beam to generate the reflected amplified beam (droplet reflection Beam or return beam).

During use of the EUV source, the illumination amplified beam can be removed from the target, reducing the likelihood of converting the target material into a plasma. As discussed below, the measurement of the reflected amplified beam is used to monitor the illumination of the amplified beam in multiple dimensions relative to the target material. The monitored location is used to determine an adjustment to the illumination amplified beam such that the illumination amplified beam remains aligned with the target during operation of the source. The techniques discussed below allow monitoring of the focus position of the magnified beam relative to the target position and controlling the beam focus so that it remains in an optimal position relative to the target position.

The complex physical effect causes the magnified beam to move away from the target. For example, heating of a focusing optical element such as a lens or curved mirror that focuses the illumination amplified beam changes the focal length of the focusing optical element and moves along a "z" direction parallel to the direction of propagation of the illumination amplified beam. Irradiating one of the focal planes of the amplified beam. Manipulating and directing the vibration of the rotating magnifying beam toward the rotating mirror of the target and other optical elements will shift the magnifying beam in the "x" and / or "y" directions transverse to the direction of propagation of the magnifying beam From the target premises. For pulsed amplification of the beam, movement between the focal position and the target material along the "x" direction, parallel to the path along which the droplet travels toward the target, may indicate that the pulse is at the target material Arrived in the target area before or after.

To determine where the amplified beam is, individual sensors have different data acquisition rates for imaging the reflected amplified beam, and the data derived from the sensors are used to determine the amplified beam in multiple dimensions. The location in the middle. The use of sensors having different data acquisition rates can provide additional information because of the time-scale changes that cause the physical effects of the illumination-amplified beam to move relative to the target. For example, a thermal effect on a lens that focuses the magnifying beam, such as the lens material, by absorbing the magnifying beam or heating of the plasma, causing the focal plane of the magnifying beam to move in the "z" direction compared to the Some movements in the "x" and / or "y" directions occur more slowly, which can be caused by high frequency vibrations of the optical components.

For its part, the monitoring technique discussed below can improve the performance of an EUV source by adjusting the illumination to amplify the beam in multiple dimensions relative to the location of the target location or target material, thus improving the illumination amplification beam. Align and increase the total amount of EUV light produced by the source.

The EUV source is discussed in more detail before discussing these monitoring techniques. 4 shows an example of a beam positioning system 260 that monitors and determines the location of the illumination magnified beam in multiple dimensions relative to the target material. The beam positioning system 260 can also generate signals that, when provided to an actuator or other component coupled to the optical assembly, cause the components to change position to reposition the illumination amplified beam.

Referring to FIG. 1A, an target LPS EUV source 100 is formed by illuminating a target mixture 114 with a magnifying beam 110 traveling along a beam path toward a target mixture 114 at a target location 105. The target location 105, which is also considered to be the location of illumination, is located within one of the interiors 107 of a vacuum chamber 130. When When the magnifying beam 110 strikes the target mixture 114, a target material in the target mixture 114 is converted to a plasma state having a composition in which the radiation is located in the EUV range. The resulting plasma has certain characteristics depending on the composition of the target material within the target mixture 114. The characteristics may include the wavelength of the EUV light generated by the plasma and the type and total amount of debris released from the plasma.

The light source 100 also includes a target material delivery system 125 for transporting, controlling, and directing liquid droplets, liquid streams, solid particles or agglomerates, solid particles contained within the liquid droplets, or contained within a liquid stream. The target mixture 114 is in the form of solid particles. The target mixture 114 includes the target material such as, for example, water, tin, lithium, cesium or any material having a radiation in the EUV range when converted to a plasma state. For example, the composition can be used as pure tin, tin (Si); as a tin compound, _{e.g., SnBr 4, SnBr 2, SnH} 4; as a tin alloy, for example, tin - gallium alloy, tin - indium alloys, tin - Indium-gallium alloys or any combination of such alloys. The target mixture 114 can also include impurities such as non-target particles. Thus, in the absence of impurities, the target mixture 114 is made only from the target material. The target mixture 114 is delivered into the interior 107 of the vacuum chamber 130 and to the target location 105 by the target material delivery system 125.

The light source 100 includes a drive laser system 115 that is generated due to the gain medium of the laser system 115 or a reversal of a quantity within the gain medium. The light source 100 includes a beam delivery system between the laser system 115 and the target location 105. The beam delivery system includes a beam delivery system 120 and a focusing assembly 122. The beam transport system 120 The laser system 115 receives the amplified beam 110 and manipulates and modifies the amplified beam 110 as desired and outputs the amplified beam 110 to the focusing assembly 122. The focus assembly 122 receives the amplified beam 110 and focuses the beam 110 to the target location 105.

In some implementations, the laser system 115 can include one or more optical amplifiers, lasers, and/or lamps for providing one or more main pulses and, in some examples, one or more pre- pulse. Each optical amplifier includes a gain medium capable of optically amplifying the desired wavelength, an excitation source and internal optical components, at a high gain. The optical amplifier may or may not have a laser mirror or other feedback device that forms a laser chamber. Thus, the laser system 115 produces an amplified beam 110 due to the reversal of the gain in the gain medium of the laser amplifier or even the absence of a laser chamber. In addition, the laser system 115 can generate an amplified beam 110 that is a coherent laser beam if there is no laser chamber to provide sufficient feedback to the laser system 115. The term "amplifying beam" includes one or more of the following: light rays originating from the laser system 115 are only amplified, not necessarily a coherent laser oscillation, and the light rays originating from the laser system 115 are Amplification is also a coherent laser oscillation.

The optical amplifiers located in the laser system 115 can include a carbon dioxide (CO ₂ ) fill gas as a gain medium and can amplify light at a wavelength between about 9100 and about 11,000 nm. More specifically, at about 10600 nm, a gain greater than or equal to. Suitable amplifiers and lasers for use in the laser system 115 can include a pulsed laser device, for example, a pulsed, gas-discharged carbon dioxide laser device at about 9300 nm or about 10600 nm, for example, utilizing The DC or RF excitation produces radiation at a relatively high power, for example, 10 kW or higher and a high pulse repetition rate, for example, 50 kHz or higher. Located in the laser system 115, the optical amplifiers can also include a cooling system such as water that can be used when operating the laser system 115 at higher power.

FIG. 1B shows a block diagram of an exemplary driven laser system 180. The drive laser system 180 can be used as the drive laser system 115 in the light source 100. The drive laser system 180 includes three power amplifiers 181, 182, and 183. Any or all of the power amplifiers 181, 182, and 183 can include internal optical components (not shown).

Light 184 exits from the power amplifier 181 via an output window 185 and is reflected off a curved mirror 186. After reflection, the light 184 passing through a spatial filter 187 is reflected off a curved mirror 188 and enters the power amplifier 182 via an input window 189. The light ray 184 is amplified and redirected from the power amplifier 182 from the power amplifier 182 as a light ray 191 via an output window 190. The ray 191 is directed to the amplifier 183 by a folding mirror 192 and enters the amplifier 183 via an input window 193. The amplifier 183 amplifies the light 191 and directs the light 191 from the amplifier 183 via an output window 194 as an output beam 195. A folding mirror 196 directs the output beam 195 upward (from the page) and toward the beam transport system 120.

The spatial filter 187 defines an aperture 197, which may be, for example, a circle having a diameter between about 2.2 mm and 3 mm. The curved mirrors 186 and 188, for example, may be off-axis parabolic mirrors having focal lengths of about 1.7, respectively. Metric and 2.3 meters. The spatial filter 187 can be positioned such that the aperture 197 coincides with a focus of the drive laser system 180.

Referring again to FIG. 1A, the light source 100 includes a collector mirror 135 having an aperture 140 to allow the amplified beam 110 to pass through and reach the target location 105. The collector mirror 135, for example, can be an ellipsoidal mirror having a primary focus at the target location 105 and a primary focus (also referred to as an intermediate focus) in an intermediate location 145, wherein the EUV light can The light source 100 is outputted and can be input to, for example, an integrated circuit beam positioning tool (not shown). The light source 100 can also include an open ended, hollow conical shroud 150 (eg, a gas cone) that is tapered toward the target location 105 by the collector mirror 135 to reduce plasma generation into the focusing assembly 122. And/or the total amount of debris of the beam transport system 120 while allowing the amplified beam 110 to reach the target location 105. To this end, an air flow directed to the target space 105 can be provided in the shield.

The light source 100 can also include a main controller 155 coupled to a droplet detection feedback system 156, a laser control system 157, and a beam control system 158. The light source 100 can include one or more targets or droplet imagers 160 that provide a droplet, for example, an output indication relative to the location of the target location 105, and provide this output to the droplet detection feedback System 156, for example, can calculate droplet position and orbit, from which a droplet position error can be calculated on a droplet-to-microdrop basis or on an average basis. The droplet detection feedback system 156 thus provides the droplet position error as an input to the main controller 155. The main controller 155 can thus provide a laser position, direction and timing correction signal, for example, to the laser control system 157, available For example, controlling the laser timing circuit and/or providing to the beam steering system 158 to control the beam position and shaping operation of one of the beam delivery systems 120, changing the focal spot of the beam within the vacuum chamber 130 Or power.

The target material delivery system 125 includes a target material delivery control system 126 that can be actuated after sensing a signal originating from the primary controller 155, for example, to correct when a target material supply device 127 releases droplets. The release points of the droplets correct the errors of the droplets arriving at the desired target location 105.

In addition, the light source 100 can include a light source detector 165 to measure one or more EUV light parameters including, but not limited to, pulse energy, energy distribution as a function of wavelength, energy in a particular wavelength band, and a specific wavelength band. The energy, as well as the angular distribution of EUV intensity and/or average power. The light source detector 165 generates a feedback signal for use by the main controller 155. The feedback signal, for example, can be an error in the indicated parameters, such as the timing and focus of the laser pulses, to properly intercept the droplets at the correct location and for efficient and efficient generation of EUV light. .

The light source 100 can also include a guiding laser 175 that can be used to align the different segments of the light source 100 or to facilitate manipulation of the amplified beam 110 to the target location 105. In connection with the pilot laser 175, the light source 100 includes a metrology system 124 disposed within the focus assembly 122 to sample a portion of the light from the pilot laser 175 and the amplified beam 110. In other implementations, the metrology system 124 is housed in the beam transport system 120. The metrology system 124 can include an optical component that samples or redirects a subset of rays that is capable of resisting directing the laser beam and the amplification The material of the power of the beam 110 is made of any material. A beam analysis system is comprised of the metrology system 124 and the main controller 155 because the main controller 155 analyzes the sampled light originating from the pilot laser 175 and uses this information to adjust via the beam control system 158. The components within the focus assembly 122.

Thus, in summary, the light source 100 produces an amplified beam 100 that is directed along the beam path to illuminate the target mixture 114 at the target location 105 for converting the target material within the mixture 114 to The plasma of the emitted light in the EUV range. The amplified beam 110, which is determined according to the design and characteristics of the laser system 115, operates at a particular wavelength (also referred to as a source wavelength). Moreover, the amplified beam 110 may be provided when the target material provides sufficient feedback into the laser system 115 to produce coherent laser light or if the drive laser system 115 includes suitable optical feedback to form a laser chamber. A laser beam.

Referring to FIG. 2A, a top view of an exemplary optical imaging system 200 is shown. The optical imaging system 200 includes an LPP EUV source 205 that provides EUV light to a lithography tool 210. The light source 205 can be similar to and/or include some or all of the components of the light source 100 of FIGS. 1A and 1B.

As discussed in more detail below, to increase the total amount of EUV light generated by the light source 205, the light source 205 includes a beam positioning system 260 that maintains an illumination amplified beam 216 in three dimensions during operation of the source 205. The position relative to a target material 246. The beam localization system 260 receives and measures a property of the reflected amplified beam 217 produced when the illumination amplified beam 216 is reflected from at least a portion of the target material 246. quality. The nature of these measurements is used to determine and monitor the location of the illumination amplified beam 216 in multiple dimensions. The beam positioning system 260 is discussed in more detail with respect to FIG.

The light source 205 includes a drive laser system 215 that produces the illumination amplified beam 216, a steering system 220, a vacuum chamber 240, the beam positioning system 260, and a controller 280. The steering system 220 receives the illumination amplified beam 216 and manipulates and focuses the illumination amplified beam toward a target location 242 located in the vacuum chamber 240. The steering system 220 includes optical elements 222 and 224. In the example shown in FIG. 2A, the optical element 222 is a portion of a reflective optical element that receives the illumination amplified beam 216 and reflects the illumination amplified beam 216 toward the optical element 224 and the focusing system 226.

The component 224 can be a collection of optical and/or mechanical components, such as a beam transport system, that receives the illumination amplified beam 216 and manipulates the illumination amplified beam 216 as desired toward the focusing system 226. The component 224 can also include a beam expansion system that extends the illumination amplification beam 216. An exemplary beam-expansion system is described in U.S. Patent No. 8,173,985, filed on Dec. 15, 2009, which is hereby incorporated by reference herein in This case is considered as reference material.

The focusing system 226 includes a focusing optic that receives the illuminated amplified beam 216 and focuses the beam 216 to a focus position. The focus position is a location or area within a focal plane 244 of the vacuum chamber 240. The focusing optical element can be a collection of refractive optical elements, a reflective optical element, or an optical element comprising both refractive and reflective optical components. The focusing system 226 can also include additional optical components, such as a rotary A mirror capable of positioning the focusing optic relative to an amplified beam passing through the focusing optic.

2B and 2C, the vacuum chamber 240 receives the target material 246 at the target region 242. 2B shows a side perspective view of the light source 205, and FIG. 2C shows a cross-sectional plan view of the light source 205 taken along line 2C-2C. The target material 246 can be a metal droplet that is included in the target material stream 248 that is released from a target material supply device 247. The target material stream 248 is released from the target material supply device 247 and travels toward the target location 242 along the "x" direction. The illumination amplified beam 216 strikes the target material 246 and can be reflected to produce and/or be absorbed by the reflected amplified beam 217. The reflected amplified beam 217 propagates away from the target location 242 in a "-z" direction opposite the direction in which the illumination amplified beam 216 propagates toward the target material 246. The reflected amplified beam 217 travels through all or part of the steering system 220 and into the beam positioning system 260.

As discussed above, EUV light is generated as the target material 246 is converted to plasma. When the target material 246 is anchored at the most desirable position of the beam of the amplified beam 216, the target material 246 is more likely to be converted to plasma. The most desirable location for the focal length of the beam is the location at which the maximum EUV light is produced. The most desirable position may be at two points along the direction of propagation of the magnified beam. For example, there may be two most desirable locations within the focal length of the beam, one location upstream of a minimum point location (in the "-z" direction) and the other location downstream of the minimum point location (in the "z" direction). . In another example, the optical location within the focal length of the beam can be at The minimum point position is such that the focus position coincides with the target material 246.

Thus, controlling the position of the illumination amplified beam 216 to maintain a constant focus position relative to the target material 246 while the source 205 is in operation, can be optimal by maintaining the target material 246 Increase in position produces EUV light. In other words, actively aligning the illumination amplification beam 216 with respect to the target material 246 can improve the performance of the source 205.

Referring again to FIG. 2A, the beam positioning system 260 measures information indicative of the position of the illumination amplified beam 216, the focus position, and/or the focal plane 244, and provides the information to the controller 280 via an interface 262. The interface 262 can be any wired or wireless communication mechanism that allows for the exchange of data between the controller 280 and the beam positioning system 260. The controller 280 includes an electronic processor 282 and an electronic storage device 284. The controller 280 uses information indicative of the location of the illumination amplified beam 216 to generate signals that are provided to the actuation system 227 and/or 228 via an interface 263.

The electronic storage device 284 can be a volatile memory such as a random access memory (RAM). In some implementations, the electronic storage device 284 can include both non-volatile and volatile portions or components. The electronic processor 282 can be one or more processors suitable for executing a computer program, such as a general or special purpose microprocessor, and one or more processors of any type of digital computer. Generally, a processor receives instructions and data from a read-only memory or a random access memory or both.

The electronic processor 282 can be any type of electronic processor and can be more than one electronic processor. The electronic storage device 284 stores the finger Thus, as a computer program, when executed, the electronic processor 282 is caused to communicate with other components in the beam positioning system 260 and/or the controller 280.

The actuation system 227 includes one or more actuators coupled to one or more components of the focusing system 226. The actuators in the actuation system 227 receive signals originating from the controller 280 and, upon induction, cause one or more components in the focusing system 226 to move and/or change position. Due to the change in one or more optical elements in the focusing system 226, the focal plane 244 is moved in the "z" direction. For example, the measurements taken by the beam positioning system 260 may indicate that the focal plane 244 is not coincident with the target location 242. In this example, the actuation system 227 can include an actuator that is mechanically coupled to a mount that holds a lens that focuses the illumination amplified beam 216 to the focal plane 244. To move the focal plane 244 in the "z" direction, the actuator moves the lens in the "z" direction. The actuation system 227 can also move the focus position in the "x" or "y" direction by adjusting the rotary mirror and other optical components that can be included in the focusing system 226.

The actuation system 228 includes one or more actuators coupled to one or more of the elements 224. For example, the actuation system 228 can include an actuator that is mechanically coupled to a mount that holds a folding mirror (not shown). The actuator can move the folding mirror to manipulate the illumination amplification beam 216 in an "x" or "y" direction transverse to the "z" propagation direction.

The illumination amplifies the beam 216 by shifting the determined position of the illumination beam 216 according to the illumination and/or repositioning the elements 224 and 226. This is maintained therewith relative to the target material 246, thus increasing the total amount of EUV light produced by the source 205.

Referring to Figures 3A-3C, another example of an imaging system is shown. FIG. 3A shows a top view of an exemplary imaging system 300. FIG. 3B shows a side perspective view of the imaging system 300, and FIG. 3C shows a cross-sectional plan view of the imaging system 300 taken along line 3C-3C. The imaging system 300 is similar to the imaging system 200.

The imaging system 300 includes a light source 305 and the EUV lithography tool 210. The light source 305 includes a steering system 320 that receives an illumination amplified beam 216 originating from the driven laser system 215. The steering system 320 is similar to the steering system 220 except that the steering system 320 does not include the optical component 222 to direct the amplified beam 217 to the beam positioning system 260. Instead, the reflected amplified beam 217 is reflected from a window 335 of the driven laser system and is positioned on an optical element 340. The optical element 340 directs the reflected amplified beam 217 to the beam positioning system 260. The optical component 340 can be, for example, a plane mirror or a curved mirror. The window 335 can be a window on the power amplifier that is part of the drive laser system 215. For example, the reflected amplified beam 217 can be reflected from the window 194 of the amplifier 183 (Fig. 1B).

Referring to Figure 4, a block diagram of one example of the beam positioning system 260 is shown. The beam localization system 260 receives the reflected amplified beam 217, separates the reflected amplified beam 217 into multiple channels, and measures the characteristics of the reflected amplified beam 217 located in each channel. The characteristics of the reflected amplified beam 217 are used to determine the amplified beam in multiple dimensions 216 is relative to the location of the target material 246. The first, second, and third channels 415-417 can be paths along which light travels in free space. In some implementations, the channels 415-417 can also include components that direct and at least partially include the light propagating in the channels, such as optical fibers and other waveguides.

The beam positioning system 260 includes a folding mirror 405 and partially reflective optical elements 410a and 410b. The partially reflective optical elements 410a and 410b can be, for example, a beam splitter or a partial mirror. The folding mirrors 405 manipulate the reflected amplified beam 217 through the beam positioning system 260. The partially reflective optical element 410a receives the reflected amplified beam 217 and reflects a portion of the beam 217 into the first channel 415. The partially reflective optical element 410b receives the transmitted portion of the beam 217 and reflects a portion of the light entering the second channel 416. The partially reflective optical element 410b transmits the remaining amplified amplified light beam 217 into the third channel 417.

Thus, a portion of the reflected amplified beam 217 travels in the first channel 415, the second channel 416, and the third channel 417. The portion of the reflected amplified beam 217 traveling in the first channel 415 is the beam 411, the portion traveling in the second channel 416 is the beam 412, and traveling in the third channel 417 This portion of the beam is the beam 413.

The beam positioning system 260 also includes an inductor 420 and an inductor 421. The sensor 420 is positioned to sense the beam 411, and the sensor 421 is positioned to sense the beam 412 and the beam 413. Data derived from the sensor 420 can be used to generate a representation including the beam 411 Image 424 of 426. Data derived from the sensor 421 can be used to generate an image 425 comprising a reproduction 428 of the beam 412 and a reproduction 430 of the beam 413. The focal plane 244 (Figs. 2A and 2B) and/or the focus position may be determined in a plurality of dimensions by analyzing the shape of the representations 426, 428, and 430 and/or the locations of the representations 426, 428, and 430. This location of the target material 246.

The sensors 420 and 421 acquire data at different acquisition rates and thus provide information relating to physical effects occurring on different time scales. In the example shown, the sensor 420 has a higher data acquisition rate than the sensor 421. The sensor 420 can have an acquisition rate similar to or the same as the repetition rate of the drive laser 215. In some implementations, the inductor 420 has an acquisition rate of at least about 50 kHz or a data acquisition rate of about 63 kHz. The high acquisition rate allows the sensor 420 to collect data that can be used to monitor high frequency system interference and occurrence, such as mirror vibrations in the beam delivery system 224 or vibrations in the trajectory of the target material stream 114, which can result in The location of the illumination amplified beam 216 rapidly changes in a direction transverse to the direction of propagation of the illumination amplified beam 216. The dimensions transverse to the direction of propagation of the illumination amplified beam 216 are included in the "x" and "y" directions shown in Figures 2A and 2B. The change in the lateral direction of the illumination amplified beam 216 in the lateral direction causes a corresponding change in the location of the reflected amplified beam 217, and the changes can be measured by the inductor 420.

The sensor 421 has a lower data acquisition rate than the sensor 420 and can provide relatively more information than the sensor 420. The sensor 421 can have a data acquisition rate of, for example, about 48 Hz. The sensor 421 can be any sensor that is sensitive to the wavelengths included in the reflected amplified beam 217. For example, the sensor 421 can be a PYROCAM camera sold by Ophir-Spiricon, LLC of North Logan, Utah, USA. Although the example shown in FIG. 4 includes a single sensor 421 to generate an image 425, in other implementations, individual sensors may be used for the second channel 416 and the third channel 417, respectively. Each of the devices can generate a different image of the reproduction of the light traveling in the respective channel.

The beam positioning system 260 also includes optical elements in each of the channels 415, 416, and 417. The channel 415 includes an optical element 442, which may include, for example, a lens or other component capable of focusing the beam 411 onto the inductor 420. Referring also to Figures 5A-5C, the sensor 420 of the example of Figure 4 is a quadrant sensor that includes multiple, individual sensing elements 422a-422d arranged in a square array. To measure the position of the beam 411 on the sensor 420, the total amount of energy sensed at each of the sensing elements 422a-422d is measured. An example of determining the location of the beam 411 on the sensor is discussed below with respect to FIG.

To ensure accurate measurement of the position of the reflected amplified beam 217, the diameter of the beam 411 at the sensor 420 is greater than the diameter of any of the sensing elements 422a-422d, but less than the sensing elements. The diameter of the square array is defined by 422a-422d. In this configuration, the beam 411 tends to land on more than one of the sensing elements 422a-422d of the inductor 420. In order to form a sensor on the sensor 420 With respect to a relatively large diameter beam, the optical element 432 can be positioned such that the beam 411 is not focused on the inductor 420. In other words, the optical element 432 can be positioned in a defocused state such that the sensor 420 detects the beam 411, but the beam 411 is not focused on the inductor 420. In some implementations, the optical component 432 can include one or more optical components to expand the light to form a relatively large spot of light on the inductor 420.

The beam positioning system 260 also includes the optical element 434 positioned in the channel 416. The optical element 434 is positioned in the channel 416 between the partially reflective optical element 410b and the inductor 421. The optical element 434 receives and transmits light reflected from the optical element 410b, and thus the position or focus position of the focal plane 244 in the "z" direction can be determined. The optical element 434 can include an astigmatic optical element that corrects the focus of the wavefront and changes the ellipticity of the reproduction 428 as the focal plane 244 moves in the "z" direction. An example of an implementation of the optical element 434 comprising an astigmatic optical element is shown in FIG.

In some implementations, the optical component 410b includes a collection of optical components, wherein no optical components are astigmatic, and a path of different lengths is provided for the reflected amplified beam 217 to propagate from the target material 246 to the inductor 421. . In such an implementation, the size of the beam diameter of the reflected amplified beam 217 is measured to provide a location indicative of the focal plane 244 in the "z" direction and the focal length of the focus. An example of an implementation of the optical element 436 that does not include an astigmatic optical element is shown in FIGS. 12 and 14.

The beam positioning system 260 also includes the optical element 436 positioned between the optical element 410b and the inductor 421. The optical component The light beam 413 is received and directed toward the inductor 421. The light sensed by the sensor 421 is used to form the reproduction 430. In conjunction with measuring the location of the reflected amplified beam 217 on the inductor 420, the location of the reproduction 430 provides the illumination amplified beam 216 in a dimension transverse to the direction of propagation of the illumination amplified beam 216 relative to the target. A second indication of the location of material 246.

For its part, the beam localization system 260 provides multiple measurements of the position and/or shape of the reflected amplified beam 217. The system 260 provides two measurements, one of which results from the sensor 420 having a relatively high data acquisition rate and the other measurement resulting from the sensor 421 having a relatively low data acquisition rate that can be used to illuminate the illumination. The amplified beam 216 is positioned relative to the target material 246 in a dimension transverse to the direction of propagation of the illumination amplified beam 216 ("x" or "y"). The system 260 also provides measurements that can be used to position the focal plane 244 or focus position relative to the target material 246 in the direction of propagation of the illumination amplified beam 216.

The beam positioning system 260 can also include a spectral filter 442 that can be removed from the beam path. The spectral filter transmits some wavelengths while blocking other wavelengths. In some implementations, the illumination beams of the two different pulses are directed toward the target material 246. The two-illuminated amplified beam is regarded as a main pulse and a pre-pulse. The main pulse and the pre-pulse are separated in time such that the pre-pulse is directed toward the target material 246 prior to the main pulse. The main pulse and the pre-pulse can have different wavelengths. For example, the pre-pulse can have a wavelength of about 1.06 microns and the main pulse can have a wavelength of about 10.6 microns. The illumination amplification beam 216 includes a pre-pulse and a In the example of a main pulse, the reflected amplified beam 217 can include the reflection of the main pulse and the pre-pulse.

When arranged to receive the reflected amplified beam 217, the spectral filter 442 separates the pre-pulse from the main pulse, allowing the beam positioning system 260 to use either or both of the pre-pulse and the main pulse The illumination amplified beam 216 is determined to be relative to one of the target locations 242. In some examples, the pre-pulse provides a closer focus and more accurate results than the main pulse.

Referring to Figures 5A-5C, an example of the beam 411 on the inductor 420 is shown. The beam 411 travels through the channel 415 to the inductor 420 where it forms a spot 505. When the illumination beam 216 is aligned with the target material 246, the beam 411 falls in the center of the inductor 420 and each sensing element 422a-422d senses an equal amount of energy. When the illumination amplified beam 216 is misaligned relative to the target material 246 in a lateral dimension (eg, "x" or "y" as shown in Figures 2A-2C), the spot 505 is associated with the illumination The misalignment of the magnified beam 216 corresponds to a distance from the center of the inductor 420.

Figures 5A-5C show the spot 505 at three different times. In FIGS. 5A and 5C, the spot 505 is off-center, indicating that the illumination amplified beam 216 is misaligned relative to the target location 242 in a lateral direction. In FIG. 5B, the spot 505 is positioned at the center of the sensor 420, indicating that the illumination amplified beam 216 is aligned relative to the target in a lateral direction. As discussed above, the change in the location of the spot 505 on the sensor 420 is indicative of the high frequency in the location of the illumination amplified beam 216. The rate changes.

Referring to Figure 6, an example of the difference in the total amount of energy on the sensing elements 422a-422d as a function of the lateral distance between the target material 246 and the focal position is shown. 6 shows the reaction of the inductor 420 as the target material 246 moves relative to the illumination magnifying beam 216 on the vertical plane (the "y" direction shown in FIG. 2A).

Referring to Figure 7, a block diagram of another exemplary beam positioning system is shown. The beam positioning system 700 can be used in conjunction with the light source 100, 205 or 305 instead of the system 260. The beam positioning system 700 includes an astigmatic optical element to measure the location of the focus position relative to the target material 246.

The beam positioning system 700 includes a folding mirror 705 and partially reflective optical elements 710a and 710b. The partially reflective optical elements 710a and 710b may be, for example, a beam splitter or a partial mirror. The beam positioning system 700 receives the reflected amplified beam 217 and divides the beam 217 into three individual channels 715, 716, and 717. The reflected amplified beam 217 impacts the partially reflective optical element 710a and a portion (beam 711) is reflected into the first channel 715. The first channel 715 is also considered a fast lateral channel. A folding mirror 705 directs the beam 711 toward the optical element 732, and the optical element 732 directs and/or focuses the beam 711 onto a sensor 720. The optical element 732 is similar to the optical element 432 (FIG. 4), and the sensor 720 is a quadrant sensor 720 similar to the inductor 420 (FIG. 4).

The partially reflective optical element 710b receives the portion of the return beam 217 transmitted by the reflective optical element 710a. Reflective optical element The portion of the return beam 217 transmitted by the member 710b enters the third channel 717 as the beam 713. This third channel 717 is considered to be the "slow lateral channel". The folding mirror 705 directs the beam 713 through the third channel 717 to an optical element 736 that focuses and/or directs the beam 713 to the inductor 721. The data collected by the sensor 721 can be used to generate an image 750 that includes a spot 752 representing the beam 712 and a spot 754 representing the beam 713.

The partially reflective optical element 710b reflects a portion of the channel 716 as a beam 712. This channel 716 is considered to be the "slow z channel". The partially reflective optical element 710b directs the beam 712 to the optical assembly 734, which focuses and directs the beam 712 to an inductor 721. The inductor 721 is similar to the inductor 421 (Fig. 4). The beam 712 enters and passes through the components of the optical assembly 734, exits the optical assembly 734 and is sensed by the inductor 421. The beam 712 forms a spot on the inductor 421.

The optical assembly 734 includes a flat reflective element 740, a spatial filter 741, an astigmatic optical element 746, and a lens 748. The flat reflective element 740 can be a flat mirror. The astigmatic optical element 746 is, for example, a cylindrical lens or mirror, a collection of cylindrical lenses and mirrors, or a double-cone mirror.

The beam 712 enters the optical assembly 734 and is reflected from the planar reflective element 740 into the spatial filter 741. The spatial filter 741 includes a lens 742, a lens 743, and an aperture 744. The aperture 744 defines a pair of openings 745 positioned at the focus of the lens 742, and the aperture 744 filters the beam 712 before the beam 712 reaches the inductor 721. Let The beam 712 passes through the opening 745 to help remove background radiation and scattering originating from the beam 712. The flat mirror 705 used with the spherical optical element 736 allows the position of the focus to be more accurately measured in the "x" and/or "y" direction than a channel comprising a cylindrical or astigmatic optical element.

The lens 743 collimates the beam 712 and directs the beam to the astigmatic optical element 746. After passing through the astigmatic optical element 746, the beam 712 passes through the lens 748 and forms a spot on the inductor 721. Since the optical assembly 734 includes a astigmatism element, the ellipticity of the spot changes as the focus position of the illumination amplified beam 216 moves in a direction of propagation relative to the target material 246.

Referring to Figures 8A-8C and 9A-9B, an example of a different relative configuration of the focal plane 244 and the target material 246 and an exemplary image produced by the inductor 721 are shown. Figures 8A-8C show an example of the movement of the focus position resulting from the heating and/or operation of the optical components in the optical components in the "z" and "y" directions. Figures 9A-9C respectively show exemplary images 750A-750C resulting from data collected by the sensor 721.

In the beam positioning system 700, the beam 712 travels through the channel 716 and is received by the inductor 721. The beam 713 travels through the channel 717 and is received by the inductor 721. The optical components of the channels 716 and 717 are aligned such that light from the channel 716 falls on the left side of the sensor 721, and light from the channel 717 falls on the sensor 721. On the right side. Thus, the left side of the images 750A-750C shows that one of the beams 712 is reproduced, and the right side of the images 750A-750C shows that one of the beams 713 is reproduced.

The image 750A of FIG. 9 shows an image produced by the sensor 721 when the sensor 721 monitors a situation similar to that of FIG. 8A, wherein the focal plane 244 coincides with the target material 246. In this example, there is no displacement between the target material 246 and the focal position in the "z" or "y" direction and the illumination amplified beam 216 is aligned with the target material 246. The image 750A indicates the alignment state because the reproduction 752A of the beam 712 (which passes through the optical assembly 734 and the astigmatism optical element 746) is circular. In addition, the reproduction 754A of the light beam 713 coincides with the center of the right side of the inductor 721, indicating that the illumination amplified beam 216 is in phase with the target material 246 in the "y" direction shown in FIG. 8A. Consistent.

The image 750B of Figure 9B shows an image produced by the sensor 721 when the sensor 721 monitors a situation similar to one of Figure 8C. In this example, the target material 246 is displaced from the focus position in the "z" and "-y" directions. The image 750B indicates this and the ellipticity of the reproduction 752B on the sensor 751 and the location of the reproduction 754B is misaligned. In particular, the horizontal axis of the reproduction 752B is wider than the vertical axis, indicating that the focus position is displaced relative to the target material 246 in the "-z" direction. The reproduction 754B of the beam 713 has been shifted to the left as compared to the reproduction 754A, indicating that the target material 246 is displaced relative to the target material 246 in the "-y" direction.

The image 750C of Figure 9C shows an image produced by the sensor 721 when the sensor monitors a situation similar to one of Figure 9C. In this example, the target material 246 is tied behind and below the focal position. The image 750C indicates that the ellipticity of the reproduction 752C on the sensor 751 and the location of the reproduction 754C are misaligned. In particular, the reproduction of the light beam 712 is 752C The vertical axis is wider than the horizontal axis, indicating that the target material 246 is displaced from the focus position in the "-z" direction. The reproduction 754C indicates that the target material 246 is displaced relative to the target material 246 in the "y" direction.

FIG. 10A shows that the ellipticity of the reproduction of the beam 712 varies with the position of the target material 246 in the "z" direction. The ellipticity is zero when the focal position of the illumination amplified beam 216 coincides with the target material 246. This context is shown in Figures 8A and 9A. When the focus position is formed prior to reaching the target material 246, the ellipticity is negative (the horizontal axis is greater than the vertical axis), as shown in Figures 8B and 9B. When the focus position is formed after the target material 246, the ellipticity is positive (the horizontal axis is less than the vertical axis), as shown in Figures 8C and 9C.

FIG. 10B shows an example of the position of the center of the reproduction of the beam 713 as the position of the target material 246 in the "y" direction. When the centroid is located to the left of the center of the right side of the inductor 721, the centroid is understood to have a negative value and the target material 246 is positioned in the "-y" direction relative to the focus position. Upper (Figure 8B). When the centroid is located to the right of the center of the right side of the inductor 721, the target material 246 is positioned in the "y" direction relative to the focus position (Fig. 8C).

11 is a block diagram of another exemplary beam positioning system 1100. The beam positioning system 1100 can be used in conjunction with the light source 205 or 305 to replace the beam positioning system 260 or the beam positioning system 700. The beam positioning system 1100 includes three channels through which the reflected amplified beam 217 travels, and the beam positioning system 1100 provides data for positioning the illumination amplified beam 216 in multiple dimensions relative to the target material 246. Beam locating system The system 1100 includes one or more astigmatic optical elements in a channel for being in a direction parallel to the direction of propagation of the illumination amplified beam 216 (in the "z" direction shown in Figure 2B) The illumination amplification beam 216 is provided.

The beam positioning system 1100 also includes a spectral filter 1142. The spectral filter 1142 is similar to the spectral filter 442 discussed with respect to FIG. The beam positioning system 1100 receives the reflected amplified beam 217. The reflected amplified beam 217 impacts a portion of the reflective optical element 1110a, and a portion of the reflected amplified beam 217 is reflected into a channel 1115. The reflected amplified beam 217 reflected into the portion of the channel 1115 is the beam 1111. The beam 1111 passes through the optical element 1132 to the inductor 1120. The optical element 1132 can be similar to the optical element 432 (FIG. 4) and the sensor 1120 can be the quadrant detector 420 discussed with respect to FIG.

The portion of the reflected amplified beam 217 transmitted by the partially reflective optical element 1110a is divided into beams 1112 and 1113 by a portion of the reflective optical element 1110b. The beam 1112 travels in the channel 1116 and the beam 1113 travels in the channel 1117. The channel 1116 includes an optical component 1134, and the beam 1112 passes through the optical component 1134 to an inductor 1121. The optical element 1134 can be similar to the optical element 434.

The channel 1117 includes a polarizer 1140 coupled to a filter controller 1144, a flat reflective element 1146, a lens 1148, and an astigmatism optical element 1150. The polarizer 1140 and the spectral filter 1142 can be removed from the channel 1117. When the polarizer 1140 and the spectral filter 1142 are not in the channel 1117, the beam 1113 does not pass through the elements. The spectral filter 1142 can be located for a transmission A light beam in a first wavelength band and a spectral filter blocking light rays in a second wavelength band. The first wavelength band can include the wavelength of the pre-pulse, and the second wavelength band can include the wavelength of the main pulse. In this example, the spectral filter 1142 transmits the pre-pulse and blocks the main pulse. The spectral filter 1142 can include a plurality of spectral filters, one of which blocks the pre-pulse and transmits the main pulse, and another spectral filter blocks the main pulse and transmits the pre-pulse. The filter controller 1144 is configured to take the spectral filter 1142 out of the channel 1117 and to place the spectral filter 1142 in the channel 1117. In implementations where the spectral filter 1142 includes more than one filter, the filter controller 1144 allows one of more than one filter to be placed in the channel 1117.

The beam 1113 exits the astigmatism optical element 1150 and is sensed by an inductor 1152. The sensor 1152 and the sensor 1121 have a lower data acquisition rate than the sensor 1120. The sensor 1152 and the sensor 1121 may be PYROCAM cameras sold by Ophir-Spiricon, LLC of North Logan, Utah, USA. In some implementations, the beams 1112 and 1113 can be directed to a similar location so that only one sensor (the sensor 1152 or the sensor 1121) is required.

Referring to Figure 12, another exemplary optical assembly 1200 for use with a beam positioning system is shown. The optical assembly 1200 can be used in the beam positioning system 260 as an optical component 434 in which the optical assembly 734 is replaced or located in the channel 1117 in the beam positioning system 1100.

The optical assembly 1200 provides information that can be used to determine the position of the focus position relative to the target material 246 in the direction of propagation of the illumination amplified beam 216. The optical assembly 1200 does not include an astigmatic optical element. Instead, the optical assembly 1200 utilizes a plurality of non-astigmatic optical elements to create a series of optical paths, each path having a different length between the target material 246 and an inductor 1221. The portion of the return beam 217 traveling in each path is imaged on the sensor 1221. Since the paths have different lengths, the image of a beam that follows a particular path is an image of a cross-section of the illumination amplified beam 216 at a particular location along the direction of propagation. By analyzing a series of beam images that follow different paths, the location of the focus relative to the target material 246 can be determined and adjusted as needed.

The optical assembly 1200 includes a lens 1202 and partially reflective optical elements 1205a and 1205b. The optical assembly 1200 receives the return beam 217 originating from the light source 1204 (which may be similar to the light source 205 or 305). For purposes of illustration, Figure 12 shows two examples of the return beam 217 occurring at different times. A return beam 217a is a reflected amplified beam that is produced when the illumination amplified beam 216 is focused on the target location 242. The return beam shown in Figure 12 is the beam 217b. The return beam 217b is generated when the illumination amplified beam 216 reaches a focus before reaching the target material 246. Referring also to Figures 13A and 13B, a side view of a light source having the illumination amplified beam 216 focused on the target material is shown in Figure 13A. A side view of a light source having the illumination amplified beam 216 focused prior to reaching the target material 246 is shown in Figure 13B.

The beam 217a travels through the lens 1202 and is transmitted and reflected by the partially reflective optical element 1205a. The transmitting portion of the light beam 217a forms a spot 1210 on the inductor 1221. The reflected portion of the beam 217a is shown as a beam 1218a. The beam 1218a is reflected and transmitted by the reflective optical element 1205b. The portion of the light beam 217a reflected by the optical element 1205b forms a spot 1211 on the inductor 1221. The beam 217a travels through the lens 1202 and is transmitted and reflected by the partially reflective optical element 1205a. The transmitting portion of the light beam 217b forms a spot 1212 on the inductor 1221. The reflected portion (beam 1218b) of the beam 217b is reflected and transmitted by the reflective optical element 1205b. A portion of the beam 217b reflected by the reflective optical element 1205b forms a spot 1212 on the inductor 1221.

As shown in the image 1250, the lens 1202 brings the beam 217a to a focus at the sensor 1221. Therefore, the spot 1210 has a smaller diameter. The beam 1218a follows a longer path to the sensor 1221 and reaches a focus at point 1225 before reaching the sensor 1221. The beam 1218a begins to diverge after the point 1225 and the spot 1211 has a larger diameter than the spot 1210.

The lens 1202 focuses the beam 217b to a point 1226 before the beam 217b reaches the sensor 1221. The beam 217b begins to diverge before reaching the sensor 1221. Thus, the spot 1221 formed by the beam 217b on the inductor has a larger diameter than if the beam 217b were focused at the sensor 1221. The path followed by the beam 1218b to the sensor 1221 is longer and the focus 1226 appears more Keep away from the sensor 1221. For its part, the spot 1213 formed by the beam 1218b has a larger diameter than the spot 1212.

By comparing the diameters of the spots 1212 and 1213, it is determined that the beam 217b is convergent, and the focal plane 244 and the focal position of the illumination magnifying beam 216 appear before the target material 246 (in the "- z" direction). The focal plane 244 can be adjusted to move toward the target material 246 along the direction of propagation or the target material 246 can be moved toward the location of the focal plane 244.

Referring to FIG. 13C, in an example, the amplified beam 216 has a focus position after the target material 246 (in the "+z" direction), the reflected amplified beam 217 is diverged, and the spot 1213 has a spot. 1212 is a large diameter. Thus, the focus position of the magnified beam 216 can be adjusted to move closer to the desired location of the target material 246. In other words, the focus position of the magnified beam 216 can be moved toward the target location 247 by moving the focus position in the "-z" direction.

Referring to Figure 14, an example of another optical assembly 1400 is shown. The optical assembly 1400 is similar to the optical assembly 1200 except that the optical assembly 1400 includes five partially reflective optical elements 1405a-1405e. The optical assembly 1400 can be used in a beam positioning system in place of the optical assembly 1200.

The partially reflective optical elements 1405a-1405e respectively provide a path of a different length from the target material 246 to the inductor 1221 and produce corresponding spots 1410-1414 on the sensor 1221. In the example shown in FIG. 14, a lens 1402 focuses a collimated return beam 217, which is produced when the focus position of the illumination magnifying beam 216 coincides with the target material 246. Raw, a spot 1412 on the sensor 1221. Thus, the spot 1410, as compared to the spot 1412, is a measure of a different cross-section of the return beam 217 having a larger diameter. In this example, the spot 1412 has the smallest diameter of the spots 1410-1414.

By comparing the diameters of the spots 1410-1414, the location of the focus position of the magnified beam 216 relative to the target material 246 (or target location 242) can be determined. For example, if the smallest diameter spot is a spot 1410, the focus of the illumination amplified beam 216 can be adjusted, for example, to move toward the target material 246 along the direction of propagation or the target material 246 can be moved toward The focal plane 244 and the location of the focal position. If the smallest diameter spot is a spot 1414, the focus of the illumination amplified beam 216 can be adjusted to move away from the target material 246.

Although the example of Figure 12 shows two partially reflective optical elements 1205a and 1205b, and the example of Figure 14 shows five partially reflective optical elements 1405a-1405e, other numbers of reflective optical elements can be used.

FIG. 14B shows an exemplary flow 1400B for adjusting a focus position of the amplified beam 216 using a non-dispersive optical element such as the assembly 1200 or 1400. The process 1400B can be performed based on data collected using the assembly 1200 or 1400 alone or using the assembly 1200 or 1400 as part of any of the beam positioning systems 260, 700, or 1100. The process 1400B can be performed by the controller 280 and/or an electronic processor in one or more of the sensors of the beam positioning system. In the following discussion, the process 1400 is related to the beam positioning system 260, the assembly. 1400 and the sensor 1221 are discussed.

The return beam 217 interacts with at least one optical element to form a plurality of beams, each beam following a different length path to the inductor 1221 and each beam individually forming a spot 1410 on the inductor 1221. 1414 (1450). The returning beam 217 interacting with the at least one optical element can include passing the return beam 217 through the lens 1402 to focus the return beam 217. In other implementations, the returning beam 217 interacting with the at least one optical element can include reflecting the returning beam 217 from a reflective element such as a curved mirror that focuses the returning beam 217.

The returning beam 217 interacting with the at least one optical element includes passing the returning beam 217 through at least a portion of the reflective element to form a plurality of beams. Each beam follows a different length path from the target material 246 and/or lens 1202 to the sensor 1221 and forms a spot on a different portion of the sensor 1221 (as shown in FIG. 12). For example, as shown in FIG. 14, five reflective elements can be used to divide the return beam 217 into five beams, each beam following a different length path to the inductor 1221. More or fewer reflective elements can be used. The reflective elements can be, for example, beam splitters, partial mirrors, or any other optical element that splits the beam into two or more beams propagating along different paths.

Each of the plurality of beams forms a spot on the inductor 1221. The diameter of the spot varies due to different length paths between the lens 1402 and the sensor 1221 for each of the plurality of beams. Due to the change in path length to the sensor 1221, the spots 1410-1414 on the sensor 1221 can be understood as being different along the direction of propagation. A sample of the cross section of the beam taken at the plane. Comparing the relative dimensions of the spots 1410-1414 provides an indication of the focus of the illumination amplified beam 216 relative to the target material 246 in the direction of propagation of the illumination amplified beam 216.

The size of each spot in the complex spots 1410-1414 is determined (1460). The size, for example, can be the spot or a diameter of a region of the spot. The determined dimensions are compared (1470). A location of the focus position of the magnified beam 216 is determined based on the comparison (1480). For example, the sensor 1221, the reflective elements 1405a-1405e, and the lens 1402 can be disposed opposite each other such that if the focus position of the amplified beam 216 partially overlaps the target material 246, such that the return beam passes through the lens 1402. Upon collimation, the return beam 217 is focused at the spot 1412. In this example, if the spot 1411 is measured to be smaller than the spot 1412, the focus position of the magnified beam 216 does not partially overlap the target material 246. For example, the return beam 217 can be converged to replace collimation, which can indicate that the focus position of the magnified beam 216 should be moved toward the target location 242 in the "+z" direction. Other implementations may have such optical components of the light source 1204 arranged in a different configuration. For example, in other implementations, a converged return beam 217 can indicate that the amplified beam 216 should move relative to the target location 242 in the "-z" direction.

To position the focus position of the illumination amplified beam 216 in the "z" direction (the direction of propagation of the beam 216), one or more actuators in the actuation systems 228 and 227 move the beam a mirror, lens and/or mount in the transport system 224 and/or the focusing system 226 (Fig. 2A) to manipulate the The illumination amplification beam 216 is directed toward the target material 246. Where the process 1400B is performed, in whole or in part, by or with the controller 280, the location of the focus location may be provided to or calculated by the controller 280, and the control The 280 can generate a signal corresponding to the total amount used by the components in the delivery system 224 and/or the focusing system 226 to move or adjust the location of the focus of the amplified beam 216.

Referring to Figures 15A-15C, an exemplary image produced by an inductor is shown that includes two channels of a beam positioning system of the optical assembly 1200. The beam positioning system can be any of the beam positioning systems 260, 700 or 1100, allowing the optical assembly 1200 to be used in channels 316, 716 or 1116, respectively. Image 1505A-1505C displays an image of the sensor at three different times as the focus position of the illumination amplified beam 216 moves relative to the target material 246. The left side of the images 1505A-1505C displays spots 1210 and 1211. Referring also to Figure 12, the spot 1210 is the spot that is produced when the return beam 217 passes the lens 1202 before it reaches the sensor 1221. Spot 1211 is the spot produced by the return beam 217 as it passes through the lens 1202 and is reflected off the partially reflective optical elements 1205a and 1205b before reaching the sensor 1221.

In the image 1505A, the spot 1210A has a larger diameter than the spot 1211A, indicating that the focus position of the illumination amplified beam 216 occurs prior to reaching the target material 246. In the image 1505B, the spot 1210B has a smaller diameter than the spot 1211B, indicating that the focus position of the illuminated magnified beam 216 occurs after reaching the target material 246. Therefore, an adjustment of the focus position is completed according to the image 1505A. The position is in the correct direction, but the focus position does not partially overlap the target material 246. In the image 1505C, the spot 1210C is punctiform, indicating that the lens 1202 focuses the beam 217 on the sensor 1221, and, therefore, the illumination amplified beam 216 is focused on the target material.

The right side of the images 1505A-1505C displays a spot 1520A-1520C as an image of a portion of the return beam 217 that travels through the channel 317, 717 or 1116. Similar to the right side of the images 905A-905C (Figs. 9A-9C), the spots 1520A-1520C are displayed in a direction transverse to the direction of propagation of the illumination amplified beam 216. The illumination amplified beam 216 is relative to the target material. 246 moves. Image 1505A shows that the illumination amplified beam 216 is positioned above the target material 246 in the vertical plane (in the "y" direction in FIG. 2A), and image 1505B shows that the illumination amplified beam 216 is in the vertical plane (in Below the target material 246 in the "-y" direction in Figure 2B. At this time, as indicated in image 1505C, the illumination amplified beam 216 partially overlaps the target material 246 in the vertical plane.

Referring to Figure 16, an exemplary flow 1600 for aligning an illumination amplified beam with respect to a target material is shown. The process 1600 can be performed based on data collected using any of the beam positioning systems 260, 700, or 1100. The process 1600 can be performed by the controller 280 and/or an electronic processor in one or more of the sensors of the beam positioning system. In the discussion that follows, the process 1600 is discussed in relation to the beam positioning system 260.

The first, second, and third measurements of the amplified amplified beam are accessed (1610). The reflected amplified beam is a beam that reflects off the target material. For example, the reflected amplified beam can be the return beam 217. By a first induction The first measurement is obtained by the device, and the second and third measurements are obtained by a second sensor. For example, the first measurement can be obtained by the quadrant detector 420, and the second and third measurements can be obtained by the sensor 421. The first sensor has a higher data acquisition rate than the second sensor. As discussed above, sensors using different data acquisition rates allow the process 1600 to consider multiple physical effects, some of which occur in shorter time frames than others, resulting in a pair of the amplified light beams 216. Changes in quasi-work. The second and third measurements may be obtained by a single inductor, such as the sensor 421, or the second and third measurements may be obtained by two different sensors. Obtaining the second and third measurements from the same sensor can result in a beam positioning system that is relatively small and has fewer components. In some implementations, the second and third measurements are obtained by two different sensors, which may be the same.

Based on the first measurement, a first location (1620) of the illumination amplified beam 216 relative to the target material is determined. The first location is in a direction transverse to the direction of propagation of the illumination amplified beam 216. For example, the direction can be the "x" direction or the "y" direction shown in Figure 2B. Thus, the first location can be a location relative to the target material in the "x" or "y" direction. The first location can be represented as a value representing the distance between the illumination amplification beam 216 and the target material 246. In some implementations, the length of the segment may be the distance between the target material 246 of the focal plane 244 of the illumination amplification beam 216. The length of the segment may be the distance between the illumination amplification beam 216 and the target location 242 (a location intended to receive the target material). The length of the segment may be between the illumination amplification beam 216 The focal position is between the target location 242 or the target material.

In the implementation of the first sensor as the quadrant detector, the first location can be determined by the location of the spot 411 on the sensor 420. For example, if the spot 411 is tied to the left side of the sensor 420, the target material 246 is displaced from the focus position in the "y" direction. To determine the location of the spot 505 on the sensor 420, the energy sensed by each of the sensing elements 422a-422d is measured and compared.

When each sensing element 422a-422d receives the same amount of energy from the beam 411, the spot 505 is centered at the center of the inductor 420 and the illumination amplified beam 216 is in the lateral direction with the target material. 246 alignment. To determine that the spot 505 is offset from the center of the sensor 420, the energy is different at each of the sensing elements 422a-422d. The vertical offset of the spot 505 from the center can be deducted from the sum of the energy originating from the sensing elements 422a and 422b on the top portion of the sensor 420 at the bottom of the sensor 420. Partially determined from the sum of the energies of the sensing elements 422c and 422d. A negative value indicates that the center of the spot 505 is below the center of the sensor 420, and a positive value indicates that the center of the spot 505 is above the center of the sensor 420. The horizontal offset of the spot 505 is determined by subtracting the sum of the energy on the left side of the sensor 420 from the sum of the energies on the right side of the sensor 420. A negative value indicates that the center of the spot 505 is to the right of the center of the sensor 420, and a positive value indicates that the center of the spot 505 is located to the left of the center of the sensor 420.

Based on the total amount of offset, the controller 280 determines a corresponding one. The total amount is used to move one or more actuators in the actuation system 227 and/or the actuation system 228 for adjusting the illumination amplification beam 216 to align with the indicator material 246.

The difference in signal between the sensing elements 422a-422d can be determined by a single data frame derived from the inductor 420. In some implementations, the complex data frames originating from the inductor 420 are averaged prior to determining the lateral distance between the droplet and the illumination amplified beam 216. For example, 16 or 250 data frames originating from the sensor 420 may be averaged prior to determining the signal difference. Again, this signal difference can be divided by the total signal across all of the sensing elements 422a-422d.

Based on the second measurement, the illumination amplification beam 216 is determined relative to a second location of the target material (1630). The second location is also in a direction that is transverse to the direction of propagation of the illumination amplified beam 216 (the "x" or "y" direction of Figure 2A). The second location may be in a direction that is perpendicular to the first location. For example, if the first location is a distance between the target material 246 and the illumination amplification beam 216 in the "x" direction, the second location may be in the "y" direction. A distance between the target material 246 and the illumination amplified beam 216.

The second location is determined by data obtained using an inductor, such as the inductor 421, which has a lower data acquisition rate than the first sensor. Thus, the second and first locations provide different information even in the implementation of the second location and the first location along the same direction. For example, using the data derived from the first sensor to track the location of the illumination amplified beam 216 that changes with time in a particular direction. Displaying a high frequency change in the position of the illumination amplified beam 216, while tracking the change of the position of the illumination amplified beam 216 in the direction with time by using data derived from the second inductor, displayed in the forward direction Low frequency changes in the beam.

Based on the third measurement, the focus position of the amplified beam is determined relative to a location of the target material (1640). The location of the focus position of the illumination amplified beam 216 is determined to be in a direction parallel to the direction of propagation of the forward beam (in the "z" direction in Figure 2A). By measuring the ellipticity of a spot formed by the light passing through an astigmatic optical element (Figs. 7 and 11), or by using a series of non-astigmatic optical elements to produce a different horizontal display of the illumination amplified beam 216, respectively. The spots of the cross-section (Figs. 12 and 14) can determine the location of the focus relative to the target material 246.

The illuminating beam is repositioned relative to the target material based on the first location, the second location, or one or more of the focal planes to polarize the illuminating beam relative to the target material pair Standard (1650). To align the illumination amplification beam 216 in the "x" or "y" direction, one or more actuators of the actuation systems 228 and 227 move the beam delivery system 224 and/or the focusing system 226 ( 2A) an internal mirror, lens and/or mount to manipulate the illumination amplification beam 216 toward the target material 246. In the implementation of a pulsed forward beam, the illumination is delayed or advanced in the "x" direction by a period of time corresponding to the distance between the pulse and the target material. The amplified beam 216 can be aligned alternately or additionally in the "x" direction. To align the focal plane 244 or focus position of the beam 216 along the "z" direction, one or more actuators in the actuation system 227 move A lens in the focusing system 227 causes repositioning of the focal plane 244 and the focus position.

Other implementations are within the scope of the following patent application.

217‧‧‧Reflected amplified beam

260‧‧‧beam positioning system

405‧‧‧Folding mirror

410a, 410b‧‧‧Partial reflective optical components

411,412,413‧‧‧beam

415-417‧‧‧ channel

420,421‧‧‧ sensor

422a-422d‧‧‧Sensor components

424,425‧‧ images

426,428,430‧‧‧Reproduction

432,434,436‧‧‧Optical components

442‧‧‧Optical components/spectral filters

Claims (25)

A system for an extreme ultraviolet light source, the system comprising: one or more optical components positioned to receive a reflected amplified beam and configured to direct the reflected amplified light beam into the first, second, and third channels, the reflection The amplified beam includes a reflection of at least a portion of an illumination amplified beam that interacts with a target material; a first sensor that senses light from the first channel; a sense is derived from the second channel and a second sensor of the light of the third channel, the second sensor having a lower acquisition rate than the first sensor; and an electronic processor coupled to a computer readable storage medium, The computer readable storage medium storage instructions, when executed, causing the electronic processor to: receive data from the first sensor and the second sensor, and, based on the received data, determine the illumination amplified beam relative to the The target material is in one of more than one dimension. The system of claim 1, wherein the computer readable storage medium further stores instructions that, when executed, cause the electronic processor to determine an adjustment to the illuminated amplified beam based on the determined location. A system of claim 2, wherein the determined adjustments comprise a distance, in more than one dimension, to move the illumination to amplify the beam. The system of claim 1, wherein the instructions causing the electronic processor to determine the location of the illumination amplification beam include, when executed, causing the An electronic processor: determining, in a direction parallel to a direction of propagation of the illumination amplified beam, a location of the illumination amplified beam relative to a focus position of the target material, and determining a propagation of the amplified beam with the illumination One of the directions perpendicular to the first lateral direction, the illumination amplifies the direction of the beam relative to one of the focal positions of the target material. The system of claim 4, wherein the instructions further comprise, when executed, causing the electronic processor to determine one of the second transverse directions that is perpendicular to the first lateral direction and perpendicular to the direction of propagation of the illumination amplified beam The illumination illuminates the command at one of the intended focus positions of the amplified beam. The system of claim 1, further comprising an astigmatism optical element positioned in the third channel to modify a wavefront of the reflected amplified beam. The system of claim 1 further comprising a plurality of partially reflective non-astigmatic optical elements respectively positioned at a different one of the third channels and respectively receiving at least a portion of the reflected amplified beam, each of the multiple partially reflective optical elements One forms a beam that follows one of a different length between the target material and the second inductor. The system of claim 1, wherein the first, second, and third channels are three separate paths defined by one or more refractive or reflective optical elements that direct a portion of the reflected amplified beam. The system of claim 1, wherein the reflected amplified beam comprises a pre-pulse beam and a reflection of a driving beam, the driving beam being an amplified light The beam converts the target material into a plasma upon interaction, and the pre-pulse and drive beam comprise different wavelengths, and the system further includes one or more spectral filters that only the pre-pulse beam and the drive beam One of them is permeable. The system of claim 1, wherein the first sensor senses a light ray originating from the first channel at a high acquisition rate; the second sensor comprises a two-dimensional imaging sensor sensing derived from Light rays of the second channel and the third channel and measuring an intensity distribution of the light; and, when executed, causing the electronic processor to determine, based on the received data, the instructions of the one of the illumination amplified beams to cause The electronic processor is caused to determine a focus position of the illumination amplified beam in one or more dimensions relative to the target material. A method of aligning an illumination amplified beam from an extreme ultraviolet light system with respect to a target material, the method comprising: accessing a first, second, and third measurements of a reflected amplified beam, by a first The sensor obtains the first measurement, and the second and third measurements are obtained by a second sensor having a lower acquisition rate than the first sensor, and the reflected amplified beam is derived from the target material. Reflecting at one of the amplified beams; determining, according to the first measurement, a first direction of the illumination amplified beam relative to the target material in a direction perpendicular to a direction of propagation of the illumination amplified beam; according to the second measurement, Determining the illumination amplification beam relative to the target in a direction perpendicular to a direction in which the illumination amplification beam propagates a second location of material; determining, according to the third measurement, a location of the illumination amplification beam relative to a focus position of the target material in a direction parallel to a direction of propagation of the illumination amplification beam; and One or more of the first location, the second location, or the focus location repositions the illumination amplified beam relative to the target material to align the illumination amplified beam with respect to the target material. The method of claim 11, further comprising determining an adjustment to the focus position of the magnified beam based on the determined location of the focus position, and wherein the illuminating the beam repositioning operation comprises including the focus position The determined adjustment of the location moves the focus position of the illumination amplified beam. The method of claim 11, further comprising determining an adjustment to the amplified beam based on the one or more of the determining the first location or the determining the second location. The method of claim 13, wherein: the amplified beam can be a pulsed light, the determined first location comprising the amplified beam focus in a direction parallel to a direction in which the target material travels relative to the target material a location, and the determined adjustment for alignment with the magnified beam comprises a distance between the magnified beam and the target material in a direction parallel to a direction in which the target material travels, and The illuminating beam pulse repositioning operation is included in the amplified beam to produce a delay that matches the distance between the amplified beam and the target material such that a subsequent pulsed light intersects a target material . The method of claim 13, wherein: the determined second location includes a location of the amplified beam in a direction that is perpendicular to a direction of travel of the target material and perpendicular to a direction in which the amplified beam propagates, and for the amplified beam The determining adjustment of the alignment includes a distance between the magnified beam and the target material, and repositioning the illumination magnifying beam includes: generating an output based on the determined adjustment, the output being sufficient to cause Repositioning the optical assembly that manipulates the amplified beam; and providing an output to the optical assembly. The method of claim 11, further comprising determining an adjustment of the location of the focus position of the magnified beam based on the determined location of the focus position. The method of claim 12, wherein the illuminating the beam repositioning operation comprises: generating an output based on the determined adjustment of the location of the focus position, the output being sufficient to cause repositioning of an optical component that focuses the amplified beam; And providing an output to an optical assembly including the optical component. The method of claim 11, wherein the third measurement comprises the reflected amplified light An image of the beam, and an operation of determining a location of the focus of the magnified beam, includes analyzing the image to determine a shape of the reflected amplified beam. The method of claim 18, wherein analyzing the image to determine the shape of one of the reflected amplified beams comprises an operation of determining an ellipticity of the reflected amplified beam. The method of claim 11, wherein: the third measurement comprises an image of the reflected amplified beam sampled at the plurality of locations, and an operation of determining a location of the focus position of the amplified beam comprises comparing two or more of the plurality of locations The plurality of spaces reflect the width of the amplified beam. An extreme ultraviolet light system comprising: a source for generating an illumination amplified beam; a manipulation system that manipulates the illumination amplification beam toward a target material and focuses in a vacuum chamber; a beam positioning system comprising: a plurality of optical elements positioned to receive a reflected amplified beam reflected from the target material and configured to direct the reflected amplified beam into the first, second, and third channels; a first inductor, Sensing the light from the first channel; a second sensor comprising a two-dimensional imaging sensor for sensing light originating from the second channel and the third channel, the second sensor having a a lower acquisition rate than the first sensor; An electronic processor coupled to a computer readable storage medium, the computer readable storage medium storage instructions, when executed, causing the electronic processor to: receive data from the first sensor and the second sensor, And determining, based on the received data, a location of the illuminated amplified beam in one or more dimensions relative to the target material. The system of claim 21, wherein the computer readable storage medium further stores instructions that, when executed, cause the electronic processor to determine an adjustment of the location of the amplified light beam for the illumination based on the determined location. The system of claim 22, wherein the determined adjustment comprises an adjustment in one or more dimensions. The system of claim 23, wherein the electronic processor causing the electronic processor to determine the illumination of the amplified beam relative to a location of the target material comprises, when executed, causing the electronic processor to: determine the amplified beam with the illumination One of the directions in which the one direction of the propagation is parallel, the illumination amplifying beam is at a position relative to a focus of the target material, and is determined in a first and second lateral directions, each of which is coupled to the illumination amplification beam The direction of propagation is vertical, the illumination amplifying the focus of the beam relative to a location of the target material. The system of claim 21, wherein the instructions further comprise, when executed, causing the electronic processor to: determine the amplified beam according to the determined location of the amplified beam An adjustment of the output and the resulting output to the steering system.