Mobile station for lithographic apparatus

Abstract

A lithographic apparatus includes an illumination system, a projection system, and a stage. The irradiation system irradiates the pattern of the pattern forming apparatus. The projection system projects an image of the pattern onto the substrate. The platform moves a patterning device or a substrate. The platform includes a support structure, an actuator device, first, second and third actuator targets, and a tension member. A third actuator target is attached to the first side of the support structure. An actuator device is disposed at the proximal ends of the first and third targets and magnetically interacts with the first and third targets to move the support structure in a direction. First and second actuator targets are disposed on opposite sides of the support structure and attached at opposite ends of the tension member. The tension member transmits the mechanical load to the second side of the support structure via the second actuator target.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Application No. 63 / 341,304 filed on May 12, 2022 and U.S. Application No. 63 / 450,877 filed on March 8, 2023, and the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to actuation stages, for example, stages for supporting reticles used in lithographic apparatus and systems. Background Art

[0004] A lithographic apparatus is a machine that applies a desired pattern to a substrate (usually a target portion of a substrate). A lithographic apparatus can be used, for example, to manufacture an integrated circuit (IC). In this case, a pattern forming device (also referred to as a mask or reticle) can be used to generate a circuit pattern to be formed on a single layer of an IC. The pattern can be transferred to a target portion (e.g., including a portion, one or more dies) on a substrate (e.g., a silicon wafer). The transfer of the pattern is usually via imaging onto a layer of radiation-sensitive material (resist) disposed on the substrate. Typically, a single substrate will contain a network of adjacent target portions that are patterned continuously. Known lithographic apparatus include so-called steppers, in which each target portion is irradiated by exposing the entire pattern to the target portion at once, and so-called scanners, in which each target portion is irradiated by scanning the pattern with a radiation beam along a given direction (the "scanning" direction), while simultaneously scanning the target portion parallel or antiparallel to the scanning direction. The pattern can also be transferred from the pattern forming device to the substrate by imprinting the pattern onto the substrate.

[0005] During a lithography operation, different processing steps may require that different layers be formed sequentially on a substrate. Therefore, it may be necessary to position the substrate relative to a previous pattern formed thereon with high accuracy. Typically, alignment marks are placed on the substrate to be aligned and positioned with reference to a second object. The lithographic apparatus may use an alignment device to detect the position of the alignment marks and use the alignment marks to align the substrate to ensure accurate exposure of the mask. Misalignment between alignment marks at two different layers is measured as overlay error.

[0006] In order to monitor the lithography process, it is necessary to measure the parameters of the patterned substrate. These parameters may include, for example, the overlay error between successive layers formed in or on the patterned substrate and the critical line width of the developed photoresist. Such measurements may be performed on a product substrate and / or a dedicated measurement target. Various techniques are available for measuring the microstructures formed in the lithography process, including the use of scanning electron microscopes and various dedicated tools. A fast and non-invasive dedicated inspection tool is a scatterometer, in which a radiation beam is directed to a target on the surface of the substrate and the characteristics of the scattered or reflected beam are measured. By comparing the characteristics of the beam before and after being reflected or scattered by the substrate, the characteristics of the substrate can be determined. This can be achieved, for example, by comparing the reflected beam with data stored in a known measurement library associated with known substrate characteristics. A spectral scatterometer directs a broadband radiation beam onto a substrate and measures the spectrum (intensity as a function of wavelength) of the radiation scattered into a specific narrow angular range. In contrast, an angularly resolved scatterometer uses a monochromatic radiation beam and measures the relationship between the scattered radiation intensity and the angle.

[0007] Such optical scatterometers can be used to measure parameters such as the critical dimension of a developed photoresist or the overlay error (OV) between two layers formed in or on a patterned substrate. The properties of a substrate can be determined by comparing the properties of an illuminating beam before and after the beam is reflected or scattered by the substrate.

[0008] A lithography system can only output a limited number of fabricated devices in a given time. Rapid scanning of the wafer stage and reticle stage can increase fabrication speed. However, high accelerations can cause the stage to deform under mechanical stress. Summary of the invention

[0009] Therefore, it is desirable to increase manufacturing speed and throughput. According to aspects described herein, the wafer and reticle stage can withstand high accelerations.

[0010] In some aspects, a lithographic apparatus includes an illumination system, a projection system, and a platform. The illumination system is configured to illuminate a pattern of a pattern forming device. The projection system is configured to project an image of the pattern onto a substrate. The platform is configured to move the pattern forming device or the substrate. The platform includes first and second support structures, an actuator device, an actuator target, and an axis. The first support structure is configured to support the pattern forming device or the substrate. The second support structure is configured to support the first support structure. The actuator device is disposed on the second support structure and is configured to move the first support structure in a direction. The actuator target is configured to interact with the actuator device. The axis is fixed to the actuator target and is located at a position of the first support structure. The axis is configured to transmit a mechanical load from the actuator target to the position.

[0011] In some aspects, the movable platform includes first and second support structures, an actuator device, an actuator target, and an axis. The first support structure is configured to support an object. The second support structure is configured to support the first support structure. The actuator device is disposed on the second support structure and is configured to move the first support structure in a direction. The actuator target is configured to interact with the actuator device. The axis is fixed to the actuator target and is located at the first support structure. The axis is configured to transmit a mechanical load from the actuator target to the location.

[0012] In some aspects, a lithographic apparatus includes an illumination system, a projection system, and a platform. The illumination system is configured to illuminate a pattern of a pattern forming device. The projection system is configured to project an image of the pattern onto a substrate. The platform is configured to move the pattern forming device or the substrate. The platform includes a support structure, an actuator device, a tension member, and first, second, and third actuator targets. The support structure is configured to support the pattern forming device or the substrate. The first actuator target is disposed at a first side of the support structure. The second actuator target is disposed at a second side of the support structure opposite to the first side. The third actuator target is attached to the first side of the support structure. The actuator device is disposed near the first and third targets. The actuator device is configured to magnetically interact with the first and third targets to move the support structure in a direction. The first and second actuator targets are attached to opposite ends of the tension member. The tension member is configured to transmit a mechanical load to a second side of the support structure via the second actuator target based on a magnetic force applied to the first actuator target.

[0013] In some aspects, a platform includes a support structure, an actuator device, a tension member, and first, second, and third actuator targets. The support structure is configured to support an object. The first actuator target is disposed at a first side of the support structure. The second actuator target is disposed at a second side of the support structure opposite the first side. The third actuator target is attached to the first side of the support structure. The actuator device is disposed near the first and third targets. The actuator device is configured to magnetically interact with the first and third targets to move the support structure in a direction. The first actuator target and the second actuator target are attached at opposite ends of the tension member. The tension member is configured to transmit a mechanical load to a second side of the support structure via the second actuator target based on a magnetic force applied to the first actuator target.

[0014] Other features of the present disclosure and the structure and operation of various aspects 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. These aspects are presented herein for illustrative purposes only. Based on the teachings contained herein, those skilled in the relevant art will clearly understand other aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings, which are incorporated herein and constitute a part of the specification, illustrate the present disclosure and, together with the description, further explain the principles of the present disclosure and enable those skilled in the relevant art to make and use the aspects described herein.

[0016] Figure 1A A schematic diagram of a reflective lithography apparatus according to some aspects is shown.

[0017] Figure 1B A schematic diagram of a transmissive lithography apparatus according to some aspects is shown.

[0018] Figure 2 A more detailed schematic diagram of a reflective lithography apparatus according to some aspects is shown.

[0019] Figure 3 A schematic diagram of a lithography cell according to some aspects is shown.

[0020] Figure 4A and Figure 4B A schematic diagram of an inspection apparatus according to some aspects is shown.

[0021] Figures 5 and 6 , Fig. 7A and Figure 7B An actuation platform according to certain aspects is shown.

[0022] Figure 8 A cross-section of a support structure of an actuation platform is shown in accordance with some aspects.

[0023] Fig. 9 and Fig.10 An actuation platform according to some aspects is shown.

[0024] Features of the present disclosure will become more apparent from the following detailed description in conjunction with the accompanying drawings, in which like reference symbols always represent corresponding elements. In the accompanying drawings, like reference numerals generally represent identical, functionally similar, and / or structurally similar elements. In addition, generally, the leftmost digit of a reference numeral indicates the drawing in which the reference numeral first appears. Unless otherwise indicated, the drawings provided in the present disclosure should not be construed as drawings drawn to scale. DETAILED DESCRIPTION

[0025] The specification discloses one or more aspects incorporating features of the present disclosure. The disclosed aspects are provided as examples. The scope of the present disclosure is not limited to the disclosed aspects. The claimed features are defined by the appended claims.

[0026] The aspects and references in the specification to "one aspect," "an aspect," "an exemplary aspect," etc. indicate that the aspects may include certain features, structures, or characteristics, but each aspect does not necessarily include certain features, structures, or characteristics. Furthermore, these phrases do not necessarily refer to the same aspect. Furthermore, when a certain feature, structure, or characteristic is described in conjunction with an aspect, it should be understood that those skilled in the art may implement such feature, structure, or characteristic in conjunction with other aspects, whether or not explicitly described.

[0027] For ease of description, spatially relative terms such as "below," "beneath," "lower," "above," "upper," etc. may be used herein to describe the relationship of one element or feature to another element or feature, as shown in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientations shown in the figures. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein should be interpreted accordingly.

[0028] As used herein, the term "about" refers to a numerical value of a given quantity that may vary according to a particular technology. Depending on the particular technology, the term "about" may refer to a value of a given quantity that varies within a range of 10-30% of that value (e.g., ±10%, ±20%, or ±30% of that value).

[0029] 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 machine-readable medium, 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 a read-only memory (ROM); a random access memory (RAM); a disk storage medium; an optical storage medium; a flash memory device; an electrical, optical, acoustic, or other form of propagation signal (e.g., a carrier wave, an infrared signal, a digital signal, etc.), etc. In addition, firmware, software, routines, and / or instructions may be described herein as performing certain actions. However, it should be understood that such descriptions are merely for convenience, and such actions are actually generated by a computing device, processor, controller, or other device that executes firmware, software, routines, instructions, etc.

[0030] Before describing these aspects in further detail, however, it is helpful to provide an example environment in which aspects of the present disclosure may be implemented.

[0031] Example Lithography System

[0032] Figure 1A and Figure 1BSchematic diagrams of lithographic apparatus 100 and lithographic apparatus 100' are shown, respectively, in which various aspects of the present disclosure may be implemented. Lithographic apparatus 100 and lithographic apparatus 100' each include the following: an illumination system (illuminator) IL, which is configured to condition a radiation beam B (e.g., deep ultraviolet or extreme ultraviolet radiation); a support structure (e.g., a mask stage) MT, which is configured to support a pattern forming device (e.g., a mask, a reticle, or a dynamic pattern forming device) MA and is connected to a first positioner PM, which is configured to accurately position the pattern forming device MA; and a substrate stage (e.g., a wafer stage) WT, which is configured to hold a substrate (e.g., a resist-coated wafer) W and is connected to a second positioner PW, which is configured to accurately position the substrate W. Lithographic apparatus 100 and 100' also have a projection system PS, which is configured to project a pattern imparted by the pattern forming device MA to the radiation beam B onto a target portion (e.g., including one or more tube cores) C of the substrate W. 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.

[0033] The illumination system IL may include various types of optical elements for directing, shaping or controlling the radiation beam B, such as refractive, reflective, catadioptric, magnetic, electromagnetic, electrostatic or other types of optical components, or any combination thereof.

[0034] The support structure MT holds the patterning device MA in a manner that depends on the orientation of the patterning device MA relative to the reference frame, the design of at least one of the lithographic apparatuses 100 and 100', and other conditions, such as whether 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 be, for example, a frame or a stage, which may be fixed or movable as desired. By using sensors, the support structure MT may ensure that the patterning device MA is in a desired position (e.g., relative to the projection system PS).

[0035] The term “patterning device” MA should be broadly interpreted as referring to any device that can be used to impart a pattern in the cross-section of the radiation beam B, such as to create a pattern in a target portion C of the substrate W. The pattern imparted to the radiation beam B may correspond to a specific functional layer in a device created in the target portion C to form an integrated circuit.

[0036] The terms "inspection device", "measurement system", etc. may be used herein to refer to, for example, an apparatus or system for measuring structural characteristics (e.g., overlay error, critical dimension parameters), or an apparatus or system (e.g., alignment device) used in a lithography device to check wafer alignment.

[0037] The pattern forming device MA can be a transmissive type (such as Figure 1B lithographic apparatus 100') or a reflective (eg Figure 1A 100 in the lithographic apparatus). Examples of pattern forming 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. One example of a programmable mirror array employs a matrix arrangement of small mirrors, each of which can be individually tilted to reflect an incoming radiation beam into different directions. The tilted mirrors impart a pattern in the radiation beam B, which is reflected by the matrix of small mirrors.

[0038] The term "projection system" PS may cover any type of projection system, including refractive, reflective, catadioptric, magnetic, electromagnetic and electrostatic optical systems, or any combination thereof, depending on 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, since other gases may absorb too much radiation or electrons. Therefore, a vacuum environment may be provided for the entire beam path with the aid of vacuum walls and a vacuum pump.

[0039] The 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, additional substrate tables WT may be used in parallel, or preparatory steps may be performed on one or more tables while exposure is being carried out using one or more other substrate tables WT. In some cases, the additional table may not be a substrate table WT.

[0040] The lithographic apparatus may also be an apparatus in which at least a portion of the substrate may be covered by a liquid having a relatively high refractive index (e.g., water) so as to fill the space between the projection system and the substrate. Immersion liquid may also be applied to other spaces in the lithographic apparatus, such as between the mask and the projection system. Immersion techniques are well known in the art and are used to increase the numerical aperture of the projection system. The term "immersion" as used herein does not mean that the structure (such as the substrate) must be immersed in the liquid, but only means that the liquid is located between the projection system and the substrate during exposure.

[0041] refer to Figure 1A and Figure 1B , the illuminator IL receives a radiation beam from a radiation source SO. The source SO and the lithographic apparatus 100, 100' may be separate physical entities, for example, when the source SO is an excimer laser. In this case, the source SO is not considered to be part of the lithographic apparatus 100 or 100', and the radiation beam B is delivered to the lithographic apparatus 100 or 100' by means of a beam delivery system BD (in Figure 1BThe radiation beam is transferred from the source SO to the illuminator IL, the beam delivery system BD comprising, for example, suitable guide mirrors and / or a beam expander. In other cases, the source SO may be an integral part of the lithographic apparatus 100, 100', for example, when the source SO is a mercury lamp. The source SO and the illuminator IL, as well as the beam delivery system BD if necessary, may be referred to as a radiation system.

[0042] The illuminator IL may include an adjuster AD ( Figure 1B ) for adjusting the angular intensity distribution of the radiation beam. Typically, at least the outer and / or inner radial extent of the intensity distribution in a pupil plane of the illuminator (commonly referred to as the "σ-outer" and "σ-inner", respectively) can be adjusted. In addition, the illuminator IL may include various other components ( Figure 1B In the embodiment of the present invention, there are two types of devices (integrators), 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.

[0043] refer to Figure 1A , the radiation beam B is incident on a patterning device (e.g., a mask) MA, which is held on a support structure (e.g., a mask table) MT and is patterned by the patterning device MA. In the lithographic apparatus 100, the radiation beam B is reflected from the patterning device (e.g., a mask) MA. After reflection from the patterning device (e.g., a mask) MA, the radiation beam B passes through a projection system PS, which focuses the radiation beam B onto a target portion C of a substrate W. With the aid of a second positioner PW and a position sensor IF2 (e.g., an interferometer, a linear encoder, or a capacitive sensor), the substrate table WT can be precisely moved (e.g., so as to position different target portions C in the path of the radiation beam B). Similarly, a first positioner PM and a further position sensor IF1 can be used to precisely position the patterning device (e.g., a mask) MA relative to the path of the radiation beam B. The patterning device (e.g., a mask) MA and the substrate W can be aligned using mask alignment marks M1, M2 and substrate alignment marks P1, P2.

[0044] refer to Figure 1B , the radiation beam B is incident on a patterning device (e.g., a mask MA), which is held on a support structure (e.g., a mask table MT) and patterned by the patterning device. After passing through the mask MA, the radiation beam B passes through a projection system PS, which focuses the beam onto a target portion C of the substrate W. The projection system has a pupil PPU conjugate to the illumination system pupil IPU. Part of the radiation is emitted from the intensity distribution at the illumination system pupil IPU and passes through the mask pattern without being affected by diffraction at the mask pattern and creates an image of the intensity distribution at the illumination system pupil IPU.

[0045] The projection system PS projects an image of a mask pattern MP onto a resist layer coated on a substrate W, wherein the image is formed by a diffracted beam generated from the marking pattern MP by radiation from an intensity distribution. For example, the mask pattern MP may include an array of lines and spaces. The diffraction of radiation at the array is different from the zero-order diffraction, producing a steered diffraction beam whose direction changes in a direction perpendicular to the line. The undiffracted beam (i.e., the so-called zero-order diffraction beam) passes through the pattern without any change in the propagation direction. The zero-order diffraction beam passes through the upper lens or upper lens group of the projection system PS, upstream of the pupil conjugate PPU of the projection system PS, and arrives at the pupil conjugate PPU. The portion of the intensity distribution associated with the zero-order diffraction beam in the plane of the pupil conjugate PPU is an image of the intensity distribution in the illumination system pupil IPU of the illumination system IL. The aperture device PD is, for example, arranged or substantially arranged on a plane including the pupil conjugate PPU of the projection system PS.

[0046] The projection system PS is arranged to capture not only the zero-order diffracted beam, but also the first-order or first-order and higher-order diffracted beams (not shown) through a lens or lens group L. In some aspects, the resolution enhancement effect of dipole illumination can be utilized using dipole illumination for imaging a line pattern extending in a direction perpendicular to the line. For example, the first-order diffracted beam interferes with the corresponding zero-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., the available depth of focus combined with the tolerable exposure dose deviation). In some aspects, astigmatic aberrations can be reduced by providing a radiation pole (not shown) in the opposite quadrant of the illumination system pupil IPU. In addition, in some aspects, astigmatic aberrations can be reduced by blocking the zero-order beam in the pupil conjugate PPU of the projection system associated with the radiation pole in the opposite quadrant. This is described in more detail in US7,511,799B2 issued on March 31, 2009, the entire text of which is incorporated herein by reference.

[0047] With the help of a second positioner PW and a position sensor IFD (e.g. an interferometer, a linear encoder or a capacitive sensor), the substrate table WT can be precisely moved (e.g. in order to position a different target portion C in the path of the radiation beam B). Similarly, the first positioner PM and another position sensor ( Figure 1B ) can be used to accurately position the mask MA relative to the path of the radiation beam B (e.g., after mechanical retrieval from a mask library or during scanning).

[0048] Typically, movement of the mask table MT can be achieved with the aid of 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 can be achieved 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 only to a short-stroke actuator or may be fixed. Mask alignment marks M1, M2 and substrate alignment marks P1, P2 may be used to align the mask MA and the substrate W. Although the substrate alignment marks (as shown) occupy dedicated target portions, they may be located in the space between the target portions (called scribe lane alignment marks). Similarly, where a plurality of dies are provided on the mask MA, the mask alignment marks may be located between the dies.

[0049] The mask table MT and the patterning device MA may be located in the vacuum chamber V, wherein a vacuum robot IVR may be used to move the patterning device, such as a mask, into and out of the vacuum chamber. Alternatively, when the mask table MT and the patterning device MA are located outside the vacuum chamber, an out-of-vacuum robot may be used for various transport operations, similar to the vacuum robot IVR. Both the in-vacuum and out-of-vacuum robots require calibration in order to smoothly transfer any payload, such as a mask, to the fixed kinematic support of the transfer station.

[0050] The lithographic apparatus 100 and 100' may be used in at least one of the following modes:

[0051] 1. In step mode, the support structure (e.g. mask table) MT and the substrate table WT remain essentially stationary while an entire pattern imparted to the radiation beam B is projected onto a target portion C at one time (i.e. a single static exposure). The substrate table WT is then moved in the X and / or Y direction so that a different target portion C can be exposed.

[0052] 2. In scan mode, the support structure (e.g. mask table) MT and substrate table WT are scanned synchronously while projecting a pattern imparted to the radiation beam B onto a target portion C (i.e. single dynamic exposure). The speed 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.

[0053] 3. In another mode, the support structure (e.g., mask table) MT remains essentially stationary to hold the programmable patterning device, and 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 may be used, and the programmable patterning device is updated as required after each movement of the substrate table WT or between successive radiation pulses during a scan. This mode of operation can be readily applied to maskless lithography using a programmable patterning device (e.g., a programmable mirror array).

[0054] Combinations and / or variations on the described modes of use or entirely different modes of use may also be employed.

[0055] In another aspect, the lithographic apparatus 100 includes an extreme ultraviolet (EUV) source configured to generate an EUV radiation beam for EUV lithography. Typically, 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.

[0056] Figure 2 The lithographic apparatus 100 is shown in more detail, including a source collector device SO, an illumination system IL and a projection system PS. The source collector device SO is constructed and arranged so that a vacuum environment can be maintained in a closed structure 220 of the source collector device SO. A plasma 210 emitting EUV radiation can be formed by a plasma source generated by a discharge. EUV radiation can be generated by a gas or vapor, for example, Xe gas, Li vapor or Sn vapor, in which a very hot plasma 210 is generated to emit radiation in the EUV range of the electromagnetic spectrum. The very hot plasma 210 is generated by, for example, an electrical discharge that causes an at least partially ionized plasma. In order to effectively generate radiation, a partial pressure of Xe, Li, Sn vapor or any other suitable gas or vapor, for example 10Pa, may be required. In some aspects, a plasma that excites tin (Sn) is provided to generate EUV radiation.

[0057] The radiation emitted by the hot plasma 210 is transferred from the source chamber 211 to the collection chamber 212 via an optional gas barrier or contaminant trap 230 (also referred to as a contaminant barrier or foil trap in some cases), which is located within or behind the opening of the source chamber 211. The contaminant trap 230 may include a channel structure. The contaminant trap 230 may also include a gas barrier or a combination of a gas barrier and a channel structure. The contaminant trap or contaminant barrier 230 further noted herein includes at least a channel structure.

[0058] The collector cavity 212 may include a radiation collector CO, which may be a so-called grazing incidence collector. The radiation collector CO has an upstream radiation collector side 251 and a downstream radiation collector side 252. The radiation passing through the collector CO may be reflected from the grating spectral filter 240 to be focused in a virtual source point INTF. The virtual source point INTF is often referred to as an intermediate focus, and the source collector arrangement is arranged so that the intermediate focus INTF is located at or near the opening 219 in the enclosed structure 220. The virtual source point INTF is an image of the radiation emitting plasma 210. The grating spectral filter 240 is particularly useful for suppressing infrared (IR) radiation.

[0059] The radiation then passes through an illumination system IL, which may include a faceted field mirror arrangement 222 and a faceted pupil mirror arrangement 224, arranged to provide a desired angular distribution of the radiation beam 221 at the patterning device MA, and a desired uniformity of radiation intensity at the patterning device MA. When the radiation beam 221 is reflected at the patterning device MA held by the support structure MT, a patterned beam 226 is formed, and the projection system PS images the patterned beam 226 via reflective elements 228, 229 onto a substrate W held by a wafer stage or substrate table WT.

[0060] There may typically be more elements in the illumination optics unit IL and the projection system PS than shown. The grating spectral filter 240 may depend on the type of lithographic apparatus. In addition, there may be more than Figure 2 For example, there may be more than 10 mirrors in the projection system PS. Figure 2 There are 1 to 6 additional reflective elements as shown.

[0061] like Figure 2 As shown, the collector optics CO is depicted as a nested collector with grazing incidence reflectors 253, 254 and 255, just as an example of a collector (or collector mirror). The grazing incidence reflectors 253, 254 and 255 are arranged axisymmetrically around the optical axis O. This type of collector optics CO is used in conjunction with a discharge produced plasma source (commonly referred to as a DPP source).

[0062] Exemplary Lithography Cell

[0063] Figure 3A lithography unit 300 is shown, which is sometimes also referred to as a lithography unit or a lithography cluster, depending on certain aspects. The lithography apparatus 100 or 100' may form part of the lithography unit 300. The lithography unit 300 may also include one or more devices for performing pre-exposure and post-exposure processing on a substrate. Typically, these devices include a spin coater SC for depositing a resist layer, a developer DE for developing the exposed resist, a cooling plate CH, and a baking plate BK. A substrate handler or robot RO picks up substrates from input / output ports I / O1, I / O2, moves them between different process devices, and transfers them to a loading bay LB of the lithography apparatus 100 or 100'. These devices are generally collectively referred to as tracks, which are controlled by a track control unit TCU, which itself is controlled by a monitoring system SCS, which also controls the lithography apparatus via a lithography control unit LACU. Thus, different devices may be operated to maximize yield and processing efficiency.

[0064] Exemplary Inspection Devices

[0065] In order to control the lithography process to accurately place the device features on the substrate, alignment marks are usually provided on the substrate, and the lithography equipment includes one or more inspection devices for accurately locating the marks on the substrate. These alignment devices are actually position measuring devices. Different types of marks and different types of alignment devices and / or systems are known at different times and by different manufacturers. A system widely used in current lithography equipment is based on a self-reference interferometer, as described in U.S. Patent No. 6,961,116 (den Boef et al.). Usually, the marks are measured separately to obtain the X and Y positions. However, the technology described in U.S. Publication No. 2009 / 195768A (Bijnen et al.) can be used to perform combined X and Y measurements. The entire contents of these two disclosures are incorporated herein by reference.

[0066] According to some aspects, Figure 4A A schematic cross-sectional view of an inspection apparatus 400 that can be implemented as part of a lithographic apparatus 100 or 100' is shown. In some aspects, the inspection apparatus 400 can be configured to align a substrate (e.g., substrate W) relative to a patterning device (e.g., patterning device MA). The inspection apparatus 400 can also be configured to detect the positions of alignment marks on the substrate and use the detected positions of the alignment marks to align the substrate relative to the patterning device or other components of the lithographic apparatus 100 or 100'. Such alignment of the substrate can ensure accurate exposure of one or more patterns on the substrate.

[0067] In some aspects, the detection device 400 may include an illumination system 412, a beam splitter 414, an interferometer 426, a detector 428, a beam analyzer 430, and an overlay calculation processor 432. The illumination system 412 may be configured to provide an electromagnetic narrowband radiation beam 413 having one or more passbands. In one example, the one or more passbands may be within a wavelength spectrum between about 500 nm and about 900 nm. In another example, the one or more passbands may be discrete narrow passbands within a wavelength spectrum between about 500 nm and about 900 nm. The illumination system 412 may also be configured to provide one or more passbands having a substantially constant center wavelength (CWL) value over a long period of time (e.g., over the entire useful life of the illumination system 412). This configuration of the illumination system 412 helps prevent the actual CWL value in the current alignment system from deviating from the desired CWL value (as described above). Therefore, using a constant CWL value may improve the long-term stability and accuracy of the alignment system (e.g., the inspection device 400) compared to the current alignment device.

[0068] In some aspects, beam splitter 414 can be configured to receive radiation beam 413 and split radiation beam 413 into at least two radiation sub-beams. Figure 4AAs shown, the radiation beam 413 may be split into radiation sub-beams 415 and 417. The beam splitter 414 may also be configured to direct the radiation sub-beam 415 onto a substrate 420 placed on a platform 422. In one example, the platform 422 may be moved along a direction 424. The radiation sub-beam 415 may be configured to illuminate an alignment mark or target 418 located on the substrate 420. The alignment mark or target 418 may be coated with a radiation sensitive film. In some aspects, the alignment mark or target 418 may have a one hundred and eighty degree (i.e., 180°) symmetry. That is, when the alignment mark or target 418 is rotated 180° around a symmetry axis perpendicular to the plane of the alignment mark or target 418, the rotated alignment mark or target 418 may be substantially the same as the unrotated alignment mark or target 418. The target 418 on the substrate 420 can be (a) a resist layer grating including strips formed by solid resist lines, or (b) a product layer grating, or (c) a composite grating stack in an overlay target structure, including a resist grating overlying or interlaced on a product layer grating. The strips can also be etched into the substrate. The pattern is sensitive to chromatic aberrations in the lithographic projection equipment, particularly the projection system PL and illumination symmetry, and the presence of such aberrations will manifest as variations in the printed grating. One in-line method used in device manufacturing for measuring line width, pitch, and critical dimensions utilizes a technique called "scatterometry". Scatterometry is described in Raymond et al., "Multiparameter Grating Metrology Using Optical Scatterometry", J. Vac. Sci. Tech. B, Vol. 15, no. 2, pp. 361-368 (1997) and Niu et al., "Specular Spectroscopic Scatterometry in DUV Lithography", SPIE, Vol. 3677 (1999), both of which are incorporated herein by reference in their entirety. In scatterometry, light is reflected by a periodic structure in the target and the resulting reflection spectrum at a given angle is detected. The structure that produces the reflection spectrum is reconstructed, for example using rigorous coupled wave analysis (RCWA) or by comparison with a library of patterns derived by simulation. Therefore, the scatterometry data of the printed grating are used to reconstruct the grating. The parameters of the grating (such as line width and shape) can be input into the reconstruction process performed by the processing unit PU based on knowledge of the printing step and / or other scatterometry processes.

[0069] In some aspects, according to one aspect, beam splitter 414 can also be configured to receive diffracted radiation beam 419 and split diffracted radiation beam 419 into at least two radiation sub-beams. Diffracted radiation beam 419 can be split into diffracted radiation sub-beams 429 and 439, such as Figure 4A shown.

[0070] It should be noted that although the beam splitter 414 is shown to direct the radiation sub-beam 415 to the alignment mark or target 418 and to direct the diffracted radiation sub-beam 429 to the interferometer 426, the present disclosure is not limited thereto. It should be understood by those skilled in the relevant art that other optical arrangements may be used to achieve similar results, i.e., illuminating the alignment mark or target 418 on the substrate 420 and detecting an image of the alignment mark or target 418.

[0071] like Figure 4A As shown, interferometer 426 may be configured to receive radiation sub-beam 417 and diffracted radiation sub-beam 429 via beam splitter 414. In an example aspect, diffracted radiation sub-beam 429 may be at least a portion of radiation sub-beam 415 that may be reflected from alignment mark or target 418. In one example of this aspect, interferometer 426 includes any suitable set of optical elements, such as a prism combination, which may be configured to form two images of alignment mark or target 418 based on the received diffracted radiation sub-beam 429. It should be understood that high quality images need not be formed, but features of alignment mark 418 should be resolved. Interferometer 426 may also be configured to rotate one of the two images by 180° relative to the other image, and to interferometrically recombine the rotated image and the unrotated image.

[0072] In some aspects, the detector 428 can be configured to receive the recombined image via the interferometer signal 427 and detect interference caused by the recombined image when the alignment axis 421 of the inspection device 400 passes through the center of symmetry of the alignment mark or target 418 (not shown). According to an example aspect, this interference may be due to the alignment mark or target 418 being 180° symmetrical and the recombined image interfering constructively or destructively. Based on the detected interference, the detector 428 can also be configured to determine the position of the center of symmetry of the alignment mark or target 418, thereby detecting the position of the substrate 420. According to an example, the alignment axis 421 can be aligned with a light beam that is perpendicular to the substrate 420 and passes through the center of the image rotation interferometer 426. The detector 428 can also be configured to estimate the position of the alignment mark or target 418 by implementing sensor characteristics and interacting with wafer marking process variations.

[0073] In another aspect, the detector 428 determines the location of the center of symmetry of the alignment mark or target 418 by performing one or more of the following measurements:

[0074] 1. Measure the position change of different wavelengths (position shift between colors);

[0075] 2. Measure the position changes of different orders (position shifts between diffraction orders);

[0076] 3. Measure the position change of various polarizations (position shift between polarizations).

[0077] For example, this data can be obtained using any type of alignment sensor, such as a SMASH (Smart Alignment Sensor Hybrid) sensor as described in U.S. Pat. No. 6,961,116, which employs a self-referencing interferometer with a single detector and four different wavelengths and extracts the alignment signal in software, or Athena (Advanced Techniques using High-Order Enhanced Alignment) as described in U.S. Pat. No. 6,297,876, which directs each of the seven diffraction orders to a dedicated detector, both of which are incorporated herein by reference in their entirety.

[0078] In some aspects, the beam analyzer 430 can be configured to receive and determine the optical state of the diffracted radiation sub-beam 439. The optical state can be a measure of the beam wavelength, polarization, or beam profile. The beam analyzer 430 can also be configured to determine the position of the platform 422 and relate the position of the platform 422 to the position of the center of symmetry of the alignment mark or target 418. In this way, the position of the alignment mark or target 418 can be accurately known with reference to the platform 422, and thus the position of the substrate 420. Alternatively, the beam analyzer 430 can be configured to determine the position of the inspection device 400 or any other reference element, so that the center of symmetry of the alignment mark or target 418 can be known with reference to the inspection device 400 or any other reference element. The beam analyzer 430 can be a point or imaging polarimeter with some form of wavelength band selectivity. In some aspects, the beam analyzer 430 can be directly integrated into the inspection device 400, or according to other aspects, it can be connected via several types of optical fibers: polarization-maintaining single mode, multimode, or imaging.

[0079] In some aspects, the beam analyzer 430 may also be configured to determine overlay data between two patterns on the substrate 420. One of the patterns may be a reference pattern on a reference layer. Another pattern may be an exposure pattern on an exposure layer. The reference layer may be an etching layer already present on the substrate 420. The reference layer may be generated by a reference pattern exposed on the substrate by the lithography apparatus 100 and / or 100'. The exposure layer may be a resist layer exposed adjacent to the reference layer. The exposure layer may be generated by an exposure pattern exposed on the substrate 420 by the lithography apparatus 100 or 100'. The exposure pattern on the substrate 420 may correspond to the movement of the substrate 420 through the platform 422. In some aspects, the measured overlay data may also indicate an offset between the reference pattern and the exposure pattern. The measured overlay data may be used as calibration data to calibrate the exposure pattern exposed by the lithography apparatus 100 or 100' so that after calibration, the offset between the exposure layer and the reference layer may be minimized.

[0080] In some aspects, the beam analyzer 430 can also be configured to determine a model of the product stack profile of the substrate 420 and can be configured to measure the overlay, critical dimensions, and focus of the target 418 in a single measurement. The product stack profile contains information of the stacked product, such as alignment marks, the target 418, or the substrate 420, and can include optical feature measurements caused by mark process variations as a function of illumination variations. The product stack profile can also include product raster profiles, mark stack profiles, and mark asymmetry information. An example of a beam analyzer 430 is Yieldstar TM , manufactured by ASML of Veldhoven, The Netherlands, as described in U.S. Patent No. 8,706,442, which is incorporated herein by reference in its entirety. The beam analyzer 430 may also be configured to process information related to specific properties of the exposure pattern in the layer. For example, the beam analyzer 430 may process overlay parameters (an indication of the accuracy of positioning of the layer relative to the previous layer on the substrate or the accuracy of positioning of the first layer relative to a mark on the substrate), focus parameters, and / or critical dimension parameters (e.g., line width and its variation) of the image depicted in the layer. Other parameters are image parameters related to the quality of the depicted image of the exposure pattern.

[0081] In some aspects, a detector array (not shown) can be connected to the beam analyzer 430 and allow accurate stack profile detection, as described below. For example, the detector 428 can be a detector array. For the detector array, there are several options: multimode fiber bundles, discrete pin detectors for each channel, or CCD or CMOS (linear) arrays. The use of multimode fiber bundles allows any dissipative elements to be remotely located for stability reasons. Discrete PIN detectors provide a larger dynamic range, but each detector requires a separate preamplifier. Therefore, the number of elements is limited. CCD linear arrays provide many elements that can be read out at high speed, which is particularly interesting if phase-stepped detection is used.

[0082] In some aspects, the second beam analyzer 430' can be configured to receive and determine the optical state of the diffracted radiation sub-beam 429, such as Figure 4BAs shown. The optical state can be a measure of the beam wavelength, polarization, or beam profile. The second beam analyzer 430' can be the same as the beam analyzer 430. Alternatively, the second beam analyzer 430' can be configured to perform at least all the functions of the beam analyzer 430, such as determining the position of the platform 422 and associating the position of the platform 422 with the position of the symmetry center of the alignment mark or target 418. In this way, the position of the alignment mark or target 418 can be accurately known with reference to the platform 422, thereby knowing the position of the substrate 420. The second beam analyzer 430' can also be configured to determine the position of the inspection device 400 or any other reference element, so that the symmetry center of the alignment mark or target 418 can be known with reference to the inspection device 400 or any other reference element. The second beam analyzer 430' can also be configured to determine the overlay data between the two patterns and a model of the product stack profile of the substrate 420. The second beam analyzer 430' can also be configured to measure the overlay, critical dimensions, and focus of the target 418 in a single measurement.

[0083] In some aspects, the second beam analyzer 430' can be directly integrated into the inspection device 400, or according to other aspects, can be connected through several types of optical fibers: polarization-maintaining single mode, multimode or imaging. Alternatively, the second beam analyzer 430' and the beam analyzer 430 can be combined to form a single analyzer (not shown) configured to receive and determine the optical state of the two diffracted radiation sub-beams 429 and 439.

[0084] In some aspects, the processor 432 receives information from the detector 428 and the beam analyzer 430. For example, the processor 432 can be an overlay calculation processor. The information can include a product stack profile model constructed by the beam analyzer 430. Alternatively, the processor 432 can use the received information about the product marking to construct a model of the product marking profile. In either case, the processor 432 uses or incorporates the model of the product marking profile to construct a model of the stacked product and the overlay marking profile. The stack model is then used to determine the overlay offset and minimize the spectral impact on the overlay offset measurement. The processor 432 can create a basic correction algorithm based on the information received from the detector 428 and the beam analyzer 430, including but not limited to the optical state of the illuminating beam, the alignment signal, the related position estimate, and the optical state in the pupil, image, and additional planes. The pupil plane is a plane where the radial position of the radiation defines the angle of incidence and the angular position defines the azimuth angle of the radiation. The processor 432 can use the basic correction algorithm to characterize the inspection device 400 with reference to the wafer mark and / or alignment mark 418.

[0085] In some aspects, the processor 432 may also be configured to determine the print pattern position offset error relative to the sensor estimate for each mark based on information received from the detector 428 and the beam analyzer 430. The information includes, but is not limited to, the product stack profile, overlay measurement, critical dimensions, and focus of each alignment mark or target 418 on the substrate 420. The processor 432 may group the marks into similar constant offset error groups using a clustering algorithm and create an alignment error offset correction table based on this information. The clustering algorithm may be based on overlay measurement, position estimation, and additional optical stack process information associated with each group of offset errors. Overlay is calculated for multiple different marks, for example, the overlay target has positive and negative deviations around the programmed overlay offset. The target with the smallest overlay measured is used as a reference (because it is measured with the best accuracy). From this measured small overlay, and the known programmed overlay of its corresponding target, the overlay error can be inferred. Table 1 illustrates how to do this. The minimum overlay measured in the example is -1nm. However, this is relative to a target with a programmed overlay of -30nm. This process may introduce an overlay error of 29nm.

[0086]

[0087] The minimum value can be used as a reference point, and the offset between the measured overlay and the expected overlay due to programmed overlay is calculated relative to this. This offset determines the overlay error of each mark or group of marks with similar offsets. Therefore, in the example of Table 1, at the target position where the programmed overlay is 30nm, the minimum measured overlay is -1nm. The difference between the expected overlay and the measured overlay at other targets is compared with this reference. A table such as Table 1 can also be obtained from the marks and targets 418 under different illumination settings, and the illumination settings that result in the minimum overlay error and their corresponding calibration factors can be determined and selected. Subsequently, the processor 432 can group the marks into groups with similar overlay errors. The criteria for grouping the marks can be adjusted based on different process controls (e.g., different error tolerances for different processes).

[0088] In some aspects, the processor 432 can determine that all or most members of the group have similar offset errors and apply individual offset corrections from the clustering algorithm to each mark based on its additional optical stack measurement. The processor 432 can determine the correction for each mark and feed the correction back to the lithographic apparatus 100 or 100' to correct the error in the overlay, for example, by feeding the correction into the inspection device 400.

[0089] Exemplary Actuation Platform

[0090] In some aspects, the term "throughput" can be used to describe the rate at which a wafer completes a particular manufacturing step and proceeds to the next step. Throughput can be a performance indicator of the marketability of a lithography system. A lithography system is expected to output as many products as possible in the shortest possible time. Lithography manufacturing can include several complex manufacturing processes. Each manufacturing process has technical characteristics that balance the desired manufacturing quality and disadvantages (e.g., sub-nanometer accuracy, high yield per wafer, high throughput, etc., compared to slower manufacturing, printing errors, cost, etc.).

[0091] In a lithographic apparatus (or inspection device), a wafer or mask can be scanned in a given direction at a given speed. The wafer and mask can be supported on a chuck, which is located on a rapidly moving platform. However, forces from high accelerations can cause the chuck to bend (e.g., stretch), which can cause positioning errors of the wafer or mask. Positioning errors can cause printing errors of devices manufactured from the wafer.

[0092] Aspects disclosed herein include means and functionality for addressing structural issues for mobile platforms with little to no compromise in terms of space requirements, complexity, and cost.

[0093] Figure 5 A platform 500 for supporting an object 502 is shown according to some aspects. In some aspects, the platform 500 can include a support structure 504 (e.g., a first support structure), a support structure 506 (e.g., a second support structure), an actuator device 510, and an actuator target 508. The actuator device 510 can include a coil winding 512. The actuator target 508 can be disposed and fixed on the support structure 504 using a fixing structure 514 (e.g., epoxy resin). The number and configuration of actuator-related elements are not limited to Figure 5 The number and configuration shown in . Fewer or more actuator-related elements may be used, as well as other configurations. The platform 500 may also include one or more position indicators 516 (eg, encoder scales).

[0094] It should be understood that in some aspects, enumerated adjectives (e.g., "first," "second," "third," etc.) may be used as a naming convention and are not intended to indicate an order or hierarchy (unless otherwise specified). For example, the terms "first support structure" and "second support structure" may distinguish between two support structures without specifying whether the support structures have a particular order or hierarchy. In addition, the elements in the figure are not limited to any particular enumerated adjectives. For example, if (multiple) other actuator devices use appropriate distinguishing enumerated adjectives, then an actuator device 510 may be referred to as a second actuator device. In another non-limiting example, one may choose to name the actuator device 510 in the upper right corner as the first actuator device, and then identify the remaining actuator devices as the second, third, and fourth in a clockwise, counterclockwise, cross-shaped, etc. manner.

[0095] In some aspects, platform 500 may be used in lithographic apparatus 100 or 100 ′ ( Figure 1A , Figure 1B and Figure 2 )、Photolithography unit 300( Figure 3 )、Inspection device 400( Figure 4A and Figure 4B ), or generally any device implemented with a platform for supporting and moving an object. For example, platform 500 may represent a wafer table WT or a mask table MT ( Figure 1A , Figure 1B and Figure 2 ) or Platform 422( Figure 4A and Figure 4B )'s specific implementation.

[0096] In certain aspects, support structure 506 can be an actuating structure (e.g., for gross motion of object 502). In a photolithographic manufacturing process, object 502 can be a semiconductor wafer having a diameter of 300 mm (this is a non-limiting example, as one skilled in the art will appreciate that wafers of different sizes are available on the market). In addition, platform 500 can also include additional motion budgets to move object 502 to and from a loading area. Thus, support structure 506 can be responsible for gross motion of platform 500, e.g., on the order of tens, hundreds, or thousands of millimeters. Other distances can be selected based on the suitability of a particular embodiment. However, in embodiments where gross motion is not required, support structure 506 can be a static frame.

[0097] In some aspects, support structure 504 may be supported by support structure 506 while also allowing relative motion between the two support structures. The motion of support structure 504 may be limited to an axis (e.g., Y axis) using a guide rail or a non-contact method (e.g., magnetic levitation) (guide device not shown). Actuator device 510 may be responsible for fine-tuning the position of support structure 504. Therefore, in some aspects, a small gap is used between 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 millimeter). In a scanning lithography process, the printed device may have a critical dimension in the submicron or subnanometer range. A one millimeter movement budget is large enough for scanning printing of subnanometer devices.

[0098] In some aspects, the actuator device 510 can be disposed and fixed to the support structure 506. The actuator device 510 can actuate the support structure 504 by interacting with the actuator target 508. The actuator target 508 can include a material that responds to a magnetic field (e.g., metal, iron, ferrite, etc.). The actuator device 510 can be an electromagnet. The electromagnet can generate and adjust a magnetic field. The electromagnet can include a coil 512 of wire wrapped around a metal core (e.g., a ferrite core). If the actuator target 508 is not a permanent magnet, the actuator device 510 can operate only as an attraction device. Conversely, the actuator device 510 can repel and attract a permanent magnet version of the actuator target 508 by reversing the direction of the magnetic field. The actuator arrangement described herein can be referenced by other professional terms (e.g., a reluctance actuator; and it can be understood that the actuator target 508 can be referred to as a reluctance target).

[0099] In some aspects, the actuator device 510 can use high acceleration to actuate the support structure 504. The acceleration can be, for example, about 4-100g, 10-50g, 20-40g, etc. (where g is 9.8m / s 2 ). High acceleration can increase photolithographic printing throughput (e.g., increase production). Photolithographic pattern transfer can be performed while the support structure 504 is in motion, for example, when it reaches a constant glide speed. The glide speed can 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 scan speed can result in a more accurate transfer of the printed pattern, while printing during acceleration can be accompanied by greater positional uncertainty.

[0100] In some aspects, the nature of the magnetic field can be that the repulsive interaction is unstable and produces undesirable lateral forces (orthogonal to the repulsive direction) and undesirable orthogonal torques. The orthogonal force / torque tends to move the magnets in a way that changes the interaction from repulsion to attraction in order to minimize the total potential energy of the magnet group. Without external lateral guidance or restraining forces, the arrangement is unstable and jumps to the closest stable equilibrium position, where the gap closes (no longer suspended). Therefore, repulsive systems using permanent magnets may be difficult to design and may prompt the addition of active control to prevent the arrangement from collapsing or external mechanical guidance. The additional complexity of the lithography system may significantly increase the engineering difficulty. Therefore, in some aspects, the actuator device 510 can be designed to operate using only attraction (or only pulling). By placing the actuator device 510 on the opposite side of the support structure 504, forward and backward motion can be imparted to the support structure 504 while using a pull-only configuration. However, there may be certain disadvantages in the pull-only method, as will be discussed further below.

[0101] In some aspects, the object 502 can be temporarily fixed to the support structure 504 by pressing the object 502 onto the support structure 504. This can be achieved by vacuum clamping (suction), electrostatic clamping (electrostatic force), mechanical clamping, etc. Under ideal conditions, the mutual friction between the object 502 (e.g., mask) and the support structure 504 (e.g., chuck) can ensure that there is no slippage between them. However, the mechanical stress caused by high acceleration can cause some slippage, resulting in printing errors. These errors can be very harmful because thousands of device products may be lost when the errors are detected.

[0102] The following is an example of a positioning error of an object 502 when using the platform 500. In some aspects, the object 502 can be fixed to the support structure 504. In order to determine the position of a feature on the object 502, a calibration measurement can be performed using, for example, an optical inspection system. The calibration measurement can determine the position of the feature on the object 502 relative to one or more position indicators 516. The position indicator 516 can be fixedly fixed to the support structure 504. After the relationship between the object 502 and the one or more position indicators 516 is established, the object 502 can be used for a high-precision process (e.g., a lithography process) and there is no need to perform calibration again as long as the object 502 remains stationary relative to the support structure 504. Instead, any relative motion between the object 502 and the support structure 504 can be considered a positioning error - the error is then transferred to each process after an error event occurs.

[0103] The following is an example of conditions and mechanisms that can induce positioning errors. In certain aspects, the actuator device 510 can apply an electromagnetic force to the actuator target 508. For example, the actuator device 510 on the left side of the support structure 504 can be activated, which then pulls the corresponding actuator 508, the fixed structure 514, and finally the support structure 504. Therefore, the actuator device 510 on the right side of the support structure 504 can be used to pull in the opposite direction (for deceleration) and allow the support structure 504 to be stationary. During acceleration / deceleration, the combined mass of the object 502 and the support structure 504 is inertial, and the force they exert is equal and opposite to the force exerted by the actuator target 508 during pulling (drawn as an arrow "ma" (mass×acceleration) pointing to the right). In contrast, if two actuator targets 508 are pulling, the pulling force can be distributed between the two actuator targets 508 (drawn as two arrows "F=ma / 2").

[0104] A disadvantage of the pull-only approach is that, in some aspects, the support structure 504 may be under a high tension gradient due to high accelerations (e.g., 4-100 g). The tension may cause the support structure 504 to deform (e.g., stretch). Even if the support structure 504 is made of a rigid structure (e.g., made of glass and ribbed reinforcements), even a few picometers of deformation may cause the object 502 to move a few picometers relative to the one or more position indicators 516, thereby introducing positioning errors. While the push-pull approach (some actuator devices 510 pull, and some push from behind) can offset most of the tension and deformation issues, it can also introduce the issues mentioned above regarding magnet repulsion.

[0105] Another disadvantage of the pull-only approach is that, in some aspects, due to the high accelerations, the fixed structure 514 may also be subjected to significant tension. In a non-limiting example where the fixed structure 514 is made of epoxy, the epoxy, which is only subjected to tension, may creep (e.g., slowly stretch over time), making mechanical failure more likely than a pull-push approach where the epoxy stress is zero on average (e.g., subjected to tension when pulled in one direction, but also subjected to compression when pushed in the opposite direction).

[0106] Some aspects described herein provide structure and functionality that address the problems of pull-only approaches.

[0107] According to some aspects, Figure 6 A platform 600 is shown for supporting an object 602. In some aspects, the platform 600 may have some of the features already described in reference Figure 5 Describe the characteristics. Figure 6 Additional elements may be shown, while some elements may be hidden (for clarity). Unless otherwise noted, the previous descriptions of Figure 5 The structure and function of the components described can also be applied to Figure 6 Like-numbered elements in the drawings (eg, reference numerals share the two rightmost digits). Figure 6 At least some of the structure and functionality of the elements should be derived from Figure 5 The description of the corresponding elements is obvious and will not be repeated.

[0108] In some respects, in addition to Platform 500 ( Figure 5), the platform 600 may also include additional internal actuator devices 610i and extension structures 618 (e.g., cantilevers). Like the actuator devices 610, the internal actuator devices 610i may be disposed and secured to the support structure 606. The extension structures 618 may be used to structurally secure the actuator targets 608 at a distance from the sides of the support structure 604 with the aid of the securing structures 614 (e.g., epoxy). With the space created by the extension structures 618, a given device in the actuator devices 610i may be disposed within the internal space defined by its corresponding actuator target 608, its corresponding extension structure 618, and the sides of the support structure 604 (e.g., cantilever). Figure 6 shown).

[0109] In some aspects, the configuration of platform 600 can be used to solve the above platform 500 ( Figure 6 ) at least some of the problems. For example, while the two actuator devices 610 on the left are pulling the support structure 604, the other two internal actuator devices 610i on the right side of the support structure 604 can be used to "push" the support structure 604. The four activated actuator devices are represented by four arrows, labeled "F = ma / 4", because the total force is distributed to its corresponding four actuator targets 608 (fewer or more actuator devices can be implemented). However, the two actuator devices 610i on the right use attractive force (pull) to move the support structure 604 to the left, so it can be said that Figure 6 The preferred solution is a pull-pull solution. Thus, the above-mentioned repulsion problem can be avoided, while also reducing the deformation of the support structure 604 and balancing the stress on the fixed structure 614 (i.e., the average stress generated by the tension and pressure of the forward and backward movement is zero). In order to slow down and / or reverse the direction of movement, the corresponding actuator device 610 and the internal actuator device 610i can be used in a pull-pull configuration.

[0110] In some respects, the addition of the internal actuator device 610i and the extension structure 618 may have some undesirable consequences. One disadvantage is the increased construction cost (additional parts and manufacturing complexity). Another disadvantage is the increased overall weight of the moving parts, increasing their inertia. Figure 6 In the embodiment of the present invention, the mass of the coarse motion structure (support structure 606 and all objects supported by it) is increased due to the addition of four heavy electromagnets (internal actuator device 610i). The mass of the fine (support structure 606 and all objects supported by it) is increased due to the addition of extension structure 618. In addition, extension structure 618 may be sensitive to vibrations, resulting in poor motion dynamics of support structure 604. When object 602 is used as a mask for a photolithography process, the additional uncertainty caused by vibrations will affect the pattern transfer accuracy.

[0111] Certain aspects described herein provide structure and functionality to address the issues of pull-only and pull-pull approaches.

[0112] According to some aspects, Fig. 7A and Figure 7B A platform 700 is shown for supporting an object 702. In some aspects, the platform 700 may have some of the features already described with reference to FIG. Figure 5 and Figure 6 Describe the characteristics. Figure 5 and Figure 6 Additional elements may be shown, while some elements may be hidden (for clarity). Unless otherwise noted, the previous descriptions of Figure 5 and Figure 6 The structure and function of the components described can also be applied to Fig. 7A and Figure 7B Like-numbered elements in the drawings (eg, reference numerals share the two rightmost digits). Fig. 7A and Figure 7B At least some of the structure and function of the elements should be derived from Figure 5 and Figure 6 The corresponding elements are obvious from the description of the drawings and will not be reintroduced again.

[0113] See also Fig. 7A , in some respects, except for Platform 500 or 600 ( Figure 5 and Figure 6 ), the platform 700 may include an axis 718. The axis 718 may be secured to the support structure 704 using a fastener 720 (e.g., a pin, bolt, etc.). One or more load distributors 722 may be used to surround a portion of the fastener 720. One or more actuator targets 708 may be secured to the axis 718 (e.g., one actuator target 708 at each end of the axis) (securing may be accomplished via welding, glue, epoxy, etc.). The actuator target 708 may be coupled to one or more stabilizers 724. The axis implementation may be iterated so as to have multiple axes and corresponding attachment elements, such as Fig. 7A shown.

[0114] In certain aspects, the shaft 718 can be fixed to the support structure 704 at a location 726 of the support structure 704. The location 726 can be substantially along a centerline 728 of the support structure 704 (e.g., bisecting the centerline of the support structure). When the corresponding actuator device 710 is activated to pull the actuator target 708, the shaft 718 can transfer a mechanical load from the actuator target 708 to the location 726 of the support structure 704. By distributing the mechanical load in this manner, the platform 500 can be lowered ( Figure 5). Instead, the deformation effect can be divided into a compressive region to the left of location 726 (assuming the pulling force is directed to the left) and a tensile region to the right of location 726. Due to the reconfiguration of the compressive and tensile stresses of the support structure 704, the risk of object 702 slipping can be significantly reduced. In addition, by fixing the two actuator targets 708 to opposite ends of the same shaft 718, the mechanical load can be distributed more evenly. For example, when one actuator target is pulled to the left, a portion of the mechanical load transmitted by the shaft will be transmitted to the trailing actuator target. The force applied by the trailing actuator can push on the support structure 704, thereby counteracting the inertial tendency of the chuck to extend and zeroing the average stress in the epoxy over a large number of scan cycles.

[0115] Figure 7B 726 of the support structure 704 according to some aspects. In some aspects, the shaft 718 can pass through the interior of the support structure 704. However, other embodiments are contemplated, such as attaching the shaft 718 to the exterior of the support structure 704 (e.g., see FIG. Fig. 7A 726). The support structure 704 may include a hole at position 726. The shaft 718 may also include a hole aligned with the hole of the support structure 704. Fasteners 720 may be disposed in the holes of the support structure 704 and the shaft 718 to secure the shaft at position 726.

[0116] In some aspects, support structure 704 can include one or more countersunk holes aligned with holes at locations 726. Load distributors 722 can be disposed in each countersunk hole and around fasteners 720 to distribute mechanical loads during acceleration. Load distributors 722 can include, for example, diaphragm flexures. One or more load distributors 722 can be secured to the countersunk holes using adhesive structure 730 (epoxy). Considering the motion of support structure 704 (e.g., front-to-back, side-to-side scanning), the stress on the epoxy has a balance of compressive and tensile forces, which addresses the need for platform 500 ( Figure 5 ) in the epoxy resin used in the present invention. In some aspects, the design can be such that the clearance hole surrounds the fastener 720 (not shown) so that no direct contact occurs between the fastener 720 and the support structure 704.

[0117] review Fig. 7A In some aspects, the features of platform 700 may implement certain desirable features of platforms 500 and 600 while mitigating the disadvantages discussed above. Figure 6), the arrangement of the platform 700 allows for a reduction in components and footprint. Thus, by eliminating the need to use additional internal actuator devices 610i and extension structures 618 ( Figure 6 ) needs, which can reduce cost, weight and space. Although the actuator device 510 ( Figure 5 ) than platform 600( Figure 6 ) are few and there are problems with high tension and deformation, but platform 700 can alleviate tension deformation without increasing the actuator device count.

[0118] In certain aspects, the platform 700 can employ low mass solutions to further enhance the dynamic performance of the platform 700. For example, a stabilizer 724 can be used to reduce the effects of vibration. The stabilizer 724 can be coupled to the actuator target 708. The stabilizer 724 can include a flexure.

[0119] According to some aspects, Figure 8 A cross section of support structure 804 is shown. In some aspects, support structure 804 can have an alternative shaft implementation compared to support structure 704 (FIG. 7). It should be understood that certain features of support structure 704 are not shown for drawing clarity. However, other features of support structure 804 should be understood from the drawings. Figure 5 - This is obvious from the description of FIG. 7 and will not be repeated.

[0120] In some aspects, shaft 818 can be used to transfer loads from an actuator target (e.g., 708 ( FIG. 7 )) to multiple locations of support structure 804. Support structure 804 can include first, second, and / or third holes located at corresponding first, second, and / or third locations of support structure 804. Shaft 818 can also include first, second, and / or third holes aligned with corresponding holes of support structure 804. Fasteners 820 can be disposed in holes of support structure 804 and shaft 818 to secure the shaft at the first, second, and / or third locations of support structure 804. The diameter of fastener 820 can be smaller than the diameter of fastener 720 ( FIG. 7 ) because the load is distributed across multiple fasteners rather than placing all of the load on a single fastener 720 ( FIG. 7 ).

[0121] Exemplary Actuation Platform with Tension Members

[0122] Fig. 9 A portion of a platform 900 for supporting an object (eg, a wafer, a mask, etc.) is shown in accordance with some aspects. In some aspects, the platform 900 may have some of the Figure 5-Figure 8 Describe the characteristics. Figure 5-Figure 8 Additional elements may be shown, while some elements may be hidden (for clarity). Unless otherwise noted, the previous descriptions of Figure 5-Figure 8The structure and function of the components described can also be applied to Fig. 9 Like-numbered elements in the drawings (eg, reference numerals share the rightmost two digits). Fig. 9 At least some of the structure and functionality of the elements should be derived from Figure 5-Figure 8 It will be apparent from the description of the corresponding elements.

[0123] In some aspects, platform 900 may include support structure 904, actuator targets 908 (e.g., three or more), one or more actuator devices 910, and tension members 918'. A support structure may be a support structure located on another support structure (e.g., Fig. 7A and Figure 7B As a non-limiting example, actuator devices 910-a and 910-b are shown as E-shaped electromagnet cores. Other types of electromagnet cores are also contemplated. For example, reference is disclosed herein Fig.10 Some aspects of the C-shaped core. Fig. 9 The wire coils are not explicitly shown in the drawings, but their presence and function should be apparent to those skilled in the art based on the previous figures (e.g., coil windings 512 ( Figure 5 )) and the description of the magnetic field 930 are self-explanatory. The tension member 918' can be a loose or flexible material (eg, a rope), a rigid rod (eg, shaft 718 ( Fig. 7A and Figure 7B )wait.

[0124] In some aspects, support structure 904 can include a hollow portion 932 (e.g., a groove or channel). Tension member 918' is disposed in hollow portion 932. The size (e.g., cross-section, diameter, etc.) of hollow portion 932 can be larger than the size of tension member 918', thereby allowing tension member 918' to move within hollow portion 932. Hollow portion 932 can be implemented in a variety of different ways (e.g., as a hollow channel, a groove on the exterior of support structure 904, one or more rings, etc.). Actuator targets 908-a, 908-b, 908-c, 908-d, 908-e, and 908-f are explicitly shown (e.g., a first actuator target, a second actuator target, another actuator target, etc.). However, it should be understood that more or fewer actuator targets can be implemented.

[0125] In some aspects, actuator device 910-a and actuator targets 908-a, 908-c, and 908-e can be disposed on side 934 (e.g., a first side) of support structure 904. Actuator device 910-a can be disposed proximate to actuator targets 908-a, 908-c, and 908-e (e.g., such that when the electromagnet is turned on, the electromagnet can attract the actuator target). Actuator device 910-b and actuator targets 908-b, 908-d, and 908-f can be disposed at side 936 (e.g., a second side) of support structure 904 opposite side 934. Actuator device 910-b can be disposed proximate to actuator targets 908-b, 908-d, and 908-f.

[0126] In certain aspects, for an E-shaped core, the first, second, and third structural protrusions of the E-shaped core can be arranged to face the corresponding actuator targets. A C-shaped core can be arranged similarly (e.g., instead of three protrusions, two protrusions face two actuator targets). The E-shaped core can be constructed from a single piece of magnetically conductive material or an assembly of two or more components (e.g., two C-shaped cores 938 attached to each other).

[0127] In certain aspects, actuator targets 908-c and 908-e can be attached to side 934 of support structure 904. Attachment can be achieved using, for example, adhesive structure 914 (e.g., an adhesive such as epoxy). Actuator targets 908-a and 908-b can be attached at opposite ends of tension member 918'. For example, when actuator device 910-a is turned on to generate magnetic field 930 at side 934 of support structure 904, the magnetic interaction can attract actuator targets 908-a, 908-c, and 908-e to move support structure 904 in a given direction. In addition, tension member 918' can transfer a mechanical load to side 936 of support structure 904 via actuator target 908-b (e.g., the mechanical load transfer is based on the magnetic force applied to the first actuator target).

[0128] In some aspects, the size (e.g., cross-section, diameter) of targets 908-a and 908-b can be larger than the size of hollow portion 932, such that targets 908-a and 908-b cannot enter hollow portion 932. In this case, by pulling target 908-a using magnetic field 930, target 908-b can "hook" onto side 936, thereby allowing the pushing motion of support structure 904 to supplement the pushing motion occurring at side 934 via targets 908-c and 908-e. In this way, the acceleration and velocity of support structure 904 can be increased, as well as reducing the undesirable effects of pulling from only one side of the support structure, as described above with reference to previous figures (e.g., deformation).

[0129] In some aspects, actuator target 908-b can include a load distributor 940 to distribute the mechanical load transferred to side 936. Actuator target 908-a can also include a load distributor 940. Load distributor 940 can include, for example, a cushion, a coil spring, a flexure, an accordion structure, or the like.

[0130] In some aspects, the separation gap between actuator targets 908-a and 908-c can be small to prevent attenuation of magnetic field 930. Specifically, the gap between adjacent actuator targets can be much smaller than the operating gap between the actuator target (e.g., 908-a) and the pole of the actuator device (e.g., 910-a). In a non-limiting example, much smaller can be 20% or less, 15% or less, 10% or less, 5% or less, 20% to 5%, 15% to 5%, 15% to 10%, 10% to 5%, etc. When such conditions are applied, the flux reduction caused by the gap between the actuator targets can be negligible compared to the flux reduction caused by the operating gap between the actuator device and the actuator target (e.g., the effect on the force generated per unit current through the coil is less than a few percent and can be negligible).

[0131] In some aspects, the operating gap between the actuator device and the actuator target can be 1500 microns or less, 1000 microns or less, 500 microns or less, etc. Using a 500 micron operating gap and a constraint of 10% or less as a non-limiting example, a 50 micron gap between two actuator targets can be considered negligible. On the other hand, there may be manufacturability issues that prevent such a small gap from becoming practical or economical to produce. But aside from practicality considerations, the smaller the gap, the better the actuation performance (e.g., force divided by the current in the coil).

[0132] In some respects, if reducing manufacturing costs is more favored than improving performance, then a gap of 200 microns or less may be ideal because it has looser tolerances (arguably easier to manufacture). But the trade-off is that it uses more current, and for the same output force, it also worsens heating. There are also thermal expansion considerations. It is desirable to minimize the heat generation caused by the actuator device by maximizing its electromagnetic performance. The separation gap between adjacent actuator targets 908-a and 908-c can be, for example, about 2 mm or less, 1 mm or less, 500 microns or less, 200 microns or less, 100 microns or less, 50 microns or less, 20 microns or less, or 10 microns or less. This feature of separation can be extended to the gaps between actuator targets 908-a and 908-e, 908-b and 908-d, and 908-b and 908-f.

[0133] It should be understood that in some aspects, the functionality described above for moving support structure 904 to the left side of the figure (e.g., a first direction) can be applied in reverse to actuator device 910-b and actuator targets 908-b, 908-d, and 908-f to move in the opposite direction.

[0134] According to some aspects, Fig.10 A portion of a platform 1000 for supporting an object (eg, a wafer, a mask, etc.) is shown. In some aspects, the platform 1000 may have some of the features described above. Figure 5-Figure 9 Describe the characteristics. Figure 5-Figure 9 Additional elements may be shown, while some elements may be hidden (for clarity). Unless otherwise noted, the previous descriptions of Figure 5-Figure 9 The structure and function of the components described can also be applied to Fig.10 Like-numbered elements in the drawings (eg, reference numerals share the rightmost two digits). Fig.10 At least some of the structure and function of the elements should be derived from Figure 5-Figure 9 The corresponding elements will be apparent from the description.

[0135] In certain aspects, the actuator device 1010 - a can be a C-shaped core. The actuator targets 1008 - a and 1008 - c can be disposed near the poles of the actuator device 1010 - a. Fig.10 The structure and / or function of other elements appearing in can be as described above with reference to previous figures (e.g., support structure 1004, bonding structure 1014, tension member 1018', magnetic field 1030, hollow portion 1032, side 1034 and / or load distributor 1040).

[0136] Although specific reference may be made herein to the use of lithographic equipment in IC manufacturing, it should be understood that the lithographic equipment described herein may have other applications, such as manufacturing integrated optical systems, guidance and detection patterns for magnetic domain memories, flat panel displays, LCDs, thin film heads, etc. Those skilled in the art will understand that in the context of such alternative applications, any use of the term "wafer" or "die" herein may be considered as a specific example of the more general term "substrate" or "target portion", respectively. The substrates referred to herein may be processed before or after exposure in, for example, a track unit (a tool that typically applies a resist layer to a substrate and develops the exposed resist) and / or a measurement unit. Where applicable, the disclosure herein may be applied to such and other substrate processing tools. In addition, the substrate may be processed multiple times, for example to create a multi-layer IC, so the term substrate used herein may also refer to a substrate that already contains multiple processing layers.

[0137] Although specific reference has been made above to the use of aspects of the present disclosure in the context of optical lithography, it should be understood that the present disclosure can be used in other applications, such as imprint lithography, and is not limited to optical lithography wherever the context permits. In imprint lithography, the topography in the patterning device defines the pattern created on the substrate. The topography of the patterning device can be pressed into a layer of resist supplied to the substrate, and the resist is then cured by applying electromagnetic radiation, heat, pressure, or a combination thereof. After the resist is cured, the patterning device is removed from the resist, leaving a pattern therein.

[0138] It should be understood that the phraseology or terminology herein is for the purpose of description rather than limitation, so that the phraseology or terminology of the present disclosure may be interpreted by those skilled in the relevant art based on the teachings herein.

[0139] As used herein, the terms "radiation", "radiation beam", etc. may cover all types of electromagnetic radiation, such as ultraviolet (UV) radiation (e.g., with a wavelength λ of 365nm, 248nm, 193nm, 157nm or 126nm), extreme ultraviolet (EUV or soft X-ray) radiation (e.g., with a wavelength in the range of 5-20nm, such as 13.5nm), or hard X-rays with a wavelength less than 5nm, as well as material beams, such as ion beams or electron beams. The terms "light", "irradiation", etc. may refer to non-material radiation (e.g., photons, UV, X-rays, etc.). Generally, radiation with a wavelength between about 400nm and about 700nm is considered visible radiation; radiation with a wavelength between about 780-3000nm (or greater) is considered infrared radiation. UV refers to radiation with a wavelength of about 100-400nm. In lithography, the term "UV" also applies to wavelengths that can be produced by mercury discharge lamps: G line 436nm; H line 405nm; and / or I line 365nm. 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 range of 126 nm to 428 nm, and in certain aspects, excimer lasers can produce DUV radiation used in lithographic equipment. It should be understood that radiation having a wavelength range of, for example, 5-20 nm relates to radiation having a specific wavelength band, at least a portion of which is within the range of 5-20 nm.

[0140] It should be understood that the Detailed Description section (rather than 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 of the present disclosure contemplated by the inventor(s), and therefore, are not intended to limit the present disclosure and the appended claims in any way.

[0141] The disclosure has been described above by means of functional building blocks, which have illustrated the realization of its specific functions and its relationship. For ease of description, the boundaries of these functional building blocks are arbitrarily defined herein. As long as its specific functions and its relationship are suitably performed, alternative boundaries can also be defined.

[0142] Although specific aspects of the present disclosure have been described above, it will be appreciated that aspects of the present disclosure may be implemented in a manner other than that described. The description is intended to be illustrative, not limiting. Therefore, it will be appreciated by those skilled in the art that modifications may be made to the present disclosure without departing from the scope of the claims described below.

[0143] The above description of specific aspects will fully reveal the general nature of the present disclosure, and others can easily modify and / or adapt these specific aspects for various applications without departing from the general concept of the present disclosure by applying knowledge within the technical scope of the art, without undue experimentation. Therefore, based on the teaching and guidance provided herein, such adjustments and modifications are intended to fall within the meaning and scope of equivalents of the disclosed aspects.

[0144] The breadth and scope of the protected subject matter 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.

[0145] Various aspects of the present disclosure may be further described using the following terms:

[0146] 1. A lithographic apparatus, comprising:

[0147] an illumination system configured to illuminate the pattern forming device with a pattern;

[0148] a projection system configured to project an image of the pattern onto a substrate;

[0149] a stage configured to move the pattern forming device or the substrate, the stage comprising:

[0150] a first support structure configured to support the patterning device or the substrate;

[0151] a second support structure configured to support the first support structure;

[0152] an actuator device disposed on the second support structure and configured to move the first support structure in a direction;

[0153] an actuator target configured to interact with the actuator device;

[0154] A shaft is secured to the actuator target and to a location at the first support structure, wherein the shaft is configured to transfer a mechanical load from the actuator target to the location.

[0155] 2. A lithographic apparatus according to clause 1, wherein:

[0156] The first support structure includes a hole located at the location;

[0157] The shaft includes a bore; and

[0158] The platform also includes fasteners disposed in the first support structure and the holes of the shaft to secure the shaft in the position.

[0159] 3. A lithographic apparatus according to clause 2, wherein:

[0160] The first support structure includes a second hole located at a second position of the first support structure;

[0161] The shaft includes a second hole; and

[0162] The actuation platform also includes a second fastener disposed in the first support structure and the second hole of the shaft to secure the shaft in the second position.

[0163] 4. The lithographic apparatus of clause 2, wherein the fastener is a pin or a bolt.

[0164] 5. The lithographic apparatus of clause 2, wherein the platform further comprises a load distributor disposed around the fastener and configured to distribute the mechanical load.

[0165] 6. The lithographic apparatus of clause 5, wherein the load distributor comprises a diaphragm flexure.

[0166] 7. The lithographic apparatus of clause 5, wherein the load distributor is fixed to the first support structure by epoxy.

[0167] 8. The lithographic apparatus of clause 1, wherein the platform further comprises:

[0168] a second actuator device disposed on the second support structure and configured to move the first support structure in the direction;

[0169] a second actuator target configured to interact with the second actuator device; and

[0170] A second shaft is secured to the second actuator target and a second location of the first support structure, wherein the second shaft is configured to transfer a mechanical load from the second actuator target to the second location.

[0171] 9. A lithographic apparatus according to clause 1, wherein:

[0172] The actuator target is a first actuator target fixed to one end of the shaft;

[0173] The platform also includes:

[0174] a second actuator arrangement disposed on the second support structure and configured to move the first support structure in the direction; and

[0175] a second actuator target configured to interact with the second actuator device;

[0176] The second actuator target is fixed to an end of the shaft opposite the first actuator target; and

[0177] The shaft is also configured to transfer a portion of the mechanical load from the first actuator target to the second actuator target.

[0178] 10. A lithographic apparatus according to clause 1, wherein the shaft is arranged through an interior of the first support structure.

[0179] 11. The lithographic apparatus of clause 1, wherein the platform further comprises a stabilizer coupled to the actuator target, wherein the stabilizer is configured to reduce vibration.

[0180] 12. The lithographic apparatus of clause 1, wherein the actuator arrangement comprises an electromagnet.

[0181] 13. The lithographic apparatus of clause 1, the first support structure comprising one or more position indicators.

[0182] 14. A movable platform comprising:

[0183] a first support structure configured to support an object;

[0184] a second support structure configured to support the first support structure;

[0185] an actuator device disposed on the second support structure and configured to move the first support structure in a direction;

[0186] an actuator target configured to interact with the actuator device; and

[0187] A shaft is secured to the actuator target and to a location located at the first support structure, wherein the shaft is configured to transfer a mechanical load from the actuator target to the location.

[0188] 15. A movable platform according to clause 14, wherein:

[0189] The first support structure includes a hole located at the location;

[0190] The shaft includes a bore; and

[0191] The movable platform also includes a fastener disposed in the first support structure and the hole of the shaft to secure the shaft in the position.

[0192] 16. A movable platform according to clause 15, wherein:

[0193] The first support structure includes a second hole located at a second position of the first support structure;

[0194] The shaft includes a second hole; and

[0195] The movable platform also includes a second fastener disposed in the first support structure and the second hole of the shaft to secure the shaft at the second position.

[0196] 17. The movable platform of clause 15, further comprising a load distributor disposed about the fastener and configured to distribute the mechanical load.

[0197] 18. The moveable platform of clause 16, wherein the load distributor comprises a diaphragm flexure.

[0198] 19. The movable platform according to clause 14, further comprising:

[0199] a second actuator device disposed on the second support structure and configured to move the first support structure in the direction;

[0200] a second actuator target configured to interact with the second actuator device; and

[0201] A second shaft is secured to the second actuator target and a second location of the first support structure, wherein the second shaft is configured to transfer a mechanical load from the second actuator target to the second location.

[0202] 20. A movable platform according to clause 14, wherein:

[0203] The actuator target is a first actuator target fixed to one end of the shaft;

[0204] The platform also includes:

[0205] a second actuator arrangement disposed on the second support structure and configured to move the first support structure in the direction; and

[0206] a second actuator target configured to interact with the second actuator device;

[0207] The second actuator target is fixed to an end of the shaft opposite the first actuator target; and

[0208] The shaft is also configured to transfer a portion of the mechanical load from the first actuator target to the second actuator target.

[0209] 21. The movable platform of clause 14, further comprising a stabilizer coupled to the actuator target, wherein the stabilizer is configured to reduce vibration.

[0210] 22. The moveable platform of clause 14, wherein the actuator arrangement comprises an electromagnet.

Claims

1. A lithographic apparatus, comprising: an illumination system configured to illuminate the pattern forming device with a pattern; a projection system configured to project an image of the pattern onto a substrate; as well as a stage configured to move the pattern forming device or the substrate, the stage comprising: a support structure configured to support the patterning device or the substrate; a first actuator target disposed at a first side of the support structure; a second actuator target disposed at a second side of the support structure opposite the first side; a third actuator target attached to the first side of the support structure; an actuator device disposed proximate the first target and the third target and configured to magnetically interact with the first target and the third target to move the support structure in a direction; and A tensile member, wherein the first actuator target and the second actuator target are attached at opposite ends of the tensile member, and the tensile member is configured to transmit a mechanical load to the second side of the support structure via the second actuator target based on a magnetic force applied to the first actuator target.

2. The lithographic apparatus according to claim 1, wherein: The tension member is a flexible rope; The lithographic apparatus further comprises a frame configured to support the support structure and to allow the support structure to move relative to the frame; and The actuator arrangement comprises a C-shaped core.

3. The lithographic apparatus according to claim 1 , wherein: The platform further includes another actuator target attached to the first side of the support structure; The actuator device comprises an E-shaped core; The first structural protrusion, the second structural protrusion and the third structural protrusion of the E-shaped core are arranged facing the first target, the second target and another target respectively; and The E-shaped core includes two C-shaped cores attached to each other.

4. The lithographic apparatus according to claim 1, wherein the actuator arrangement is further configured to move the support structure by pulling the first side via the third actuator target and pushing the second side by transmitting the mechanical load to the second side of the support structure via the second actuator target.

5. The lithographic apparatus according to claim 1, wherein: The actuator device is a first actuator device; The direction is a first direction; The platform also includes: a fourth actuator target attached to the second side of the support structure, a second actuator device disposed proximate the second target and the fourth target and configured to magnetically interact with the second target and the fourth target to move the support structure in a second direction opposite to the first direction; The tensile member is further configured to transmit a mechanical load to the first side of the support structure via the first actuator target based on a magnetic force exerted on the second actuator target; and The second actuator arrangement is further configured to move the support structure by pulling the second side via the fourth actuator target and pushing the first side by transmitting the mechanical load to the first side of the support structure via the first actuator target.

6. The lithographic apparatus according to claim 1, wherein: The first actuator target and / or the second actuator target comprises a load distributor to distribute the mechanical load on the second side; the third actuator target being attached to the first side via an epoxy adhesive; and A separation gap between the first actuator target and the third actuator target is 200 microns or less.

7. The lithographic apparatus of claim 1, wherein a separation gap between the first actuator target and the third actuator target is 50 microns or less.

8. A platform comprising: a support structure configured to support the object; a first actuator target disposed at a first side of the support structure; a second actuator target disposed at a second side of the support structure opposite to the first side, a third actuator target attached to the first side of the support structure; an actuator device disposed proximate the first target and the third target and configured to magnetically interact with the first target and the third target to move the support structure in a direction; as well as A tension member, wherein the first actuator target and the second actuator target are attached at opposite ends of the tension member, and the tension member is configured to transmit a mechanical load to the second side of the support structure via the second actuator target based on a magnetic force applied to the first actuator target.

9. The platform of claim 8, wherein: The tension member is a flexible rope; The platform further includes a frame configured to support the support structure and to allow the support structure to move relative to the frame; and The actuator arrangement comprises a C-shaped core.

10. The platform of claim 8, wherein: The platform further includes another actuator target attached to the first side of the support structure; The actuator device comprises an E-shaped core; and The first structural protrusion, the second structural protrusion and the third structural protrusion of the E-shaped core are arranged facing the first target, the second target and another target respectively; and The E-shaped core includes two C-shaped cores attached to each other.

11. The platform of claim 8, wherein the actuator arrangement is further configured to move the support structure by pulling the first side via the third actuator target and pushing the second side by transmitting the mechanical load to the second side of the support structure via the second actuator target.

12. The platform of claim 8, wherein: The actuator device is a first actuator device; The direction is a first direction; The platform also includes: a fourth actuator target attached to the second side of the support structure, a second actuator device disposed proximate the second target and the fourth target and configured to magnetically interact with the second target and the fourth target to move the support structure in a second direction opposite to the first direction; The tensile member is further configured to transmit a mechanical load to the first side of the support structure via the first actuator target based on a magnetic force exerted on the second actuator target; and The second actuator arrangement is further configured to move the support structure by pulling the second side via the fourth actuator target and pushing the first side by transmitting the mechanical load to the first side of the support structure via the first actuator target.

13. The platform of claim 8, wherein: The first actuator target and / or the second actuator target comprises a load distributor to distribute the mechanical load on the second side; the third actuator target being attached to the first side via an epoxy adhesive; and A separation gap between the first actuator target and the third actuator target is 200 microns or less.

14. The platform of claim 8, wherein a separation gap between the first actuator and the third actuator target is 50 microns or less.

Images