WO2022017741A1

WO2022017741A1 - Systems, methods, and devices for thermal conditioning of reticles in lithographic apparatuses

Info

Publication number: WO2022017741A1
Application number: PCT/EP2021/067913
Authority: WO
Inventors: Andrew JUDGE; Walter Joseph TARESH; Dustin Anthony FIGUEROA
Original assignee: Asml Holding N.V.
Priority date: 2020-07-21
Filing date: 2021-06-29
Publication date: 2022-01-27
Also published as: CN116157742A

Abstract

Embodiments herein describe systems, methods, and devices for thermal conditioning of reticles at a patterning device handling apparatus and a support structure in lithographic apparatuses. A patterning device handling apparatus includes a gripping device (510) with a plurality of pneumatic lines (530). The patterning device handling apparatus positions a first surface of a patterning device (502) below the gripping device, and the gripping device applies a first air flow to the patterning device using the plurality of pneumatic lines. The patterning device handling apparatus positions a second surface of the patterning device in the support structure. One or more vacuum pads (516) in clamping interfaces (506) in the support structure apply a second air flow (520) to the patterning device. The first and second air flows result in thermal conditioning of the patterning device.

Description

SYSTEMS, METHODS, AND DEVICES FOR THERMAL CONDITIONING OF RETICLES

IN LITHOGRAPHIC APPARATUSES

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority of U.S. Provisional Patent Application No. 63/054,535, which was filed on July 21, 2020, and which is incorporated herein in its entirety by reference.

FIELD

[0002] The present disclosure relates to systems, methods, and devices for thermal conditioning and reticle cooling in lithographic apparatuses.

BACKGROUND

[0003] A lithographic apparatus is a machine that applies a desired pattern onto a substrate, usually onto a target portion of the substrate. A lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In that instance, a patterning device, which is alternatively referred to as a mask or a reticle, can be used to generate a circuit pattern to be formed on an individual layer of the IC. This pattern can be transferred onto a target portion (e.g., comprising part of, one, or several dies) on a substrate (e.g., a silicon wafer). Transfer of the pattern is typically via imaging onto a layer of radiation- sensitive material (resist) provided on the substrate. In general, a single substrate will contain a network of adjacent target portions that are successively patterned. Known lithographic apparatus include so-called steppers, in which each target portion is irradiated by exposing an entire pattern onto the target portion at one time, and so-called scanners, in which each target portion is irradiated by scanning the pattern through a radiation beam in a given direction (the “scanning”- direction) while synchronously scanning the target portions parallel or anti-parallel to this scanning direction. It is also possible to transfer the pattern from the patterning device to the substrate by imprinting the pattern onto the substrate.

[0004] To project a pattern on a substrate a lithographic apparatus may use electromagnetic radiation. The wavelength of this radiation determines the minimum size of features which can be formed on the substrate. A lithographic apparatus may use extreme ultraviolet (EUV) radiation, having a wavelength within the range 4-20 nm, for example 6.7 nm or 13.5 nm, or deep ultraviolet (DUV) radiation, having a wavelength in the range of about 120 to about 400 nm, for example 193 or 248 nm. [0005] In DUV lithography, the radiation beam may cause thermal responses in the reticle. In particular, the reticle may absorb a large amount of thermal energy from the DUV radiation beam, which can cause the reticle to heat up and expand. Other sources, such as various mechatronic devices throughout the reticle handler and reticle stage modules, can contribute to reticle heating as well. Reticle heating, which results in a non-uniform thermal profile of the reticle, may serve as a major contribution to image distortion and overlay errors in the lithography system. Thus, reticle cooling methods can be utilized to prevent deformation and overlay issues. In some cases, thermal conditioning systems that utilize customized nozzles and gas outlets may be implemented in patterning apparatuses for providing a gas flow parallel to the surface of a reticle and support structure for reticle cooling. However, such systems and methods for cooling and controlling reticle temperatures may necessitate customized parts and additional hardware that result high costs and increased system complexity.

SUMMARY

[0006] Accordingly, there may be a need for low cost solutions with reduced complexities for reticle cooling and thermal conditioning in DUV lithography. Thus, the present disclosure provides systems, methods, and devices for thermal conditioning of reticles at a patterning device handling apparatus and a support structure in lithographic apparatuses.

[0007] In some embodiments, a lithographic apparatus includes an illumination system, a support structure, a projection system, and a patterning device handling apparatus. The illumination system is configured to condition a radiation beam. The support structure is constructed to support a patterning device, the patterning device being capable of imparting the radiation beam with a pattern in its cross-section to form a patterned radiation beam. The projection system is configured to project a pattern imparted to the radiation beam by the patterning device onto a target portion of a substrate. The patterning device handling apparatus is configured to handle and position the patterning device. The patterning device handling apparatus includes a gripping device with a plurality of pneumatic lines. The patterning device handling apparatus is configured to position a first surface of the patterning device below the gripping device. The gripping device is configured to apply a first air flow to the patterning device using the plurality of pneumatic lines to thermally condition the patterning device.

[0008] In some embodiments, a patterning device support structure is disclosed. The patterning device support structure includes a patterning area, in which a patterning device is positioned in the patterning area. The patterning device support structure also includes two clamping interfaces arranged on parallel sides of the patterning area. The clamping interfaces each comprise one or more vacuum pads. The two opposite edges of the patterning device are adjacent to the two clamping interfaces, and the one or more vacuum pads are configured to apply an air flow to the patterning device. [0009] In some embodiments, a method of thermally conditioning a patterning device is disclosed. The method includes positioning a first surface of the patterning device below a gripping device of a patterning device handling apparatus, in which the patterning device is coupled to the gripping device, applying a first air flow to the patterning device using a plurality of pneumatic lines in the gripping device, and positioning a second surface of the patterning device in a patterning area of a patterning device support structure, in which the patterning device support structure comprises two clamping interfaces arranged on parallel sides of the patterning area, the clamping interfaces each comprising one or more vacuum pads. The method further includes uncoupling the first surface of the patterning device from the gripping device, and applying a second air flow to the patterning device using the one or more vacuum pads in the clamping interfaces, in which the first and second air flows provide thermal conditioning of the patterning device.

[0010] Further features of the disclosure, as well as the structure and operation of various embodiments of the disclosure, are described in detail below with reference to the accompanying drawings. It is noted that the disclosure is not limited to the specific embodiments described herein. Such embodiments are presented herein for illustrative purposes only. Additional embodiments will be apparent to persons skilled in the relevant art(s) based on the teachings contained herein.

BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES

[0011] The accompanying drawings, which are incorporated herein and form part of the specification, illustrate the present disclosure and, together with the description, further serve to explain the principles of the disclosure and to enable a person skilled in the relevant art(s) to make and use the disclosure.

[0012] FIG. 1A is a schematic illustration of a reflective lithographic apparatus, according to embodiments of the present disclosure.

[0013] FIG. IB is a schematic illustration of a transmissive lithographic apparatus, according to embodiments of the present disclosure.

[0014] FIG. 2 depicts a perspective view of a patterning device support and a gripping device of a patterning device handling apparatus coupled with a patterning device, according to embodiments of the present disclosure.

[0015] FIG. 3 depicts a perspective view of the patterning device support of FIG. 2 with the patterning device positioned on the patterning device support, according to embodiments of the present disclosure.

[0016] FIG. 4 schematically illustrates a patterning device handling apparatus, according to embodiments of the present disclosure.

[0017] FIG. 5 depicts a perspective view of a patterning device positioned at a clamping interface of a patterning device support, according to embodiments of the present disclosure.

[0018] FIG. 6 schematically illustrates a side view of a patterning device at a clamping interface of a patterning device support for thermal conditioning, according to embodiments of the present disclosure.

[0019] FIG. 7 schematically illustrates a side view of a patterning device coupled to a gripping device for thermal conditioning, according to embodiments of the present disclosure.

[0020] FIG. 8 schematically illustrates a side view of a patterning device coupled to a gripping device and positioned at a clamping interface of a patterning device support for thermal conditioning, according to embodiments of the present disclosure.

[0021] FIG. 9 is a flowchart of an exemplary method for providing thermal conditioning of a reticle at the patterning device support, according to embodiments of the present disclosure. [0022] FIG. 10 is a flowchart of an exemplary method for providing thermal conditioning of a reticle through the gripping device and at the patterning device support, according to embodiments of the present disclosure.

[0023] The features of the present disclosure will become more apparent from the detailed description set forth below when taken in conjunction with the drawings, in which like reference characters identify corresponding elements throughout. In the drawings, like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements. Additionally, generally, the left-most digit(s) of a reference number identifies the drawing in which the reference number first appears. Unless otherwise indicated, the drawings provided throughout the disclosure should not be interpreted as to-scale drawings.

DETAILED DESCRIPTION

[0024] This specification discloses one or more embodiments that incorporate the features of this disclosure. The disclosed embodiment(s) merely exemplify the disclosure. The scope of the disclosure is not limited to the disclosed embodiment(s). The disclosure is defined by the claims appended hereto.

[0025] The embodiment(s) described, and references in the specification to “one embodiment,” “an embodiment,” “an example embodiment,” etc., indicate that the embodiment(s) described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is understood that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0026] Spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “on,” “upper” and the like, may be used herein for ease of description to describe one element or feature’ s relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The apparatus may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may likewise be interpreted accordingly. [0027] The term “about” as used herein indicates the value of a given quantity that can vary based on a particular technology. Based on the particular technology, the term “about” can indicate a value of a given quantity that varies within, for example, 10-30% of the value (e.g., ±10%, ±20%, or ±30% of the value).

[0028] Embodiments of the disclosure may be implemented in hardware, firmware, software, or any combination thereof. Embodiments of the 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 read only memory (ROM); random access memory (RAM); magnetic disk storage media; optical storage media; flash memory devices; electrical, optical, acoustical or other forms of propagated signals (e.g., carrier waves, infrared signals, digital signals, etc.), and others. Further, firmware, software, routines, and/or instructions may be described herein as performing certain actions. However, it should be appreciated that such descriptions are merely for convenience and that such actions in fact result from computing devices, processors, controllers, or other devices executing the firmware, software, routines, instructions, etc.

[0029] Before describing such embodiments in more detail, however, it is instructive to present an example environment in which embodiments of the present disclosure may be implemented.

[0030] Example Lithographic Systems

[0031] FIGS. 1A and IB are schematic illustrations of a lithographic apparatus 100 and lithographic apparatus 100’, respectively, in which embodiments of the present disclosure may be implemented. Lithographic apparatus 100 and lithographic apparatus 100’ each include the following: an illumination system (illuminator) IL configured to condition a radiation beam B (e.g., deep ultra violet (DUV) radiation beam or an extreme ultra violet (EUV) radiation beam); a support structure (e.g., a mask table) MT configured to support a patterning device (e.g., a mask, a reticle, or a dynamic patterning device) MA and connected to a first positioner PM configured to accurately position the patterning device MA; and, a substrate table (e.g., a wafer table) WT configured to hold a substrate (e.g., a resist coated wafer) W and connected to a second positioner PW configured to accurately position the substrate W. Lithographic apparatus 100 and 100’ also have a projection system PS configured to project a pattern imparted to the radiation beam B by patterning device MA onto a target portion (e.g., comprising one or more dies) C of the substrate W. In lithographic apparatus 100, the patterning device MA and the projection system PS are reflective. In lithographic apparatus 100’, the patterning device MA and the projection system PS are transmissive.

[0032] The illumination system IL may include various types of optical components, such as refractive, reflective, catadioptric, magnetic, electromagnetic, electrostatic, or other types of optical components, or any combination thereof, for directing, shaping, or controlling the radiation beam B. [0033] The support structure MT holds the patterning device MA in a manner that depends on the orientation of the patterning device MA with respect to a reference frame, the design of at least one of the lithographic apparatus 100 and 100’, and other conditions, such as whether or not the patterning device MA is held in a vacuum environment. The support structure MT may use mechanical, vacuum, electrostatic, or other clamping techniques to hold the patterning device MA. The support structure MT can be a frame or a table, e.g., which can be fixed or movable, as required. By using sensors, the support structure MT can ensure that the patterning device MA is at a desired position, e.g., with respect to the projection system PS. [0034] The term “patterning device” MA should be broadly interpreted as referring to any device that can be used to impart a radiation beam B with a pattern in its cross-section, such as to create a pattern in the target portion C of the substrate W. The pattern imparted to the radiation beam B can correspond to a particular functional layer in a device being created in the target portion C to form an integrated circuit.

[0035] The patterning device MA may be transmissive (as in lithographic apparatus 100’ of

FIG. IB) or reflective (as in lithographic apparatus 100 of FIG. 1A). Examples of patterning devices MA include reticles, masks, programmable mirror arrays, or programmable LCD panels. Masks can include mask types such as binary, alternating phase shift, or attenuated phase shift, as well as various hybrid mask types. In one example, a programmable mirror array can include a matrix arrangement of small mirrors, each of which can be individually tilted so as to reflect an incoming radiation beam in different directions. The tilted mirrors impart a pattern in the radiation beam B, which is reflected by a matrix of small mirrors.

[0036] The term “projection system” PS can encompass any type of projection system, including refractive, reflective, catadioptric, magnetic, electromagnetic and electrostatic optical systems, or any combination thereof, as appropriate for the exposure radiation being used, or for other factors, such as the use of an immersion liquid on the substrate W or the use of a vacuum. A vacuum environment can be used for EUV or electron beam radiation since other gases can absorb too much radiation or electrons. A vacuum environment can therefore be provided to the whole beam path with the aid of a vacuum wall and vacuum pumps.

[0037] Lithographic apparatus 100 and/or lithographic apparatus 100’ can be of a type having two (dual stage) or more substrate tables WT (and/or two or more mask tables). In such “multiple stage” machines, the additional substrate tables WT can be used in parallel, or preparatory steps can be carried out on one or more tables while one or more other substrate tables WT are being used for exposure. In some aspects, the additional table may not be a substrate table WT.

[0038] Referring to FIGS. 1A and IB, the illuminator IL receives a radiation beam B from a radiation source SO. The source SO and the lithographic apparatus 100, 100’ can be separate physical entities, e.g., when the source SO is an excimer laser. In such cases, the source SO is not considered to form part of the lithographic apparatus 100 or 100’, and the radiation beam B passes from the source SO to the illuminator IL with the aid of a beam delivery system BD (in FIG. IB) including, e.g., suitable directing mirrors and or a beam expander. In other cases, the source SO can be an integral part of the lithographic apparatus 100, 100’, e.g., when the source SO is a mercury lamp. The source SO and the illuminator IL, together with the beam delivery system BD, if required, can be referred to as a radiation system.

[0039] The illuminator IL can include an adjuster AD (in FIG. IB) for adjusting the angular intensity distribution of the radiation beam. Generally, at least the outer and or inner radial extent (commonly referred to as “s-outer” and “s-inner,” respectively) of the intensity distribution in a pupil plane of the illuminator can be adjusted. In addition, the illuminator IL can comprise various other components (in FIG. IB), such as an integrator IN and a condenser CO. The illuminator IL can be used to condition the radiation beam B to have a desired uniformity and intensity distribution in its cross section.

[0040] Referring to FIG. 1A, in operation, the radiation beam B is incident on the patterning device (e.g., mask) MA, which is held on the support structure (e.g., mask table) MT, and is patterned by the patterning device MA. In lithographic apparatus 100, the radiation beam B is reflected from the patterning device (e.g., mask) MA. After being reflected from the patterning device (e.g., mask) MA, the radiation beam B passes through the projection system PS, which focuses the radiation beam B onto a target portion C of the substrate W. With the aid of the second positioner PW and position sensor IF2 (e.g., an interferometric device, linear encoder, or capacitive sensor), the substrate table WT can be moved accurately (e.g., so as to position different target portions C in the path of the radiation beam B). Similarly, the first positioner PM and another position sensor IF1 can be used to accurately position the patterning device (e.g., mask) MA with respect to the path of the radiation beam B. Patterning device (e.g., mask) MA and substrate W can be aligned using mask alignment marks Ml, M2 and substrate alignment marks PI, P2.

[0041] Referring to FIG. IB, the radiation beam B is incident on the patterning device (e.g., mask MA), which is held on the support structure MT (e.g., mask table), and is patterned by the patterning device. Having traversed the mask MA, the radiation beam B passes through the projection system PS, which focuses the beam onto a target portion C of the substrate W. The projection system has a pupil conjugate PPU to an illumination system pupil IPU. Portions of radiation emanate from the intensity distribution at the illumination system pupil IPU and traverse a mask pattern without being affected by diffraction at the mask pattern and create an image of the intensity distribution at the illumination system pupil IPU.

[0042] With the aid of the second positioner PW and position sensor IF (e.g., an interferometric device, linear encoder, or capacitive sensor), the substrate table WT can be moved accurately (e.g., so as to position different target portions C in the path of the radiation beam B). Similarly, the first positioner PM and another position sensor (not shown in FIG. IB) can be used to accurately position the mask MA with respect to the path of the radiation beam B (e.g., after mechanical retrieval from a mask library or during a scan).

[0043] In general, movement of the support structure MT can be realized 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 realized using a long- stroke module and a short-stroke module, which form part of the second positioner PW. In the case of a stepper (as opposed to a scanner), the support structure MT can be connected to a short-stroke actuator only or can be fixed. Mask MA and substrate W can be aligned using mask alignment marks Ml, M2, and substrate alignment marks PI, P2. Although the substrate alignment marks (as illustrated) occupy dedicated target portions, they can be located in spaces between target portions (known as scribe-lane alignment marks). Similarly, in situations in which more than one die is provided on the mask MA, the mask alignment marks can be located between the dies.

[0044] Support structure MT and patterning device MA can be in a vacuum chamber V, where an in-vacuum robot IVR can be used to move patterning devices such as a mask in and out of vacuum chamber. Alternatively, when support structure MT and patterning device MA are outside of the vacuum chamber, an out-of-vacuum robot can be used for various transportation operations, similar to the in-vacuum robot IVR. Both the in-vacuum and out-of- vacuum robots need to be calibrated for a smooth transfer of any payload (e.g., mask) to a fixed kinematic mount of a transfer station.

[0045] The lithographic apparatus 100 and 100’ can be used in at least one of the following modes:

[0046] 1. In step mode, the support structure (e.g., mask table) MT and the substrate table

WT are kept 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 shifted in the X and/or Y direction so that a different target portion C can be exposed.

[0047] 2. In scan mode, the support structure (e.g., mask table) MT and the substrate table WT are scanned synchronously while a pattern imparted to the radiation beam B is projected onto a target portion C (i.e., a single dynamic exposure). The velocity and direction of the substrate table WT relative to the support structure (e.g., mask table) MT can be determined by the (de-)magnification and image reversal characteristics of the projection system PS.

[0048] 3. In another mode, the support structure (e.g., mask table) MT is kept substantially stationary holding a 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 can be employed and the programmable patterning device is updated as required after each movement of the substrate table WT or in between successive radiation pulses during a scan. This mode of operation can be readily applied to maskless lithography that utilizes a programmable patterning device, such as a programmable mirror array.

[0049] Combinations and or variations on the described modes of use or entirely different modes of use can also be employed.

[0050] In a further embodiment, lithographic apparatus 100’ includes a deep ultra violet

(DUV) source, which is configured to generate a beam of DUV radiation for DUV lithography. In general, the DUV source is configured in a radiation system, and a corresponding illumination system is configured to condition the DUV radiation beam of the DUV source.

[0051] Exemplary Embodiments of Reticle Handling Apparatus

[0052] Some lithographic apparatuses include a patterning device handling apparatus that exchanges the patterning devices. To load the patterning device on a patterning device support of the lithographic apparatus, a gripping device of the patterning device handling apparatus couples with the patterning device, for example, by using vacuum suction. Then, the patterning device handling apparatus moves the patterning device (for example, by rotating about a turret) towards the patterning device support to load the patterning device.

[0053] FIG. 2 depicts a perspective view of an object support 200 and a gripping device 210 of an object handling apparatus coupled with an object 202, and FIG. 3 depicts a perspective view of object support 200 with object 202 positioned on object support 200, according to embodiments of the present disclosure. In some embodiments, object 202 can be a patterning device for use in a lithographic apparatus, for example, a mask or reticle, or a substrate (for example, a wafer) for use with a lithographic apparatus. In some embodiments, object support 200 can be a patterning device support, a mask table or a reticle stage, or can be a substrate support, for example, a wafer table. In some embodiments, gripping device 210 may comprise a robot arm that uses vacuum suction to pick up and position a reticle in a reticle stage area of object support 200. Gripping device 210 can comprise one or more vacuum units 212 that generate the vacuum suction to couple the reticle to the object handling apparatus.

[0054] In some embodiments, patterning device support 200 can include a patterning area 203

(e.g., a reticle area) where patterning device 202 may be positioned. In some embodiments, patterning device support 200 can include a moveable component 204 configured to move patterning device 202, for example, translation along a plane or out of the plane. For example, as illustrated in FIGs. 2 and 3, patterning device 202 can translate along a plane defined by the x-axis and the y-axis (the X-Y plane). Movable component 204 can be movable relative to a second component (not shown) along a plane substantially parallel to the plane in which patterning device 202 translates. In some embodiments, the second component is movable relative to a reference, for example, a frame or balance mass (not shown). [0055] In some embodiments, movable component 204 is a short-stroke component, and the second component (not shown) is a long-stroke component. A long stroke actuator (not shown) moves the second movable component with respect to the reference. One or more short stroke actuators (not shown) can move movable component 204 with respect to the second movable component. Typically, the short stroke actuators position movable component 204 relative to the second movable component with a relatively high accuracy. The short stroke actuators have a limited working range. Typically, the long stroke actuator has a large working range, for example, the whole working space of patterning device support 200. The long stroke actuator positions the second movable component with a relatively low accuracy. In operation, the long stroke actuator and the second movable component move patterning device 202 to a position within a workable range of the short stroke actuators that includes a desired position of patterning device 202. Then the short stroke actuators and movable component 204 move patterning device 202 to the desired position. In some embodiments, first movable component 204 and the second component can have any suitable shape.

[0056] In some embodiments, patterning device support 200 can include one or more clamping interfaces configured to selectively and securely couple patterning device 202 to moveable component 204. As shown in FIGs. 2 and 3, for example, patterning device support 200 can include a first clamping interface 206a and a second clamping interface 206b. Each clamping interface 206a and 206b can be configured to selectively and substantially couple with patterning device 202 to prevent movement of patterning device 202 relative to moveable component 204.

[0057] In some embodiments, clamping interfaces 206a and 206b may comprise vacuum pads.

In some embodiments, the vacuum pads of clamping interfaces 206a and 206b may be configured such that the vacuum force generated by one of clamping interfaces 206a or 206b is selectively reduced or set equal to about atmospheric pressure while the vacuum force generated by the other clamping interface 206a or 206b is maintained above atmospheric pressure.

[0058] In some embodiments, each clamping interface, for example, clamping interfaces 206a and 206b, can be in fluid communication with a vacuum generator, for example, any suitable device capable of creating a negative pressure at each clamping interface. In some embodiments, clamping interfaces 206a and 206b can be membranes that create, for example, a leaking vacuum seal that securely couples patterning device 202 to moveable component 204. In such membrane embodiments, clamping interfaces 206a and 206b may comprise one or more openings for allowing fluid flow there through to create a vacuum force that pulls patterning device 202 against clamping interfaces 206a and 206b, coupling patterning device 202 to moveable component 204. The vacuum force generates friction between patterning device 202 and clamping interfaces 206a and 206b. This friction can prevent internal stresses of patterning device 202 from being either partially or fully relieved after gripping device 210 releases patterning device 202.

[0059] In some embodiments, patterning device 202 is transferred or exchanged from a gripping device 210 of a patterning device handling apparatus (not shown in FIG. 2) to patterning device support 200 and coupled to movable component 204 for operational use. In some embodiments, the patterning device handling apparatus is a turret-type handling apparatus as schematically illustrated in FIG. 4. In particular, FIG. 4 illustrates a schematic diagram of a patterning device handling apparatus 430, according to embodiments of the present disclosure. In some embodiments, patterning device handling apparatus 430 may be referred to as turret-type handling apparatus. Device handling apparatus 430 can be configured to move a patterning device from a storage location 432 (e.g., from a patterning device handling robot or a reticle library), to patterning device support 200 (e.g., to a position proximal to the clamping interfaces of the patterning device support 200). In some embodiments, patterning device handling apparatus 430 comprises a rotatable turret 434 and at least two gripping devices 210a and 210b attached to turret 434. Patterning device handling apparatus 430 can be configured such that as gripping device 210a positions a patterning device 202a proximal to the clamping interfaces of patterning device support 200, second gripping device 210b is retrieving a second patterning device 202b from storage location 432. Turret 434 can then rotate (not shown in FIG. 4) such that gripping device 210b positions patterning device 202b proximal to the clamping interfaces of the patterning device support 200. This configuration can increase device throughput. [0060] In some embodiments, gripping device 210 couples patterning device 202 to the patterning device handling apparatus 430 as the device handling apparatus 430 moves patterning device 202 close to patterning device support 200. The patterning device 202 may be arranged at a distance from surfaces of clamping interfaces 206a and 206b of patterning device support 200. In some embodiments, patterning device 202 can be uncoupled from gripping device 210. For example, a vacuum generated by vacuum units 212 of gripping device 210 can be fully released to uncouple patterning device 202, and gripping device 210 can be moved out of contact with patterning device 202. [0061] Patterning device 202 can be selectively and securely coupled to patterning device support 200. For example, clamping interfaces 206a and 206b can be activated, for example, by creating a vacuum that couples patterning device 202 to movable component 204 of patterning device support 200, substantially preventing movement of patterning device 202 relative to movable component 204. [0062] FIG. 5 depicts a perspective view of patterning device 502 positioned at the clamping interface(s) (e.g., at clamping interfaces 506a and 506b) of a patterning device support 500, according to some embodiments. In some embodiments, FIG. 5 illustrates patterning device 502 after decoupling from the gripping device of the patterning device handling apparatus (not shown) and positioning patterning device 502 at the clamping interface(s) 506a and 506b. In some embodiments, the clamping interfaces 506a and 506b may be positioned on parallel sides of a reticle area or a patterning area (e.g., patterning area 203) of the patterning device support 500. In some embodiments, clamping interfaces 506a and 506b comprise a plurality of vacuum pads 516.

[0063] Exemplary Embodiments of Reticle Conditioning at a Patterning Device Support

[0064] In some embodiments, it may be desirable to provide systems and methods for thermal conditioning of the reticle utilizing vacuum port hardware in the patterning device support. FIG. 6 illustrates a schematic diagram showing a side view of patterning device 502 at a clamping interface of a patterning device support for thermal conditioning, according to embodiments of the present disclosure. In some embodiments, patterning device support may be a reticle stage.

[0065] In particular, FIG. 6 depicts patterning device 502 coupled to gripping device 510 and positioned at clamping interface 506. In some embodiments, gripping device 510 may be coupled to a reticle backside of the patterning device 502, and the clamping interface 506 may be positioned at the imaging side of the patterning device 502. In some embodiments, clamping interface 506 may represent an exemplary embodiment of clamping interfaces 206a and 206b shown in FIG. 2 and clamping interfaces 506a and 506b shown in FIG. 5. Clamping interface 506 may comprise one or more vacuum pads 516. In some embodiments, it should be appreciated that any number of vacuum pads 516 may be used in clamping interface 506. In some embodiments, vacuum pads 516 may typically be used to provide a vacuum force or suction that pulls patterning device 502 against the clamping interface 506 when coupling the patterning device 502 to the reticle stage. However, in order to provide thermal conditioning, in some embodiments, the vacuum force from vacuum pads 516 may be reversed to provide an air flow 520 that thermally conditions the reticle surface. In some embodiments, vacuum pads 516 may be connected to pneumatic lines that allow for air flow 520 to flow out and thermally condition the patterning device 502 in the reticle stage before a scan. In some embodiments, air flow 520 may comprise clean gas or air that thermally conditions the surface of the patterning device 502. In some embodiments, air flow 520 may comprise extremely clean dry air (XCDA). In some embodiments, air flow 520 may flow perpendicularly to the surface (e.g., the imaging side) of the patterning device 502.

[0066] In some embodiments, the air flow 520 from the vacuum pads 516 may be applied in an open loop system or a closed loop system. In some embodiments, in an open loop system, the vacuum pads 516 may be configured to output an air flow 520 at predetermined times during a reticle exchange operation and prior to a scan, without any feedback. In some embodiments, in a closed loop system, the vacuum pads 516 may be configured to output an air flow 520 on-demand or in response to a detected temperature of the patterning device 502 surface. For example, a temperature sensor may be utilized at the reticle stage to determine or detect a temperature of the surface of the patterning device 502, and determine whether the detected temperature is within a predetermined temperature range. In some embodiments, the predetermined temperature range may comprise a predetermined minimum temperature threshold value and a predetermined maximum temperature threshold value. In some embodiments, a predetermined minimum temperature threshold value of the predetermined temperature range may be about 21.82 °C, and a predetermined maximum temperature threshold value of the predetermined temperature range may be about 22.18 °C. If the temperature is determined to be greater than a predetermined maximum temperature threshold value and/or less than a predetermined minimum temperature threshold value, then the vacuum pads 516 may be configured to apply air flow to the patterning device 502 in response to the determination. In some embodiments, the vacuum pads 516 may apply the air flow 520 until the surface of the patterning device 502 reaches a temperature that is less than or equal to the predetermined maximum temperature threshold value and or greater than or equal to the predetermined minimum temperature threshold value.

[0067] In some embodiments, the systems and methods described herein for thermal conditioning of the reticle by utilizing the vacuum pads in the reticle stage may provide a cost-effective solution with a reduction in mechatronic complexity for reticle thermal conditioning.

[0068] Exemplary Embodiments of Reticle Conditioning in a Reticle Handling Device

[0069] In further embodiments, it may be desirable to provide additional and or alternative thermal conditioning steps prior to a reticle exchange and before a reticle is positioned at the patterning device support. In particular, in some embodiments, a reticle may be stored in a storage location, such as reticle library, where a plurality of reticles may be thermally conditioned by purging air (e.g., extremely clean dry air (XCDA)) through each reticle’s slots in the reticle library. When a reticle is needed for exposure, a robot may remove the reticle from the reticle library and move the reticle to a rotatable turret (e.g., turret 434) of a patterning device handling apparatus (e.g., patterning device handling apparatus 430). In some embodiments, the reticle might not be thermally conditioned after the reticle leaves the reticle library and is placed on the turret of the patterning device handling apparatus. [0070] Thus, it may be desirable to provide methods and systems for thermal conditioning of the reticle when the reticle is on the turret of the patterning device handling apparatus (e.g., reticle handling device).

[0071] FIG. 7 illustrates a side view of a patterning device coupled to a gripping device for thermal conditioning, according to embodiments of the present disclosure. In some embodiments, FIG. 7 shows gripping device 510 of a patterning device handling apparatus (not shown) that is holding patterning device 502 prior to positioning the patterning device 502 on a patterning device support (not shown). In some embodiments, gripping device 510 may be coupled to a reticle backside of the patterning device 502. In some embodiments, gripping device 510 may include a plurality of vacuum lines 525 (e.g., one or more vacuum units 212 shown in FIG. 2) that generate vacuum suction to couple the reticle to the patterning device handling apparatus.

[0072] In some embodiments, the body of the gripping device 510 of the patterning device handling apparatus may be modified to include additional pneumatic lines 530. The pneumatic lines 530 may provide air for thermal conditioning of the patterning device 502. In some embodiments, the pneumatic lines 530 may provide extremely clean dry air (XCDA) to purge the patterning device 502 prior to placing the reticle on the patterning device support. In some embodiments, one or more lines for providing air flow through the pneumatic lines 530 may also be added in the body of the turret of the patterning device handling apparatus (e.g., rotatable turret 434 of patterning device handling apparatus 430).

[0073] Exemplary Embodiments of Reticle Conditioning in a Reticle Handling Device and at the Patterning Device Support

[0074] In some embodiments, the systems and methods described herein for thermal conditioning by using vacuum port hardware of the patterning device support and additional pneumatic lines in the gripping device of the reticle handling device may be used together.

[0075] FIG. 8 schematically illustrates a side view of a patterning device coupled to a gripping device and positioned at a clamping interface of a patterning device support for thermal conditioning, according to embodiments of the present disclosure. In some embodiments, gripping device 510 may be coupled to a reticle backside of the patterning device 502, and the clamping interface 506 may be positioned at the imaging side of the patterning device 502. FIG. 8 shows that the patterning device 502 undergoing two thermal conditioning steps which may occur in tandem. In a first thermal conditioning step, the reticle backside of patterning device 502 may be positioned below gripping device 510, and a first air flow may be applied to the patterning device 502 through the plurality of pneumatic lines 530. The imaging side of the patterning device 502 may then be positioned adjacent to one or more vacuum pads 516 in the patterning device support structure (not shown). In the second thermal conditioning step, the patterning device 502 may be uncoupled from the gripping device 510, and an air flow 520 may be applied to the imaging side of the patterning device 502 through the one or more vacuum pads 516. In some embodiments, a temperature sensor in the patterning device support structure (not shown) may be utilized to determine a temperature of the patterning device 502, and the air flow 520 may be applied to the patterning device 502 in response to the temperature sensor determining a value of the temperature of the patterning device to be above or equal to a predetermined temperature threshold value.

[0076] Example Methods of Operation

[0077] FIG. 9 is a flowchart of an exemplary method 900 for providing thermal conditioning of a reticle at the patterning device support, according to embodiments of the present disclosure. In some embodiments, method 900 may describe the positioning and thermal conditioning of a patterning device at a patterning device support structure of a lithographic apparatus, such as patterning device support, as discussed above with FIGS. 2-6. It should be understood that the operations shown in method 900 are not exhaustive and that other operations can be performed as well before, after, or between any of the illustrated operations. In various embodiments of the present disclosure, the operations of method 900 can be performed in a different order and/or vary.

[0078] In operation 902, a surface of a patterning device is positioned in a patterning area of a patterning device support structure. The patterning device support structure may include two clamping interfaces arranged on parallel sides of the patterning area, and the clamping interfaces may each include one or more vacuum pads. The surface of the patterning device that is positioned in the patterning area may be the imaging side of the patterning device.

[0079] In operation 904, a temperature of the patterning device may be determined by a temperature sensor. The temperature sensor may be located in the patterning device support structure. In operation 906, the temperature sensor determines whether the temperature of the patterning device is within a predetermined temperature range. In some embodiments, the temperature sensor determines whether the temperature is greater than or equal to a predetermined minimum threshold value and less than or equal to a predetermined maximum threshold value.

[0080] If it is determined that the temperature is within the predetermined temperature range

(e.g., the temperature is greater than or equal to a predetermined minimum threshold value and less than or equal to a predetermined maximum threshold value), then the method proceeds back to operation 904, in which the temperature may continue to be monitored. If it is determined that the temperature is not within the predetermined temperature range (e.g., the temperature is less than the predetermined minimum threshold value or greater than the predetermined maximum threshold value), then the method proceeds to operation 908. In operation 908, an air flow may be applied to the patterning device using one or more vacuum pads in the clamping interfaces of the patterning device support structure.

[0081] FIG. 10 is a flowchart of an exemplary method 1000 for providing thermal conditioning of a reticle through the gripping device and at the patterning device support, according to embodiments of the present disclosure. In some embodiments, method 1000 may describe the positioning and thermal conditioning of a patterning device using a patterning device handling apparatus and a patterning device support structure of a lithographic apparatus, such as patterning device handling apparatus and patterning device support, as discussed above with FIGS. 2-4 and 7. It should be understood that the operations shown in method 1000 are not exhaustive and that other operations can be performed as well before, after, or between any of the illustrated operations. In various embodiments of the present disclosure, the operations of method 1000 can be performed in a different order and/or vary.

[0082] In operation 1002, a first surface of a patterning device is positioned below a gripping device of a patterning device handling apparatus. The patterning device may be coupled to the gripping device. The first surface of the patterning device may be the reticle backside of the patterning device. In operation 1004, a first air flow may be applied to the patterning device using a plurality of pneumatic lines in the gripping device.

[0083] In operation 1006, a second surface of the patterning device is positioned in a patterning area of the patterning device support structure. The patterning device support structure may include two clamping interfaces arranged on parallel sides of the patterning area, and the clamping interfaces may each include one or more vacuum pads. The second surface of the patterning device may be the imaging side of the patterning device.

[0084] In operation 1008, the first surface of the patterning device may be uncoupled from the gripping device. In operation 1010, a second air flow may be applied to the patterning device using the one or more vacuum pads in the clamping interfaces. The first and second air flows may allow for thermal conditioning of the patterning device.

[0085] The embodiments may further be described using the following clauses:

1. A lithographic apparatus comprising: an illumination system configured to condition a radiation beam; a support structure constructed to support a patterning device, the patterning device being capable of imparting the radiation beam with a pattern in its cross-section to form a patterned radiation beam; a projection system configured to project the patterned radiation beam onto a target portion of a substrate, and a patterning device handling apparatus configured to handle and position the patterning device, wherein: the patterning device handling apparatus comprises a gripping device with a plurality of pneumatic lines, the patterning device handling apparatus is configured to position a first surface of the patterning device below the gripping device, and the gripping device is configured to apply a first air flow to the patterning device using the plurality of pneumatic lines to thermal condition the patterning device.

2. The lithographic apparatus of clause 1, wherein: the patterning device handling apparatus is further configured to position a second surface of the patterning device in a patterning area of the support structure; the support structure comprises two clamping interfaces arranged on parallel sides of the patterning area; and the two clamping interfaces each comprise one or more vacuum pads.

3. The lithographic apparatus of clause 2, wherein the first surface of the patterning device comprises a reticle backside and the second surface of the patterning device comprises an imaging side.

4. The lithographic apparatus of clause 2, wherein: the patterning device handling apparatus is further configured to uncouple the first surface of the patterning device from the gripping device; and the one or more vacuum pads of the clamping interfaces in the support structure are configured to apply a second air flow to the patterning device.

5. The lithographic apparatus of clause 4, wherein the first and second air flows comprise extremely clean dry air (XCDA).

6. The lithographic apparatus of clause 4, wherein the first and second air flows are perpendicular to the first and second surfaces of the patterning device, respectively.

7. A patterning device support structure comprising: a patterning area, wherein a patterning device is positioned in the patterning area; and two clamping interfaces arranged on parallel sides of the patterning area, the clamping interfaces each comprising one or more vacuum pads, wherein two opposite edges of the patterning device are adjacent to the two clamping interfaces, and wherein the one or more vacuum pads are configured to apply an air flow to the patterning device.

8. The patterning device support structure of clause 7, wherein the patterning device is positioned in the patterning area using a patterning device handling apparatus.

9. The patterning device support structure of clause 7, further comprising: a temperature sensor configured to determine a temperature of the patterning device.

10. The patterning device support structure of clause 9, wherein the one or more vacuum pads are configured to apply the air flow to the patterning device in response to the temperature sensor determining a value of the temperature to be greater than a predetermined maximum threshold value or less than a predetermined minimum threshold value.

11. The patterning device support structure of clause 9, wherein the one or more vacuum pads are configured to apply the air flow until the temperature sensor determines the temperature to be a value less than or equal to a predetermined maximum threshold value and greater than or equal to a predetermined minimum threshold value. 12. The patterning device support structure of clause 7, wherein the air flow comprises extremely clean dry air (XCDA).

13. The patterning device support structure of clause 7, wherein the air flow is perpendicular to a surface of the patterning device.

14. A method of thermally conditioning a patterning device, the method comprising: positioning a first surface of the patterning device below a gripping device of a patterning device handling apparatus, wherein the patterning device is coupled to the gripping device; applying a first air flow to the patterning device using a plurality of pneumatic lines in the gripping device; positioning a second surface of the patterning device in a patterning area of a patterning device support structure, wherein the patterning device support structure comprises two clamping interfaces arranged on parallel sides of the patterning area, the clamping interfaces each comprising one or more vacuum pads; uncoupling the first surface of the patterning device from the gripping device; and applying a second air flow to the patterning device using the one or more vacuum pads in the clamping interfaces, wherein the first and second air flows provide thermal conditioning of the patterning device.

15. The method of clause 14, further comprising: retrieving the patterning device from a storage location comprising a reticle library using a turret of the patterning device handling apparatus prior to positioning of the first surface of the patterning device.

16. The method of clause 15, wherein positioning the second surface of the patterning device comprises rotating the turret of the patterning device handling apparatus such that the gripping device positions the second surface of patterning device at the patterning device support structure.

17. The method of clause 14, wherein the first and second air flows comprise extremely clean dry air (XCDA).

18. The method of clause 14, wherein the first and second air flows are perpendicular to the first and second surfaces of the patterning device, respectively.

19. The method of clause 14, wherein the first surface of the patterning device comprises a reticle backside and the second surface of the patterning device comprises an imaging side.

20. The method of clause 14, further comprising: determining a temperature of the patterning device using a temperature sensor in the patterning device support structure; and applying the second air flow to the patterning device in response to the temperature sensor determining a value of the temperature of the patterning device to be greater than a predetermined maximum threshold value or less than a predetermined minimum threshold value.

[0086] Final Remarks [0087] Although specific reference may be made in this text to a “reticle,” it should be understood that this is just one example of a patterning device and that the embodiments described herein may be applicable to any type of patterning device. Additionally, the embodiments described herein may be used to provide safety support for any object to ensure a clamping failure does not cause the object to fall and damage either itself or other equipment.

[0088] Although specific reference may be made in this text to the use of lithographic apparatus in the manufacture of ICs, it should be understood that the lithographic apparatus described herein may have other applications, such as the manufacture of integrated optical systems, guidance and detection patterns for magnetic domain memories, flat-panel displays, LCDs, thin-film magnetic heads, etc. The skilled artisan will appreciate that, in the context of such alternative applications, any use of the terms “wafer” or “die” herein may be considered as synonymous with the more general terms “substrate” or “target portion”, respectively. The substrate referred to herein may be processed, before or after exposure, in for example a track unit (a tool that typically applies a layer of resist to a substrate and develops the exposed resist), a metrology unit and/or an inspection unit. Where applicable, the disclosure herein may be applied to such and other substrate processing tools. Further, the substrate may be processed more than once, for example in order to create a multi-layer IC, so that the term substrate used herein may also refer to a substrate that already contains multiple processed layers. [0089] Although specific reference may have been made above to the use of embodiments of the disclosure in the context of optical lithography, it will be appreciated that the disclosure can be used in other applications, for example imprint lithography, and where the context allows, is not limited to optical lithography. In imprint lithography a topography in a patterning device defines the pattern created on a substrate. The topography of the patterning device can be pressed into a layer of resist supplied to the substrate whereupon the resist is cured by applying electromagnetic radiation, heat, pressure or a combination thereof. The patterning device is moved out of the resist leaving a pattern in it after the resist is cured.

[0090] It is to be understood that the phraseology or terminology herein is for the purpose of description and not of limitation, such that the terminology or phraseology of the present disclosure is to be interpreted by those skilled in relevant art(s) in light of the teachings herein.

[0091] The term “substrate” as used herein describes a material onto which material layers are added. In some embodiments, the substrate itself can be patterned and materials added on top of it may also be patterned, or may remain without patterning.

[0092] Although specific reference can be made in this text to the use of the apparatus and/or system according to the disclosure in the manufacture of ICs, it should be explicitly understood that such an apparatus and or system has many other possible applications. For example, it can be employed in the manufacture of integrated optical systems, guidance and detection patterns for magnetic domain memories, LCD panels, thin-film magnetic heads, etc. The skilled artisan will appreciate that, in the context of such alternative applications, any use of the terms “reticle,” “wafer,” or “die” in this text should be considered as being replaced by the more general terms “mask,” “substrate,” and “target portion,” respectively.

[0093] While specific embodiments of the disclosure have been described above, it will be appreciated that the disclosure can be practiced otherwise than as described. The description is not intended to limit the disclosure.

[0094] It is to be appreciated that the Detailed Description section, and not the Summary and

Abstract sections, is intended to be used to interpret the claims. The Summary and Abstract sections may set forth one or more but not all exemplary embodiments of the present disclosure as contemplated by the inventor(s), and thus, are not intended to limit the present disclosure and the appended claims in any way.

[0095] The present disclosure has been described above with the aid of functional building blocks illustrating the implementation of specified functions and relationships thereof. The boundaries of these functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternate boundaries can be defined so long as the specified functions and relationships thereof are appropriately performed.

[0096] The foregoing description of the specific embodiments will so fully reveal the general nature of the disclosure that others can, by applying knowledge within the skill of the art, readily modify and/or adapt for various applications such specific embodiments, without undue experimentation, without departing from the general concept of the present disclosure. Therefore, such adaptations and modifications are intended to be within the meaning and range of equivalents of the disclosed embodiments, based on the teaching and guidance presented herein.

[0097] The breadth and scope of the present disclosure should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.

Claims

2. The lithographic apparatus of claim 1, wherein: the patterning device handling apparatus is further configured to position a second surface of the patterning device in a patterning area of the support structure; the support structure comprises two clamping interfaces arranged on parallel sides of the patterning area; and the two clamping interfaces each comprise one or more vacuum pads.

3. The lithographic apparatus of claim 2, wherein the first surface of the patterning device comprises a reticle backside and the second surface of the patterning device comprises an imaging side.

4. The lithographic apparatus of claim 2, wherein: the patterning device handling apparatus is further configured to uncouple the first surface of the patterning device from the gripping device; and the one or more vacuum pads of the clamping interfaces in the support structure are configured to apply a second air flow to the patterning device.

5. The lithographic apparatus of claim 4, wherein the first and second air flows comprise extremely clean dry air (XCDA) and/or wherein the first and second air flows are perpendicular to the first and second surfaces of the patterning device, respectively.

6. A patterning device support structure comprising: a patterning area, wherein a patterning device is positioned in the patterning area; and two clamping interfaces arranged on parallel sides of the patterning area, the clamping interfaces each comprising one or more vacuum pads, wherein two opposite edges of the patterning device are adjacent to the two clamping interfaces, and wherein the one or more vacuum pads are configured to apply an air flow to the patterning device.

7. The patterning device support structure of claim 6, further comprising: a temperature sensor configured to determine a temperature of the patterning device and/or wherein the patterning device is positioned in the patterning area using a patterning device handling apparatus.

8. The patterning device support structure of claim 7, wherein the one or more vacuum pads are configured to apply the air flow to the patterning device in response to the temperature sensor determining a value of the temperature to be greater than a predetermined maximum threshold value or less than a predetermined minimum threshold value, and/or wherein the one or more vacuum pads are configured to apply the air flow until the temperature sensor determines the temperature to be a value less than or equal to a predetermined maximum threshold value and greater than or equal to a predetermined minimum threshold value.

9. The patterning device support structure of claim 6, wherein the air flow comprises extremely clean dry air (XCDA) and or wherein the air flow is perpendicular to a surface of the patterning device.

10. A method of thermally conditioning a patterning device, the method comprising: positioning a first surface of the patterning device below a gripping device of a patterning device handling apparatus, wherein the patterning device is coupled to the gripping device; applying a first air flow to the patterning device using a plurality of pneumatic lines in the gripping device; positioning a second surface of the patterning device in a patterning area of a patterning device support structure, wherein the patterning device support structure comprises two clamping interfaces arranged on parallel sides of the patterning area, the clamping interfaces each comprising one or more vacuum pads; uncoupling the first surface of the patterning device from the gripping device; and applying a second air flow to the patterning device using the one or more vacuum pads in the clamping interfaces, wherein the first and second air flows provide thermal conditioning of the patterning device.

11. The method of claim 10, further comprising: retrieving the patterning device from a storage location comprising a reticle library using a turret of the patterning device handling apparatus prior to positioning of the first surface of the patterning device.

12. The method of claim 11, wherein positioning the second surface of the patterning device comprises rotating the turret of the patterning device handling apparatus such that the gripping device positions the second surface of patterning device at the patterning device support structure.

13. The method of claim 10, wherein the first and second air flows comprise extremely clean dry air (XCDA) and/or wherein the first and second air flows are perpendicular to the first and second surfaces of the patterning device, respectively.

14. The method of claim 10, wherein the first surface of the patterning device comprises a reticle backside and the second surface of the patterning device comprises an imaging side.

15. The method of claim 10, further comprising: determining a temperature of the patterning device using a temperature sensor in the patterning device support structure; and applying the second air flow to the patterning device in response to the temperature sensor determining a value of the temperature of the patterning device to be greater than a predetermined maximum threshold value or less than a predetermined minimum threshold value.