Thermally actuated cooling system

Abstract

Systems, apparatuses, and methods for manufacturing thermally actuated cooling apparatuses are provided. An example method may include providing a cooling member. The cooling member may include a contact plate, a fin extending in a first direction from the contact plate, and a protrusion extending in a second direction from the contact plate. An exemplary method may then include mounting the protrusion to a portion of an extreme ultraviolet (EUV) radiation source. The contact plate may include a first coefficient of thermal expansion (CTE) that is greater than a second CTE of the portion.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Application No. 63 / 335,118, filed on April 26, 2022, entitled “Thermal Actuated Cooling System,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to thermally activated cooling systems, apparatus, and methods of manufacture. Background Art

[0004] A lithographic apparatus is a machine that applies a desired pattern to a substrate (usually to a target portion of the substrate). A lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In that case, a pattern forming device (which can be a mask or a reticle) can be used to produce a circuit pattern to be formed on a single layer of the IC being formed. This pattern can be transferred to a target portion (e.g., a portion including a die, a die, or several dies) on a substrate (e.g., a silicon wafer). The transfer of the pattern is usually performed 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. Conventional lithographic apparatus include so-called steppers, in which each target position is irradiated by exposing the entire pattern to the target position at one time, and so-called scanners, in which each target position is irradiated by scanning a target portion parallel or antiparallel (e.g., opposite to the scanning direction) while simultaneously scanning the radiation beam in a given direction (the "scanning" direction) while scanning the pattern. The pattern may also be transferred from the patterning device to the substrate by printing the pattern onto the substrate.

[0005] As semiconductor manufacturing processes continue to advance, the size of circuit elements has continued to decrease, while the number of functional elements (such as transistors) per device has been steadily increasing for decades, following a trend often referred to as "Moore's Law." To keep up with Moore's Law, the semiconductor industry has been pursuing technologies that can create smaller and smaller features. To project a pattern on a substrate, a lithography device can use electromagnetic radiation. The wavelength of this radiation determines the minimum size of the features patterned on the substrate. Typical wavelengths currently in use are 365nm (i-line), 248nm, 193nm, and 13.5nm.

[0006] Extreme ultraviolet (EUV) radiation, such as electromagnetic radiation having a wavelength of about 50 nanometers (nm) or less (sometimes also referred to as soft x-rays) and including light with a wavelength of about 13.5 nm, can be used in or with a lithographic apparatus to produce extremely small features in or on a substrate (e.g., a silicon wafer). A lithographic apparatus using EUV radiation having a wavelength in the range of 4 nm to 20 nm (e.g., 6.7 nm or 13.5 nm) can be used to form smaller features on a substrate than a lithographic apparatus using radiation having a wavelength of, for example, 193 nm.

[0007] Methods of generating EUV light include, but are not necessarily limited to, converting a material having an element with emission lines in the EUV range, such as xenon (Xe), lithium (Li), or tin (Sn), into a plasma state. For example, in one method known as laser produced plasma (LPP), a plasma can be generated by irradiating a target material, which in the context of an LPP source may be interchangeably referred to as a fuel, such as a material in the form of droplets, sheets, ribbons, streams, or clusters, with an amplified beam of light, which may be referred to as a drive laser. For this process, the plasma is typically generated in a sealed container, such as a vacuum chamber, and monitored using various types of metrology equipment. Summary of the invention

[0008] The present disclosure describes various aspects of systems, apparatus, and methods for making and using thermally actuated cooling systems in extreme ultraviolet (EUV) radiation sources.

[0009] In some aspects, the present disclosure describes a system. The system may include: a cooling member. The cooling member may include a contact plate, a fin extending from the contact plate in a first direction, and a protrusion extending from the contact plate in a second direction and configured to couple the contact plate to a portion of an EUV radiation source. The portion may include a heating element. The contact plate may include a first coefficient of thermal expansion (CTE), the first CTE being greater than a second CTE of the portion.

[0010] In some aspects, the present disclosure describes an apparatus. The apparatus may include a contact plate and a protrusion extending from the contact plate and configured to couple the contact plate to a portion of an EUV radiation source. The protrusion is configured to be in a physically strained relationship with the portion such that when the portion is heated, a first surface of the contact plate is configured to disengage from a second surface of the portion; and when the portion is not exposed to heat, the first surface of the contact plate is configured to contact the second surface of the portion.

[0011] In some aspects, the present disclosure describes a method of manufacturing an apparatus. The method may include providing a cooling member. The cooling member may include a contact plate, a fin extending from the contact plate in a first direction, and a protrusion extending from the contact plate in a second direction. The method may also include mounting the protrusion to a portion of an EUV radiation source. The contact plate may include a first CTE, the first CTE being greater than a second CTE of the portion. In some aspects, when the portion is exposed to heat, the first surface of the contact plate is configured to disengage from the second surface of the portion.

[0012] Other features, structures and operations of various aspects are 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, (multiple) relevant technical personnel will understand other aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate the present disclosure and, together with the description, serve to explain the principles of aspects of the present disclosure and to enable one skilled in the relevant art(s) to make and use aspects of the present disclosure.

[0014] Figure 1A is a schematic diagram of an exemplary reflective lithography apparatus according to some aspects of the present disclosure.

[0015] Figure 1B is a schematic diagram of an exemplary transmissive lithography apparatus according to some aspects of the present disclosure.

[0016] Figure 2 According to some aspects of the present disclosure Figure 1A A more detailed schematic diagram of the reflective lithography apparatus shown in FIG.

[0017] Figure 3 is a schematic diagram of an exemplary lithography cell according to some aspects of the present disclosure.

[0018] Figure 4 is a schematic diagram of an exemplary radiation source for an exemplary reflective lithographic apparatus according to some aspects of the present disclosure.

[0019] Figure 5A and Figure 5B is a schematic diagram of an exemplary thermally actuated cooling system according to some aspects of the present disclosure.

[0020] Figure 6 is a graphical representation of an exemplary conceptual cooling curve produced by adding an exemplary thermally actuated cooling system to a portion of a lithographic apparatus according to some aspects of the present disclosure.

[0021] Figure 7 are exemplary methods of making a device according to some aspects of the present disclosure or portion(s) thereof.

[0022] Figure 8 is an exemplary computer system for implementing some aspects of the present disclosure or portion(s) thereof.

[0023] Features and advantages of the present disclosure will be apparent from the following detailed description set forth in conjunction with the accompanying drawings, wherein like reference numerals identify corresponding elements throughout. In the accompanying drawings, similar reference numerals generally indicate identical, functionally similar, and / or structurally similar elements unless otherwise noted. In addition, the leftmost digit(s) of a reference numeral generally identifies the drawing in which the reference numeral first appears. Unless otherwise noted, the drawings provided throughout the disclosure should not be construed as drawings drawn to scale. DETAILED DESCRIPTION

[0024] This specification discloses one or more embodiments incorporating features of the present disclosure. The disclosed (multiple) embodiments merely describe the present disclosure. The scope of the present disclosure is not limited to the disclosed (multiple) embodiments. The breadth and scope of the present disclosure are defined by the appended claims and their equivalents.

[0025] The described embodiment(s) and references in the specification to "one embodiment", "embodiment", "exemplary embodiment", "example embodiment", etc. indicate that the described embodiment(s) may include specific features, structures, or characteristics, but each embodiment may not necessarily include the specific features, structures, or characteristics. In addition, these phrases do not necessarily refer to the same embodiment. In addition, when specific features, structures, or characteristics are described in conjunction with an embodiment, it should be understood that the effects of these features, structures, or characteristics in conjunction with other embodiments are within the knowledge of those skilled in the art, whether or not explicitly described.

[0026] For ease of description, spatially relative terms, such as "below," "lower," "above," "above," "upper," etc., may be used herein to describe the relationship of one element or feature to other (multiple) elements or (multiple) features shown 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 device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0027] As used herein, the term "about" refers to a value of a given amount that can vary based on a particular technology. The term "about" can refer to a value of a given amount that varies, for example, within 10%-30% of a value (e.g., ±10%, ±20%, or ±30% of a value), based on a particular technology.

[0028] Overview

[0029] In some aspects, EUV radiation source components, such as a droplet generator assembly (DGA), must be cooled before they can be serviced. In one example, a heat sink can be used to dissipate heat from an EUV radiation source by using two thermally mismatched materials in contact with each other, such as a heat sink made of a material that has excellent heat dissipation and is interleaved with components that generate heat. In another example, the EUV radiation source can be cooled using natural convection, forced convection, fins, or Peltier elements (e.g., thermoelectric devices).

[0030] However, these techniques often require additional power or flow input. For example, adding cooling water to cool the DGA can cause excessive vibration, which can adversely affect droplet stability. In another example, adding fins to the DGA to enhance convection can require additional power to maintain operating temperatures during operation, which can put additional stress on the electrical infrastructure and waste energy unnecessarily.

[0031] In addition, the cooling time using these technologies is too long and will extend system downtime. For example, several components on the EUV radiation source operate above the touch-safe temperature and must be cooled before maintenance actions. This cooling time often takes more than an hour, which increases the mean time to repair (MTTR) and additional machine downtime.

[0032] In contrast, some aspects of the present disclosure may provide a thermally actuated cooling system including a heat sink with fins and a threaded post with a stainless steel insert that is torque-fitted into a heat-generating EUV component such as a DGA, thereby creating strain. When heated, the heat sink expands, and when the strain of the threads is released, the heat sink lifts away from the heat-generating EUV component.

[0033] In some aspects, the present disclosure provides a thermally actuated cooling system, the thermally actuated cooling system comprising a cooling member coupled to a molybdenum member by a threaded protuberance, the threaded protuberance being partially surrounded by an insert and received in a receptacle in the molybdenum member, the cooling member comprising a contact plate and a rod extending from the contact plate and having a higher CTE than the molybdenum. The threaded protuberance is in a physical strain relationship with the molybdenum member such that heating causes a contact plate surface to disengage from a molybdenum member surface and cooling causes the contact plate surface to contact a molybdenum member surface to cool the molybdenum member.

[0034] There are many exemplary aspects of the thermally actuated cooling systems, apparatuses, and methods disclosed herein. For example, aspects of the present disclosure provide faster cooling times for cooling components associated with EUV radiation sources in preparation for maintenance actions. In yet another example, the present disclosure provides a reduction in MTTR and mean time between intervals (MTBI).

[0035] However, before describing these aspects in greater detail, it is helpful to present an exemplary environment in which aspects of the present disclosure may be implemented.

[0036] Exemplary Lithography System

[0037] Figure 1A and Figure 1B 1 and 2 are schematic diagrams of a lithographic apparatus 100 and a lithographic apparatus 100', respectively, in which aspects of the present disclosure may be implemented. Figure 1A and Figure 1B As shown, the lithography apparatus 100 and 100' are shown from a perspective (e.g., a side view perspective) perpendicular to the XZ plane (e.g., the X-axis points to the right, the Z-axis points upward, and the Y-axis points toward the page away from the observer), while the pattern forming device MA and the substrate W are presented from another perspective (e.g., a top view perspective) perpendicular to the XY plane (e.g., the X-axis points to the right, the Y-axis points upward, and the Z-axis points toward the page toward the observer).

[0038] In some aspects, the lithographic apparatus 100 and / or the lithographic apparatus 100' may include one or more of the following structures: an illumination system IL (e.g., an illuminator) configured to condition a radiation beam B (e.g., a deep ultraviolet (DUV) radiation beam or an extreme ultraviolet (EUV) radiation beam); a support structure MT (e.g., a mask stage) configured to support a patterning device MA (e.g., a mask, a reticle, or a dynamic patterning device) and connected to a first positioner PM configured to accurately position the patterning device MA; and a substrate holder, such as a substrate table WT (e.g., a wafer stage) configured to hold a substrate W (e.g., a resist-coated wafer) and connected to a second positioner PW configured to accurately position the substrate W. The lithographic apparatus 100 and 100' also has a projection system PS (e.g., a refractive projection lens system) configured to project a pattern imparted by the patterning device MA to the radiation beam B onto a target portion C of the substrate W (e.g., a portion including one or more dies). In lithographic apparatus 100, patterning device MA and projection system PS are reflective. In lithographic apparatus 100', patterning device MA and projection system PS are transmissive.

[0039] In some aspects, in operation, the illumination system IL can receive a radiation beam from a radiation source SO (e.g., via Figure 1B The illumination system IL may include various types of optical structures, such as refractive, reflective, catadioptric, magnetic, electromagnetic, electrostatic, and other types of optical components, or any combination thereof, for directing, shaping, or controlling radiation. In some aspects, the illumination system IL may be configured to condition the radiation beam B so that it has a desired spatial and angular intensity distribution in its cross-section at the plane of the pattern forming device MA.

[0040] In some aspects, the support structure MT can hold 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 can use mechanical, vacuum, electrostatic or other clamping techniques to hold the patterning device MA. The support structure MT can be a frame or a stage, for example, the support structure MT can be fixed or movable as desired. By using sensors, the support structure MT can ensure that the patterning device MA is at a desired position, for example relative to the projection system PS.

[0041] 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 a radiation beam B so as to form a pattern in a target portion C of a substrate W. The pattern imparted to the radiation beam B may correspond to a specific functional layer in a device to be formed in the target portion C to form an integrated circuit.

[0042] In some aspects, the patterning device MA can be a transmissive type (e.g. Figure 1B The pattern forming device MA in the lithographic apparatus 100' in the embodiment of the present invention is a reflective type (such as Figure 1A The pattern forming device MA in the lithographic apparatus 100 in FIG. 1 ). The pattern forming device MA may include various structures, such as a reticle, a mask, a programmable mirror array, a programmable LCD panel, other suitable structures, or a combination thereof. The mask may include mask types such as binary, alternating phase shift, and attenuated phase shift, as well as various hybrid mask types. In one example, the programmable mirror array may include a matrix arrangement of small mirrors, each of which may be individually tilted so as to reflect an incident radiation beam in different directions. The tilted mirrors may impart a pattern in a radiation beam B reflected by the matrix of small mirrors.

[0043] The term "projection system PS" should be interpreted broadly and may cover any type of projection system, including refractive, reflective, catadioptric, magnetic, anamorphic, electromagnetic and electrostatic optical systems, or any combination thereof, that is suitable for the exposure radiation used, and / or for other factors such as the use of immersion liquid (e.g., on substrate W) or the use of vacuum. A vacuum environment may be used for EUV or electron beam radiation, as other gases may absorb too much radiation or electrons. Therefore, with the help of vacuum walls and vacuum pumps, a vacuum environment may be provided for the entire beam path. Furthermore, in some aspects, any use of the term "projection lens" herein may be interpreted as being synonymous with the more general term "projection system" PS.

[0044] In some aspects, the lithographic apparatus 100 and / or the lithographic apparatus 100' may be of a type having two (e.g., "dual stage") or more substrate tables WT and / or two or more mask tables. In such a "multi-stage" machine, the additional substrate tables WT may be used in parallel, or preparatory steps may be performed on one or more tables while one or more other substrate tables WT are used for performing exposures. In one example, preparatory steps for subsequent exposure of a substrate W may be performed on a substrate W located on one of the substrate tables WT, with another substrate W located on another of the substrate tables WT being used to expose a pattern on the other substrate W. In some aspects, the additional table may not be a substrate table WT.

[0045] In some aspects, the lithographic apparatus 100 and / or the lithographic apparatus 100' may include a measurement table in addition to the substrate table WT. The measurement table may be arranged to hold a sensor. The sensor may be arranged to measure a property of the projection system PS, a property of the radiation beam B, or both. In some aspects, the measurement table may hold a plurality of sensors. In some aspects, the measurement table may be moved under the projection system PS when the substrate table WT is away from the projection system PS.

[0046] In some aspects, the lithographic apparatus 100 and / or lithographic apparatus 100' may also be of a type 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 PS and the substrate W. Immersion liquid may also be applied to other spaces in the lithographic apparatus, such as the space between the patterning device MA and the projection system PS. Immersion techniques are provided for increasing the numerical aperture of the projection system. The term "immersion" as used herein does not mean that structures 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. Various immersion techniques are described in U.S. Patent No. 6,952,253, entitled "Lithographic Apparatus and Device Manufacturing Method," issued on October 4, 2005, which is incorporated herein by reference in its entirety.

[0047] refer to Figure 1A and Figure 1B , the illumination system IL receives a radiation beam B from a radiation source SO. For example, when the radiation source SO is an excimer laser, the radiation source SO and the lithographic apparatus 100 or 100' may be separate entities. In such a case, the radiation source SO is not considered to form a part of the lithographic apparatus 100 or 100', and the radiation beam B is delivered to the lithographic apparatus 100 or 100' with the aid of a beam delivery system BD (e.g., a beam expander) comprising, for example, suitable directional mirrors and / or a beam expander. Figure 1B The radiation source SO and the illuminator IL together with the beam delivery system BD (when necessary) are referred to as a radiation system.

[0048] In some aspects, the illumination system IL can include an adjuster AD for adjusting the angular intensity distribution of the radiation beam. Typically, at least the outer radial extent and / or the inner radial extent (commonly referred to as "σ-outer" and "σ-inner", respectively) of the intensity distribution in a pupil plane of the illuminator can be adjusted. In addition, the illumination system IL can include various other components, such as an integrator IN and a radiation collector CO (e.g., a condenser or collector optics). In some aspects, the illumination system IL can be used to adjust the radiation beam B to have a desired uniformity and intensity distribution in its cross-section.

[0049] refer to Figure 1A In operation, a radiation beam B may be incident on a patterning device MA (e.g., a mask, a reticle, a programmable mirror array, a programmable LCD panel, any other suitable structure, or a combination thereof), which may be held on a support structure MT (e.g., a mask stage), and may be patterned by a pattern (e.g., a design layout) present on the patterning device MA. In the lithographic apparatus 100, the radiation beam B may be reflected from the patterning device MA. Having traversed the patterning device MA (e.g., after reflecting from the patterning device MA), the radiation beam B may pass through a projection system PS, which may focus the radiation beam B onto a target portion C of a substrate W or a sensor disposed at a stage.

[0050] In some aspects, with the aid of a second positioner PW and a position sensor IF2 (e.g. an interferometry device, a linear encoder, or a capacitive sensor), the substrate table WT can be accurately moved, for example, so as to position different target portions C in the path of the radiation beam B. Similarly, the patterning device MA can be accurately positioned relative to the path of the radiation beam B using a first positioner PM and another position sensor IF1 (e.g. an interferometry device, a linear encoder, or a capacitive sensor).

[0051] In some aspects, mask alignment marks M1 and M2 and substrate alignment marks P1 and P2 can be used to align patterning device MA with substrate W. Although Figure 1A and Figure 1B The substrate alignment marks P1 and P2 are shown occupying dedicated target portions, but the substrate alignment marks P1 and P2 can be located in the space between the target portions. The substrate alignment marks P1 and P2 are called scribe alignment marks when they are located between the target portions C. The substrate alignment marks P1 and P2 can also be arranged in the target portion C area like in-die marks. These in-die marks can also be used as metrology marks, for example for overlay measurement.

[0052] In some aspects, for the purpose of illustration and not limitation, one or more figures in this article may use a Cartesian coordinate system. A Cartesian coordinate system includes three axes: an X-axis; a Y-axis; and a Z-axis. Each of the three axes is orthogonal to the other two axes (e.g., the X-axis is orthogonal to the Y-axis and the Z-axis, the Y-axis is orthogonal to the X-axis and the Z-axis, and the Z-axis is orthogonal to the X-axis and the Y-axis). A rotation around the X-axis is referred to as an Rx rotation. A rotation around the Y-axis is referred to as an Ry rotation. A rotation around the Z-axis is referred to as an Rz rotation. In some aspects, the X-axis and the Y-axis define a horizontal plane, while the Z-axis is in a vertical direction. In some aspects, the orientation of the Cartesian coordinate system may be different, for example, the Z-axis may have a component along the horizontal plane. In some aspects, another coordinate system may be used, such as a cylindrical coordinate system.

[0053] refer to Figure 1B , the radiation beam B is incident on the patterning device MA held on the support structure MT and is patterned by the patterning device MA. After traversing the patterning device MA, the radiation beam B passes through the projection system PS, which focuses the beam onto a target portion C of the substrate W. In some aspects, the projection system PS can have a pupil that is conjugate to the illumination system pupil IPU. In some aspects, portions of the radiation can be emitted at the intensity distribution at the illumination system pupil IPU and traverse the mask pattern without being affected by diffraction at the mask pattern MP and form an image of the intensity distribution at the illumination system pupil IPU.

[0054] 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 diffraction beam generated from the mask pattern MP by radiation from an intensity distribution. For example, the mask pattern MP may include an array of lines and spaces. Diffraction of radiation at the array that is different from the zero-order diffraction produces a diverted diffraction beam that changes direction in a direction perpendicular to the line. The reflected light (e.g., the zero-order diffraction beam) traverses the pattern without any change in the propagation direction. The zero-order diffraction beam traverses an upper lens or upper lens group of the projection system PS, upstream of the pupil conjugate PPU of the projection system PS, to reach 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. In some aspects, the aperture device PD may be disposed at or substantially disposed at a plane including the pupil conjugate PPU of the projection system PS.

[0055] The projection system PS is arranged to capture not only the zeroth order diffraction beam, but also the first order diffraction beam or the first and higher order diffraction beams (not shown) by means of a lens or lens group. Some aspects are described in U.S. Patent No. 7,511,799, entitled "Photolithographic Projection Apparatus and Device Manufacturing Method", issued on March 31, 2009, which is incorporated herein by reference.

[0056] In some aspects, with the help of a second positioner PW and a position sensor IFD (e.g., an interferometry device, a linear encoder, a capacitive sensor), the substrate table WT can be accurately moved, for example in order to position different target portions C at focus and alignment positions in the path of the radiation beam B. Similarly, the substrate table WT can be accurately moved using a first positioner PM and another position sensor (e.g., an interferometry device, a linear encoder, a capacitive sensor) Figure 1B The patterning device MA may be accurately positioned relative to the path of the radiation beam B (e.g. after mechanical retrieval from a mask library, or during scanning) using mask alignment marks M1 and M2 and substrate alignment marks P1 and P2.

[0057] Typically, movement of the support structure MT may 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 may 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 support structure MT may be connected only to the short-stroke actuator, or may be fixed. Mask alignment marks M1, M2 and substrate alignment marks P1, P2 may be used to align the pattern forming device MA with the substrate W. Although the substrate alignment marks (as shown) occupy dedicated target portions, the substrate alignment mark marks may be located in the space between target portions (e.g. scribe alignment marks). Similarly, in the case where more than one die is arranged on the pattern forming device MA, the mask alignment marks M1 and M2 may be located between the dies.

[0058] The support structure MT and the patterning device MA may be located in a vacuum chamber V, wherein an intra-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 support structure MT and the patterning device MA are located outside the vacuum chamber, various transport operations may be performed using an extra-vacuum robot, similar to the intra-vacuum robot IVR. In some cases, both the intra-vacuum robot and the extra-vacuum robot may need to be calibrated in order to smoothly transfer any payload (e.g., a mask) to the fixed kinematic support of the transfer station.

[0059] In some aspects, the lithographic apparatus 100 and 100' can be used in at least one of the following modes:

[0060] 1. In step mode, while the support structure MT and the substrate table WT are held substantially stationary, the entire pattern imparted to the radiation beam B is projected once onto a target portion C (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.

[0061] 2. In scan mode, the support structure MT and 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 speed and direction of the substrate table WT relative to the support structure MT (e.g. a mask table) may be determined by the (de-)magnification and image reversal characteristics of the projection system PS.

[0062] 3. In another mode, the support structure MT is held substantially stationary, thereby holding the programmable patterning device MA, 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 employed, and the programmable patterning device updated as required after each movement of the substrate table WT, or between successive radiation pulses during a scan. This mode of operation may be readily applicable to maskless lithography using a programmable patterning device MA, such as a programmable mirror array.

[0063] In some aspects, the lithographic apparatus 100 and 100 ′ may employ combinations and / or variations of the modes of use described above, or entirely different modes of use.

[0064] In some aspects, such as Figure 1A As shown, the lithographic apparatus 100 may include an EUV radiation source configured to generate an EUV radiation beam B for EUV lithography. Generally, the EUV radiation source may be configured in a radiation source SO, and a corresponding illumination system IL may be configured to condition the EUV radiation beam B of the EUV radiation source.

[0065] Figure 2 The lithographic apparatus 100 is shown in more detail, comprising a radiation source SO (eg, a source collector device), an illumination system IL, and a projection system PS. Figure 2 As shown, the lithographic apparatus 100 is shown from a perspective (eg, a side view perspective) that is perpendicular to the XZ plane (eg, the X-axis points to the right and the Z-axis points upward).

[0066] The radiation source SO is constructed and arranged so that a vacuum environment can be maintained in the closed structure 220. The radiation source SO includes a source chamber 211 and a collector chamber 212, and is configured to generate and emit EUV radiation. EUV radiation can be generated by a gas or vapor (e.g., xenon (Xe) gas, lithium (Li) vapor, or tin (Sn) vapor), wherein an EUV radiation emitting plasma 210 is generated to emit radiation in the EUV range of the electromagnetic spectrum. The at least partially ionized EUV radiation emitting plasma 210 can be formed, for example, by the discharge of a laser beam. Radiation can be effectively generated using, for example, a partial pressure of about 10.0 Pascal (Pa) of Xe gas, Li vapor, Sn vapor, or any other suitable gas or vapor. In some aspects, an excited tin plasma is provided to generate EUV radiation.

[0067] Radiation emitted by EUV radiation emitting plasma 210 enters collector chamber 212 from source chamber 211 via optional gas barrier or contaminant trap 230 (e.g., also referred to as contaminant barrier or fin trap in some cases), which is positioned in or behind an opening of source chamber 211. Contaminant trap 230 may include a channel structure. Contaminant trap 230 may also include a gas barrier or a combination of a gas barrier and a channel structure. Contaminant trap 230 is also referred to herein as including at least a channel structure.

[0068] The collector chamber 212 may include a radiation collector CO (e.g., a concentrator or collector optics), 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. Radiation passing through the radiation collector CO may be reflected by a grating spectral filter 240 to be focused at a virtual source point INTF. The virtual source point INTF is often referred to as an intermediate focus, and the source collector device is arranged so that the virtual source point INTF is positioned at or near an opening 219 of the enclosure structure 220. The virtual source point INTF is an image of the EUV radiation emitting plasma 210. The grating spectral filter 240 may be used to suppress infrared (IR) radiation.

[0069] 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 which are 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 is imaged by the projection system PS via reflective elements 228, 229 onto a substrate W held by a wafer stage or substrate table WT.

[0070] Typically, there may be more elements in the illumination system IL and the projection system PS than shown. Optionally, a grating spectral filter 240 may be present depending on the type of lithographic apparatus. Furthermore, there may be more than Figure 2 For example, compared to the reflectors shown in Figure 2 As shown in , one to six further reflective elements may be present in projection system PS.

[0071] Radiation collector CO (such as Figure 2) is depicted as a nested collector with grazing incidence reflectors 253, 254 and 255, which is only an example of a collector (or collector mirror). The grazing incidence reflectors 253, 254 and 255 are arranged axially symmetrical around the optical axis O, and this type of radiation collector CO is preferably used in combination with a discharge produced plasma (DPP) source.

[0072] Exemplary Lithography Cell

[0073] Figure 3 A lithography unit 300, sometimes also referred to as a lithography cell or cluster, is shown. Figure 3 As shown, the lithography unit 300 is shown from a perspective (eg, a top-down perspective) perpendicular to the XY plane (eg, the X-axis points to the right and the Y-axis points upward).

[0074] 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 processes and post-exposure processes on the substrate. For example, these devices may include a spin coater SC for depositing a resist layer, a developer DE for developing the exposed resist, a chill plate CH, and a baking plate BK. A substrate transport device (e.g., a robot) RO picks up a substrate from input / output ports I / O1 and I / O2, moves the substrate between different process devices, and transfers the substrate to a feed table LB of the lithography apparatus 100 or 100'. These devices, often collectively referred to as tracks, are under the control of a track control unit TCU, which itself is controlled by a management control system SCS, which also controls the lithography apparatus via a lithography control unit LACU. Therefore, different devices may be operated to maximize yield and processing efficiency.

[0075] Exemplary Radiation Sources

[0076] Figure 4 , for a reflective lithography apparatus (e.g., Figure 1A An example of a radiation source SO of a lithographic apparatus 100. Figure 4 As shown, as described below, the radiation source SO is shown from a perspective perpendicular to the XY plane (eg, a top-down perspective).

[0077] Figure 4The radiation source SO shown is of a type that may be referred to as a laser produced plasma (LPP) source. The laser system 401 may include, for example, a carbon dioxide (CO2) laser, and the laser system 401 is arranged to deposit energy into a fuel target 403' (such as, one or more discrete tin (Sn) droplets) through one or more laser beams 402, which are provided from a fuel target generator 403 (e.g., a fuel emitter, a droplet generator assembly (DGA)). According to some aspects, the laser system 401 may be a pulsed, continuous wave, or quasi-continuous wave laser, or may be operated in a pulsed, continuous wave, or quasi-continuous wave laser manner. The trajectory of the fuel target 403' (e.g., droplets) emitted from the fuel target generator 403 may be parallel to the X axis. According to some aspects, the one or more laser beams 402 propagate in a direction parallel to the Y axis, which is perpendicular to the X axis. The Z axis is perpendicular to the X and Y axes and generally extends into the plane of the page (or extends out of the plane of the page), but in other aspects, other configurations are used. In some embodiments, laser beam 402 may propagate in directions other than parallel to the Y-axis (eg, in directions other than perpendicular to the X-axis direction of the trajectory of fuel target 403 ′).

[0078] In some aspects, the one or more laser beams 402 may include a pre-pulse laser beam and a main pulse laser beam. In these aspects, the laser system 401 may be configured to hit each fuel target 403' with a pre-pulse laser beam to produce a modified fuel target. The laser system 401 may also be configured to hit each modified fuel target with a main pulse laser beam to produce plasma 407.

[0079] Although reference is made to tin in the following description, any suitable target material may be used. For example, the target material may be in liquid form, and may be, for example, a metal or alloy. The fuel target generator 403 may include a nozzle configured to direct, for example, tin (e.g., discrete droplets) in the form of a fuel target 403' along a trajectory toward the plasma formation region 404. In the remainder of this specification, references to "fuel," "fuel target," or "fuel droplets" should be understood to refer to the target material (e.g., droplets) emitted by the fuel target generator 403. The fuel target generator 403 may include a fuel emitter. One or more laser beams 402 are incident on a target material (e.g., tin) at the plasma formation region 404. Depositing laser energy into the target material generates a plasma 407 at the plasma formation region 404. During de-excitation and recombination of electrons and ions of the plasma, radiation (including EUV radiation) is emitted from the plasma 7.

[0080] EUV radiation is collected and focused by a radiation collector 405 (e.g., radiation collector CO). In some aspects, radiation collector 405 can include a near normal incidence radiation collector (sometimes more generally referred to as a normal incidence radiation collector). Radiation collector 405 can be a multi-layer structure arranged to reflect EUV radiation (e.g., EUV radiation having a desired wavelength, such as about 13.5 nm). According to some aspects, radiation collector 405 can be an elliptical configuration with two focal points. As discussed herein, a first focal point can be at plasma formation region 404, and a second focal point can be at intermediate focus 406.

[0081] In some aspects, the laser system 401 can be located relatively far from the radiation source SO. In this case, one or more laser beams 402 can be delivered from the laser system 401 to the radiation source SO with the aid of a beam delivery system (not shown) including, for example, suitable directing mirrors and / or beam expanders and / or other optical devices. The laser system 401 and the radiation source SO can be considered together as a radiation system.

[0082] The radiation reflected by the radiation collector 405 forms a radiation beam B. The radiation beam B is focused at a point (e.g., intermediate focus 6) to form an image of the plasma formation region 4, which serves as a virtual radiation source for the illumination system IL. The point at which the radiation beam B is focused may be referred to as an intermediate focus (IF) (e.g., intermediate focus 406). The radiation source SO is arranged such that the intermediate focus 406 is located at or adjacent to an opening 408 in an enclosure 409 of the radiation source SO.

[0083] A radiation beam B is passed from a radiation source SO to an illumination system IL which is configured to condition the radiation beam B. The radiation beam B is passed from the illumination system IL and is incident on a patterning device MA held by a support structure MT. The patterning device MA reflects and patterns the radiation beam B. After reflection from the patterning device MA, the patterned radiation beam B enters a projection system PS. The projection system comprises a plurality of mirrors which are configured to project the radiation beam B onto a substrate W held by a substrate table WT. The projection system PS may apply a reduction factor to the radiation beam so as to form an image having features which are smaller than corresponding features on the patterning device MA. For example, a reduction factor of 4 may be applied. Although in Figure 2 The projection system PS is shown in FIG. 5 as having two mirrors, but the projection system may include any number of mirrors (eg, six mirrors).

[0084] The radiation source SO may also include Figure 4 For example, a spectral filter may be provided in the radiation source SO. The spectral filter may substantially transmit EUV radiation but substantially block radiation of other wavelengths, such as infrared radiation.

[0085] The radiation source SO (or radiation system) may also include a fuel target imaging system to obtain an image of a fuel target (e.g., a droplet) in the plasma formation region 404, or more specifically, to obtain an image of a shadow of a fuel target. The fuel target imaging system may detect light diffracted from the edge of the fuel target. The application of an image of a fuel target hereinafter should also be understood as a reference to an image of a shadow of a fuel target or an image of a diffraction pattern caused by a fuel target.

[0086] The fuel target imaging system may include a photodetector, such as a CCD array or a CMOS sensor, but it should be understood that any imaging device suitable for obtaining an image of the fuel target may be used. It should be understood that the fuel target imaging system may also include optical components other than the photodetector, such as one or more lenses. For example, the fuel target imaging system may include a camera 410, such as a combination of a light sensor or photodetector and one or more lenses. The optical components may be selected so that the light sensor or camera 410 obtains near-field images and / or far-field images. The camera 410 may be located at any suitable position within the radiation source SO from which the camera can see the plasma formation region 404 and one or more markers ( Figure 4 410). However, in some aspects, it may be desirable to position camera 410 away from the propagation path of one or more laser beams 402, and away from the trajectory of the fuel target emitted from fuel target generator 403, to avoid damaging camera 410. According to some aspects, camera 410 is configured to provide an image of the fuel target to controller 411 via connection 412. Connection 412 is shown as a wired connection, but it should be understood that connection 412 (and other connections mentioned herein) can be implemented as a wired connection or a wireless connection or a combination thereof.

[0087] like Figure 4 As shown, the radiation source SO may include a fuel target generator 403, which is configured to generate fuel targets 403' (e.g., discrete tin droplets) and emit the fuel targets 403' toward the plasma formation region 404. The radiation source SO may also include a laser system 401, which is configured to hit one or more fuel targets 403' with one or more laser beams 402 to generate plasma 407 at the plasma formation region 404. The radiation source SO may also include a radiation collector 405 (e.g., a radiation collector CO), which is configured to collect radiation emitted by the plasma 407.

[0088] Exemplary Thermally Actuated Cooling System

[0089] In some aspects, the lithographic apparatus 100 or any of the various components of the lithographic apparatus 100 including the radiation source SO can include a thermally activated cooling system as described further below.

[0090] Figure 5A and Figure 5B is a schematic diagram of a thermally actuated cooling system 500 according to some aspects of the present disclosure.

[0091] like Figure 5A As shown, the thermally actuated cooling system 500 may include a cooling member 502. For example, the cooling member 502 may include a contact plate 504, a fin 506 extending from the contact plate 504 along a first direction (e.g., along a positive Z-axis), and a fin 506 extending from the contact plate 504 along a second direction (e.g., substantially opposite to the first direction, such as along a negative Z-axis) and configured to couple the contact plate 504 to an EUV radiation source (e.g., Figure 4 508 of a portion 512 of a radiation source 504 (e.g., a DGA) is shown. The protrusion 508 can have various suitable shapes and sizes corresponding to the receiving portion 514. For example, the portion 512 can include the fuel target generator 403 (e.g., DGA), any other suitable part, component, or structure, or any portion thereof.

[0092] In some aspects, the fins 506 can include rods. According to other aspects, the fins 506 can take other shapes (such as, bent or curved), they can include various aspect ratios and sizes, and can be spaced at various distances from each other. Various numbers of fins in various arrangements can extend from the contact plate 504. In some aspects, the protrusion 508 can include a threaded rod or post. In some aspects, the protrusion 508 can also be configured to be partially surrounded by an annular member 516 and disposed in a receptacle 514 of the portion 512. In some aspects, the receptacle 514 can include a threaded hole. In some aspects, the receptacle 514 can be threadedly engaged with the protrusion 508. The receptacle 514 can have various depths and diameters corresponding to the protrusion 508. In some aspects, the annular member 516 can include a stainless steel insert (e.g., an N60 insert). In some aspects, the portion 512 can also include a countersunk hole 518 having a precisely controlled depth 520. As Figure 5B As shown and described, the counterbore 518 may limit contact between the cooling member 502 and the portion 512 to the annular member 516 when the contact plate 504 is disengaged from the portion 512 .

[0093] In some aspects, the contact plate 504 can have a first CTE that is greater than a second CTE of the portion 512. For example, the contact plate 504 can include aluminum and have a CTE of about 22.0 to 24.0×10 -6 K-1 The first CTE of portion 512 may include molybdenum and have a CTE of about 4.0 to 6.0×10 -6 K -1 Thus, the second CTE of portion 512 can be approximately 75% to 85% lower than the first CTE of contact plate 504. According to other aspects, contact plate 504 and portion 512 can be formed of various other materials, and various other suitable CTEs and relative CTEs can be used.

[0094] In some aspects, protrusion 508 can be configured to be in a physically strained relationship with portion 512 .

[0095] In some aspects, portion 512 can include heating element 522. Heating element 522 can be various cartridge heaters, ceramic heaters, etc. In some aspects, portion 512 can include additional heating elements. In some aspects, heating element 522 can be activated independently of the EUV radiation source. For example, heating element 522 can be turned on before EUV production begins and can remain on until after EUV production ends. Heating element 522 can heat portion 512 and protrusion 508.

[0096] In some embodiments, the controller may activate the heating element 522. In some aspects, the controller 411 may be used to activate the heating element 522. In some aspects, another controller (not shown) may be coupled to the heating element 522. The controller may control a switch configured to turn the heating element 522 on or off. The controller may be configured to control the heating element 522 based on the operating state of the radiation source SO. For example, the controller may turn on the heating element 522 when the radiation source SO is turned on or before the radiation source SO is turned on (e.g., based on a preset schedule). The controller may turn off the heating element 522 when the radiation source SO is turned off or after a preset time period after the radiation source is turned off.

[0097] In some embodiments, a thermocouple 524 (or other temperature measuring device) can be coupled to the heating element 522. In some aspects, the portion 512 can include the thermocouple 524. In some aspects, the thermocouple 524 can also be coupled to a controller. The thermocouple 524 can be used in a control loop with the heating element 522 to maintain a target temperature. In some embodiments, the controller can compare the temperature received from the thermocouple 524 to the target temperature. The controller can turn the heating element 522 on or off based on the comparison result. Figure 5A The location of the heating element 522 in FIG. 5 is for illustration purposes only. The heating element and thermocouple 524 may be located at other locations in the portion 512 .

[0098] Portion 512 may operate at elevated temperatures and thus may be heated in a variety of other ways.

[0099] For example, Figure 5B As shown, when portion 512 is heated, such as when portion 512 is exposed to heat from heating element 522, first surface 503 of contact plate 504 is configured to disengage from second surface 513 of portion 512 (e.g., to stop additional cooling of portion 512 by fins 506 during EUV radiation generating operation). In another example, as Figure 5A As shown, the first surface 503 of the contact plate 504 is configured to contact the second surface 513 of the portion 512 when the portion 512 is not exposed to heat from the heating element 522 (eg, the heating element is off).

[0100] In one illustrative and non-limiting exemplary embodiment, portion 512 may be a molybdenum portion that serves as a source of EUV radiation (e.g., Figure 4 502) and operates at high temperatures. In some aspects, the cooling member 502 can be an aluminum member having a protrusion 508 (e.g., an aluminum threaded post) and can be connected to the portion 512 using a torque, wherein the applied torque determines the strain in the protrusion 508. The cooling member 502 and the portion 512 can be assembled at room temperature. As the assembly heats up, the molybdenum of the portion 512 and the aluminum of the cooling member 502 can expand at different rates (e.g., the molybdenum CTE is about 5.2 ppm / K; the aluminum CTE is about 23.1 ppm / K). The aluminum protrusion 508 expands faster than the molybdenum portion 512, and the strain in the protrusion 508 can relax at a rate of about 17.9 ppm / K. Once the strain is substantially completely relaxed, the contact plate 504 can be lifted out of the portion 512, and the conductive heat transfer to the fin 506 can now be limited by the annular member 516 (e.g., an N60 stainless steel insert). Upon cooling, protrusion 508 may contract faster than portion 512, eventually bringing contact plate 504 back into contact with portion 512, thereby cooling portion 512. The temperature at which contact plate 504 and portion 512 are brought into contact may be adjusted by varying the thread diameter used, the precisely controlled depth 520 of counterbore 518, the torque applied during assembly, and the materials used.

[0101] In some aspects, without thermally activated cooling system 500 (and without permanent fins), the amount of heat transferred from portion 512 may be determined according to Equation 1:

[0102] (1)

[0103] Where q represents the heat transfer rate, represents the convection heat transfer coefficient, A represents the area of ​​the cooling surface, TS represents the temperature of portion 512, and T ∞ Indicates the temperature of the surrounding environment.

[0104] In some aspects, by adding a thermally actuated cooling system 500 (eg, thermally actuated fins), the amount of heat transferred may be determined according to Equation 2:

[0105] (2)

[0106] Where q' represents the modified heat transfer rate (e.g., with the addition of thermally activated cooling system 500), q represents the heat transfer rate given by Equation 1 (e.g., without the addition of thermally activated cooling system 500), N represents the number of fins (e.g., the number of fins included in fin 506), and η f Indicates the efficiency of each fin.

[0107] Figure 6 FIG. 5 is a graphical representation of a notional cooling curve produced by adding the thermally actuated cooling system 500 shown in FIG. 5 to a portion of a lithographic apparatus, such as a DGA, according to some aspects of the present disclosure. Figure 6 As shown, the experimental temperature measurement signal 602 represents an experimental cooling curve of the DGA, which requires about two hours to cool from the operating temperature (e.g., greater than about 250°C) to the contact safe temperature (e.g., less than about 50°C). Figure 6 As further shown, the conceptual temperature measurement signal 604 represents the conceptual cooling curve of the DGA with the addition of the thermally activated cooling system 500 shown in FIG. 5 , which only requires about one hour to cool from the operating temperature to the contact safe temperature. Figure 6 As further shown, until point 606 (e.g., approximately 250° C.) when contact plate 504 (e.g., aluminum) contacts portion 512 (e.g., molybdenum), the cooling rate of experimental temperature measurement signal 602 and the cooling rate of conceptual temperature measurement signal 604 are approximately the same. At point 606, the cooling rate of conceptual temperature measurement signal 604 increases dramatically, thereby significantly improving the cooling time of the DGA.

[0108] Exemplary Device Fabrication Process

[0109] Figure 7 700 of manufacturing a device according to some aspects of the present disclosure or part(s) thereof. The operations described with reference to method 700 may be performed by or according to any of the systems, devices, components, techniques, or combinations thereof described herein, such as with reference to FIGS. 1-6 above and below. Figure 8 Those described.

[0110] At operation 702, the method may include providing a cooling member (e.g., cooling member 502). In some aspects, the cooling member may include a contact plate (e.g., contact plate 504), a fin (e.g., fin 506) extending from the contact plate in a first direction, and a protrusion (e.g., protrusion 508) extending from the contact plate in a second direction (e.g., substantially opposite to the first direction). In some aspects, the cooling member may be provided using suitable optical, electrical, mechanical, or other methods, and includes the steps described above with reference to FIGS. 1-6 and below. Figure 8 Any aspect or combination of aspects described may be used to provide a cooling component.

[0111] At operation 704, the method may include mounting a protrusion to a portion (e.g., portion 512) of an EUV radiation source (e.g., radiation source SO). The contact plate may include a first CTE that is greater than a second CTE of the portion. For example, the contact plate may include aluminum, the portion may include molybdenum, and the first CTE of the aluminum may be greater than the second CTE of the molybdenum. In some aspects, mounting the protrusion to the portion may include: mounting an annular member (e.g., annular member 516) to the protrusion, wherein the annular member partially surrounds the protrusion; and arranging the protrusion and the annular member in a receptacle (e.g., receptacle 514) of the portion. In some aspects, when the protrusion is mounted to the portion, the protrusion may be in a physically strained relationship with the portion such that: (i) when the portion is exposed to heat (e.g., when the heating element 522 of the portion 512 is turned on or when operating at an elevated temperature), the first surface (e.g., first surface 503) of the contact plate is configured to disengage from the second surface (e.g., second surface 513) of the portion (e.g., as Figure 5B and (ii) when the portion is not exposed to heat, the first surface of the contact plate is configured to contact the second surface of the portion (e.g., as Figure 5A In some aspects, mounting the protrusion to the portion may be accomplished using suitable optical, electrical, mechanical, or other methods, and includes methods described with reference to FIGS. 1-6 above and below. Figure 8 Any aspect or combination of aspects described may be used to mount the protrusion to the part.

[0112] Exemplary Computing System

[0113] Aspects of the present disclosure may be implemented in hardware, firmware, software, or any combination thereof. For example, the design of one or more materials of the contact plate 504 and portion 512, the CTE, the relative CTE, the size of the receiving portion 514, the precise control of the depth 512 may be implemented using hardware, firmware, software, or any combination thereof. Aspects of the present invention may also be implemented by 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 that can be read 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.), and the like. In addition, firmware, software, routines, instructions, and combinations thereof may be described in the present invention as performing certain actions. However, it should be understood that such description is for convenience only and that these actions are in fact produced by a computing device, processor, controller, or other device executing firmware, software, routines, instructions, etc., and that the performance of such operations may cause actuators or other devices (e.g., servo motors, robotic equipment) to interact with the physical world.

[0114] For example, one or more computing systems (such as Figure 8 The computing system 800 shown in the figure can be used to implement various aspects. The computing system 800 can be a special-purpose computer capable of performing the functions described herein, such as the following: Figure 4 5; any other suitable system, subsystem, or component; or any combination thereof. The computing system 800 may include one or more processors (also referred to as central processing units or CPUs), such as a processor 804. The processor 804 is connected to a communication infrastructure 806 (e.g., a bus). The computing system 800 may also include (multiple) user input / output devices 803, such as a monitor, a keyboard, a pointing device, etc., which communicate with the communication infrastructure 806 through (multiple) user input / input interfaces 802. The computing system 800 may also include a main memory 808 (e.g., one or more main storage devices), such as a random access memory (RAM). The main memory 808 may include one or more levels of cache. Control logic (e.g., computer software) and / or data are stored in the main memory 808.

[0115] The computing system 800 may also include secondary storage 810 (e.g., one or more secondary storage devices). The secondary storage 810 may include, for example, a hard disk drive 812 and / or a removable storage drive 814. The removable storage drive 814 may be a floppy disk drive, a tape drive, an optical drive, an optical storage device, a tape backup device, and / or any other storage device / drive.

[0116] The removable storage drive 814 can interact with a removable storage unit 818. The removable storage unit 818 includes a computer usable or readable storage device having computer software (control logic) and / or data stored thereon. The removable storage unit 818 can be a floppy disk, a magnetic tape, a compact disk, a DVD, an optical storage disk, and / or any other computer data storage device. The removable storage drive 814 reads from and / or writes to the removable storage unit 818.

[0117] According to some aspects, secondary memory 810 may include other devices, tools, or other methods for allowing computing system 800 to access computer programs and / or other instructions and / or data. For example, such devices, tools, or other methods may include a removable storage unit 822 and an interface 820. Examples of removable storage unit 822 and interface 820 may include a program cartridge and cartridge interface (such as found in a video game device), a removable storage chip (such as an EPROM or PROM) and associated housing, a memory stick and USB port, a memory card and associated memory card slot, and / or any other removable storage unit and associated interface.

[0118] The computing system 800 may also include a communication interface 824 (e.g., one or more network interfaces). The communication interface 824 enables the computing system 800 to communicate and interact with any combination of remote devices, remote networks, remote entities, and the like (individually and collectively referred to as remote devices 828). For example, the communication interface 824 may allow the computing system 800 to communicate with the remote device 828 via a communication path 826, which may be wired and / or wireless and may include any combination of a LAN, a WAN, the Internet, and the like. Control logic, data, or both may be transmitted to or from the computing system 800 via the communication path 826.

[0119] The operations in the foregoing aspects of the present disclosure may be implemented in various configurations and architectures. Therefore, some or all of the operations in the foregoing aspects may be performed in hardware, software, or both. In some aspects, a tangible, non-transient device or article includes a tangible, non-transient computer-usable or readable medium having control logic (software) stored thereon, also referred to herein as a computer program product or program storage device. This includes, but is not limited to, a computing system 800, a main memory 808, an auxiliary memory 810, and removable storage units 818 and 822, and tangible articles embodying any combination of the foregoing. Such control logic, when executed by one or more data processing devices (such as the computing system 800), causes these data processing devices to operate as described herein.

[0120] Based on the teachings contained in this disclosure, it will be clear to those skilled in the relevant art(s) how to use the Figure 8 Data processing devices, computer systems, and / or computer architectures other than those shown can be used to make and use aspects of the present disclosure. In particular, aspects of the present disclosure can be operated with software, hardware, and / or operating system implementations other than those described herein.

[0121] 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 "substrate" or "die" herein may be considered synonymous with the more general term "substrate" or "target portion", respectively. The substrates mentioned herein may be processed in, for example, a track unit (a tool that typically applies a resist layer to a substrate and develops the exposed resist), a measurement tool, and / or a detection tool before or after exposure. Where applicable, the disclosure herein may be applied to these and other substrate processing tools. In addition, the substrate may be processed more than once, for example to form a multi-layer IC, so that the term substrate used herein may also refer to a substrate that already contains multiple processed layers.

[0122] 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 this specification will be interpreted by (multiple) relevant art(s) skilled in the art based on the teachings herein.

[0123] The term "substrate" as used herein describes a material onto which a layer of material is added. In some embodiments, the substrate itself may be patterned, and the material added on top of the substrate may also be patterned, or may remain unpatterned.

[0124] The examples disclosed herein are illustrative, rather than limiting, embodiments of the present disclosure. Other suitable modifications and adjustments to the various conditions and parameters normally encountered in the art (and those skilled in the relevant art(s) will appreciate these modifications and adjustments) will fall within the spirit and scope of the present disclosure.

[0125] Although specific embodiments of the present disclosure have been described above, it should be appreciated that aspects may be practiced in ways other than as described. The description is not intended to limit the embodiments of the present disclosure.

[0126] It should be understood that the detailed description section (rather than the background, summary, and abstract sections) is intended to be used to interpret the claims. The summary and abstract sections may set forth one or more exemplary embodiments contemplated by the inventor(s), but not all exemplary embodiments, and thus the summary and abstract sections are not intended to limit the present embodiments and the appended claims in any way.

[0127] Some aspects of the present disclosure have been described above with the aid of functional building blocks, which illustrate the implementation of specific functions and their relationships. For ease of description, the boundaries of these functional building blocks have been arbitrarily defined in this article. As long as the specific functions and their relationships are properly performed, alternative boundaries can be defined.

[0128] The above description of the specific aspects of the present disclosure will fully reveal the general nature of the various aspects, so that others can easily modify and / or adjust the various applications of these specific aspects by applying the knowledge within the art without undue experimentation and without departing from the general concepts of the present disclosure. Therefore, based on the teachings and guidance presented herein, such modifications and adjustments are intended to fall within the meaning and scope of equivalents of the disclosed aspects.

[0129] Further aspects of the invention are set out in the following numbered clauses:

[0130] 1. A system comprising:

[0131] A cooling member, the cooling member comprising:

[0132] Contact plate;

[0133] a fin extending from the contact plate in a first direction; and

[0134] a protrusion extending from the contact plate in a second direction and configured to couple the contact plate to a portion of an extreme ultraviolet (EUV) radiation source,

[0135] Wherein the contact plate comprises a first coefficient of thermal expansion (CTE), the first CTE being greater than a second CTE of the portion.

[0136] 2. The system of clause 1, wherein the portion of the EUV radiation source comprises a heating element, and wherein the protrusion is configured to be in a physically strained relationship with the portion such that:

[0137] The first surface of the contact plate is configured to disengage from the second surface of the portion when the portion is heated by the heating element; and

[0138] The first surface of the contact plate is configured to contact the second surface of the portion when the portion is not exposed to heat.

[0139] 3. The system of clause 1 , wherein the fins comprise rods.

[0140] 4. The system of clause 1 , wherein the protrusion comprises a threaded rod.

[0141] 5. A system according to clause 1, wherein:

[0142] The contact plate comprises aluminum; and

[0143] The moiety includes molybdenum.

[0144] 6. The system of clause 1, wherein the protrusion is further configured to be surrounded by a portion of the annular member and disposed in a receptacle of the portion.

[0145] 7. The system of clause 6, wherein the receiving portion comprises a threaded hole and the protrusion comprises a threaded rod.

[0146] 8. The system of clause 6, wherein the annular member comprises a stainless steel insert, the contact plate comprises aluminum, and the portion comprises molybdenum.

[0147] 9. A device comprising:

[0148] contact plate; and

[0149] a protrusion extending from the contact plate and configured to couple the contact plate to a portion of an extreme ultraviolet (EUV) radiation source, wherein the protrusion is configured to be in a physically strained relationship with the portion such that:

[0150] The first surface of the contact plate is configured to disengage from the second surface of the portion when the portion is heated; and

[0151] The first surface of the contact plate is configured to contact the second surface of the portion when the portion is not exposed to heat.

[0152] 10. The apparatus of clause 9, further comprising a fin extending from the contact plate in a first direction, and wherein the protrusion extends in an opposite second direction.

[0153] 11. An apparatus according to item 10, wherein the fin comprises a rod and the portion comprises a heating element.

[0154] 12. An apparatus according to clause 9, wherein the protrusion comprises a threaded rod and is configured to be received in a receptacle of the portion.

[0155] 13. The apparatus of clause 9, wherein:

[0156] The contact plate comprises aluminum; and

[0157] The moiety includes molybdenum.

[0158] 14. An apparatus according to clause 9, wherein the protrusion is also configured to be surrounded by a portion of the annular member and disposed in a receiving portion of the portion.

[0159] 15. An apparatus according to clause 14, wherein the contact plate comprises aluminum, the portion comprises molybdenum, and the annular member comprises stainless steel.

[0160] 16. An apparatus according to clause 12, wherein the receiving portion includes a threaded hole.

[0161] 17. A method comprising:

[0162] A cooling member is provided, the cooling member comprising:

[0163] Contact plate;

[0164] a fin extending from the contact plate in a first direction; and

[0165] a protrusion extending from the contact plate in a second direction; and

[0166] mounting the protrusion to a portion of an extreme ultraviolet (EUV) radiation source,

[0167] Wherein the contact plate comprises a first coefficient of thermal expansion (CTE), the first CTE being greater than a second CTE of the portion.

[0168] 18. A method according to clause 17, wherein when the protrusion is mounted to the part, the protrusion is in a physically strained relationship with the part such that:

[0169] The first surface of the contact plate is configured to disengage from the second surface of the portion when the portion is heated; and

[0170] The first surface of the contact plate is configured to contact the second surface of the portion when the portion is not exposed to heat.

[0171] 19. The method of clause 18, wherein the protrusion is threaded, and the method further comprises:

[0172] The projection is mounted by engaging the projection with corresponding threads of a threaded receptacle of the portion, and wherein strain in the projection is relieved when the portion is heated.

[0173] 20. A method according to clause 17, wherein:

[0174] The contact plate comprises aluminum; and

[0175] The moiety includes molybdenum.

[0176] 21. The method of clause 17, wherein mounting the protrusion to the portion comprises:

[0177] mounting an annular member to the protrusion, wherein the annular member partially surrounds the protrusion; and

[0178] The protrusion and the annular member are disposed in the receiving portion of the portion.

[0179] The breadth and scope of the present disclosure should not be limited by any of the above-described exemplary aspects or embodiments, but should be defined only in accordance with the following claims and their equivalents.

Claims

1. A system comprising: A cooling member, the cooling member comprising: Contact plate; a fin extending from the contact plate in a first direction; and a protrusion extending from the contact plate in a second direction and configured to couple the contact plate to a portion of an extreme ultraviolet (EUV) radiation source, Wherein the contact plate comprises a first coefficient of thermal expansion (CTE), the first CTE being greater than a second CTE of the portion.

2. The system of claim 1 , wherein the portion of the EUV radiation source comprises a heating element, and wherein the protrusion is configured to be in a physically strained relationship with the portion such that: The first surface of the contact plate is configured to disengage from the second surface of the portion when the portion is heated by the heating element; and The first surface of the contact plate is configured to contact the second surface of the portion when the portion is not exposed to heat. The system of claim 1 , wherein the fins comprise rods. The system of claim 1 , wherein the projection comprises a threaded rod.

5. The system of claim 1, wherein: The contact plate comprises aluminum; and The moiety includes molybdenum.

6. The system of claim 1, wherein the protrusion is further configured to be surrounded by a portion of the annular member and disposed in a receiving portion of the portion.

7. The system of claim 6, wherein the receiving portion comprises a threaded hole and the protrusion comprises a threaded rod.

8. The system of claim 6, wherein the annular member comprises a stainless steel insert, the contact plate comprises aluminum, and the portion comprises molybdenum.

9. A device comprising: Contact plate; and a protrusion extending from the contact plate and configured to couple the contact plate to a portion of an extreme ultraviolet (EUV) radiation source, wherein the protrusion is configured to be in a physically strained relationship with the portion such that: The first surface of the contact plate is configured to disengage from the second surface of the portion when the portion is heated; as well as The first surface of the contact plate is configured to contact the second surface of the portion when the portion is not exposed to heat.

10. The apparatus of claim 9, further comprising a fin extending from the contact plate in a first direction, and wherein the protrusion extends in an opposite second direction.

11. The apparatus of claim 10, wherein the fin comprises a rod and the portion comprises a heating element.

12. The apparatus of claim 9, wherein the projection comprises a threaded rod and is configured to be received in a receiving portion of the portion.

13. The apparatus of claim 9, wherein: The contact plate comprises aluminum; and The moiety includes molybdenum.

14. The apparatus of claim 9, wherein the protrusion is further configured to be surrounded by a portion of the annular member and disposed in a receiving portion of the portion.

15. The apparatus of claim 14, wherein the contact plate comprises aluminum, the portion comprises molybdenum, and the annular member comprises stainless steel.

16. The apparatus of claim 12, wherein the receiving portion comprises a threaded hole.

17. A method comprising: A cooling member is provided, the cooling member comprising: Contact plate; a fin extending from the contact plate in a first direction; and a protrusion extending from the contact plate in a second direction; and mounting the protrusion to a portion of an extreme ultraviolet (EUV) radiation source, Wherein the contact plate comprises a first coefficient of thermal expansion (CTE), the first CTE being greater than a second CTE of the portion.

18. A method according to claim 17, wherein when the protrusion is mounted to the portion, the protrusion is in a physically strained relationship with the portion such that: The first surface of the contact plate is configured to disengage from the second surface of the portion when the portion is heated; and The first surface of the contact plate is configured to contact the second surface of the portion when the portion is not exposed to heat.

19. The method of claim 18, wherein the protrusion is threaded, and the method further comprises: The projection is mounted by engaging the projection with corresponding threads of a threaded receptacle of the portion, and wherein strain in the projection is relieved when the portion is heated.

20. The method of claim 17, wherein: The contact plate comprises aluminum; and The moiety includes molybdenum.

21. The method of claim 17, wherein: Mounting the protrusion to the portion comprises: mounting an annular member to the protrusion, wherein the annular member partially surrounds the protrusion; and The protrusion and the annular member are disposed in the receiving portion of the portion.

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