Systems and methods for compact uniformity correction module (unicom)

Abstract

A uniformity correction system includes a first set of fingers, a second set of fingers, a first actuator coupled to the first set of fingers to independently move each finger of the first set of fingers, and a second actuator coupled to the second set of fingers to independently move each finger of the second set of fingers. The first and second actuators are arranged in a stacked assembly. Advantageously the stacked assembly can independently control each finger of the first and second sets of fingers into and out of a path of a radiation beam to correct an intensity of the radiation beam, decrease an overall volume (footprint) of the system, increase a transverse stiffness and an actuation speed of the first and second sets of fingers, arrange the first and second sets of fingers in the same plane, and increase cooling of the first and second actuators.

Description

SYSTEMS AND METHODS FOR COMPACT UNIFORMITY CORRECTION MODULE (UNICOM)CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority of US application 63 / 643,243 which was filed on May 6, 2024 and which is incorporated herein in its entirety by reference.FIELD

[0002] The present disclosure relates to uniformity correction apparatuses, systems, and methods, for example, compact uniformity correction apparatuses, systems, and methods to condition a radiation beam in a lithographic process.BACKGROUND

[0003] A lithographic apparatus is a machine constructed to apply a desired pattern onto a substrate. A lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). A lithographic apparatus may, for example, project a pattern of a patterning device (e.g., a mask, a reticle) onto a layer of radiation-sensitive material (resist) provided on a substrate.

[0004] To project a pattern on a substrate a lithographic apparatus may use electromagnetic radiation. The wavelength of this radiation determines the minimum size of features which can be formed on the substrate. A lithographic apparatus, which uses extreme ultraviolet (EUV) radiation, having a wavelength within the range 4-20 nm, for example 6.7 nm or 13.5 nm, may be used to form smaller features on a substrate than a lithographic apparatus which uses, for example, deep ultraviolet (DUV) radiation with a wavelength of 157 nm or 193 nm or 248 nm.

[0005] An illumination system of a lithographic apparatus can include a uniformity correction system to correct or reduce non-uniformities in a radiation beam before the radiation beam is incident on a patterning device. The uniformity correction system can employ actuated fingers that are inserted into a path of the radiation beam to correct intensity variations. However, multiple fingers are needed to more accurately control the uniformity of the radiation beam, which increases the overall size of the uniformity correction system and length of the fingers. Further, the longer length of the fingers can cause low stiffness in a transverse direction, which can result in slower actuation and decreased throughput and accuracy.SUMMARY

[0006] Accordingly, there is a need to, e.g., reduce an overall volume (footprint) of a uniformity correction system, increase a transverse stiffness of the fingers to improve stability, increase an actuation speed of the fingers to improve throughput and accuracy, arrange the fingers in the same plane (e.g., not stacked atop each other) to allow for longer travel range and increased control of a radiationbeam, utilize a stacked assembly (e.g., vertically aligned) of two or more actuators, and increase a cooling of the actuators with two or more channels.

[0007] In some aspects, a uniformity correction system can include a first set of fingers, a second set of fingers, a first actuator, and a second actuator. In some aspects, the first set of fingers can be configured to shape a radiation beam. In some aspects, the second set of fingers can be configured to shape the radiation beam. In some aspects, the first actuator can be coupled to the first set of fingers. In some aspects, the first actuator can be configured to independently move each finger of the first set of fingers. In some aspects, the second actuator can be coupled to the second set of fingers. In some aspects, the second actuator can be configured to independently move each finger of the second set of fingers. In some aspects, the first and second actuators can be arranged in a stacked assembly.

[0008] In some aspects, the first and second actuators can be vertically aligned in the stacked assembly. In some aspects, the stacked assembly can be configured to decrease an overall volume of the uniformity correction system. In some aspects, the overall volume can be no greater than 0.25 m3.

[0009] In some aspects, the stacked assembly can be configured to decrease a length of the first and second sets of fingers along a movement direction thereby increasing a transverse stiffness of the first and second sets of fingers in a transverse direction perpendicular to the movement direction. In some aspects, the transverse stiffness can be at least 10 N / m.

[0010] In some aspects, the stacked assembly can be configured to decrease a length of the first and second sets of fingers along a movement direction thereby increasing an actuation speed of the first and second sets of fingers into and out of a path of the radiation beam. In some aspects, the actuation speed can be at least 0.1 m / s.

[0011] In some aspects, the first and second sets of fingers can be configured to adjust an intensity cross-section of one or more portions of the radiation beam. In some aspects, the first and second sets of fingers can be configured to adjust a uniformity of the radiation beam. In some aspects, for example, the uniformity can be adjusted to provide a constant intensity across the entire radiation beam. In some aspects, for example, the uniformity can be adjusted to provide a target illumination (e.g., flat profile, non-flat profile, etc.) to a patterning device.

[0012] In some aspects, the first and second sets of fingers can be arranged in a plane. In some aspects, the first and second sets of fingers can be arranged adjacent to each other in the same plane. In some aspects, a length of the first and second sets of fingers in the plane can be increased. In some aspects, for example, the length of the first and second sets of fingers can be in a range of about 1 mm to about 25 mm. In some aspects, a range of travel of the first and second sets of fingers in the plane can be increased. In some aspects, for example, the range of travel of the first and second sets of fingers can be in a range of about 1 mm to about 25 mm.

[0013] In some aspects, the first set of fingers can be arranged in a first plane and the second set of fingers can be arranged in a second plane. In some aspects, the first and second planes can be coplanar. In some aspects, the first and second planes can be different. In some aspects, the first and second planescan be separated from each other along a direction perpendicular to the first and second planes (e.g., parallel planes).

[0014] In some aspects, a width of a tip of each of the first and second sets of fingers can be larger than a width of the first and second actuators. In some aspects, for example, the width of the tip of each of the first and second sets of fingers can be in a range of about 1 mm to about 10 mm. In some aspects, for example, the width of the first and second actuators (e.g., width of finger necks) can be in a range of about 0.1 mm to about 5 mm.

[0015] In some aspects, a width of a tip of each of the first and second sets of fingers can be larger than a spacing between fingers such that adjacent fingers overlap. In some aspects, for example, the width of the tip of each of the first and second sets of fingers can be in a range of about 1 mm to about 10 mm. In some aspects, for example, the spacing between fingers (e.g., a pitch) can be in a range of about 0.1 mm to about 5 mm.

[0016] In some aspects, a length of the first set of fingers can be different than a length of the second set of fingers. In some aspects, for example, the length of the first set of fingers can be in a range of about 1 mm to about 25 mm. In some aspects, for example, the length of the second set of fingers can be in a range of about 1 mm to about 25 mm.

[0017] In some aspects, the system can further include a frame having a plurality of channels configured to cool the first and second actuators. In some aspects, the first and second actuators can be disposed in the plurality of channels.

[0018] In some aspects, the first and second actuators can each include a coil plate assembly and corresponding magnets for linear actuation of each of the first and second sets of fingers. In some aspects, the first actuator can include a first coil plate and a first set of magnets adjacent the first coil plate to form a first linear motor to independently move one or more fingers of the first set of fingers. In some aspects, the second actuator can include a second coil plate and a second set of magnets adjacent the second coil plate to form a second linear motor to independently move one or more fingers of the second set of fingers.

[0019] In some aspects, the system can further include a third set of fingers configured to shape the radiation beam. In some aspects, the system can further include a third actuator coupled to the third set of fingers. In some aspects, the third actuator can be configured to independently move each finger of the third set of fingers. In some aspects, the third actuator can be arranged in the stacked assembly.

[0020] In some aspects, a lithographic apparatus can include an illumination system and a projection system. In some aspects, the illumination system can be configured to illuminate a reticle with a radiation beam. In some aspects, the illumination system can include a uniformity correction system adjacent the reticle. In some aspects, the uniformity correction system can include a first set of fingers configured to condition the radiation beam, a second set of fingers configured to condition the radiation beam, a first actuator coupled to the first set of fingers and configured to independently move each finger of the first set of fingers, and a second actuator coupled to the second set of fingers and configuredto independently move each finger of the second set of fingers. In some aspects, the first and second actuators can be arranged in a stacked assembly. In some aspects, the projection system can be configured to project an image of the reticle onto a substrate.

[0021] In some aspects, the uniformity correction system can further include a frame having a plurality of channels configured to cool the first and second actuators. In some aspects, the first and second actuators can be disposed in the plurality of channels. In some aspects, the first and second sets of fingers are arranged in a plane (e.g., coplanar).

[0022] In some aspects, a method can include illuminating a reticle with a radiation beam. In some aspects, the method can further include conditioning the radiation beam with a uniformity correction system adjacent the reticle. In some aspects, the conditioning can be performed by independently moving one or more fingers of first and second sets of fingers coupled to first and second actuators into and out of a path of the radiation beam. In some aspects, the first and second actuators can be arranged in a stacked assembly. In some aspects, the method can further include projecting an image of the reticle onto a substrate.

[0023] In some aspects, the conditioning can include moving each of the first and second sets of fingers in a plane to adjust an intensity cross-section of one or more portions of the radiation beam.

[0024] Implementations of any of the techniques described above may include an EUV light source, a DUV light source, a system, an apparatus, a device, a method, a process, and / or a computer program product. The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims.

[0025] Further features and exemplary aspects of the present disclosure, as well as the structure and operation of various aspects, are described in detail below with reference to the accompanying drawings. It is noted that the aspects are not limited to the specific aspects described herein. Such aspects are presented herein for illustrative purposes only. Additional aspects will be apparent to persons skilled in the relevant art(s) based on the teachings contained herein.BRIEF DESCRIPTION OF THE DRAWINGS / FIGURES

[0026] The accompanying drawings, which are incorporated herein and form part of the specification, illustrate the aspects and, together with the description, further serve to explain the principles of the aspects and to enable a person skilled in the relevant art(s) to make and use the aspects.

[0027] FIG. 1 is a schematic illustration of a lithographic apparatus, according to an exemplary aspect.

[0028] FIG. 2 is a schematic side view illustration of a uniformity correction system with a stacked assembly, according to an exemplary aspect.

[0029] FIG. 3 is a flow diagram for conditioning a radiation beam with a uniformity correction system, according to an exemplary aspect.

[0030] FIG. 4 is a schematic illustration of a computing system, according to an exemplary aspect.

[0031] The features and exemplary aspects of the present disclosure will become more apparent from the detailed description set forth below when taken in conjunction with the drawings, in which like reference characters identify corresponding elements throughout. In the drawings, like reference numbers generally indicate identical, functionally similar, and / or structurally similar elements. Additionally, generally, the left-most digit(s) of a reference number identifies the drawing in which the reference number first appears. Unless otherwise indicated, the drawings provided throughout the disclosure should not be interpreted as to-scale drawings.DETAILED DESCRIPTION

[0032] Provided herein are system, apparatus, device, method, process, and / or computer program product aspects, and / or combinations and sub-combinations thereof, for conditioning a radiation beam in a lithographic process.

[0033] A system as described below can include first and second sets of fingers configured to condition a radiation beam and first and second actuators arranged in a stacked assembly coupled to the first and second sets of fingers and configured to independently move each finger of the first and second sets of fingers, respectively.

[0034] This specification discloses one or more aspects that incorporate the features of this present disclosure.

[0035] The aspect(s) described, and references in the specification to “one aspect,” “an aspect,” “an example aspect,” “an exemplary aspect,” etc., indicate that the aspect(s) described may include a particular feature, structure, or characteristic, but every aspect may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same aspect. Further, when a particular feature, structure, or characteristic is described in connection with an aspect, it is understood that it is within the knowledge of one skilled in the art to effect such feature, structure, or characteristic in connection with other aspects whether or not explicitly described.

[0036] Spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “on,” “upper” and the like, may be used herein for ease of description to describe one element or feature’s relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The apparatus may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may likewise be interpreted accordingly.

[0037] The term “about” or “substantially” or “approximately” as used herein indicates the value of a given quantity that can vary based on a particular technology. Based on the particular technology, the term “about” or “substantially” or “approximately” can indicate a value of a given quantity that varies within, for example, 1-15% of the value (e.g., ±1%, ±2%, ±5%, ±10%, or ±15% of the value).

[0038] Numerical values, including endpoints of ranges, can be expressed herein as approximations preceded by the term “about,” “substantially,” “approximately,” or the like. In such cases, other aspectsinclude the particular numerical values. Regardless of whether a numerical value is expressed as an approximation, two aspects are included in this disclosure: one expressed as an approximation, and another not expressed as an approximation. It will be further understood that an endpoint of each range is significant both in relation to another endpoint, and independently of another endpoint.

[0039] Aspects of the disclosure may be implemented in hardware, firmware, software, or any combination thereof. Aspects of the disclosure may also be implemented as instructions stored on a machine -readable medium (e.g., memory), which may be read and executed by one or more processors. A machine -readable medium may include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computing device). For example, a machine-readable medium may include read only memory (ROM); random access memory (RAM); magnetic disk storage media; optical storage media; flash memory devices; electrical, optical, acoustic, or other forms of propagated signals (e.g., carrier waves, infrared signals, digital signals, etc.); and others. Further, firmware, software, routines, and / or instructions may be described herein as performing certain actions. However, it should be appreciated that such descriptions are merely for convenience and that such actions in fact result from computing devices, processors, controllers, or other devices executing the firmware, software, routines, instructions, etc.

[0040] Before describing such aspects in more detail, however, it is instructive to present example environments in which aspects of the present disclosure may be implemented.

[0041] Exemplary Lithographic System

[0042] FIG. 1 shows a lithographic system comprising a radiation source SO and a lithographic apparatus LA. The radiation source SO is configured to generate an EUV and / or a DUV radiation beam B and to supply the EUV and / or DUV radiation beam B to the lithographic apparatus LA. The lithographic apparatus LA comprises an illumination system IL, a support structure MT (e.g., a mask table, a reticle table, a reticle stage) configured to support a patterning device MA (e.g., a mask, a reticle), a projection system PS, and a substrate table WT configured to support a substrate W.

[0043] The illumination system IL is configured to condition the EUV and / or DUV radiation beam B before the EUV and / or DUV radiation beam B is incident upon the patterning device MA. Thereto, the illumination system IL may include a faceted field mirror device 10 and a faceted pupil mirror device 11. The faceted field mirror device 10 and faceted pupil mirror device 11 together provide the EUV and / or DUV radiation beam B with a desired cross-sectional shape and a desired intensity distribution. The illumination system IL may include other mirrors or devices in addition to, or instead of, the faceted field mirror device 10 and faceted pupil mirror device 11.

[0044] After being thus conditioned, the EUV and / or DUV radiation beam B interacts with the patterning device MA. This interaction may be reflective (as shown), which may be preferred for EUV radiation. This interaction may be transmissive, which may be preferred for DUV radiation. As a result of this interaction, a patterned EUV and / or DUV radiation beam B’ is generated. The projection system PS is configured to project the patterned EUV and / or DUV radiation beam B’ onto the substrate W. Forthat purpose, the projection system PS may comprise a plurality of mirrors 13, 14 which are configured to project the patterned EUV and / or DUV radiation beam B’ onto the substrate W held by the substrate table WT. The projection system PS may apply a reduction factor to the patterned EUV and / or DUV radiation beam B ’ , thus forming an image with features that are smaller than corresponding features on the patterning device MA. For example, a reduction factor of 4 or 8 may be applied. Although the projection system PS is illustrated as having only two mirrors 13, 14 in FIG. 1, the projection system PS may include a different number of mirrors (e.g. six or eight mirrors).

[0045] The substrate W may include previously formed patterns. Where this is the case, the lithographic apparatus LA aligns the image, formed by the patterned EUV and / or DUV radiation beam B’, with a pattern previously formed on the substrate W.

[0046] Exemplary Uniformity Correction System with Stacked Assembly

[0047] As discussed above, an illumination system of a lithographic apparatus can include a uniformity correction system to correct or reduce non-uniformities in a radiation beam before the radiation beam is incident on a patterning device. The uniformity correction system can employ actuated fingers that are inserted into a path (e.g., edge) of the radiation beam to correct intensity variations.

[0048] However, multiple fingers (e.g., multiple finger arrays) are needed to more accurately control the uniformity of the radiation beam, which increases the overall size of the uniformity correction system and length of the fingers. Further, the longer length of the fingers can cause low stiffness in a transverse direction, which can result in slower actuation and decreased throughput and accuracy.

[0049] Aspects of uniformity correction apparatuses, systems, and methods with a stacked assembly as discussed below can reduce an overall volume (footprint) of a uniformity correction system, increase a transverse stiffness of the fingers to improve stability, increase an actuation speed of the fingers to improve throughput and accuracy, arrange the fingers in the same plane (e.g., not stacked atop each other) to allow for longer travel range and increased control of a radiation beam, utilize a stacked assembly (e.g., vertically aligned) of two or more actuators, and increase a cooling of the actuators with two or more channels.

[0050] FIG. 2 illustrates uniformity correction system 200, according to an exemplary aspect. The aspects of uniformity correction system described in U.S. Patent No. 9,134,620, which is incorporated by reference herein in its entirety, and the aspects of uniformity correction system 200 shown in FIG. 2 may be similar. One difference between the aspects of uniformity correction system described in U.S. Patent No. 9,134,620 and the aspects of uniformity correction system 200 shown in FIG. 2 is that uniformity correction system 200 includes stacked assembly 230 of first and second actuators 240, 250 for a reduced overall volume and decreased length of frame 260 (e.g., finger body), rather than a uniformity correction system described in U.S. Patent No. 9,134,620 with a single linear motor and an extended frame.

[0051] Uniformity correction system 200 can be configured to condition a radiation beam for a lithographic process. Uniformity correction system 200 can be further configured to reduce an overallvolume (footprint) of uniformity correction system 200 (e.g., as compared to uniformity correction system 200 (FIG. 2)). Uniformity correction system 200 can be further configured to increase a transverse stiffness of first and second sets of fingers 210, 220 to improve stability. Uniformity correction system 200 can be further configured to increase an actuation speed of first and second sets of fingers 210, 220 to improve throughput and accuracy.

[0052] Uniformity correction system 200 can be further configured to arrange first and second sets of fingers 210, 220 in the same plane (e.g., coplanar) to allow for longer travel range and increased control of a radiation beam. Uniformity correction system 200 can be further configured to utilize stacked assembly 230 (e.g., vertically aligned) of two or more actuators. Uniformity correction system 200 can be further configured to increase a cooling of first and second actuators 240, 250 with two or more channels. Although uniformity correction system 200 is shown in FIG. 2 as a stand-alone system and / or apparatus, the aspects of this disclosure can be used with other apparatuses, systems, and / or methods, such as, but not limited to, lithographic apparatus LA, illumination system IL, flow diagram 300, and / or computing system 400.

[0053] As shown in FIG. 2, uniformity correction system 200 can include encoder 206, first set of fingers 210, second set of fingers 220, and stacked assembly 230. In some aspects, uniformity correction system 200 can move one or more of first and second sets of fingers 210, 220 via stacked assembly 230 (e.g., via first and second actuators 240, 250) into or out of a path of a radiation beam (e.g., EUV and / or DUV radiation beam B (FIG. 1)) to condition (e.g., shape, make uniform, adjust an intensity crosssection) the radiation beam prior to illuminating a reticle.

[0054] Encoder 206 can be configured to measure a position of each of first and second sets of fingers 210, 220 and control movement of each of first and second sets of fingers 210, 220. Encoder 206 can be further configured to convert motion of first and second sets of fingers 210, 220 into one or more electrical signals. In some aspects, encoder 206 can include a linear encoder (e.g., optical, magnetic, inductive, capacitive, eddy current, etc.). In some aspects, encoder 206 can include control circuitry to control movement of first and second sets of fingers 210, 220. As shown in FIG. 2, encoder 206 can include measurement mechanism 208 and be coupled to frame 260. Measurement mechanism 208 can be configured to measure a displacement of each of first and second sets of fingers 210, 220. Measurement mechanism 208 can be further configured to provide a feedback signal of linear displacement of each of first and second sets of fingers 210, 220 along movement direction 202 (e.g., Y-axis). In some aspects, measurement mechanism 208 can include a transducer or a sensor (e.g., optical sensor, magnetic sensor, inductive sensor, capacitive sensor, eddy current sensor, etc.) measure a position of each of first and second sets of fingers 210, 220.

[0055] First set of fingers 210 can be configured to control a uniformity of a radiation beam (e.g., intensity cross-section). As shown in FIG. 2, first set of fingers 210 can include first set of finger tips 212 located at a distal end of first set of fingers 210 (e.g., opposing a path of a radiation beam). In some aspects, one or more of first set of finger tips 212 can be moved into and out of a path of the radiationbeam. In some aspects, for example, a length of first set of fingers 210 can be in a range of about 1 mm to about 25 mm. In some aspects, for example, a width of first set of finger tips 212 can be in a range of about 1 mm to about 10 mm.

[0056] First set of finger necks 214 can be coupled to first set of fingers 210 and be configured to transfer linear motion from first actuator 240 (e.g., linear motor) to first set of fingers 210. In some aspects, for example, a width of first set of finger necks 214 can be in a range of about 0.1 mm to about 5 mm. In some aspects, first set of finger necks 214 can be secured to frame 260. In some aspects, first set of finger necks 214 can be part of frame 260. In some aspects, first set of fingers 210 can be positioned in first plane 218. In some aspects, one or more of first set of finger tips 212 can be translated along first plane 218 and moved into and out of a path of the radiation beam. Adjacent fingers of first set of fingers 210 can be separated from each other by first set of finger spacing 216. In some aspects, for example, first set of finger spacing 216 between first set of fingers 210 (e.g., a pitch) can be in a range of about 0.1 mm to about 5 mm.

[0057] Second set of fingers 220 can be configured to control a uniformity of a radiation beam (e.g., intensity cross-section). As shown in FIG. 2, second set of fingers 220 can include second set of finger tips 222 located at a distal end of second set of fingers 220 (e.g., opposing a path of a radiation beam). In some aspects, one or more of second set of finger tips 222 can be moved into and out of a path of the radiation beam. In some aspects, for example, a length of second set of fingers 220 can be in a range of about 1 mm to about 25 mm. In some aspects, for example, a width of second set of finger tips 222 can be in a range of about 1 mm to about 10 mm.

[0058] Second set of finger necks 224 can be coupled to second set of fingers 220 and be configured to transfer linear motion from second actuator 250 (e.g., linear motor) to second set of fingers 220. In some aspects, for example, a width of second set of finger necks 224 can be in a range of about 0.1 mm to about 5 mm. In some aspects, second set of finger necks 224 can be secured to frame 260. In some aspects, second set of finger necks 224 can be part of frame 260. In some aspects, second set of fingers 220 can be positioned in second plane 228. In some aspects, first plane 218 and second plane 228 can be coplanar. In some aspects, for example, first and second sets of fingers 210, 220 can be arranged in the same plane and one or more of first and second sets of fingers 210, 220 can be translated into and out of a path of a radiation beam to condition the radiation beam. In some aspects, first and second planes 218, 228 can be different. In some aspects, first and second planes 218, 228 can be separated from each other along a direction perpendicular to first and second planes 218, 228 (e.g., parallel planes).

[0059] In some aspects, one or more of second set of finger tips 222 can be translated along second plane 228 and moved into and out of a path of the radiation beam. Adjacent fingers of second set of fingers 220 can be separated from each other by second set of finger spacing 226. In some aspects, for example, second set of finger spacing 226 between second set of fingers 220 (e.g., a pitch) can be in a range of about 0.1 mm to about 5 mm.

[0060] In some aspects, first and second sets of fingers 210, 220 can be configured to adjust an intensity cross-section of one or more portions of a radiation beam by moving into and out of a path of the radiation beam. In some aspects, first and second sets of fingers 210, 220 can be configured to adjust a uniformity of the radiation beam. In some aspects, for example, the uniformity can be adjusted to provide a constant intensity across the entire radiation beam. In some aspects, for example, the uniformity can be adjusted to provide a target illumination (e.g., flat profile, non-flat profile) to a patterning device.

[0061] In some aspects, first and second sets of fingers 210, 220 can be arranged in a plane (e.g., coplanar). In some aspects, first and second sets of fingers 210, 220 can be arranged adjacent to each other in the same plane (e.g., first plane 218). In some aspects, a length of first and second sets of fingers 210, 220 in the plane (e.g., first plane 218) can be increased. In some aspects, for example, the length of first and second sets of fingers 210, 220 can be at least about 10 mm. In some aspects, a range of travel of first and second sets of fingers 210, 220 in the plane (e.g., first plane 218) can be increased. In some aspects, for example, the range of travel of first and second sets of fingers 210, 220 can be in a range of about 1 mm to about 25 mm.

[0062] Stacked assembly 230 can be configured to reduce an overall volume (footprint) of uniformity correction system 200. Stacked assembly 230 can be further configured to increase a transverse stiffness and increase an actuation speed of first and second sets of fingers 210, 220. Stacked assembly 230 can be further configured to arrange first and second sets of fingers 210, 220 in the same plane (e.g., coplanar) to allow for longer travel range and increased control of a radiation beam. Stacked assembly 230 can be further configured to increase a cooling of first and second actuators 240, 250 with two or more channels (e.g., first and second channels 262, 264). As shown in FIG. 2, stacked assembly 230 can include first actuator 240, second actuator 250, and frame 260.

[0063] First actuator 240 can be configured to independently actuate each of first set of fingers 210 along movement direction 202 (e.g., Y-axis) into and out of a path of a radiation beam. As shown in FIG. 2, first actuator 240 can include first coil plate 242 and first set of magnets 244 to move each of first set of fingers 210 in a translational manner along movement direction 202 (e.g., Y-axis). In some aspects, a length of first coil plate 242 can be adjusted (e.g., decreased) to adjust (e.g., increase) a travel range of first set of fingers 210. In some aspects, for example, a length of first coil plate 242 can be a fraction of a length of frame 260 (e.g., finger body).

[0064] Second actuator 250 can be configured to independently actuate each of second set of fingers 220 along movement direction 202 (e.g., Y-axis) into and out of a path of a radiation beam. As shown in FIG. 2, second actuator 250 can include second coil plate 252 and second set of magnets 254 to move each of second set of fingers 220 in a translational manner along movement direction 202 (e.g., Y-axis). In some aspects, a length of second coil plate 252 can be adjusted (e.g., decreased) to adjust (e.g., increase) a travel range of second set of fingers 220. In some aspects, for example, a length of second coil plate 252 can be a fraction of a length of frame 260 (e.g., finger body).

[0065] Frame 260 (e.g., finger body) can be configured to translate first and second sets of finger necks 214, 224 and first and second sets of fingers 210, 220 along movement direction 202 based on actuation of first and second actuators 240, 250, respectively. As shown in FIG. 2, frame 260 can be coupled to first and second actuators 240, 250 and first and second sets of finger necks 214, 224 such that frame 260 can move relative to first and second actuators 240, 250 (e.g., along Y-axis). In some aspects, frame 260 (e.g., finger body) can have a length no greater than about 50 mm.

[0066] In some aspects, as shown in FIG. 2, frame 260 can include first and second channels 262, 264 for first and second actuators 240, 250, respectively. In some aspects, first and second actuators 240, 250 can be disposed in first and second channels 262, 264, respectively. In some aspects, first and second channels 262, 264 can be configured to increase cooling of first and second actuators 240, 250 during operation.

[0067] In some aspects, frame 260 can include a plurality of frames (e.g., finger bodies) corresponding to first and second sets of fingers 210, 220. In some aspects, for example, frame 260 (e.g., finger body) can be coupled to first set of finger necks 214 for translating first set of fingers 210 and can include first channel 262 for first actuator 240. In some aspects, for example, frame 260 (e.g., finger body) can be coupled to second set of finger necks 224 for translation second set of fingers 220 and can include second channel 264 for second actuator 250.

[0068] In some aspects, as shown in FIG. 2, first and second actuators 240, 250 can be vertically aligned in stacked assembly 230. In some aspects, stacked assembly 230 can be configured to decrease an overall volume of uniformity correction system 200. In some aspects, the overall volume can be no greater than 0.25 m3. In some aspects, the overall volume can be no greater than 0.1 m3. In some aspects, the overall volume can be in a range of about 0.01 m3to about 1 m3.

[0069] In some aspects, stacked assembly 230 can be configured to decrease a length of first and second sets of fingers 210, 220 along movement direction 202 (e.g., Y-axis) thereby increasing a transverse stiffness of first and second sets of fingers 210, 220 in transverse direction 204 (e.g., X-axis) perpendicular to movement direction 202. In some aspects, the transverse stiffness can be at least 10 N / m. In some aspects, the transverse stiffness can be at least 100 N / m. In some aspects, the transverse stiffness can be in a range of about 1 N / m to about 1 ,000 N / m.

[0070] In some aspects, stacked assembly 230 can be configured to decrease a length of first and second sets of fingers 210, 220 along movement direction 202 (e.g., Y-axis) thereby increasing an actuation speed of first and second sets of fingers 210, 220 into and out of a path of the radiation beam. In some aspects, the actuation speed can be at least 0.1 m / s. In some aspects, the actuation speed can be at least 1 m / s. In some aspects, the actuation speed can be in a range of about 0.01 m / s to about 10 m / s.

[0071] In some aspects, uniformity correction system 200 can further include a third set of fingers (e.g., similar to first set of fingers 210) configured to shape the radiation beam. In some aspects, uniformity correction system 200 can further include a third actuator (e.g., similar to first actuator 240) coupled to the third set of fingers. In some aspects, the third actuator can be configured to independentlymove each of the third set of fingers. In some aspects, the third actuator can be arranged in stacked assembly 230. In some aspects, for example, stacked assembly 230 can include first actuator 240, second actuator 250, and a third actuator (e.g., similar to first actuator 240) that are vertically aligned and disposed in first channel 262, second channel 264, and a third channel (e.g., similar to first channel 262) of frame 260, respectively.

[0072] Exemplary Flow Diagram

[0073] FIG. 3 illustrates flow diagram 300 for conditioning a radiation beam, according to an exemplary aspect. It is to be appreciated that not all steps in FIG. 3 are needed to perform the disclosure provided herein. Further, some of the steps may be performed simultaneously, sequentially, and / or in a different order than shown in FIG. 3. Flow diagram 300 shall be described with reference to FIGS. 1 and 2. However, flow diagram 300 is not limited to those example aspects. Although flow diagram 300 is shown in FIG. 3 as a stand-alone method, aspects of this disclosure can be used with other apparatuses, systems, and / or methods, for example, lithographic apparatus LA, uniformity correction system 200, and / or computing system 400.

[0074] In step 302, e.g., as shown in the example of FIGS. 1 and 2, a reticle (e.g., patterning device MA (FIG. 1)) can be illuminated with a radiation beam (e.g., EUV and / or DUV radiation beam B (FIG. D).

[0075] In step 304, e.g., as shown in the example of FIGS. 1 and 2, a uniformity correction system (e.g., uniformity correction system 200 (FIG. 2)) adjacent the reticle can condition the radiation beam. In some aspects, the conditioning can include moving first and second sets of fingers 210, 220 into and out of a path of the radiation beam to adjust an intensity cross-section of one or more portions of a radiation beam. In some aspects, the conditioning can include adjusting a uniformity of the radiation beam. In some aspects, for example, the uniformity can be adjusted to provide a constant intensity across the entire radiation beam. In some aspects, for example, the uniformity can be adjusted to provide a target illumination (e.g., flat profile, non-flat profile) to the reticle.

[0076] In step 306, e.g., as shown in the example of FIGS. 1 and 2, first and second sets of fingers (e.g., first and second sets of fingers 210, 220 (FIG. 2)) coupled to first and second actuators (e.g., first and second actuators 240, 250 (FIG. 2)) can independently move one or more fingers of the first and second sets of fingers into and out of a path of the radiation beam. In some aspects, each of the first and second sets of fingers (e.g., first and second sets of fingers 210, 220 (FIG. 2)) can be moved in a plane (e.g., coplanar) to adjust an intensity cross-section of one or more portions of the radiation beam. In some aspects, step 306 can be part of step 304.

[0077] In step 308, e.g., as shown in the example of FIGS. 1 and 2, the first and second actuators (e.g., first and second actuators 240, 250 (FIG. 2)) can be arranged in a stacked assembly (e.g., stacked assembly 230 (FIG. 2)). In some aspects, step 308 can be part of step 304.

[0078] In step 310, e.g., as shown in the example of FIGS. 1 and 2, an image of the reticle (e.g., patterned EUV and / or DUV radiation beam B’ (FIG. 1)) can be projected (e.g., projection system PS (FIG. 1)) onto a substrate (e.g., substrate W (FIG. 1)).

[0079] Exemplary Computing System

[0080] FIG. 4 illustrates computing system 400, according to an exemplary aspect. Computing system 400 can be configured to implement one or more of the above described aspects, or portions thereof, as computer-readable code. For example, the methods, processes, flow diagrams, and / or systems described herein can be implemented by computing system 400. Although computing system 400 is shown in FIG. 4 as a stand-alone apparatus and / or system, aspects of this disclosure can be used with other apparatuses, systems, and / or methods, for example, lithographic apparatus LA, illumination system IL, uniformity correction system 200, and / or flow diagram 300.

[0081] Various aspects of the disclosure can be implemented using one or more computing devices, such as computing system 400 shown in FIG. 4, by software, firmware, hardware, or a combination thereof. Various aspects are described herein in terms of exemplary computing system 400. One or more computing systems 400 can be used, for example, to implement any of the aspects described herein, as well as combinations and sub-combinations thereof. Cloud implementations can include one or more of exemplary computing system 400 operating locally or distributed across one or more server sites.

[0082] As shown in FIG. 4, computing system 400 can include processor 402, controller 404, main memory 406, communication infrastructure 408 (e.g., a bus), user input / output (I / O) interface(s) 410, user I / O device(s) 412, secondary memory 420, communications interface 434, and remote device(s) 438. Computing system 400 can include one or more processors (also called central processing units, or CPUs), such as processor 402. Processor 402 can be a special purpose processor or a general purpose processor. Processor 402 can be connected to communication infrastructure 408 (e.g., a bus, a network). Processor 402 can include a CPU, a graphics processing unit (GPU), an accelerated processing unit (APU), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a digital signal processor (DSP), a microprocessor, other similar general purpose or specialized processing units, or a combination thereof. In some aspects, processor 402 can include a GPU that is a specialized electronic circuit designed to process mathematically intensive applications. For example, the GPU can have a parallel structure that is efficient for parallel processing of large blocks of data, such as mathematically intensive data common to computer graphics applications, images, videos, etc.

[0083] Computing system 400 can also include a controller 404. Controller 404 can include functionalities to control data access to main memory 406 and secondary memory 420. In some aspects, controller 404 can be external to processor 402, for example, as shown in FIG. 4. In some aspects, controller 404 can be directly part of processor 402. Controller 404 can include a microcontroller or microcontroller unit (MCU).

[0084] Computing system 400 can also include a main memory 406. Main memory 406 can include volatile memory (e.g., random-access memory (RAM)) and / or non-volatile memory (e.g., read-only memory (ROM), non-volatile RAM (NVRAM), flash). Main memory 406 can include one or more levels of cache and be divided into channels. Main memory 406 can have stored therein control logic (e.g., computer software) and / or data.

[0085] Computing system 400 can also include user I / O interface(s) 410 coupled to user I / O device(s) 412. Computing system 400 can also include user I / O device(s) 412, such as monitors, keyboards, pointing devices, etc., which can communicate with communication infrastructure 408 through user I / O interface(s) 410.

[0086] Computing system 400 can also include one or more secondary storage devices or memory 420. Secondary memory 420 can include, for example, a hard disk drive 422 and / or a removable storage device or drive 424. Removable storage drive 424 can include a floppy disk drive, a magnetic tape drive, a compact disk drive, an optical storage device, a tape backup device, a flash memory, and / or any other storage device / drive.

[0087] Removable storage drive 424 can interact with a first removable storage unit 426. First removable storage unit 426 can include a computer usable or readable storage device having stored thereon control logic (e.g., computer software) and / or data. First removable storage unit 426 can be a floppy disk, a magnetic tape drive, a compact disk drive, a DVD, an optical storage device, a tape backup device, a flash memory, and / or any other computer data storage device. Removable storage drive 424 can read from and / or write to first removable storage unit 426.

[0088] Secondary memory 420 can include other means, devices, components, instrumentalities, or other approaches for allowing computer programs, other instructions, and / or data to be accessed by computing system 400. Such means, devices, components, instrumentalities, or other approaches can include, for example, a second removable storage unit 432 and an interface 430. Examples of the second removable storage unit 432 and the interface 430 can include a program cartridge and cartridge interface (e.g., such as that found in video game devices), a removable memory chip (e.g., such as an EPROM or PROM) and associated socket, a memory stick and USB port, a memory card and associated memory card slot, and / or any other removable storage unit and associated interface that allow software and / or data to be transferred from the second removable storage unit 432 to computing system 400.

[0089] Computing system 400 can further include a communications or network interface 434. Communications interface 434 can enable computing system 400 to communicate and interact with any combination of external devices, external networks, external entities, etc. (referenced individually and collectively by reference number 438). For example, communications interface 434 can allow computing system 400 to communicate with external or remote devices 438 over communications path 436, which can be wired, wireless, or a combination thereof, and which can include any combination of LANs, WANs, the Internet, etc. Control logic and / or data can be transmitted to and from computing system 400 via communications path 436. Communications interface 434 can include a modem, acommunication port, a PCMCIA slot and card, or the like. Software and / or data can be transferred via communications interface 434 in the form of signals, which can be electronic, electromagnetic, optical, or other signals capable of being transmitted and received by communications interface 434. The signals can be provided to communications interface 434 via communications path 436 (e.g., wired, wireless, etc.).

[0090] Computing system 400 can also include any computing device, for example, a laptop or notebook computer, a desktop workstation, a netbook, a tablet, a smart phone, a smart watch or other wearable device, a personal digital assistant (PDA), an Internet-of-Things (loT) device, an embedded system, or any combination thereof.

[0091] Computing system 400 can include a user device or server, accessing or hosting any applications and / or data through any delivery paradigm, including, but not limited to, remote or distributed cloud computing solutions; local or on-premises software (“on-premise” cloud-based solutions); “as a service” models (e.g., content as a service (CaaS), digital content as a service (DCaaS), software as a service (SaaS), managed software as a service (MSaaS), platform as a service (PaaS), desktop as a service (DaaS), framework as a service (FaaS), backend as a service (BaaS), mobile backend as a service (MBaaS), infrastructure as a service (laaS), etc.); and / or a hybrid model including any combination of the foregoing examples or other services or delivery paradigms.

[0092] Any applicable data structures, file formats, and schemas in computing system 400 can be derived from standard programming languages, including, but not limited to, C, C++, Python, Perl, JavaScript Object Notation (JSON), Extensible Markup Language (XML), Yet Another Markup Language (YAML), Extensible Hypertext Markup Language (XHTML), Wireless Markup Language (WML), MessagePack, XML Customer Interface Language (XUL), or any other functionally similar representations alone or in combination. Alternatively, proprietary data structures, formats or schemas can be used, either exclusively or in combination with known or open standards.

[0093] In some aspects, a tangible, non-transitory apparatus or article of manufacture comprising a tangible, non-transitory computer useable or readable medium having control logic (software) stored thereon can also be referred to herein as a computer program product or program storage device. This can include, but is not limited to, computing system 400, main memory 406, secondary memory 420, first removable storage unit 426, and second removable storage unit 432, as well as tangible articles of manufacture embodying any combination of the foregoing. Such control logic, when executed by one or more data processing devices (e.g., such as computing system 400), can cause such data processing devices to operate as described herein.

[0094] Based on the teachings contained in this disclosure, it will be apparent to persons skilled in the relevant art(s) how to make and use aspects of this disclosure using data processing devices, computing systems, and / or computing architectures other than those described herein (e.g., shown in FIG. 4). In particular, aspects can operate with software, hardware, and / or operating system implementations other than those described herein.

[0095] Although specific reference may be made in this text to the use of the apparatus, system, and / or lithographic apparatus in the manufacture of ICs, it should be understood that such an apparatus, system, and / or lithographic apparatus described herein may have other possible applications, for example, such as in the manufacture of integrated optical systems, guidance and detection patterns for magnetic domain memories, flat-panel displays, LCD panels, thin-film magnetic heads, etc. The skilled artisan will appreciate that, in the context of such alternative applications, any use of the terms “reticle,” “wafer,” or “die” herein may be considered as synonymous with the more general terms “mask,” “substrate,” or “target portion”, respectively.

[0096] Although specific reference may have been made above to the use of aspects in the context of optical lithography, it will be appreciated that aspects may be used in other applications, for example, imprint lithography, and where the context allows, is not limited to optical lithography. In imprint lithography a topography in a patterning device defines the pattern created on a substrate. The topography of the patterning device may be pressed into a layer of resist supplied to the substrate whereupon the resist is cured by applying electromagnetic radiation, heat, pressure, or a combination thereof. The patterning device is removed from the resist leaving a pattern in it after the resist is cured.

[0097] It is to be understood that the phraseology or terminology herein is for the purpose of description and not of limitation, such that the terminology or phraseology of the present specification is to be interpreted by those skilled in relevant art(s) in light of the teachings herein.

[0098] The term “substrate” as used herein describes a material onto which material layers are added. In some aspects, the substrate itself may be patterned and materials added on top of it may also be patterned, or may remain without patterning. The substrate referred to herein may be processed, before or after exposure, for example, in a track unit (e.g., a tool that typically applies a layer of resist to a substrate and develops the exposed resist), a metrology unit, and / or an inspection unit. Where applicable, the disclosure herein may be applied to such and other substrate processing tools. Further, the substrate may be processed more than once, for example, to create a multi-layer IC, so that the term substrate used herein may also refer to a substrate that already contains multiple processed layers.

[0099] The above examples are illustrative, but not limiting, of the aspects of this disclosure. Other suitable modifications and adaptations of the variety of conditions and parameters normally encountered in the field, and which would be apparent to those skilled in the relevant art(s), are within the spirit and scope of the disclosure.

[0100] While specific aspects have been described above, it will be appreciated that the aspects may be practiced otherwise than as described. The description is not intended to limit the scope of the claims.

[0101] It is to be appreciated that the Detailed Description section, and not the Summary and Abstract sections, is intended to be used to interpret the claims. The Summary and Abstract sections may set forth one or more but not all exemplary aspects as contemplated by the inventor(s), and thus, are not intended to limit the aspects and the appended claims in any way.

[0102] The aspects have been described above with the aid of functional building blocks illustrating the implementation of specified functions and relationships thereof. The boundaries of these functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternate boundaries can be defined so long as the specified functions and relationships thereof are appropriately performed.

[0103] The foregoing description of the specific aspects will so fully reveal the general nature of the aspects that others can, by applying knowledge within the skill of the art, readily modify and / or adapt for various applications such specific aspects, without undue experimentation, without departing from the general concept of the aspects. Therefore, such adaptations and modifications are intended to be within the meaning and range of equivalents of the disclosed aspects, based on the teaching and guidance presented herein.

[0104] Various example embodiments include the following numbered clauses:1. A uniformity correction system comprising: a first set of fingers configured to shape a radiation beam; a second set of fingers configured to shape the radiation beam; a first actuator coupled to the first set of fingers and configured to independently move each finger of the first set of fingers; and a second actuator coupled to the second set of fingers and configured to independently move each finger of the second set of fingers, wherein the first and second actuators are arranged in a stacked assembly.2. The system of clause 1 , wherein the first and second actuators are vertically aligned in the stacked assembly.3. The system of clause 1, wherein the stacked assembly is configured to decrease an overall volume of the uniformity correction system.4. The system of clause 3, wherein the overall volume is no greater than 0.25 m3.5. The system of clause 1, wherein the stacked assembly is configured to decrease a length of the first and second sets of fingers along a movement direction thereby increasing a transverse stiffness of the first and second sets of fingers in a transverse direction perpendicular to the movement direction.6. The system of clause 5, wherein the transverse stiffness is at least 10 N / m.7. The system of clause 1, wherein the stacked assembly is configured to decrease a length of the first and second sets of fingers along a movement direction thereby increasing an actuation speed of the first and second sets of fingers into and out of a path of the radiation beam.8. The system of clause 1, wherein the first and second sets of fingers are configured to adjust an intensity cross-section of one or more portions of the radiation beam.9. The system of clause 1, wherein the first and second sets of fingers are arranged in a plane.10. The system of clause 1, wherein the first set of fingers is arranged in a first plane and the second set of fingers is arranged in a second plane, the first and second planes separated from each other along a direction perpendicular to the first and second planes.11. The system of clause 1 , wherein a width of a tip of each of the first and second sets of fingers is larger than a width of the first and second actuators.12. The system of clause 1, wherein a width of a tip of each of the first and second sets of fingers is larger than a spacing between fingers such that adjacent fingers overlap.13. The system of clause 1, wherein a length of the first set of fingers is different than a length of the second set of fingers.14. The system of clause 1, further comprising a frame having a plurality of channels configured to cool the first and second actuators, wherein the first and second actuators are disposed in the plurality of channels.15. The system of clause 1, wherein the first and second actuators each comprise a coil plate assembly and corresponding magnets for linear actuation of each of the first and second sets of fingers.16. The system of clause 1, further comprising: a third set of fingers configured to shape the radiation beam; and a third actuator coupled to the third set of fingers and configured to independently move each finger of the third set of fingers, wherein the third actuator is arranged in the stacked assembly.17. A lithographic apparatus comprising: an illumination system configured to illuminate a reticle with a radiation beam, the illumination system comprising a uniformity correction system adjacent the reticle, the uniformity correction system comprising: a first set of fingers configured to condition the radiation beam; a second set of fingers configured to condition the radiation beam; a first actuator coupled to the first set of fingers and configured to independently move each finger of the first set of fingers; and a second actuator coupled to the second set of fingers and configured to independently move each finger of the second set of fingers, wherein the first and second actuators are arranged in a stacked assembly; and a projection system configured to project an image of the reticle onto a substrate.18. The lithographic apparatus of clause 17, wherein: the uniformity correction system further comprises a frame having a plurality of channels configured to cool the first and second actuators, the first and second actuators are disposed in the plurality of channels, and the first and second sets of fingers are arranged in a plane.19. A method comprising: illuminating a reticle with a radiation beam; conditioning the radiation beam with a uniformity correction system adjacent the reticle, the conditioning performed by independently moving one or more fingers of first and second sets of fingers coupled to first and second actuators into and out of a path of the radiation beam, the first and second actuators being arranged in a stacked assembly; and projecting an image of the reticle onto a substrate.20. The method of clause 19, wherein the conditioning comprises moving each of the first and second sets of fingers in a plane to adjust an intensity cross-section of one or more portions of the radiation beam.

[0105] The breadth and scope of the aspects should not be limited by any of the above-described exemplary aspects, but should be defined only in accordance with the following claims and their equivalents.

Claims

CLAIMS1. A uniformity correction system comprising: a first set of fingers configured to shape a radiation beam; a second set of fingers configured to shape the radiation beam; a first actuator coupled to the first set of fingers and configured to independently move each finger of the first set of fingers; and a second actuator coupled to the second set of fingers and configured to independently move each finger of the second set of fingers, wherein the first and second actuators are arranged in a stacked assembly.

2. The system of claim 1 , wherein the first and second actuators are vertically aligned in the stacked assembly.

3. The system of claim 1, wherein the stacked assembly is configured to decrease an overall volume of the uniformity correction system.

4. The system of claim 3, wherein the overall volume is no greater than 0.25 m3.

5. The system of claim 1, wherein the stacked assembly is configured to decrease a length of the first and second sets of fingers along a movement direction thereby increasing a transverse stiffness of the first and second sets of fingers in a transverse direction perpendicular to the movement direction.

6. The system of claim 5, wherein the transverse stiffness is at least 10 N / m.

7. The system of claim 1, wherein the stacked assembly is configured to decrease a length of the first and second sets of fingers along a movement direction thereby increasing an actuation speed of the first and second sets of fingers into and out of a path of the radiation beam.

8. The system of claim 1, wherein the first and second sets of fingers are configured to adjust an intensity cross-section of one or more portions of the radiation beam.

9. The system of claim 1, wherein the first and second sets of fingers are arranged in a plane.

10. The system of claim 1, wherein the first set of fingers is arranged in a first plane and the second set of fingers is arranged in a second plane, the first and second planes separated from each other along a direction perpendicular to the first and second planes.

11. The system of claim 1 , wherein a width of a tip of each of the first and second sets of fingers is larger than a width of the first and second actuators.

12. The system of claim 1, wherein a width of a tip of each of the first and second sets of fingers is larger than a spacing between fingers such that adjacent fingers overlap.

13. The system of claim 1, wherein a length of the first set of fingers is different than a length of the second set of fingers.

14. The system of claim 1, further comprising a frame having a plurality of channels configured to cool the first and second actuators, wherein the first and second actuators are disposed in the plurality of channels.

15. The system of claim 1, wherein the first and second actuators each comprise a coil plate assembly and corresponding magnets for linear actuation of each of the first and second sets of fingers.

16. The system of claim 1, further comprising: a third set of fingers configured to shape the radiation beam; and a third actuator coupled to the third set of fingers and configured to independently move each finger of the third set of fingers, wherein the third actuator is arranged in the stacked assembly.

17. A lithographic apparatus comprising: an illumination system configured to illuminate a reticle with a radiation beam, the illumination system comprising a uniformity correction system adjacent the reticle, the uniformity correction system comprising: a first set of fingers configured to condition the radiation beam; a second set of fingers configured to condition the radiation beam; a first actuator coupled to the first set of fingers and configured to independently move each finger of the first set of fingers; and a second actuator coupled to the second set of fingers and configured to independently move each finger of the second set of fingers, wherein the first and second actuators are arranged in a stacked assembly; and a projection system configured to project an image of the reticle onto a substrate.

18. The lithographic apparatus of claim 17, wherein: the uniformity correction system further comprises a frame having a plurality of channels configured to cool the first and second actuators, the first and second actuators are disposed in the plurality of channels, and the first and second sets of fingers are arranged in a plane.

19. A method comprising: illuminating a reticle with a radiation beam; conditioning the radiation beam with a uniformity correction system adjacent the reticle, the conditioning performed by independently moving one or more fingers of first and second sets of fingers coupled to first and second actuators into and out of a path of the radiation beam, the first and second actuators being arranged in a stacked assembly; and projecting an image of the reticle onto a substrate.

20. The method of claim 19, wherein the conditioning comprises moving each of the first and second sets of fingers in a plane to adjust an intensity cross-section of one or more portions of the radiation beam.

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