Actuation stage, electromagnet device, and manufacturing method

Abstract

The stage (500) for supporting and moving the object (502) includes an electromagnet (510), first and second support structures (504, 506), a target (508), and a target-side bumper structure. The electromagnet can include a core, a wire coil (512), and a core-side bumper fixed to the core. The core, disposed on the first support structure (506), is made of a magnetically permeable material. The core is shaped to have poles facing in the same direction. The wire coil generates a magnetic field. The second support structure (504) supports and moves the object relative to the first support structure. The target (508) is disposed on the second support structure (504) to actuate the second support structure in response to the magnetic field. The target-side bumper structure is fixed to the target and can collide with the core-side bumper structure to establish a collision-avoidance gap between the core and the target. The uncertainty value of the collision-avoidance gap is less than 20 microns.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Application No. 63 / 435,078, filed December 23, 2022, the entire contents of which are incorporated herein by reference.

[0002]

[0002] The present disclosure relates to actuation stages, for example stages for supporting reticles used in lithographic apparatus and systems. [Background technology]

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

[0004]

[0004] To project a pattern onto a substrate, a lithographic apparatus may use electromagnetic radiation. The wavelength of this radiation determines the minimum size of features that can be formed on the substrate. Lithographic apparatus using extreme ultraviolet (EUV) radiation having a wavelength in the range of 4 to 20 nm, e.g., 6.7 nm or 13.5 nm, can be used to form smaller features on a substrate than lithographic apparatus using radiation having a wavelength of, e.g., 193 nm.

[0005]

[0005] A lithography system can only output a limited number of manufactured devices within a given time frame. High-speed scanning of the wafer stage and reticle stage can increase manufacturing speed. However, efforts to generate large forces for high acceleration of the movable stage can be hindered by tolerance issues related to the machining of parts. Electromagnet actuators can attract the target with greater force and consume less power when the electromagnet is positioned closer to the target. However, a gap must be maintained between the electromagnet and the target (to prevent collisions), and the closer the distance, the more precise the machining tolerances required. Summary of the Invention

[0006]

[0006] Therefore, it is desirable to increase lithography production speed and throughput. According to aspects described herein, electromagnetic actuators for wafer and reticle stages can be manufactured to tight tolerances.

[0007] In some aspects, a stage for supporting and moving an object can include an electromagnet, first and second support structures, a target, and a target-side bumper structure. The electromagnet can include a core, a wire coil, and a core-side bumper structure. The core can be disposed on the first support structure. The core may include a magnetically permeable material. The core can be shaped so that the poles of the core are arranged facing the same direction. The wire coil can be configured to generate a magnetic field within the core. The core-side bumper structure can be fixed to the core. The second support structure can be configured to support the object and move the object relative to the first support structure. The target can be disposed on the second support structure. The target can be configured to actuate the second support structure in response to the generation of the magnetic field. The target-side bumper structure can be fixed to the target. The target-side bumper structure can be configured to collide with the core-side bumper structure to establish a collision avoidance gap between the core and the target. An uncertainty value of the collision avoidance gap can be less than approximately 20 microns.

[0008]

[0008] In some aspects, the electromagnetic device can include a core and a detachable wire coil assembly. The core may include a magnetically permeable material. The core can be shaped such that the poles of the core are arranged facing the same direction. The detachable wire coil assembly can include a wire coil and a housing. The wire coil can be configured to generate a magnetic field within the core. The housing can include a conduit configured to direct a cooling fluid to regulate a temperature of the wire coil.

[0009] In some aspects, a method of manufacturing an electromagnetic actuator may include one or more of the following operations. The method may include securing a core of an electromagnet to a core support structure. The core may include a magnetically permeable material. The core may be shaped so that the poles of the core are arranged facing the same direction. The core support structure may include a core-side bumper structure secured to the core. The method may include securing a target-side bumper structure to the target. The target may have a pole-facing side facing the pole. The target may be movable in response to a magnetic field generated through the core. The target-side bumper structure may be configured to collide with the core-side bumper structure to establish a collision avoidance gap between the core and the target. The method may include adjusting the collision avoidance gap to within a tolerance of about 20 microns or less. The adjusting may include surface treating the core-side structure. The surface treating the core-side structure may also include surface treating the pole. The surface treating the core-side structure may also include surface treating the pole. The adjusting may include surface treating the target-side structure. The surface treating the target-side structure may include surface treating the pole-facing side. Surface treatment of the target-side structure may also include surface treatment of the impact area of ​​the target-side bumper structure while secured to the target.

[0010]

[0010] Further features of various aspects of the present disclosure will be described in detail below with reference to the accompanying drawings. It should be noted that the present disclosure is not limited to the specific aspects described herein. Such aspects are presented herein for illustrative purposes only. Further aspects will be apparent to those skilled in the art based on the teachings contained herein. [Brief explanation of the drawings]

[0011]

[0011] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate the present disclosure and, together with the description, further serve to explain the principles of the present disclosure and to enable those skilled in the art to make and use the aspects described in this specification.

[0012]

[0012] [Figure 1A] 1 illustrates a reflective lithographic apparatus according to some embodiments.

[0013] [Figure 1B] 1 illustrates a transmissive lithographic apparatus according to some embodiments.

[0014] [Figure 1C] 1 illustrates a lithographic cell according to some embodiments.

[0015] [Figure 2] 1 illustrates a reticle stage according to some embodiments. [Figure 3] 1 illustrates a reticle stage according to some embodiments.

[0016] [Figure 4] 1 illustrates a reticle exchange apparatus according to some embodiments.

[0017] [Figure 5] 1 illustrates stages of operation according to some embodiments. [Figure 6] 1 illustrates stages of operation according to some embodiments. [Figure 7] 1 illustrates stages of operation according to some embodiments.

[0018] [Figure 8] 1 illustrates a flowchart of a method according to some aspects. [Figure 9]1 illustrates a flowchart of a method according to some aspects. DETAILED DESCRIPTION OF THE INVENTION

[0013]

[0019] Features of the present disclosure will become more apparent from the following detailed description taken in conjunction with these drawings. In the drawings, like reference symbols identify corresponding elements throughout. In the drawings, like reference numbers generally indicate identical, functionally similar, and / or structurally similar elements. Furthermore, the left-most digit(s) of a reference number generally identifies the drawing in which that reference number first appears. Unless otherwise noted, the drawings provided throughout this disclosure should not be construed as drawings to scale.

[0014]

[0020] References to embodiments described herein, and to "one embodiment," "an embodiment," "exemplary embodiment," "example embodiment," and the like in the specification, indicate that the described embodiment may include a particular feature, structure, or characteristic, but not all embodiments may necessarily include that particular feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in connection with one embodiment, it is understood that it is within the knowledge of one skilled in the art to bring about such feature, structure, or characteristic in connection with other embodiments, whether or not it is explicitly described.

[0015]

[0021] Spatially relative terms such as "beneath," "below," "lower," "above," "on," "upper," and the like may be used herein to facilitate the description of the relationship of one element or feature to another element or feature, as shown in the figures. Spatially relative terms are intended to encompass various orientations of the device in use or operation in addition to the orientation shown in the figures. The device may be otherwise oriented (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein may be similarly interpreted accordingly.

[0016]

[0022] As used herein, terms such as "approximately," "about," and the like can be used to indicate a given quantity value that can vary based on a particular technique. Based on a particular technique, terms such as "approximately," "about," and the like can indicate a given quantity value that varies within a range of, for example, 10% to 30% of the value (e.g., ±10%, ±20%, or ±30% of the value).

[0017]

[0023] Aspects of the present disclosure may be implemented in hardware, firmware, software, or any combination thereof. Aspects of the present disclosure may also be implemented as instructions stored on a computer-readable medium and readable and executable 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, or electrical, optical, acoustic, or other forms of propagated signals (e.g., carrier waves, infrared signals, digital signals, etc.). Furthermore, firmware, software, routines, and / or instructions may be described herein as performing certain actions. However, it should be understood that such description is merely for convenience and that such actions are actually performed by a computing device, processor, controller, or other device executing the firmware, software, routines, instructions, etc. The term "machine-readable medium" may be interchangeable with similar terms, such as "computer program product," "computer-readable medium," "non-transitory computer-readable medium," etc. As used herein, the term "non-transitory" may be used to characterize one or more forms of computer-readable media other than transitory propagating signals.

[0018]

[0024] However, before describing such embodiments in greater detail, it is beneficial to present an exemplary environment in which aspects of the present disclosure can be implemented.

[0019]

[0025] Exemplary Lithography System

[0020]

[0026] 1A and 1B show lithographic apparatus 100 and lithographic apparatus 100', respectively, in which aspects of the present disclosure can be implemented. Lithographic apparatus 100 and lithographic apparatus 100' each include: an illumination system (illuminator) IL configured to condition a radiation beam B (e.g., deep ultraviolet or extreme ultraviolet radiation); a support structure (e.g., a mask table) MT configured to support a patterning device (e.g., a mask, reticle, or dynamic patterning device) MA and connected to a first positioner PM configured to accurately position the patterning device MA; and a substrate table (e.g., a wafer table) WT configured to hold a substrate (e.g., a resist-coated wafer) W and connected to a second positioner PW configured to accurately position the substrate W. Lithographic apparatus 100 and 100' also include a projection system PS configured to project a pattern imparted to radiation beam B by patterning device MA onto a target portion C of the substrate W (e.g., comprising part of one or more dies). In lithographic apparatus 100, patterning device MA and projection system PS are reflective. In lithographic apparatus 100', patterning device MA and projection system PS are transmissive.

[0021]

[0027] The illumination system IL may include various types of optical components, such as refractive, reflective, catadioptric, magnetic, electromagnetic, electrostatic or other types of optical components, or any combination thereof, to direct, shape or control the radiation beam B.

[0022]

[0028] The support structure MT holds the patterning device MA in a manner that depends on the orientation of the patterning device MA relative to a reference frame, the design of at least one of lithographic apparatuses 100 and 100′, and other conditions, such as whether or not the patterning device MA is held in a vacuum environment. The support structure MT may use mechanical, vacuum, electrostatic or other clamping techniques to hold the patterning device MA. The support structure MT may, for example, be a frame or a table, which may be fixed or movable. Using sensors, the support structure MT may ensure that the patterning device MA is at a desired position, for example with respect to the projection system PS.

[0023]

[0029] The term "patterning device" MA should be interpreted broadly to refer to any device that can be used to impart a radiation beam B with a pattern in its cross-section so as to create a pattern in a target portion C of a substrate W. The pattern imparted to the radiation beam B will correspond to a particular functional layer in a device being created in the target portion C to form an integrated circuit.

[0024]

[0030] Patterning device MA may be transmissive (such as lithographic apparatus 100′ in FIG. 1B) or reflective (such as lithographic apparatus 100 in FIG. 1A). Examples of patterning devices MA include reticles, masks, programmable mirror arrays, or programmable LCD panels. Masks are well known in lithography, and include mask types such as binary, alternating phase-shift, or attenuated phase-shift, as well as various hybrid mask types. An example of a programmable mirror array uses a matrix arrangement of small mirrors, each of which can be individually tilted so as to reflect an incoming radiation beam in different directions. The tilted mirrors impart a pattern to a radiation beam B, which is reflected by the matrix of small mirrors.

[0025]

[0031] The term "projection system" PS may include any type of projection system, including refractive, reflective, catadioptric, magnetic, electromagnetic, electrostatic optical systems, or any combination thereof, appropriate to the exposure radiation used, or other factors such as the use of an immersion liquid or the use of a vacuum on the substrate W. A vacuum environment may be used for EUV or electron beam radiation, as other gases may be too absorbing of the radiation or electrons. A vacuum environment may therefore be provided throughout the beam path using a vacuum wall and vacuum pumps.

[0026]

[0032] Lithographic apparatus 100 and / or lithographic apparatus 100' may be of a type having two (dual stage) or more substrate tables WT (and / or two or more mask tables). In such a "multi-stage" machine, the additional substrate tables WT may be used in parallel, or preparatory steps may be performed on one or more tables while one or more other substrate tables WT are being used for exposure. In some circumstances, the additional tables may not be substrate tables WT.

[0027]

[0033] The lithographic apparatus may be of a type in which at least a portion of the substrate is covered by a liquid having a relatively high refractive index (e.g., water), so as to fill a space between the projection system and the substrate. An immersion liquid may also be applied to other spaces in the lithographic apparatus, for example, between the mask and the projection system. Immersion techniques are well known in the art for increasing the numerical aperture of projection systems. As used herein, the term "immersion" does not imply that a structure such as a substrate must be submerged in liquid. For example, a liquid may be disposed between the projection system and the substrate during exposure.

[0028]

[0034] 1A and 1B, the illuminator IL receives a radiation beam from a radiation source SO. The radiation source SO and the lithographic apparatus 100, 100' may be separate physical entities, for example if the radiation source SO is an excimer laser. In such a case, the radiation source SO is not considered to form part of the lithographic apparatus 100 or 100' and the radiation beam B is delivered from the radiation source SO to the illuminator IL using a beam delivery system BD ( FIG. 1B ), for example comprising appropriate directing mirrors and / or beam expanders. Alternatively, the radiation source SO may be an integral part of the lithographic apparatus 100, 100', for example if the radiation source SO is a mercury lamp. A radiation system may include the radiation source SO, the illuminator IL, and / or the beam delivery system BD.

[0029]

[0035] The illuminator IL may include an adjuster AD (FIG. 1B) for adjusting the angular intensity distribution of the radiation beam. Generally, at least the outer and / or inner radial extent (commonly referred to as "σ-outer" and "σ-inner", respectively) of the intensity distribution in a pupil plane of the illuminator may be adjusted. In addition, the illuminator IL may comprise various other components (FIG. 1B), such as an integrator IN and a condenser CO. The illuminator IL can be used to condition the radiation beam B so that it has a desired uniformity and intensity distribution in its cross-section.

[0030]

[0036] Referring to Figure 1A, radiation beam B is incident on patterning device (e.g., mask) MA, which is held on support structure (e.g., mask table) MT, and is patterned by the patterning device MA. In lithographic apparatus 100, radiation beam B is reflected from patterning device (e.g., mask) MA. After reflecting from patterning device (e.g., mask) MA, radiation beam B passes through projection system PS, which focuses radiation beam B onto a target portion C of substrate W. Using a second positioner PW, and a position sensor IF2 (e.g., an interferometer device, a linear encoder, or a capacitive sensor), the substrate table WT can be precisely moved (e.g., to position different target portions C in the path of radiation beam B). Similarly, using a first positioner PM and another position sensor IF1, the patterning device (e.g., mask) MA can be accurately positioned with respect to the path of radiation beam B. Mask alignment marks M1, M2 and substrate alignment marks P1, P2 can be used to align the patterning device (e.g., mask) MA and substrate W.

[0031]

[0037] Referring to Figure 1B, a radiation beam B is incident on a patterning device (e.g., mask MA), which is held on a support structure (e.g., mask table MT), and is patterned by the patterning device. Having traversed the mask MA, the radiation beam B passes through a projection system PS, which focuses the beam onto a target portion C of a substrate W. The projection system has a pupil PPU that is conjugate with the illumination system pupil IPU. A portion of the radiation emerges from the intensity distribution at the illumination system pupil IPU and traverses the mask pattern unaffected by diffraction at the mask pattern, producing an image of the intensity distribution at the illumination system pupil IPU.

[0032]

[0038] The projection system PS projects an image of the mask pattern MP, formed by diffracted beams generated from the mark pattern MP by radiation from the intensity distribution, onto a photoresist layer coated on the substrate W. For example, the mask pattern MP may include a line-and-space array. Diffraction of the radiation at the array, other than the zeroth-order diffraction, generates bypass diffracted beams redirected perpendicular to the lines. The undiffracted beams (i.e., the so-called zeroth-order diffracted beams) pass through the pattern without changing their direction of propagation. The zeroth-order diffracted beams pass through the upper lens or upper lens group of the projection system PS upstream of the pupil conjugate point PPU of the projection system PS and reach the pupil conjugate point PPU. The portion of the intensity distribution in the plane of the pupil conjugate point PPU associated with the zeroth-order diffracted beam is an image of the intensity distribution in the illumination system pupil IPU of the illumination system IL. For example, the aperture device PD is positioned or substantially positioned in a plane containing the pupil conjugate point PPU of the projection system PS.

[0033]

[0039] The projection system PS is positioned (e.g., using a lens or lens group L) to capture the zeroth-order diffracted beam, the first-order diffracted beam, and / or higher-order diffracted beams (not shown). In some embodiments, dipole illumination can be used to image a line pattern extending in a direction perpendicular to the line, taking advantage of the resolution-enhancing effect of dipole illumination. For example, a first-order diffracted beam interferes with a corresponding zeroth-order diffracted beam at the level of the wafer W to create an image of the line pattern MP with the highest possible resolution and process window (i.e., usable depth of focus combined with an acceptable exposure dose deviation). In some embodiments, astigmatism can be reduced by providing a radiation pole (not shown) in the opposite quadrant of the illumination system pupil IPU. Furthermore, in some embodiments, astigmatism can be reduced by blocking the zeroth-order beam at the projection system pupil conjugate point PPU associated with the radiation pole in the opposite quadrant. This is described in more detail in U.S. Patent No. 7,511,799, issued March 31, 2009, the entire contents of which are incorporated herein by reference.

[0034]

[0040] Using the second positioner PW and a position sensor IFD (e.g. an interferometer device, a linear encoder or a capacitive sensor), the substrate table WT can be accurately moved (e.g. to position different target portions C in the path of the radiation beam B). Similarly, using the first positioner PM and a further position sensor (not shown in FIG. 1B ), the mask MA can be accurately positioned with respect to the path of the radiation beam B (e.g. after mechanical retrieval from a mask library or during a scan).

[0035]

[0041] In general, movement of the mask table MT may be realized using a long-stroke module (coarse positioning) and a short-stroke module (fine positioning), which form part of the first positioner PM. Similarly, movement of the substrate table WT may be realized using a long-stroke module and a short-stroke module, which form part of the second positioner PW. In the case of a stepper (as opposed to a scanner), the mask table MT may be connected to a short-stroke actuator, or may be fixed. The mask MA and substrate W may be aligned using mask alignment marks M1, M2 and substrate alignment marks P1, P2. The substrate alignment marks as illustrated occupy dedicated target portions, but may also be located in spaces between target portions (known as scribe-lane alignment marks). Similarly, in situations in which more than one die is provided on the mask MA, the mask alignment marks may be located between the dies.

[0036]

[0042] The mask table MT and patterning device MA may be within a vacuum chamber V, where an in-vacuum robot IVR can be used to move the patterning device, such as a mask, in and out of the vacuum chamber. Alternatively, if the mask table MT and patterning device MA are outside the vacuum chamber, an out-of-vacuum robot can be used for various transfer operations similar to the in-vacuum robot IVR. Both the in-vacuum and out-of-vacuum robots can be calibrated to smoothly transfer any payload (e.g., a mask) to a fixed kinematic mount in the transfer station.

[0037]

[0043] Lithographic apparatus 100 and 100' can be used in at least one of the following modes:

[0038]

[0044] 1. In step mode, the support structure (e.g. mask table) MT and substrate table WT are kept essentially stationary, while an entire pattern imparted to the radiation beam B is projected onto a target portion C in one go (i.e. a single static exposure), and the substrate table WT is then moved in the X and / or Y direction so that a different target portion C can be exposed.

[0039]

[0045] 2. In scan mode, the support structure (e.g. mask table) MT and the substrate table WT are scanned synchronously while a pattern imparted to the radiation beam B is projected onto a target portion C (i.e. a single dynamic exposure). The velocity and direction of the substrate table WT relative to the support structure (e.g. mask table) MT may be determined by the (de-)magnification and image reversal characteristics of the projection system PS.

[0040]

[0046] 3. In another mode, the support structure (e.g. mask table) MT holds a programmable patterning device and is held substantially stationary, while the substrate table WT is moved or scanned while a pattern imparted to the radiation beam B is projected onto a target portion C. A pulsed radiation source SO is used, and the programmable patterning device is updated as required with each movement of the substrate table WT, or between successive radiation pulses during a scan. This mode of operation is readily adaptable to maskless lithography employing a programmable patterning device such as a programmable mirror array.

[0041]

[0047] Combinations and / or variations on the above described modes of use or entirely different modes of use may also be employed.

[0042]

[0048] In some embodiments, lithographic apparatus 100 includes an extreme ultraviolet (EUV) source configured to generate an EUV radiation beam for EUV lithography. Generally, the EUV source is configured in a radiation system, and a corresponding illumination system is configured to condition the EUV radiation beam of the EUV source.

[0043]

[0049] In some embodiments, the lithographic apparatus 100' includes a deep ultraviolet (DUV) source configured to generate a beam of DUV radiation for DUV lithography. Typically, the DUV source is configured in a radiation system, and a corresponding illumination system is configured to condition the DUV radiation beam of the DUV source.

[0044]

[0050] Exemplary Lithography Cell

[0045]

[0051] FIG. 1C illustrates a lithography cell 102, sometimes referred to as a lithocell or cluster, according to some embodiments. Lithography apparatus 100 or 100′ can form part of lithography cell 100. Lithography cell 102 may also include one or more devices that perform pre-exposure and post-exposure processes on a substrate. Conventionally, these include a spin coater SC for depositing a resist layer, a developer DE for developing exposed resist, a chill plate CH, and a bake plate BK. A substrate handler or robot RO picks up substrates from input / output ports I / O1, I / O2, moves them between different process tools, and delivers them to a loading bay LB of lithography apparatus 100 or 100′. These devices, often collectively referred to as a track, are under the control of a track control unit TCU, which is itself controlled by a supervisory control system SCS, which also controls the lithography apparatus via a lithography control unit LACU. Thus, the different devices can be operated to maximize throughput and processing efficiency.

[0046]

[0052] Exemplary Reticle Stage

[0047]

[0053] 2 and 3 illustrate a reticle stage 200 according to some embodiments. The reticle stage 200 may include a top stage surface 202, a bottom stage surface 204, a side stage surface 206, and a clamp 300. In some embodiments, the reticle stage 200 with the clamp 300 may be mounted to a lithography apparatus LA. For example, the reticle stage 200 may be a support structure MT in the lithography apparatus LA. In some embodiments, the clamp 300 may be disposed on the top stage surface 202. For example, as shown in FIG. 2, the clamp 300 may be disposed in the center of the top stage surface 202 with the clamp front surface 302 facing perpendicularly away from the top stage surface 202.

[0048]

[0054] In some lithography apparatus, such as lithography apparatus LA, a reticle stage 200 with clamps 300 can be used to hold and position a reticle 408 for scanning or patterning operations. As an example, the reticle stage 200 may rely on powerful drives, a large balance mass, and a heavy frame to support it. As an example, the reticle stage 200 has a large inertia and may weigh more than 500 kg to propel and position a reticle 408 weighing approximately 0.5 kg. To achieve the reciprocating motion of the reticle 408 typically seen in lithography scanning or patterning operations, acceleration and deceleration forces can be provided by linear motors that drive the reticle stage 200.

[0049]

[0055] 2 and 3, the reticle stage 200 may include a first encoder 212 and a second encoder 214 for positioning operations. For example, the first encoder 212 and the second encoder 214 may be interferometers. The first encoder 212 may be mounted along a first direction, such as a horizontal direction (i.e., X direction), of the reticle stage 200, and the second encoder 214 may be mounted along a second direction, such as a vertical direction (i.e., Y direction) of the reticle stage 200. In some embodiments, the first encoder 212 may be orthogonal to the second encoder 214, as shown in FIGS. 2 and 3.

[0050]

[0056] As shown in FIGS. 2 and 3 , the reticle stage 200 can include a clamp 300. The clamp 300 is configured to hold a reticle 408 on a fixed, flat surface on the reticle stage 200. The clamp 300 includes a front clamp surface 302 and can be disposed on the top stage surface 202. In some embodiments, the clamp 300 can hold and secure an object using mechanical, vacuum, electrostatic, or other suitable clamping techniques. In some embodiments, the clamp 300 can be an electrostatic clamp that can be configured to electrostatically clamp (i.e., hold) an object (e.g., a reticle 408 ( FIG. 4 )) in a vacuum environment. For EUV generation performed in a vacuum environment, it may be difficult to use a vacuum clamp to clamp a mask or reticle. An electrostatic clamp can be used instead. For example, the clamp 300 can include an electrode, a resistive layer on the electrode, a dielectric layer on the resistive layer, and a burl protruding from the dielectric layer. In use, a voltage of, for example, several kV, can be applied to the clamp 300. Current can then flow through the resistive layer, causing a voltage on the top surface of the resistive layer to be substantially the same as the voltage on the electrode, generating an electric field. Coulomb forces, or the attractive force between oppositely charged particles, will attract the object to clamp 300, securing the object in place. In some embodiments, clamp 300 can be a rigid material, such as, for example, a metal, a dielectric, a ceramic, or a combination thereof.

[0051]

[0057] Exemplary Reticle Exchange Apparatus

[0052]

[0058] 4 illustrates a reticle exchange apparatus 401 according to some embodiments. The reticle exchange apparatus 401 can be configured to minimize reticle exchange time, particle generation, and contact forces or stresses from the clamps 300 and / or the reticle 408, thereby reducing damage to the clamps 300 and the reticle 408 and improving overall throughput in the reticle exchange process in, for example, lithography apparatus LA.

[0053]

[0059] The reticle exchange apparatus 401 may include a reticle stage 200, a clamp 300, and an in-vacuum robot 400. The in-vacuum robot 400 may include a reticle handler 402.

[0054]

[0060] In some embodiments, reticle handler 402 may be a rapid exchange device (RED) configured to efficiently rotate and minimize reticle exchange time. For example, reticle handler 402 may save time by moving multiple reticles from one location to another substantially simultaneously, rather than sequentially.

[0055]

[0061] In some embodiments, reticle handler 402 can include one or more reticle handler arms 404. Reticle handler arm 404 can include a reticle base plate 406. Reticle base plate 406 can be configured to hold an object (e.g., a reticle 408).

[0056]

[0062] In some embodiments, reticle base plate 406 may be an extreme ultraviolet interior pod (EIP) for the reticle. In some embodiments, reticle base plate 406 includes a front reticle base plate surface 407 and reticle 408 includes a back reticle surface 409.

[0057]

[0063] In some embodiments, the reticle base plate 406 can hold the reticle 408 such that the reticle base plate front surface 407 and the reticle back surface 409, respectively, face the top stage surface 202 and the front clamp surface 302. For example, the reticle base plate front surface 407 and the reticle back surface 409 can face vertically away from the top stage surface 202 and the front clamp surface 302.

[0058]

[0064] 4, the reticle handler arms 404 can be positioned symmetrically about the reticle handler 402. For example, the reticle handler arms 404 can be spaced approximately 90 degrees, 120 degrees, or 180 degrees apart from each other. In some embodiments, the reticle handler arms 404 can be positioned asymmetrically about the reticle handler 402. For example, two reticle handler arms 404 can be spaced approximately 135 degrees apart from each other, while another two reticle handler arms 404 can be spaced approximately 90 degrees apart from each other.

[0059]

[0065] In some embodiments, during the reticle exchange process, the reticle stage 200 with the clamps 300 can be adjusted with multiple stages of motion (eg, long stroke stage (coarse movement), short stroke stage (fine movement)).

[0060]

[0066] Exemplary Actuation Stages

[0061]

[0067] FIG. 5 illustrates a stage 500 for supporting an object 502 according to some embodiments. In some embodiments, the stage 500 may represent different views of the reticle stage 200 to highlight additional details. The stage 500 may include a support structure 504 (e.g., a second support structure), a support structure 506 (e.g., a first support structure), an actuator device 510, and an actuator target 508. The actuator device 510 may include a coil 512 (e.g., a wire wound around a ferromagnetic core). The actuator target 508 may be positioned and secured on the support structure 504 using a securing structure 514 (e.g., epoxy). The number and configuration of actuator-related elements are not limited to those shown in FIG. 5. Fewer or more actuator-related elements, as well as other configurations, may be used. The stage 500 may also include one or more position indicators 516 (e.g., an encoder scale).

[0062]

[0068] In some embodiments, enumerated adjectives (e.g., "first," "second," "third," etc.) may be used to distinguish between similar elements without establishing an order, hierarchy, quantity, or permanent numerical assignment. For example, the terms "first support structure" and "second support structure" may be used similarly to "i support structure" and "j support structure," to facilitate distinguishing between two support structures without specifying a particular order, hierarchy, quantity, or permanent numerical correspondence, unless otherwise noted.

[0063]

[0069] In some embodiments, stage 500 may be used in a lithographic apparatus LA (FIG. 1), a lithographic cell (e.g., an arrangement of multiple lithographic apparatus), an inspection apparatus, or generally any apparatus having a stage implementation for supporting and moving an object. For example, stage 500 may represent a particular implementation of a wafer table WT or a mask table MT (FIG. 1).

[0064]

[0070] In some embodiments, the support structure 506 may be an actuation structure (e.g., for coarse movement of the object 502). In a lithography manufacturing process, the object 502 may be a reticle, a wafer, or the like. Additionally, the stage 500 may also include an additional movement budget for moving the object 502 to and from a loading area. Thus, the support structure 506 may be responsible for coarse movement of the stage 500 (e.g., on the order of tens, hundreds, or thousands of millimeters). Other distances may also be selected based on suitability for a particular implementation. However, in implementations where coarse movement is not required, the support structure 506 may be a static frame.

[0065]

[0071] In some embodiments, the support structure 504 is supported by the support structure 506, while allowing relative movement between the two support structures. The movement of the support structure 504 can be constrained in an axis (e.g., the Y axis) using guide rails or non-contact methods (e.g., magnetic levitation) (guide device not shown). The coordinate axes X and Y are shown by way of example and are not intended to be limiting. The actuator device 510 can be responsible for fine adjustment of the position of the support structure 504. Thus, in some embodiments, a small gap is used between the actuator device 510 and its corresponding actuator target 508. For example, the gap may be a few millimeters or less (e.g., less than about 1 mm). In scanning lithography processes, printed devices may have critical dimensions in the submicron or sub-nanometer range. A movement budget of 1 millimeter may be sufficient for scan printing of sub-nanometer devices.

[0066]

[0072] In some embodiments, the actuator device 510 can be disposed on and secured to the support structure 506. The actuator device 510 can actuate the support structure 504 by interacting with an actuator target 508. The actuator target 508 can include a material (e.g., metal, iron, ferrite, etc.) that responds to a magnetic field. The actuator device 510 can be an electromagnet. An electromagnet can generate and adjust a magnetic field. The electromagnet can include a coil 512 of wire wound around a metal core (e.g., a ferrite core). The actuator device 510 can operate as an attractor only if the actuator target 508 is not a permanent magnet. Conversely, the actuator device 510 can repel or attract a permanent magnet version of the actuator target 508 by reversing the direction of the magnetic field. The actuator configurations described herein can also be referred to by other technical terms (e.g., a reluctance actuator, and therefore the actuator target 508 can also be referred to as a reluctance target).

[0067]

[0073] In some embodiments, the actuator device 510 can use high acceleration to actuate the support structure 504. The acceleration can be, for example, about 4-100 g, 10-50 g, 20-10 g, etc. (g is 9.8 m / s 2 ). High acceleration can increase lithographic printing production (e.g., increased throughput). Lithographic pattern transfer can be performed when the support structure 504 is moving, for example, when a constant coasting velocity is reached. The coasting velocity may be, for example, 0.5-10.0 m / s, 1.0-7.0 m / s, 3.0-5.0 m / s, etc. Performing pattern transfer at a constant scanning velocity results in more accurate transfer of the printed pattern, but printing during acceleration can result in greater positional uncertainty.

[0068]

[0074] The term "throughput" can be understood as the amount of material or items passing through a system or process. In some aspects, the term "throughput" can be used to characterize the speed of lithographic manufacturing. For example, throughput can refer to the rate at which lithographic manufacturing is completed on a wafer, the rate at which a wafer moves through a particular manufacturing step and to the next step, etc. Throughput can also be a performance marker for a lithographic apparatus. In a lithographic system, it is desirable to output as many products as possible in as short a time as possible. Lithographic manufacturing may include several complex processes. Each part of the process can involve trade-offs that balance quality (e.g., sub-nanometer accuracy, high yield) with drawbacks (e.g., slower manufacturing, cost). For example, to improve pattern transfer speed, lithography can implement faster and more accurate substrate and mask movements.

[0069]

[0075] In some embodiments, the nature of the magnetic field can destabilize the repulsive interaction, creating undesirable lateral forces (orthogonal to the repulsive direction) and undesirable orthogonal torques. The orthogonal forces / torques tend to move the magnets to change the interaction from repulsive to attractive in order to minimize the total potential energy of the magnet set. Without external lateral guidance or constraint, the alignment becomes unstable and jumps to the nearest stable equilibrium position, closing the gap (no longer levitating). As a result, repulsive systems using permanent magnets are difficult to design and may require the addition of active controls or external mechanical guides to prevent alignment collapse. The added complexity of the lithography system can significantly increase the engineering difficulty. Therefore, in some embodiments, the actuator device 510 can be designed to operate using only attractive forces (or only pulling). Having the actuator device 510 on the opposite side of the support structure 504 can provide both forward and backward movement to the support structure 504 while using a pulling-only configuration. However, the pulling-only method can have certain drawbacks, as further described below.

[0070]

[0076] In some embodiments, the object 502 can be temporarily fixed onto the support structure 504 by pressing the object 502 against the support structure 504. This can be achieved by vacuum clamping (suction force), electrostatic clamping (electrostatic force), mechanical clamping, etc. Under ideal conditions, mutual friction between the object 502 (e.g., a reticle) and the support structure 504 (e.g., a chuck) ensures that no slippage occurs between them. However, mechanical stress due to high acceleration can cause slippage, resulting in printing errors. Errors can be very detrimental, as thousands of device products may be lost before the error is detected.

[0071]

[0077] The following is an example of a positioning error of the object 502 when using the stage 500. In some embodiments, the object 502 can be fixed on the support structure 504. A calibration measurement can be performed, for example, using an optical inspection system, to determine the position of features on the object 502. The calibration measurement can determine the position of the features on the object 502 relative to one or more position indicators 516. The position indicators 516 can be rigidly fixed to the support structure 504. Once the relationship between the object 502 and the one or more position indicators 516 is established, the object 502 can be used in a high-precision process (e.g., a lithography process) without the need to perform calibration again, as long as the object 502 remains stationary relative to the support structure 504.

[0072]

[0078] In some embodiments, an electromagnetic force can be applied to an actuator target 508 by an actuator device 510. For example, an actuator device 510 on the left side of the support structure 504 can be activated, which then pulls the corresponding actuator 508, which pulls the fixed structure 514, and finally the support structure 504. Thus, an actuator device 510 on the right side of the support structure 504 can be used to pull in the opposite direction (due to deceleration), bringing the support structure 504 to a standstill. During acceleration / deceleration, the combined mass of the object 502 and support structure 504 is inertial and exerts an equal and opposite force (depicted as a right-pointing arrow "ma" (mass x acceleration)) to the force exerted by the actuator target 508 during the pull. Conversely, if two actuator targets 508 are pulling, the pulling force can be divided between the two actuator targets 508 (depicted as two arrows "F=ma / 2").

[0073]

[0079] In some embodiments, the actuator target 508 and the corresponding actuator device 510 may be separated by a gap, which determines the quality and performance of the actuation. For example, if the gap is too large, the attractive magnetic force may be too weak to provide sufficient acceleration to the support structure 504 to meet throughput goals. If the gap is too small, there is a risk of collision between the actuator target 508 and the actuator device 510. To achieve tight tolerances on the gap, it is desirable to design the structural tolerances of these elements down to tens of microns.

[0074]

[0080] Some aspects described herein provide structures and functionality to address issues related to tolerances in the manufacture of actuator devices and targets.

[0075]

[0081] FIG. 6 illustrates a portion of a stage 600 according to some embodiments. In some embodiments, stage 600 may include a different view of stage 500 (FIG. 5) to show additional details. For clarity, new elements may be displayed while some elements may be hidden or unlabeled (e.g., a coil is not displayed but is understood to be present). Thus, unless otherwise noted, descriptions of elements in FIG. 5 are also applicable to FIG. 6. Elements displayed in FIG. 6 that correspond to elements in FIG. 5 may have similar reference numbers (e.g., reference numbers that share the two rightmost digits). Examples of such elements in FIG. 6 include, for example, support structures 604 and 606, actuator target 608, and core 610 (e.g., actuator device).

[0076]

[0082] In some embodiments, the core 610 can include poles 618. As a non-limiting example, the core 610 can be shaped with the poles 618 facing in the same direction (e.g., a C-shaped core). The magnetic flux can be perpendicular to the surface of the poles 618. The surface area of ​​the poles 618 (e.g., the combined area of ​​both poles) can determine the magnitude of the magnetic interaction (e.g., the magnitude of the magnetic force). The surface of the poles 618 can define a plane 620. The actuator target 608 can include pole-facing sides 622. The pole-facing sides 622 can define a plane 624.

[0077]

[0083] In some embodiments, bumper structures can be implemented to prevent collisions with fast-moving objects (e.g., if the lithography apparatus loses power). It may be undesirable for the actuation target 608 to collide with the core 610. Collisions can damage the structures and / or contaminate the clean lithography environment by releasing contaminating particles that can land on the reticle and / or wafer. Therefore, the actuator target 608 and core 610 can be protected by target-side bumper structures 628 and core-side bumper structures 630. One or more of each bumper type can be implemented. The bumpers can be positioned to maintain a non-zero gap distance d (defined in FIG. 6 as the distance between the plane 624 of the pole-facing side 622 and the plane 620 of the pole 618). The target-side bumper 628 can be fixed to the actuation target 608. The core-side bumper 630 can be fixed to the core 610.

[0078]

[0084] In some embodiments, the core-side bumper 630 can be secured to the core support structure 632. The core-side bumper 630 can be a monolithic appendage (e.g., a block of the same material) of the core support structure 632. The core support structure 632 can be secured to the core 610, thereby fixing the relative position between the surface of the pole 618 and the core-side bumper 630.

[0079]

[0085] In some embodiments, the support structure 604 (e.g., a second support structure) can be configured to move relative to the support structure 606 along a direction 626 (e.g., parallel to the X-axis). The support structure 604 can support the object 502 ( FIG. 5 ). The support structure 604 is used for fine positioning of the object 502 ( FIG. 5 ). In the context of lithographic pattern transfer, the position of the object 502 can be finely adjusted, thereby enabling precise lithographic printing down to sub-nanometer resolution. The magnetic force (force exerted on the actuator target 608) to move the support structure 604 depends on how close the electromagnet is to the target (i.e., a smaller distance d corresponds to a larger force). At a larger distance d, the force decreases unless the current through the coil 512 ( FIG. 5 ) is increased. The force exerted by the electromagnet can be quantified according to the following equation:

number

number

[0080]

[0086] In some embodiments, the force F is the force that the electromagnet using the core 610 can exert on the actuator target 608. The magnetic field B is the magnitude of the magnetic field within the core 610. The area A can be the combined surface area of ​​the poles 618. The permeability μ is the permeability of free space. The turns N is the number of turns of the coil 512 (FIG. 5) around the core 610. The current I is the current flowing through the coil 512 (FIG. 5), and the distance d is as shown in FIG. 6. Approximating Equation 2 is facilitated by considering that the permeability of the core 610 is much greater than the permeability of air or free space. An ideal material for the core 610 could support an infinite amount of B field, but in practice, permeable materials may have a saturation limit. In other words, at the saturation limit, increasing the current I can result in significant diminishing returns for increasing the B field. Thus, the power dissipation P can continue to increase (P=1 2R, where R is the resistance of the coil).

[0081]

[0087] As previously discussed, in some embodiments, it is desirable to move object 502 as fast as the system allows without affecting pattern transfer accuracy (e.g., to achieve throughput goals). Higher actuation speeds can be achieved by applying a force of 4 g, 100 g, or more to support structure 604. The magnetic saturation limit of the core 610 material may prevent efforts to increase the force by increasing the current I through the coil. However, based on Equations 1 and 2, it is also possible to increase force F by decreasing distance d. Based on the above characteristics, two conflicting interests can be identified for actuation of object 502 ( FIG. 5 ). On the one hand, it is desirable to design the full range of distance d so that the actuation budget is accommodated (e.g., support structure 604 can be configured to move within a 1 mm range) while allowing actuation target 608 and pole 618 to be as close as possible without contact. On the other hand, decreasing distance d may increase the likelihood of collision between actuation target 608 and core 610 (due to tolerances in machining and / or construction).

[0082]

[0088] The structures and methods disclosed herein allow for very low tolerance manufacturing of the bumper relative to the structure it is intended to protect, allowing the actuator target 608 to be placed closer to the core 610 while reducing the risk of collision.

[0083]

[0089] In some embodiments, each of the target-side bumper structures 628 may include a surface 634 (e.g., a contact surface). The surface 634 may define a plane 638 of the target-side bumper structure 628. Similarly, each of the core-side bumper structures 630 may include a surface 636 (e.g., a contact surface). The surface 636 may define a plane 640 of the core-side bumper structure 630. In the event of a collision, the surface 634 may come into contact with the surface 636. If the bumpers are properly designed, a non-zero collision avoidance gap is maintained (i.e., the minimum distance d is non-zero) at the moment of contact. That is, the target-side bumper may be configured to collide with the core-side bumper structure to establish a collision avoidance gap between the core and the target. Additionally, the uncertainty value of the collision avoidance gap may be less than approximately 20 microns, 50 microns, 70 microns, 100 microns, 120 microns, etc. In other words, when the distance between plane 638 and plane 640 is zero, the distance between plane 620 and plane 624 is greater than zero. Also, when fabricated in accordance with one or more aspects of the present disclosure, the collision avoidance gap can be made greater than zero but very small (e.g., with an uncertainty on the order of tens of nanometers).

[0084]

[0090] In some embodiments, fabrication of the target-side structure can include securing the target-side bumper structure 628 to the actuation target 608. Securing can be achieved using any suitable method (e.g., adhesive bonding, bolting, nailing, clamping, etc.). Once secured, the positional relationship between the polar-facing side surface 622 (flat surface 624) and the surface 634 is fixed. When securing the target-side bumper structure 628 and the actuation target 608 to each other, precision molding techniques (e.g., chemical-mechanical polishing, ablation, precision coating, etc.) can be applied to precisely set the distance between the flat surface 624 and the flat surface 638. The precision molding techniques can be applied to the polar-facing side surface 622, the surface 634, or both. The precision can be, for example, to a tolerance of + / - 5 microns. For example, the flat surface 624 and the flat surface 638 can be fabricated to be + / - 130 microns apart with an uncertainty of + / - 5 microns. The plus sign at +130 microns indicates that the surface 634 is positioned higher than the polar-facing side surface 622.

[0085]

[0091] In some embodiments, a similar manufacturing process can be performed on the core. Manufacturing the core-side structure can include fastening the core-side bumper structure 630 to the core 610. Fastening can be achieved using any suitable method (e.g., adhesive bonding, bolting, nailing, clamping, etc.). Once fastened, the positional relationship between the pole 618 (flat surface 620) and the surface 640 is fixed. When fastening the target-side bumper structure 628 and the actuation target 608 to each other, precision molding techniques (e.g., chemical mechanical polishing, ablation, precision coating, etc.) can be applied to precisely set the distance between the flat surface 620 and the flat surface 640. The precision molding techniques can be applied to the surface of the pole 618, the surface 636, or both. The precision can be, for example, to a tolerance of + / - 5 microns. For example, the flat surface 620 and the flat surface 640 can be manufactured to be -100 microns apart with an uncertainty of + / - 5 microns. The minus sign for -100 microns can indicate that the surface 636 is positioned lower than the surface of the pole 618.

[0086]

[0092] In this non-limiting example, when surfaces 634 and 636 contact, the collision avoidance gap (e.g., the minimum distance d tolerated by the bumper) is +130-100±5±5 microns = 30±10 microns. Even in the worst-case scenario (uncertainty range of -10 microns), the collision avoidance gap is guaranteed to be 20 microns. That is, the collision avoidance gap can be manufactured to a narrow set of values, such as approximately 40 microns or less, 35 microns or less, 30 microns or less, 25 microns or less, or 20 microns or less. Note that traditional bumper manufacturing methods cannot achieve such low tolerances. Traditional methods rely on precision machining of the bumper, connector, actuation target, and core before assembling the components. In traditional assembly, parameters that may contribute to uncertainty may include actuation target dimensions, target-side bumper dimensions, target-side bumper positioning on its support structure, core dimensions, core-side bumper dimensions, core-side bumper positioning on its support structure, epoxy adhesive thickness, etc. The total uncertainty resulting from a conventional assembly may be ±200 microns or more, meaning that the collision avoidance gap must be designed to be larger than 200 microns. This difference in the value of the collision avoidance gap (200 microns for a conventional assembly versus 20 microns according to embodiments of the present disclosure) can then result in a 100-fold increase in the force F (F∝1 / d according to Equations 1 and 2). 2 ).

[0087]

[0093] In some embodiments, increasing the force F by manipulating the distance d also serves to reduce the amount of power consumed by the coil 512 (FIG. 5). For a given force, reducing the collision avoidance gap can result in a significant reduction in power consumption when applying a force to the support structure 604 (F∝I / d according to Equations 1 and 2). 2 , and P=I 2 R).

[0088]

[0094] In some embodiments, stage 600 can include a kinetic energy dissipation system 642. Kinetic energy dissipation system 642 can include one or more collapsible structures (e.g., springs, flexures, hydraulics, etc.). Kinetic energy dissipation system 642 can be coupled to core 610. Kinetic energy dissipation system 642 can be coupled to core support structure 632. When surface 634 and surface 636 come into contact during a collision, kinetic energy dissipation system 642 can collapse or otherwise break, pushing core 610 from its predetermined position. Energy from the collision can be dissipated by kinetic energy dissipation system 642. Because kinetic energy dissipation system 642 can bias core 610 toward the left of the figure (toward actuation target 608), a stop structure (not shown) can be implemented to limit movement of core 610 beyond its predetermined position.

[0089]

[0095] In some embodiments, the core support structure 632 can include slots 644. The slots 644 can provide clearance for the coil wound around the core 610. The coil 512 (FIG. 5) can be tightly wrapped around one or more portions of the core 610 so that it is effectively secured to the core 610 by friction (other suitable fastening techniques, such as adhesives, can also be used). The coil can also include cooling (e.g., circulating a fluid coolant through ducts) to offset heat generated by electrical current. However, if service and / or replacement of the core 610 is required, the wiring and ducts can impose inconvenient constraints on service technicians. With the coil secured to the core, replacing the core can also include the complication of replacing the wiring / ducts along with the core. Thus, in some embodiments, the coil can be a removable assembly, as shown in FIG. 7.

[0090]

[0096] FIG. 7 illustrates a portion of a stage 700 according to some embodiments. In some embodiments, stage 700 may include different representations of stages 500 and 600 ( FIGS. 5 and 6 ) to show additional details. For clarity, new elements are shown, while some elements may be hidden or unlabeled. Thus, unless otherwise noted, descriptions of elements in FIGS. 5 and 6 also apply to FIG. 7 . Elements appearing in FIG. 7 that correspond to elements in FIGS. 5 and 6 may have the same reference numbers (e.g., reference numbers that share the two rightmost digits). Examples of such elements in FIG. 7 include, for example, support structures 704 and 706, actuator target 708, core 710, coil 712, target-side bumper structure 728, core-side bumper structure 730, core support structure 732, kinetic energy dissipation system 742, and slot 744.

[0091]

[0097] In some embodiments, the force-generating element of the stage 700 may be part of an electromagnetic device (e.g., core 710, coil 712, etc.). The electromagnetic device may include a detachable wire coil assembly 746. The detachable wire coil assembly 746 may include a housing 748, a conduit 750, and a coil 712. The coil 712 may be wrapped around the core 710 (the dashed lines indicate the portions of the coil that are above / below the core 710). The conduit 750 may be one or more conduits for providing power to the coil, circulating cooling fluid, etc. The detachable wire coil assembly 746 may be a modular component that can be secured to and detached from the support structure 706 via a connector structure 752. To enable modularity, although the coil 712 is wrapped around the core 710, the coil 712 can have a decoupled (e.g., unsecured) arrangement relative to the core 710 (e.g., the coil 712 and core 710 are movable relative to each other). The coil 712 can fit into the slot 744 .

[0092]

[0098] In some aspects, the connector structure 752 may be fixed relative to the support structure 706 (e.g., does not change within the frame of reference of the support structure 706). The support structure 706 may include a conduit 754 that corresponds to the conduit 750 of the removable wire coil assembly 746. The conduit 754 and the conduit 750 may mate via a mating interface 756. The removable wire coil assembly 746 may include one side of the mating interface. The connector structure 752 of the support structure 706 may include the other side of the mating interface. The mating interface 756 may include an O-ring groove and an O-ring inserted into the O-ring groove. The O-ring may seal the mating interface 756 to prevent leakage. The support structure 706 may be fluidly coupled to a cooling system via the conduit 754. The conduit 750 may be fluidly coupled to the cooling system via the support structure 706. The modularity of the removable wire coil assembly 746 allows a technician to conveniently repair and / or replace the removable wire coil assembly 746 without removing the core 710. (Conversely, the core 610 can also be repaired and / or replaced without removing the removable wire coil assembly 746.) In contrast, an electromagnet provided as a rigid assembly of coil, core, and conduit can be cumbersome to repair.

[0093]

[0099] In some embodiments, the core 710 may be able to move independently of the coil 712 (e.g., during a collision). FIG. 7 shows a snapshot of the stage 700 in a collision state (the target-side bumper structure 728 is in contact with the core-side bumper structure 730). As the core 710 is pushed back, the coil 712 becomes stationary within the frame of the support stage 706, while the collision energy is dissipated by the kinetic energy dissipation system 742. That is, the kinetic energy dissipation system 742 may allow for a movement budget of the core 710 relative to the support structure 706 to dissipate the collision energy. As shown in FIG. 7 , a minimum distance d (e.g., a collision avoidance gap) may be maintained and remain unchanged upon replacement of the removable wire coil assembly 746. In contrast, an electromagnet provided as a rigid assembly of coil, core, and conduit introduces additional calibration of the collision avoidance gap upon removal of the core along with the coil, which may require undesirable time to perform installation.

[0094]

[0100] In some aspects, although one core is shown in FIGS. 6 and 7, it should be understood that the configurations of FIGS. 6 and 7 can be repeated for multiple cores.

[0095]

[0101] FIG. 8 illustrates a method 800 for manufacturing the aforementioned collision avoidance gap with tight tolerances, according to some embodiments. In some embodiments, in step S802, a core of an electromagnetic device can be secured to a core support structure (e.g., core 710 secured to core support structure 732 (FIG. 6)). The core may include a magnetically permeable material. The core can be shaped so that the poles of the core are arranged to face the same direction. The core support structure can include a core-side bumper structure secured to the core. In step S804, a target-side bumper structure can be secured to the target. The target can have a pole-facing side that faces the pole of the core. The target can be movable in response to a magnetic field generated through the core. The target-side bumper structure can be configured to collide with the core-side bumper structure to establish a collision avoidance gap between the core and the target. In step S806, the collision avoidance gap can be adjusted to a tolerance of approximately 20 microns or less, 50 microns or less, 70 microns or less, 100 microns or less, 120 microns or less, etc.

[0096]

[0102] FIG. 9 illustrates a method 900 for manufacturing the above-described collision avoidance gap with tight tolerances, according to some embodiments. In some embodiments, the method 900 can include operations for the adjustment step S806 of FIG. 8. For example, the adjustment in step S806 can further include surface treatment of the core-side structure and / or surface treatment of the target-side structure. In the core-side structure, the following steps can be performed: In step S902, the poles can be surface treated using precision molding techniques (e.g., chemical mechanical polishing, ablation, precision coating, etc.). In step S904, the impact area of ​​the core-side bumper structure can be surface treated using precision molding techniques while the core-side bumper structure is fixed to the core. In this way, the relative distance between the plane of the pole and the plane of the core-side bumper structure can be adjusted with high precision. In the target-side structure, the following steps can be performed: In step S906, the pole-facing side of the target can be surface treated using precision molding techniques. In step S908, the impact area of ​​the target-side bumper structure can be surface treated using precision molding techniques while the target-side bumper structure is fixed to the target. In this way, the relative distance between the plane of the target and the plane of the target-side bumper structure can be adjusted with high precision.

[0097]

[0103] The method steps in FIGS. 8 and 9 can be performed in any conceivable order, and not all steps need to be performed. Furthermore, the method steps in FIGS. 8 and 9 described above merely reflect one example of method steps and are not limiting. That is, additional method steps and functions are contemplated based on the aspects described with reference to FIGS. 1-7 . For example, a kinetic energy dissipation system can be secured to a support structure. A detachable (modular) wire coil assembly including a wire coil can be installed. The coiled wire can be positioned to wrap around a portion of a core. The detachable wire coil assembly can be secured to the support structure while remaining detached from the core (e.g., the detachable wire coil assembly remains substantially stationary relative to the support structure during a collision event) so that the core can move relative to the support structure during a collision event. The detachable wire coil assembly can be removed without changing the collision avoidance gap by pulling the detachable wire coil assembly away from the support structure and sliding the detachable wire coil assembly off the core.

[0098]

[0104] The terms "radiation," "beam," "light," "illumination," and the like can be used herein to refer to one or more types of electromagnetic radiation, such as ultraviolet (UV) radiation (e.g., having a wavelength λ of 365, 248, 193, 157, or 126 nm), extreme ultraviolet (EUV or soft X-ray) radiation (e.g., having a wavelength in the range of 5 to 100 nm, such as 13.5 nm), or hard X-ray operating below 5 nm, as well as particle beams such as ion beams or electron beams. Generally, radiation having a wavelength between approximately 400 and approximately 700 nm is considered to be visible radiation, and radiation having a wavelength between approximately 780 and 3000 nm (or longer) is considered to be IR radiation. UV refers to radiation having a wavelength between approximately 100 and 400 nm. In lithography, the term "UV" also applies to wavelengths that can be produced by mercury discharge lamps: G-line 436 nm, H-line 405 nm, and / or I-line 365 nm. Vacuum UV or VUV (i.e., UV absorbed by gases) refers to radiation having a wavelength of approximately 100-200 nm. Deep UV (DUV) generally refers to radiation having a wavelength in the range of 126 nm to 428 nm, and in some embodiments, excimer lasers can generate DUV radiation for use in lithography equipment. It should be understood that radiation having a wavelength in the range of, for example, 5-20 nm, refers to radiation in a particular wavelength band, at least a portion of which is in the 5-20 nm range.

[0099]

[0105] Various embodiments of the present system and method are disclosed in the following list of numbered clauses. 1. A stage for supporting and moving an object, the stage comprising: An electromagnet, a core disposed on the first support structure and including a magnetically permeable material, the core being shaped so that the poles of the core are arranged facing in the same direction; a wire coil configured to generate a magnetic field within the core; an electromagnet including a core-side bumper structure fixed to the core; a second support structure configured to support and move an object relative to the first support structure; a target disposed on the second support structure and configured to actuate the second support structure in response to generation of the magnetic field; a target-side bumper structure secured to the target and configured to collide with the core-side bumper structure to establish a collision avoidance gap between the core and the target. 2. The uncertainty value of the collision avoidance gap is less than about 20 microns, and the uncertainty is The core-side bumper structure is located directly on the core, and / or 10. The stage according to clause 1, wherein the target-side bumper structure is located directly on the target. 3. The stage of clause 1, wherein the core-side bumper structure includes a polished impact surface and / or the target-side bumper includes a polished impact surface. 4. The stage of clause 1, wherein the wire coil is secured to a first support structure, shaped to wrap around at least a portion of the core, and separated from the core so that the core can move relative to the wire coil. 5. The stage described in clause 1, further comprising a kinetic energy dissipation system secured to the first support structure and the core, the kinetic energy dissipation system configured to compress upon collision between the core-side bumper structure and the target-side bumper structure and to allow the core to move relative to the first support structure to dissipate the energy of the collision. 6. A stage as described in clause 5, wherein the wire coil is separated from the core so that the core can move relative to the wire coil during impact. 7. The stage of clause 1, wherein the core includes a core support structure secured to the core and including a core-side bumper structure, the core-side bumper structure and the core support structure being monolithic. 8. The stage described in clause 1, wherein the wire coil is part of a modular wire coil assembly including a conduit configured to direct a cooling fluid to regulate the temperature of the wire coil. 9. The stage described in clause 8, wherein the mating interface of the modular wire coil assembly includes an O-ring groove configured to receive an O-ring to seal a connection between the conduit and a cooling system configured to be fluidly coupled with the conduit, and the mating interface is configured to mate with a first support structure, the first support structure being fluidly coupled to the cooling system. 10. The stage according to clause 8, wherein the collision avoidance gap is invariant to replacement of the modular wire coil assembly. 11. A core comprising a magnetically permeable material, the core being shaped so that the poles of the core are arranged facing in the same direction; With removable wire coil assembly An electromagnetic device comprising: The removable wire coil assembly a wire coil configured to generate a magnetic field within the core; and a housing including a conduit configured to direct a cooling fluid to regulate a temperature of the wire coil. 12. The electromagnetic device of clause 11, wherein the detachable wire coil assembly further includes a mating interface disposed on a surface of the housing, the mating interface including an O-ring groove configured to receive an O-ring to seal a connection between the conduit and a system configured to be fluidly coupled to the conduit. 13. The electromagnet apparatus of clause 11, wherein the core is disposed on a support structure and the electromagnet is configured to actuate a target disposed on a movable support device in response to generation of a magnetic field. 14. The electromagnetic device of clause 13, wherein the mating interface is configured to mate with a support structure, and the support structure is fluidly coupled to a cooling system. 15. An electromagnetic device as described in clause 13, wherein the core-side bumper structure is fixed to the core and the target-side bumper structure is fixed to a movable support device, and the core-side bumper structure and the target-side bumper structure are configured to collide to establish a collision avoidance gap between the core and the target, and the uncertainty value of the collision avoidance gap is less than about 20 microns. 16. An electromagnetic device as described in clause 15, wherein the collision avoidance gap is invariant to replacement of the removable wire coil assembly. 17. A method of manufacturing an electromagnetic actuator having a crash safety mechanism, the method comprising: securing a core of an electromagnet to a core support structure, the core comprising a magnetically permeable material, the core being shaped so that poles of the core are arranged facing in the same direction, the core support structure including a core-side bumper structure secured to the core; securing a target-side bumper structure to a target having a pole-facing side facing a pole, the target being movable in response to a magnetic field generated through the core, the target-side bumper structure configured to collide with the core-side bumper structure to establish a collision avoidance gap between the core and the target; adjusting the collision avoidance gap to within a tolerance of about 20 microns or less; To adjust, Surface treating the core-side structure, surface treating the pole; and / or surface treating the impact area of ​​the core-side bumper structure while secured to the core. Surface treating a target-side structure, comprising: surface treating the pole-facing side surfaces; and surface treating the impact area of ​​the target-side bumper structure while secured to the target. 18. Fixing a kinetic energy dissipation system to the support structure and the core, the kinetic energy dissipation system enabling movement budget of the core relative to the support structure to dissipate impact energy; and installing a modular wire coil assembly including a wire coil configured to generate a magnetic field; To install it, placing a wire coil around a portion of the core; and securing the modular wire coil assembly to a support structure, the modular wire coil assembly being a separate structure relative to the core such that the core can move relative to the support structure during a crash event. 19. Modular wire coil assembly a conduit configured to direct a cooling fluid to regulate the temperature of the wire coil; a mating interface including an O-ring groove; To install it, Placing an O-ring in the O-ring groove; 19. The method of clause 18, further comprising mating the mating interface to a support structure to form a seal with the conduit using an O-ring. 20. The method of clause 18, further comprising removing the modular wire coil assembly without altering the collision avoidance gap, the removing comprising pulling the wire modular coil assembly away from the support structure and sliding the separated structure off the core.

[0100]

[0106] Although some aspects of the present disclosure are described in the context of a lithographic apparatus in the manufacture of ICs, it should be understood that the lithographic apparatus described herein can be used in other applications, such as, for example, the manufacture of integrated optical systems, guidance and detection patterns for magnetic domain memories, flat panel displays, LCDs, thin-film magnetic heads, etc. In such other applications, those skilled in the art will appreciate that any reference to a “wafer” or “die” as used herein may be considered synonymous with the more general terms “substrate” or “target portion,” respectively. The substrate may be processed, before or after exposure, for example, in a track unit (a tool that typically applies a layer of resist to the substrate and develops the exposed resist), and / or a metrology unit. Where applicable, aspects disclosed herein may be applied to such and other substrate processing tools. Furthermore, a substrate may be processed multiple times, for example, to create a multi-layer IC, and thus the term substrate, as used herein, may refer to a substrate that already includes multiple processing layers.

[0101]

[0107] Although some aspects of the present disclosure have been referred to in the context of optical lithography, it will be understood that aspects of the present disclosure are not limited to optical lithography. For example, in imprint lithography, a topography in a patterning device defines the pattern created on a substrate. The topography of the patterning device is pressed into a layer of resist supplied to the substrate, where the resist is cured by applying electromagnetic radiation, heat, pressure, or a combination thereof. The patterning device is then moved out of the resist after the resist is cured, leaving a pattern in it.

[0102]

[0108] It is to be understood that the terms or terminology used herein are for purposes of description and not of limitation, as they would be interpreted by one of ordinary skill in the art in light of the teachings herein.

[0103]

[0109] The present disclosure has been described above using functional components and their relationships illustrating implementation of specific functions. The boundaries of these functional components have been arbitrarily defined herein for the convenience of description. Alternative boundaries may be defined so long as the specific functions and their relationships are appropriately performed. The foregoing description of specific aspects fully reveals the overall nature of the present disclosure, such that those skilled in the art can readily modify and / or adapt such specific aspects to various uses without undue experimentation and without departing from the overall concept of the present disclosure. Accordingly, 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 provided herein.

[0104]

[0110] It should be understood 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 describe one or more (but not all) aspects of the disclosure as contemplated by the inventors, and thus are not intended to limit the disclosure and the appended claims. The breadth and scope of protected subject matter should not be limited by any of the above-described aspects, but should be defined only by the following claims and their equivalents.

Claims

1. 1. A stage for supporting and moving an object, said stage comprising: An electromagnet, a core disposed on the first support structure and including a magnetically permeable material, the core being shaped so that the poles of the core are arranged facing in the same direction; a wire coil configured to generate a magnetic field within the core; a core-side bumper structure fixed to the core; an electromagnet including a second support structure configured to support and move the object relative to the first support structure; a target disposed on the second support structure and configured to actuate the second support structure in response to generation of the magnetic field; a target-side bumper structure secured to the target and configured to collide with the core-side bumper structure to establish a collision avoidance gap between the core and the target; A stage equipped with:

2. The collision avoidance gap has an uncertainty value of less than about 20 microns, and the uncertainty is the core-side bumper structure being disposed directly on the core; and / or The stage of claim 1 , wherein the target-side bumper structure is disposed directly on the target.

3. The stage of claim 1 , wherein the core-side bumper structure includes a polished impact surface and / or the target-side bumper includes a polished impact surface.

4. 10. The stage of claim 1, wherein the wire coil is secured to the first support structure, shaped to wrap around at least a portion of the core, and separated from the core so that the core can move relative to the wire coil.

5. 2. The stage of claim 1, further comprising a kinetic energy dissipation system secured to the first support structure and the core, the kinetic energy dissipation system configured to compress upon collision between the core-side bumper structure and the target-side bumper structure, allowing the core to move relative to the first support structure to dissipate energy of the collision, and the wire coil is separated from the core to allow the core to move relative to the wire coil during the collision.

6. The stage of claim 1 , wherein the core includes a core support structure secured to the core and including the core-side bumper structure, the core-side bumper structure and the core support structure being monolithic.

7. the wire coil is part of a modular wire coil assembly including a conduit configured to direct a cooling fluid to regulate a temperature of the wire coil; a mating interface of the modular wire coil assembly including an O-ring groove configured to receive an O-ring to seal a connection between the conduit and a cooling system configured to be fluidly coupled to the conduit; the mating interface is configured to mate with the first support structure; the first support structure is fluidly coupled to the cooling system; The stage of claim 1 , wherein the collision avoidance gap is invariant to replacement of the modular wire coil assembly.

8. a core comprising a magnetically permeable material, the core being shaped so that the poles of the core are arranged facing in the same direction; With removable wire coil assembly An electromagnetic device comprising: The detachable wire coil assembly comprises: a wire coil configured to generate a magnetic field within the core; and a housing including a conduit configured to direct a cooling fluid to regulate a temperature of the wire coil.

9. the detachable wire coil assembly further includes a mating interface disposed on a surface of the housing; 9. The electromagnetic device of claim 8, wherein the mating interface includes an O-ring groove configured to receive an O-ring to seal a connection between the conduit and a system configured to be fluidly coupled to the conduit.

10. the core is disposed on a support structure; the electromagnet is configured to actuate a target disposed on a movable support device in response to generation of the magnetic field; the mating interface is configured to mate with the support structure; The electromagnetic device of claim 8 , wherein the support structure is fluidly coupled to a cooling system.

11. a core-side bumper structure fixed to the core; a target-side bumper structure secured to the movable support device; the core-side bumper structure and the target-side bumper structure are configured to collide to establish a collision avoidance gap between the core and the target; 11. The electromagnetic device of claim 10, wherein the collision avoidance gap has an uncertainty value of less than about 20 microns, and the collision avoidance gap is invariant to replacement of the removable wire coil assembly.

12. 1. A method of manufacturing an electromagnetic actuator having a crash safety mechanism, the method comprising: fastening a core of an electromagnet to a core support structure, the core comprising a magnetically permeable material, the core being shaped so that poles of the core are arranged facing in the same direction, the core support structure including a core-side bumper structure fastened to the core; securing a target-side bumper structure to a target having a pole-facing side facing the pole, the target being movable in response to a magnetic field generated through the core, the target-side bumper structure configured to collide with the core-side bumper structure to establish a collision avoidance gap between the core and the target; adjusting the collision avoidance gap to within a tolerance of about 20 microns or less; wherein said adjusting comprises: Surface treating the core-side structure, surface treating the pole; and / or surface treating the impact area of ​​the core-side bumper structure while it is fixed to the core. Surface treating a target-side structure, comprising: surface treating the polar-facing side surfaces; and surface treating an impact area of ​​the target-side bumper structure while secured to the target.

13. securing a kinetic energy dissipation system to a support structure and the core, the kinetic energy dissipation system enabling movement budget of the core relative to the support structure to dissipate impact energy; and installing a modular wire coil assembly including a wire coil configured to generate the magnetic field, the installing comprising: placing the wire coil around a portion of the core; and securing the modular wire coil assembly to the support structure, the modular wire coil assembly being a separate structure relative to the core such that the core can move relative to the support structure during a crash event.

14. The modular wire coil assembly comprises: a conduit configured to direct a cooling fluid to regulate the temperature of the wire coil; a mating interface including an O-ring groove; The installation is placing an O-ring in the O-ring groove; The method of claim 13 , further comprising mating the mating interface to the support structure to form a seal for the conduit using the O-ring.

15. further comprising removing the modular wire coil assembly without altering the collision avoidance gap, the removing comprising: Pulling the wire modular coil assembly away from the support structure; and sliding the discrete structures from the core.

Images