Heat transfer systems for an extreme ultraviolet radiation utilization apparatus, methods of manufacturing the same and heat transfer methods for an extreme ultraviolet radiation utilization apparatus

Abstract

Heat transfer systems and methods for an extreme ultraviolet radiation source and / or lithography apparatus are described. A body; heaters configured to heat the body; and a heat transfer portion directly bonded to the body using cold spray technology are provided. The heat transfer portion is configured to couple the heaters to the body, and facilitate heat transfer through the body. Cold spray technology comprises a low temperature ultrasonic and / or hypersonic spray nozzle configured to spray various materials, for example stainless steel powder, copper or copper matrix power, nickel powder, and / or tin power to directly bond the heat transfer portion to the body. Cold spray technology relies on the high speed of metal power that is plastically deformed and physically bonded upon contact to the body. The body may comprise steel; and the heat transfer portion may comprise copper, copper and diamond, copper and aluminum oxide, or copper and silicon carbide.

Description

HEAT TRANSFER SYSTEMS FOR AN EXTREME ULTRAVIOLET RADIATION UTILIZATIONAPPARATUS, METHODS OF MANUFACTURING THE SAME AND HEAT TRANSFER METHODS FOR AN EXTREME ULTRAVIOLET RADIATION UTILIZATION APPARATUSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority of US application 63 / 601,794 which was filed on 22 November 2023 and which is incorporated herein in its entirety by reference.TECHNICAL FIELD

[0002] In some aspects, the present description relates to heat transfer systems for an extreme ultraviolet (EUV) radiation utilization apparatus and methods manufacturing the same. In other aspects, the present description relates to heat transfer methods for an extreme ultraviolet (EUV) radiation utilization apparatus.BACKGROUND

[0003] A lithographic apparatus (in the present description equally referred to as lithography apparatus) can be used, for example, in the manufacture of integrated circuits (ICs). A patterning device (e.g., a mask) may include or provide a pattern corresponding to an individual layer of the IC (“design layout”), and this pattern can be transferred onto a target portion (e.g. comprising one or more dies) on a substrate (e.g., silicon wafer) that has been coated with a layer of radiation-sensitive material (“resist”), by methods such as irradiating the target portion through the pattern on the patterning device with radiation. In general, a single substrate includes a plurality of adjacent target portions to which the pattern is transferred successively by the lithographic apparatus, one target portion at a time. In one type of lithographic projection apparatus, the pattern on the entire patterning device is transferred onto one target portion in one operation. Such an apparatus is commonly referred to as a stepper. In an alternative apparatus, commonly referred to as a step-and-scan apparatus, a projection beam scans over the patterning device in a given reference direction (the “scanning” direction) while synchronously moving the substrate parallel or anti -parallel to this reference direction. Different portions of the pattern on the patterning device are transferred to one target portion progressively.

[0004] Prior to transferring the pattern from the patterning device to the substrate, the substrate may undergo various procedures, such as priming, resist coating, and a soft bake. After exposure, the substrate may be subjected to other procedures (“post-exposure procedures”), such as a post-exposure bake (PEB), development, a hard bake and measurement / inspection of the transferred pattern. This array of procedures is used as a basis to make an individual layer of a device, e.g., an IC. The substrate may then undergo various processes such as etching, ion-implantation (doping), metallization, oxidation, deposition, chemo-mechanical polishing, etc., all intended to finish the individual layer of the device. If several layers are required in the device, then the whole procedure, or a variant thereof, is repeatedfor each layer. Eventually, a device will be present in each target portion on the substrate. These devices are then separated from one another by a technique such as dicing or sawing, such that the individual devices can be mounted on a carrier, connected to pins, etc.

[0005] Thus, manufacturing devices, such as semiconductor devices, typically involves processing a substrate (e.g., a semiconductor wafer) using a number of fabrication processes to form various features and multiple layers of the devices. Such layers and features are typically manufactured and processed using, e.g., deposition, lithography, etch, deposition, chemical -mechanical polishing, and ion implantation. Multiple devices may be fabricated on a plurality of dies on a substrate and then separated into individual devices. This device manufacturing process may be considered a patterning process. A patterning process involves a patterning step, such as optical and / or nanoimprint lithography using a patterning device in a lithographic apparatus, to transfer a pattern on the patterning device to a substrate and typically, but optionally, involves one or more related pattern processing steps, such as resist development by a development apparatus, baking of the substrate using a bake tool, etching using the pattern using an etch apparatus, deposition, etc.

[0006] Lithography is a central step in the manufacturing of devices such as ICs, where patterns formed on substrates define functional elements of the devices, such as microprocessors, memory chips, etc. Similar lithographic techniques are also used in the formation of flat panel displays, micro-electro mechanical systems (MEMS) and other devices.

[0007] As semiconductor manufacturing processes continue to advance, the dimensions of functional elements have continually been reduced while the number of functional elements, such as transistors, per device has been steadily increasing over decades, following a trend commonly referred to as “Moore’s law.” At the current state of technology, layers of devices are manufactured using lithographic apparatuses that project a design layout onto a substrate using illumination from an extreme ultraviolet (EUV) radiation source, creating individual functional elements having dimensions well below 100 nm, i.e. less than half the wavelength of the radiation from the radiation source.

[0008] To overcome difficulties with patterning features this small, sophisticated fine-tuning steps are applied to the radiation source, the lithographic apparatus, the design layout, or the patterning device. Controllable and / or otherwise predictable heat transfer to and / or through various components of the radiation source and / or the lithographic apparatus are important for these fine tuning steps and / or other aspects of a patterning process.SUMMARY

[0009] In a first aspect, a heat transfer system for an extreme ultraviolet (EUV) radiation utilization apparatus is provided. The system comprises an EUV radiation utilization apparatus housing comprising a stainless steel body; and a copper portion directly bonded to the stainless steel body. The copper portion is configured to facilitate heat transfer through the stainless steel body.

[0010] The copper portion may be directly bonded to the stainless steel body using cold spray technology. A grain structure of the copper portion and / or the stainless steel body may shows effects of cold spraying at sharp angles in the grain structure, and / or include detectable AlOx abrasives in the copper portion caused by cold spraying.

[0011] The copper portion may be directly bonded to the stainless steel body using brazing with braze detectable in a stainless steel - copper interface; using melting; or using plating.

[0012] The system may comprise one or more heaters configured to heat the stainless steel body and the copper portion. The one or more heaters comprise one or more heat sources.

[0013] The stainless steel body may comprise one or more cavities configured to accommodate the one or more heaters. The one or more cavities may comprise one or more grooves.

[0014] The copper portion may be configured to cover the one or more heaters, and couple the one or more heaters to the stainless steel body.

[0015] The copper portion may comprise one or more pockets within the stainless steel body. The one or more pockets may be located directly adjacent to the one or more heaters. Optionally, the one or more pockets may be capped with a stainless steel layer deposited using cold spray technology to encase the copper portion. A grain structure of the stainless steel layer may show effects of cold spraying at sharp angles in the grain structure caused by cold spraying.

[0016] The stainless steel layer may be welded to the stainless steel body.

[0017] The one or more pockets may be located between the one or more heaters.

[0018] The one or more heaters may be brazed to the stainless steel body.

[0019] The stainless steel body may be formed by cold spraying, additive manufacturing, and / or machining.

[0020] A first side of the stainless steel body, that is opposite a second side comprising the copper portion, may be configured to face a tin rich environment in the EUV radiation utilization apparatus. Optionally, the system may comprise a titanium nitride (TiN) coating on the first side and / or the second side of the stainless steel body; and / or an electroless nickel (Ni) layer and / or an electroplated tin (Sn) layer formed on the first side of the stainless steel body. In addition or instead thereof, the system may comprise a layer of molybdenum formed on the first side and / or the second side.

[0021] The radiation utilization apparatus may comprise an EUV radiation source, an inspection tool, a lithography apparatus, and / or other EUV radiation utilization apparatuses.

[0022] In another aspect, there is provided a heat transfer system for an extreme ultraviolet (EUV) radiation utilization apparatus. The system comprises a body; one or more heaters configured to heat the body; and a heat transfer portion directly bonded to the body using cold spray technology. The heat transfer portion is configured to couple the one or more heaters to the body, and facilitate heat transfer through the body.

[0023] The body may comprise stainless steel or mild steel; and the heat transfer portion maycomprise copper, copper and diamond, copper and aluminum oxide, or copper and silicon carbide.

[0024] In still other aspects, there are provided methods of manufacturing a heat transfer system as described hereinabove, for an extreme ultraviolet (EUV) radiation utilization apparatus described above.

[0025] In other aspects, there is provided one or more corresponding heat transfer methods comprising one or more of the operations described above.BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above aspects and other aspects and features will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments in conjunction with the accompanying figures.

[0027] Fig. 1 schematically depicts a first example of a radiation source and lithographic apparatus.

[0028] Fig. 2 shows second example of a radiation source and a lithographic apparatus.

[0029] Fig. 3 is a detailed view of the collector of the source shown in Fig. 2.

[0030] Fig. 4 illustrates a heat transfer system for an extreme ultraviolet (EUV) radiation source (e.g., as shown in Fig. 1-3) or lithographic apparatus (e.g., as shown in Fig. 1 and 2).

[0031] Fig. 5 illustrates an example of a cold spray technology system.

[0032] Fig. 6 illustrates the advantageous flexible nature of cold spray technology.

[0033] Fig. 7 illustrates an example of the heat transfer system shown in Fig. 4, where a heat transfer portion (e.g., a copper portion) comprises one or more pockets within (e.g., a stainless steel) body.

[0034] Fig. 8 illustrates another example of the heat transfer system shown in Fig. 4, with one or more pockets located between one or more heaters.

[0035] Fig. 9 illustrates a heat transfer method.

[0036] Fig. 10 is a block diagram of an example computer system.DETAILED DESCRIPTION

[0037] Heat transfer systems and methods for an extreme ultraviolet radiation source and / or lithography apparatus are described. A body; heaters configured to heat the body; and a heat transfer portion directly bonded to the body using cold spray technology are provided. The heat transfer portion is configured to couple the heaters to the body, and facilitate heat transfer through the body. Cold spray technology comprises a low temperature ultrasonic and / or hypersonic spray nozzle configured to spray various materials, for example stainless steel powder, copper or copper matrix power, nickel powder, and / or tin power to directly bond the heat transfer portion to the body. Advantageously, cold spray technology relies on the high speed of metal power that is plastically deformed and physically bonded upon contact to the body. This makes cold spray technology flexibly adaptable for directly bonding the heat transfer portion to the body. The body may comprise steel; and the heat transfer portion may comprise copper, copper and diamond, copper and aluminum oxide, or copper and silicon carbide; forexample.

[0038] As described above, controllable and / or otherwise predictable heat transfer to and / or through various components of a radiation source and / or a lithographic apparatus are important for fine tuning steps and / or other aspects of a patterning process. As one example, tin (e.g., fuel for extreme ultra violet (EUV) radiation generation as described below) tends to collect on surfaces of an EUV source chamber, an requires periodic removal. Tin collection can be managed by maintaining tin facing surfaces at target temperatures, cycling the temperature of the tin facing surfaces (so that the tin melts and flows from these surfaces), and / or by other operations. Therefore, materials chosen for these tin facing surfaces need to be highly thermal conductive, and at the same time atomic hydrogen (which flows inside the source chamber as part of the radiation generation process), EUV, and molten tin compatible.

[0039] For example, vanes used in current EUV sources comprise a tin, nickel, stainless steel, copper, and stainless steel stack. The EUV facing side of the stack has a thin coating layer coating configured to receive incoming tin produced as a byproduct of EUV generation. The stack is configured to operate in a “hot” mode above the melting temperature of tin for better tin flow and removal, yet it must also be capable of operating in a “cold” mode that is below the melting temperature of tin, to mitigate hydrogen recombination with molten tin, which forms bubbles that periodically burst. These bursts can send tin into undesired areas of the radiation source or even a downstream lithographic apparatus, lead to a shortened optics lifetime (in the radiation source and the downstream lithography apparatus), and cause high reticle and / or other patterning device defectivity rates, among other issues.

[0040] A typical stack requires an extensive number of manufacturing steps, making it one of the most difficult pieces of tin management hardware to produce. A typical stack is also very costly, and the usual lead time to obtain a stack is extraordinarily long. Further, a tin, nickel, stainless steel, copper, and stainless steel stack can only be applied to a limited number of geometrically shaped surfaces, and material combinations useable for a stack are limited by gravity, and a wide process temperature operational range (which can be greater than 900 °C), among other factors.

[0041] Advantageously, the present systems and methods utilize cold spray technology to directly bond thermally conductive surfaces together for use where controllable and / or otherwise predictable heat transfer to and / or through various components (e.g., for a stack as described above, or other components) is helpful in an EUV radiation source and / or a lithography apparatus, for example. A body, heaters configured to heat the body, and a heat transfer portion directly bonded to the body using cold spray technology are provided. Cold spray technology comprises a low temperature ultrasonic and / or hypersonic spray nozzle configured to spray various materials to directly bond the heat transfer portion to the body. Cold spray technology relies on the high speed of metal power that is plastically deformed and physically bonded upon contact to the body. This makes cold spray technology flexibly adaptable for directly bonding the heat transfer portion to the body.

[0042] In addition, cold spray technology allows for cost efficient coverage of complicated free form metal shapes with a material with high thermal conductivity, which would otherwise be costly, cumbersome or impossible. A cold sprayed coating coating also can simultaneously bond heating elements both thermally and spatially to the freeform surface. For example, 316(L) stainless steel has good liquid tin (Sn) resistance (good for EUV related applications), but poor heat conduction (e.g., 14- 16 W / mK). In some locations in an EUV radiation source where building volume is at a premium, a substantially higher heat conduction is needed to maintain desired tin facing surface temperatures. Heat conduction issues associated with stainless steel may be remedied by backing the stainless steel with a material that has superior heat conductance (e.g., copper at 400 W / mK), and substantially the same thermal expansion coefficient (CTE, e.g., around 16 PPM / K)). In near vacuum (i.e., the environment in the EUV radiation source), connecting parts together with bolts or the like results in poor thermal transfer, insufficient for EUV radiation source (and / or lithography apparatus) purposes. To optimize heat transfer, materials are physically or chemically bonded. The combination of copper and 316(L) stainless steel (as one example) is a combination with matched CTE. The matched CTE prevents deformation of a combined part when heated from room temperature to operating temperatures of 150 °C, up to 232 °C (e.g., the tin melting point) or even 300 °C. Adding 1 mm thickness of copper spreads as much heat as 25 mm thickness of 316L, for example. The material combination, together with a manufacturing method (e.g., cold spray technology) that can efficiently cover a complex free form stainless steel (as one example material) part with dense pure copper (as another example material) is advantageous. At the same time, coupling a good thermal conductivity multi -material part having a complicated shape with one or more heater(s) (e.g., again using cold spray technology) is another advantage (among many other possible advantages).

[0043] By way of a brief introduction, the description below relates to semiconductor device manufacturing and patterning processes. Although specific reference may be made in this text to the manufacture of integrated circuits (ICs) for semiconductor devices, it should be understood that the description herein has many other possible applications. For example, it may be employed in the manufacture of integrated optical systems, guidance and detection patterns for magnetic domain memories, liquid-crystal display 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 interchangeable with the more general terms “mask,” “substrate” and “target portion,” respectively.

[0044] The term “projection optics” as used herein should be broadly interpreted as encompassing various types of optical systems, including refractive optics, reflective optics, apertures and catadioptric optics, for example. The term “projection optics” may also include components operating according to any of these design types for directing, shaping or controlling the projection beam of radiation, collectively or singularly. The term “projection optics” may include any optical component in thelithographic apparatus, no matter where the optical component is located on an optical path of the lithographic apparatus. Projection optics may include optical components for shaping, adjusting and / or projecting radiation from the source before the radiation passes the patterning device, and / or optical components for shaping, adjusting and / or projecting the radiation after the radiation passes the patterning device. The projection optics generally exclude the source and the patterning device.

[0045] Fig. 1 schematically depicts an embodiment of a lithographic apparatus LA. The apparatus comprises an illumination system (illuminator) IL configured to condition a radiation beam B (e.g. EUV radiation); a support structure (e.g. a mask table) MT constructed to support a patterning device (e.g. a mask) MA and connected to a first positioner PM configured to accurately position the patterning device in accordance with certain parameters; a substrate table (e.g. a wafer table) WT (e.g., WTa, WTb or both) configured to hold a substrate (e.g. a resist-coated wafer) W and coupled to a second positioner PW configured to accurately position the substrate in accordance with certain parameters; and a projection system (e.g. a refractive projection lens system) PS configured to project a pattern imparted to the radiation beam B by patterning device MA onto a target portion C (e.g. comprising one or more dies and often referred to as fields) of the substrate W. The projection system PS is supported on a reference frame RF. As depicted, the apparatus is of a transmissive type (e.g. employing a transmissive mask). Alternatively, the apparatus may be of a reflective type (e.g. employing a programmable mirror array, or employing a reflective mask).

[0046] The illuminator IL receives a beam of radiation from a radiation source SO. The source SO and the lithographic apparatus LA may be separate entities. In such cases, the source SO is not considered to form part of the lithographic apparatus LA and the radiation beam is passed from the source SO to the illuminator IL with the aid of a beam delivery system BD comprising for example suitable directing mirrors and / or a beam expander. In other cases, the source SO may be an integral part of the apparatus. The source SO and the illuminator IL, together with the beam delivery system BD if required, may be referred to as a radiation system.

[0047] The illuminator IL may alter the intensity distribution of the beam. The illuminator may be arranged to limit the radial extent of the radiation beam such that the intensity distribution is non -zero within an annular region in a pupil plane of the illuminator IL. Additionally or alternatively, the illuminator IL may be operable to limit the distribution of the beam in the pupil plane such that the intensity distribution is non-zero in a plurality of equally spaced sectors in the pupil plane. The intensity distribution of the radiation beam in a pupil plane of the illuminator IL may be referred to as an illumination mode.

[0048] The illuminator IL may comprise adjuster AD configured to adjust the (angular / spatial) intensity distribution of the beam. Generally, at least the outer and / or inner radial extent (commonly referred to as o-outer and o-inner, respectively) of the intensity distribution in a pupil plane of the illuminator can be adjusted. The illuminator IL may be operable to vary the angular distribution of thebeam. For example, the illuminator may be operable to alter the number, and angular extent, of sectors in the pupil plane wherein the intensity distribution is non-zero. By adjusting the intensity distribution of the beam in the pupil plane of the illuminator, different illumination modes may be achieved. For example, by limiting the radial and angular extent of the intensity distribution in the pupil plane of the illuminator IL, the intensity distribution may have a multi-pole distribution such as, for example, a dipole, quadrupole or hexapole distribution. A desired illumination mode may be obtained, e.g., by inserting an optic which provides that illumination mode into the illuminator IL or using a spatial light modulator.

[0049] The illuminator IL may be operable to alter the polarization of the beam and may be operable to adjust the polarization using adjuster AD. The polarization state of the radiation beam across a pupil plane of the illuminator IL may be referred to as a polarization mode. The use of different polarization modes may allow greater contrast to be achieved in the image formed on the substrate W. The radiation beam may be unpolarized. Alternatively, the illuminator may be arranged to linearly polarize the radiation beam. The polarization direction of the radiation beam may vary across a pupil plane of the illuminator IL. The polarization direction of radiation may be different in different regions in the pupil plane of the illuminator IL. The polarization state of the radiation may be chosen in dependence on the illumination mode. For multi -pole illumination modes, the polarization of each pole of the radiation beam may be generally perpendicular to the position vector of that pole in the pupil plane of the illuminator IL. For example, for a dipole illumination mode, the radiation may be linearly polarized in a direction that is substantially perpendicular to a line that bisects the two opposing sectors of the dipole . The radiation beam may be polarized in one of two different orthogonal directions, which may be referred to as X-polarized and Y-polarized states. For a quadrupole illumination mode, the radiation in the sector of each pole may be linearly polarized in a direction that is substantially perpendicular to a line that bisects that sector. This polarization mode may be referred to as XY polarization. Similarly, for a hexapole illumination mode the radiation in the sector of each pole may be linearly polarized in a direction that is substantially perpendicular to a line that bisects that sector. This polarization mode may be referred to as TE polarization.

[0050] In addition, the illuminator IL generally comprises various other components, such as an integrator IN and a condenser CO. The illumination system may include various types of optical components, such as refractive, reflective, magnetic, electromagnetic, electrostatic or other types of optical components, or any combination thereof, for directing, shaping, or controlling radiation. Thus, the illuminator provides a conditioned beam of radiation B, having a desired uniformity and intensity distribution in its cross section.

[0051] The support structure MT supports the patterning device in a manner that depends on the orientation of the patterning device, the design of the lithographic apparatus, and other conditions, such as for example whether or not the patterning device is held in a vacuum environment. The supportstructure may use mechanical, vacuum, electrostatic or other clamping techniques to hold the patterning device. The support structure may be a frame or a table, for example, which may be fixed or movable as required. The support structure may ensure that the patterning device is at a desired position, for example with respect to the projection system. Any use of the terms “reticle” or “mask” herein may be considered synonymous with the more general term “patterning device.”

[0052] The term “patterning device” should be broadly interpreted as referring to any device that can be used to impart a pattern in a target portion of the substrate. In an embodiment, a patterning device is any device that can be used to impart a radiation beam with a pattern in its cross-section to create a pattern in a target portion of the substrate. It should be noted that the pattern imparted to the radiation beam may not exactly correspond to the desired pattern in the target portion of the substrate, for example if the pattern includes phase -shifting features or so called assist features. Generally, the pattern imparted to the radiation beam will correspond to a particular functional layer in a device being created in a target portion of the device, such as an integrated circuit.

[0053] A patterning device may be transmissive or reflective . Examples of patterning devices include masks, programmable mirror arrays, and programmable LCD panels. Masks are well known in lithography, and include mask types such as binary, alternating phase-shift, and attenuated phase-shift, as well as various hybrid mask types. An example of a programmable mirror array employs a matrix arrangement of small mirrors, each of which can be individually tilted to reflect an incoming radiation beam in different directions. The tilted mirrors impart a pattern in a radiation beam, which is reflected by the mirror matrix.

[0054] The term “projection system” should be broadly interpreted as encompassing 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 or the use of a vacuum. Any use of the term “projection lens” herein may be considered as synonymous with the more general term “projection system.”

[0055] The projection system PS may comprise a plurality of optical (e.g., lens) elements and may further comprise an adjustment mechanism configured to adjust one or more of the optical elements to correct for aberrations (phase variations across the pupil plane throughout the field). To achieve this, the adjustment mechanism may be operable to manipulate one or more optical (e.g., lens) elements within the projection system PS in one or more different ways. The projection system may have a coordinate system wherein its optical axis extends in the z direction. The adjustment mechanism may be operable to do any combination of the following: displace one or more optical elements; tilt one or more optical elements; and / or deform one or more optical elements. Displacement of an optical element may be in any direction (x, y, z, or a combination thereof). Tilting of an optical element is typically out of a plane perpendicular to the optical axis, by rotating about an axis in the x and / or y directions although arotation about the z axis may be used for a non-rotationally symmetric aspherical optical element. Deformation of an optical element may include a low frequency shape (e.g. astigmatic) and / or a high frequency shape (e.g. free form aspheres). Deformation of an optical element may be performed for example by using one or more actuators to exert force on one or more sides of the optical element and / or by using one or more heating elements to heat one or more selected regions of the optical element. In general, it may not be possible to adjust the projection system PS to correct for apodization (transmission variation across the pupil plane). The transmission map of a projection system PS may be used when designing a patterning device (e.g., mask) MA for the lithography apparatus LA. Using a computational lithography technique, the patterning device MA may be designed to at least partially correct for apodization.

[0056] The lithographic apparatus may be of atype having two (dual stage) or more tables (e.g., two or more substrate tables WTa, WTb, two or more patterning device tables, a substrate table WTa and a table WTb below the projection system without a substrate that is dedicated to, for example, facilitating measurement, and / or cleaning, etc.). In such “multiple stage” machines, the additional tables may be used in parallel, or preparatory steps may be conducted on one or more tables while one or more other tables are being used for exposure. For example, alignment measurements using an alignment sensor AS and / or level (height, tilt, etc.) measurements using a level sensor LS may be made.

[0057] The lithographic apparatus may also be of a type wherein at least a portion of the substrate may be covered by a liquid having a relatively high refractive index, e.g. water, to fill a space between the projection system and the substrate. An immersion liquid may also be applied to other spaces in the lithographic apparatus, for example, between the patterning device and the projection system. Immersion techniques are well known in the art for increasing the numerical aperture of projection systems. The term “immersion” as used herein does not mean that a structure, such as a substrate, must be submerged in liquid, but rather only means that liquid is located between the projection system and the substrate during exposure.

[0058] In operation of the lithographic apparatus, a radiation beam B is conditioned and provided by the illumination system IL. 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. Having traversed 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. With the aid of the second positioner PW and position sensor IF (e.g. an interferometric device, linear encoder, 2-D encoder or capacitive sensor), the substrate table WT can be moved accurately, e.g. to position different target portions C in the path of the radiation beam B. Similarly, the first positioner PM and another position sensor (which is not explicitly depicted in Fig. 1) can be used to accurately position the patterning device MA with respect to the path of the radiation beam B, e.g. after mechanical retrieval from a mask library, or during a scan. In general, movement of the support structure MT may be realized with theaid 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 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 may be connected to a shortstroke actuator only, or may be fixed. Patterning device MA and substrate W may be aligned using patterning device alignment marks Ml, M2 and substrate alignment marks Pl, P2. Although the substrate alignment marks as illustrated occupy dedicated target portions, they may be located in spaces between target portions (these are known as scribe -lane alignment marks). Similarly, in situations in which more than one die is provided on the patterning device MA, the patterning device alignment marks may be located between the dies.

[0059] The depicted apparatus may be used in at least one of the following modes. In step mode, the support structure MT and the substrate table WT are kept essentially stationary, while a pattern imparted to the radiation beam 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. In step mode, the maximum size of the exposure field limits the size of the target portion C imaged in a single static exposure. In scan mode, the support structure MT and the substrate table WT are scanned synchronously while a pattern imparted to the radiation beam 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 MT may be determined by the (de-) magnification and image reversal characteristics of the projection system PS. In scan mode, the maximum size of the exposure field limits the width (in the non-scanning direction) of the target portion in a single dynamic exposure, whereas the length of the scanning motion determines the height (in the scanning direction) of the target portion. In another mode, the support structure MT is kept essentially stationary holding a programmable patterning device, and the substrate table WT is moved or scanned while a pattern imparted to the radiation beam is projected onto a target portion C. In this mode, generally a pulsed radiation source is 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 programmable patterning device, such as a programmable mirror array of a type as referred to above.

[0060] Combinations and / or variations on the above-described modes of use or entirely different modes of use may also be employed.

[0061] The substrate may be processed, before or after exposure, in for example a track (a tool that typically applies a layer of resist to a substrate and develops the exposed resist) or a metrology or inspection tool. 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 includesmultiple processed layers.

[0062] The terms “radiation” and “beam” used herein with respect to lithography encompass all types of electromagnetic radiation, including extreme ultra-violet (EUV) radiation (e.g. having a wavelength in the range of 5-20 nm).

[0063] Various patterns on or provided by a patterning device may have different process windows, i.e., a space of processing variables under which a pattern will be produced within specification. Examples of pattern specifications that relate to potential systematic defects include checks for necking, line pull back, line thinning, CD, edge placement, overlapping, resist top loss, resist undercut and / or bridging. The process window of the patterns on a patterning device or an area thereof may be obtained by merging (e.g., overlapping) process windows of each individual pattern. The boundary of the process window of a group of patterns comprises boundaries of process windows of some of the individual patterns. In other words, these individual patterns limit the process window of the group of patterns.

[0064] Fig. 2 further illustrates radiation source SO and lithographic apparatus LA, along with other components shown in Fig. 1. In Fig. 2, radiation source SO is an EUV laser produced plasma (LPP) source and lithographic apparatus LA is an EUV scanner. As described above, the radiation source SO is configured to generate an EUV radiation beam B and to supply the EUV radiation beam B to the lithographic apparatus LA. The lithographic apparatus LA comprises illumination system IL, support structure MT configured to support patterning device MA (e.g., a mask), projection system PS, and a substrate table WT configured to support a substrate W.

[0065] The illumination system IL is configured to condition the EUV radiation beam B before the EUV radiation beam B is incident upon the patterning device MA. The illumination system IL may include a facetted field mirror device 210 and a facetted pupil mirror device 211. The faceted field mirror device 210 and faceted pupil mirror device 211 together provide the EUV radiation beam B with a desired cross-sectional shape and a desired intensity distribution. The illumination system IL may include other mirrors or devices in addition to, or instead of, the faceted field mirror device 210 and faceted pupil mirror device 211.

[0066] After being conditioned, the EUV radiation beam B interacts with the patterning device MA. As a result of this interaction, a patterned EUV radiation beam B’ is generated. The projection system PS is configured to project the patterned EUV radiation beam B ’ onto the substrate W. For that purpose, the projection system PS may comprise a plurality of mirrors 213, 214 which are configured to project the patterned EUV radiation beam B’ onto the substrate W held by the substrate table WT. The projection system PS may apply a reduction factor to the patterned EUV radiation beam B’, thus forming an image with features that are smaller than corresponding features on the patterning device MA. For example, a reduction factor of 4 or 8 may be applied. Although the projection system PS is illustrated as having only two mirrors 213, 214 in Fig. 2, the projection system PS may include a different number of mirrors (e.g., six or eight mirrors).

[0067] The substrate W may include previously formed patterns. Where this is the case, the lithographic apparatus LA aligns the image, formed by the patterned EUV radiation beam B’, with a pattern previously formed on the substrate W.

[0068] A relative vacuum, i.e. a small amount of gas (e.g. hydrogen) at a pressure well below atmospheric pressure, may be provided in the radiation source SO, in the illumination system IL, and / or in the projection system PS.

[0069] The radiation source SO shown in Fig. 2 is, for example, of a type which may be referred to as a laser produced plasma (LPP) source. A laser system 201, which may, for example, include a CO2 laser, is arranged to deposit energy via a laser beam 202 into a fuel, such as tin (Sn) which is provided from, e.g., a fuel emitter 203. Although tin is referred to in the following description, any suitable fuel may be used. The fuel may, for example, be in liquid form, and may, for example, be a metal or alloy. The fuel emitter 203 may comprise a nozzle configured to direct tin, e.g. in the form of droplets, along a trajectory towards a plasma formation region 204. The laser beam 202 is incident upon the tin at the plasma formation region 204. The deposition of laser energy into the tin creates a tin plasma 207 at the plasma formation region 204. Radiation, including EUV radiation, is emitted from the plasma 207 during de-excitation and recombination of electrons with ions of the plasma.

[0070] The EUV radiation from the plasma is collected and focused by a collector 205. Collector 205 comprises, for example, a near-normal incidence radiation collector 205 (sometimes referred to more generally as a normal -incidence radiation collector). Collector 205 may have a multilayer mirror structure which is arranged to reflect EUV radiation (e.g., EUV radiation having a desired wavelength such as 13.5 nm). Collector 20 5 may have an ellipsoidal configuration, having two focal points. A first one of the focal points may be at the plasma formation region 204, and a second one of the focal points may be at an intermediate focus 206, as discussed below.

[0071] The laser system 201 may be spatially separated from the radiation source SO. Where this is the case, the laser beam 202 may be passed from the laser system 201 to the radiation source SO with the aid of a beam delivery system (not shown) comprising, for example, suitable directing mirrors and / or a beam expander, and / or other optics. The laser system 201, the radiation source SO and the beam delivery system may together be considered to be a radiation system.

[0072] Radiation that is reflected by the collector 205 forms the EUV radiation beam B. The EUV radiation beam B is focused at intermediate focus 206 to form an image at the intermediate focus 206 of the plasma present at the plasma formation region 204. The image at the intermediate focus 206 acts as a virtual radiation source for the illumination system IL. The radiation source SO is arranged such that the intermediate focus 206 is located at or near to an opening 208 in an enclosing structure 209 of the radiation source SO. Although Fig. 2 depicts the radiation source SO as a laser produced plasma (LPP) source, any suitable source such as a discharge produced plasma (DPP) source or a free electron laser (FEL) may be used to generate EUV radiation.

[0073] Fig. 3 is a more detailed view of collector 205 of source SO for the lithographic apparatus LA (shown in previous figures). Laser system 201 can be arranged to deposit laser energy into a fuel (as described above), creating a highly ionized plasma at formation region 204, with electron temperatures of several 10”s of eV. The energetic radiation generated during de-excitation and recombination of these ions is emitted from the plasma, collected by near normal incidence collector 205, and focused onto the opening 208 in the enclosing structure 209.

[0074] Existing heated tin mitigation modules for use inside a source such as source SO shown in Fig. 1-3 are typically produced using 316 stainless steel as a base material. Stainless steel can be machined using existing manufacturing technology and practices. Stainless steel can also be three dimensionally (3D) printed to form more elaborate shapes. Heater grooves are often cut (or printed) into the body of a module, and heaters are brazed in place. Brazing requires a high temperature (on the order of about 1000 °C), which is close to the melting temp of copper (aboutl080 °C) and / or other thermally conductive materials that might be used in a tin mitigation module, so module damage (including heater damage) is a possibility. The solidification of the braze and cooling of a tin mitigation module can also cause deformation unless adequate mechanical structure is included as part of a module. The application of a braze on a complex shape is difficult because the location of the braze often balances surface tension and gravity. Heaters are difficult to hold in position to form a correct braze gap. Brazing also has limited thickness available due to the uncontrolled nature of the process. Finally, complete bonding of a heater to a substrate is required when operating in vacuum (e.g., as in radiation source SO).

[0075] In contrast to prior systems, Fig. 4 illustrates a heat transfer system 400 for an extreme ultraviolet (EUV) radiation utilization apparatus. The EUV radiation utilization apparatus may be an EUV radiation source (e.g., SO described above and shown in Fig. 1-3), an inspection tool (e.g., a mask inspection tool), lithography apparatus (e.g., LA described above and shown in Fig. 1 and 2), and / or other EUV radiation utilization apparatuses. System 400 may be integrated into one or more components of such a system, be used on or with spare parts for such a system, be used to retrofit such a system or the system’s spare parts, and / or may be used in other ways. System 400 may also find application in other areas where controllable and / or otherwise predictable heat transfer to and / or through various components of a system are important.

[0076] System 400 facilitates direct deposit of metal (e.g., heat transfer portion 404 described below) on a heater through the use of cold spray technology. The deposited metal forms a bond with the heater (e.g. heater 420) as well as a base material (e.g. body 406 described below). Compared to brazing, cold spray technology occurs at room temperature, allows line of sight application, allows additional material to be added to provide a protective or conductive layer, facilitates repairs after inspection, and / or has other advantages.

[0077] System 400 comprises an EUV radiation utilization apparatus housing 402, a heat transferportion 404, one or more heaters 420, and / or other components. Housing 402 is configured support, enclose, surround, border, and / or otherwise house one or more components of the EUV radiation source or the lithography apparatus. Housing 402 may comprise a body 406. Body 406 is configured to provide structural rigidity to housing 402, a shape for housing 402, and / or may have other purposes. Body 406, may have any shape, size, thickness, etc. that allows system 400 to function as described herein. Body 406 may comprise stainless steel, mild steel, and / or other materials, for example. In some embodiments, body 406 comprises stainless steel. Body 406 may be formed by cold spraying, additive manufacturing, machining, assembling one or more sub components together to form body 406 (e.g., via screws, nuts, bolts, clips, clamps, adhesive, etc.), and / or other operations.

[0078] Heat transfer portion 404 is configured to facilitate heat transfer through one or more areas and / or an entirety of (e.g., stainless steel) body 406. As shown in Fig. 4, heat transfer portion 404 may be external to body 406. Alternatively or in addition thereto, heat transfer portion 404 may occupy a space within body 406 as shown in Fig. 7 and described below. Heat transfer portion 404 efficiently spreads heat throughout heat transfer portion 404. As a result, at some places of body 406, heat may be transferred from body 406 into heat transfer portion 404, and at other places heat may be transferred from heat transfer portion 404 into body 406. Facilitating heat transfer through one or more areas and / or an entirety of body 406 includes both of these, and / or other possibilities. Heat transfer portion 404 may comprise copper, copper and diamond, copper and aluminum oxide, copper and silicon carbide, steel and / or other metals, and / or other heat conductive materials, for example. In some embodiments, heat transfer portion 404 comprises copper.

[0079] Heat transfer portion 404 (e.g., a copper portion) is directly bonded 410 to (stainless steel) body 406. Direct bonding comprises a chemical, mechanical, heat based, and / or pressure based connection between surfaces, and / or portions of surfaces, of heat transfer portion 404 and body 406, without intervening or intermediary materials and / or other components. Direct bonding ensures that heat transfer portion 404 and body 406 touch and / or are otherwise in contact with each other.

[0080] Heat transfer portion 404 may be directly bonded 410 to body 406 using cold spray technology, for example. Cold spray technology comprises a low temperature ultrasonic and / or hypersonic spray nozzle configured to spray various materials, for example stainless steel powder, copper or copper matrix power, nickel powder, tin power, and / or other materials, to directly bond the heat transfer portion to the body. In the example shown in Fig. 4, cold spray technology may be used to spray copper or copper matrix power to directly bond heat transfer portion 404 to body 406. A grain structure of the (e.g., copper) heat transfer portion 404 and / or (e.g., the stainless steel) body 406 may show effects of cold spraying at sharp angles in the grain structure, and / or may include detectable Al Ox abrasives in (e.g., copper) heat transfer portion 404 caused by cold spraying, for example, among other possible effects. In some embodiments, the (e.g., copper) heat transfer portion 404 may be directly bonded 410 to (e.g., the stainless steel) body 406 using brazing with braze detectable in a stainless steel- copper interface; using melting; using plating; and / or using other methods.

[0081] One or more heaters 420 are configured to heat (e.g., stainless steel) body 406 and the (e.g., copper) heat transfer portion 404, and / or other componentsOne or more heaters 420 may compris one or more (e.g., radiative) heat sources and / or other heaters. For example, one or more heaters 420 may be formed by thermocoax heating elements . Each heating element may have one or two straight currentcarrying cores in a flexible metal sheath, electrically insulated from one another and from the sheath by means of a highly compacted refractory powder, for example.

[0082] Body 406 may comprise one or more cavities 430 configured to accommodate one or more heaters 420. One or more cavities 430 may comprise one or more grooves, slots, channels, depressions, pockets, orifices, and / or other structures. Heat transfer portion 404 (e.g., a copper portion) may be configured to cover one or more heaters 420 and / or cavities 430, and couple one or more heaters 420 to (e.g., stainless steel) body 406. For example, as shown in Fig. 4, heat transfer portion 404 may cover over one or more heaters 420 and fill in some or all of any additional available space in grooves that form cavities 430. This may ensure effective heat transfer as described herein, and / or have other purposes.

[0083] Heat transfer portion 404 (e.g., a copper portion) may be applied (e.g., via the cold spray technology described above) to body 406, and cavities 430 may be formed in heat transfer portion 404 (and / or body 406) - by, e.g., drilling, etching, etc., or body 406 may be selectively cold sprayed such that cavities 430 are not covered by heat transfer portion 404. In such embodiments, heaters 420 may be added after cold spray, for example.

[0084] There may be thermal transfer between (copper) heat transfer portion 404, a hydrogen gap, and / or subsequent surfaces coupled to (e.g., behind in the structure of an EUV radiation source) body 406. A narrow hydrogen gap is a relatively efficient heat convector (not as efficient as bonding two parts together, but much more efficient than vacuum, since there may typically be a 100-250 °C temperature delta over the hydrogen gap). Heat transfer portion 404 facilitates an efficient transfer of heat and thereby provides a more uniform and on average higher temperature on a non-tin facing side of body 406. When corresponding thermally controlled (for example water cooled) surfaces are placed in close proximity to non-tin facing surfaces of body 406, more heat is wicked away from body 406 to these cold surfaces, which leads to a desired lower temperature of the tin facing surfaces of body 406.

[0085] Fig. 5 illustrates an example of a cold spray technology system 500. Fig. 5 also shows a copper 502 (e.g., which forms heat transfer portion 404 shown in Fig. 4) and stainless steel 504 (which forms body 406 shown in Fig. 4) interface 506 produced by the cold spray technology system. Interface 506 illustrates a direct bond between copper 502 and stainless steel 504. In cold spray technology system 500, metal particles 510 (from a metal powder feeder 512) are injected into a gas stream 514 in a gas heater and pressurization chamber 520. Particles 510 may be copper metal particles, for example. Particles 510 accelerate at supersonic speeds and exit a spray nozzle 522. Particles 510 collide with asurface 530 and deform, sticking to the surface and each other. Surface 530 may be a stainless steel surface (e.g., of body 406 shown in Fig. 4), for example. The particles build up, forming a layer 540 on surface 530 (e.g., forming heat transfer portion 404 shown in Fig. 4).

[0086] As shown in Fig. 5, gas heater and pressurization chamber 520, and / or spray nozzle 522 may be moved and / or otherwise directed toward surface 530 by one or more mechanical systems 550 (a mechanical arm that is part of a six-axis robot in this example). Mechanical systems may include various moving components, structural supports, software controls, and / or other components configured to facilitate cold spraying as described herein. For example, spray nozzle 522 may be handled by a six-axis robot that runs on a linear rail, and surface 530 may be mounted on a turn table. Such a set up enables wide flexibility in manufacturing a system like system 400 shown in Fig. 4 and / or other systems. Fig. 5 also illustrates various valves and / or other gas control mechanisms 560 configured to regulate a flow of gas 570 to metal powder feeder 512 and / or gas heater and pressurization chamber 520.

[0087] Fig. 6 illustrates the advantageous flexible nature of cold spray technology. Fig. 6 illustrates gas heater and pressurization chamber 520, and spray nozzle 522, from Fig. 5 spraying metal particles 610. Metal particles 610 are sprayed in a gas stream so they collide with a surfaces 630 and deform, sticking to surfaces 630 and each other, to form layers 632 on surfaces 630. In this example, surfaces 630 may be 3D printed and / or have any number of different shapes. As described above, cold spray technology comprises a low temperature ultrasonic and / or hypersonic spray nozzle configured to spray various materials, for example copper or copper matrix power, to directly bond a heat transfer portion (layers 632 in this example) to a body (surfaces 630 in this example). Cold sprayed copper layers 632 may be selectively (i.e., in varied locations, in varied amounts, etc.) coated on surfaces 630 by controlling an orientation of nozzle 522, parameters of gas heater and pressurization chamber 520 (and / or other aspects of system 500 shown in Fig. 5), for example. As shown in Fig. 6, cold spray technology is flexibly adaptable to surfaces of different shapes (e.g., vertical, horizontal, bending, etc.) for directly bonding the heat transfer portion to the body. The low temperature nature of cold spray technology ensures surfaces 630 do not unexpectedly deform. Different layers of different materials can be sprayed onto surfaces 630.

[0088] In this example, surfaces 630 are shown as s-curves. Note that surfaces 630 in Fig. 6 should be considered representative examples of many possible components with various complex shapes. For example, in an EUV source context, surfaces 630 may be representative of a tine exhaust throat, a donut exhaust plenum, a heated exhaust liner, and / or other components (e.g., coated with l-3mm of copper spray to achieve a target thermal conductivity). Prior methods are not capable of providing such coatings on such parts. The reader should understand that the technique(s) disclosed here may be used for other areas beyond tin management in an EUV source. The technique(s) disclosed here describe a technique for turning a low thermally conductive part of complex shape into a high thermally conductivepart, with conventional metals. This has many possible applications.

[0089] Fig. 7 illustrates an example 700 of system 400 shown in Fig. 4 where heat transfer portion 404 (e.g., a copper portion) comprises one or more pockets 702 within (e.g., stainless steel) body 406.

[0090] As described above, in a typical radiation source, a tin mitigation module comprises a tin, nickel, stainless steel, copper, and stainless steel stack. Producing this stack involves an extensive number of manufacturing steps, making it difficult to produce, along with having other disadvantages (see discussion above). The follow process steps are required to produce such a stack: 1. pouring molten copper into a preformed stainless steel cavity utilizing gravity, and solidifying the copper; 2. welding a stainless steel cap to encapsulate the copper; 3. machining grooves for cable heaters; 4. vacuum brazing the cable heaters to form solid contacts (though this most often results in only partial contact) to stainless steel; 5. applying a physical vapor deposition (PVD) or chemical vapor deposition (CVD) coating of titanium nitride (TiN) to protect braze materials from tin corrosion during usage; 6. masking the non- EUV facing side of the stack with wax; 7. performing electroless deposition of a nickel (Ni) strike on the EUV facing side of the stack; 8. electroplating of tin on the nickel; 9. removing the wax masking manually; and 10. cleaning off wax residues. These process steps are complex, requiring wet electro deposition, high temperature vacuum deposition, phase change of materials, and highly specialized brazing, making it one of the most difficult EUV source related components to manufacture.

[0091] In contrast, example 700 (along with system 400 shown in Fig. 4) is significantly less complex to manufacture because cold spray technology is utilized, as described above.

[0092] The one or more pockets 702 may be located directly adjacent to the one or more heaters 420, for example. Grooves (cavities 430) may be formed 711 in pockets 702, and heaters 420 may be placed 713 into the grooves (cavities 430). Heat transfer portion 404 (copper in this example) may be cold sprayed 715 to directly bond heat transfer portion 404 (and heaters 420) to body 406. Excess copper (in this example) may be machined 717 away.

[0093] One or more pockets 702 are capped 710 with a layer 712. Layer 712 may be a stainless steel layer, for example, and / or may be formed from other materials. Layer 712 may be also be deposited using cold spray technology (e.g., such that a grain structure of the stainless steel layer shows effects of cold spraying at sharp angles in the grain structure caused by cold spraying) and / or other technologies. Layer 712 may encase the (e.g., copper) heat transfer portion 404, for example, as shown in Fig. 7. In some embodiments, (e.g., stainless steel) layer 712 may be welded to (e.g., stainless steel) body 406 and / or coupled to body 406 using other techniques.

[0094] A first side 750 of (e.g., stainless steel) body 406, that is opposite a second side 752 comprising (e.g., copper) heat transfer portion 404, may be configured to face a tin rich environment in an EUV source. The first side 750 and / or second side 752 may be coated with titanium nitride (TiN) coating on the first side 750 and / or the second side 752 of body 406. There may be an electroless nickel (Ni) layer 780 and / or an electroplated tin (Sn) layer 790 formed (at 782 and 792, respectively) on firstside 750 of body 406. Instead or in addition, a layer of molybdenum and / or other materials may be formed on first side 750 and / or second side 752. Note that these layers (though not shown in other figures), may be included in any embodiment of the heat transfer system described herein (e.g., system 400 shown in Fig. 4, 5, 6, 7, and / or 8 (described below)).

[0095] Fig. 8 illustrates another example 800 of system 400 shown in Fig. 4 with one or more pockets 702 located between one or more heaters 420. Heat transfer portion 404 comprises copper (Cu) as shown. One or more heaters 420 may be brazed to (e.g., stainless steel) body 406, for example, and / or coupled to body 406 using other methods. This structure provides a heat transfer system (e.g., similar to and / or the system as system 400 shown in Fig. 4) with a relatively stable temperature 810 versus position 812 profile 814 (i.e., there is little variation between maxims and minimums in profile 814) across body 406.

[0096] In an EUV source context, existing heated tin mitigation modules are produced using 316 stainless steel as a base material. This material makes use of existing manufacturing technology and practices. It can also be 3D printed to form more elaborate shapes. Heater grooves are cut (or printed) into the body and heaters are brazed in place. A coating of Titanium nitride (TiN) is applied to protect the heaters, braze, and base material from liquid tin attack (at temperatures above 232C, for example). A disadvantage of most stainless steels is low thermal conductivity. Heating of modules is done with brazed heaters. However, temperature rapidly declines as the distance from the heater increases. This leads to large temperature variation and large minimum and / or maximum temperatures.

[0097] Example 800 (along with example 700 shown in Fig. 7 and system 400 shown in Fig. 4) provides better thermal control of tin facing and / or other surfaces - below melting temperature or above melting temperature, among other advantages. In the tin mitigation application, the EUV source produces a large amount of hot gasses that directly apply heat to several surfaces. This hot gas makes some of the surfaces go above tin melting temperature, without any heater input. Example 800 is a hybrid metal structure of stainless steel (for manufacturing and tin compatibility) and copper (for thermal conductivity). The stainless steel provides a rigid structure which can withstand the braze process and physical handling. The copper is bonded directly to the stainless steel (as described above) and provides a highly thermally conductive path to distribute heat - either heater supplied or external supplied (e.g., from the hot gasses discussed above). The result is a structure with a composite thermal conductivity that can be tailored to the application.

[0098] The various components (body 406, heat transfer portion 404, heaters 420, etc.) may be positioned in any location and / or at any angle relative to each other that allows system 400 (Fig. 4, Fig. 7, Fig. 8, etc.) to function as described herein. This may include positioning at specific relative distances between elements, specific angles between elements, etc. The quantity of the various components that are shown and described is also not intended to be limiting. The principles described herein may be extended such that, in some embodiments system 400 comprises additional or fewer heaters, bodies,heat transfer components, and / or other components.

[0099] Fig . 9 illustrates a heat transfer method 900 and / or method of manufacturing of a heat transfer system, for example for an extreme ultraviolet (EUV) radiation utilization apparatus. The method 900 may be performed prior to and / or as part of a patterning operation in a semiconductor device manufacturing process, for example. In some embodiments, one or more operations of method 900 may be implemented in or by system 400 illustrated in Fig. 4, a computer system (e.g., as illustrated in Fig. 10 and described below), and / or in or by other systems, for example. Method 900 may comprise providing a body (operation 902); coupling one or more heaters configured to heat the body (operation 904); directly bonding a heat transfer portion to the body (operation 906); and / or other operations. The operations of method 900 are intended to be illustrative. For example, method 900 may be accomplished with one or more additional operations not described, and / or without one or more of the operations discussed. Additionally, the order in which the operations of method 900 are illustrated in Fig. 9 and described herein is not intended to be limiting.

[0100] One or more portions of method 900 may be implemented in and / or controlled by one or more processing devices (e.g., a digital processor, an analog processor, a digital circuit designed to process information, an analog circuit designed to process information, a state machine, and / or other mechanisms for electronically processing information). For example, heating may be controlled by the one or more processing devices. The one or more processing devices may include one or more devices executing some or all of the operations of method 900 in response to instructions stored electronically on an electronic storage medium. The one or more processing devices may include one or more devices configured through hardware, firmware, and / or software to be specifically designed for execution of one or more of the operations of method 900 (e.g., see discussion related to Fig. 10 below).

[0101] At operation 902, a body may be provided. The body may be part of a housing which is configured to support, enclose, surround, border, and / or otherwise house one or more components of an EUV radiation utilization apparatus such as an EUV radiation source, an inspection tool, a lithography apparatus, and / or other EUV radiation utilization apparatuses. The body is configured to provide structural rigidity to the housing, a shape for the housing, and / or may have other purposes. The body, may have any shape, size, thickness, etc. that allows it to function as described herein. In some embodiments, the body comprises stainless steel, mild steel, and / or other materials, for example. The body may be formed by cold spraying, additive manufacturing, machining, assembling one or more sub components together to form the body (e.g., via screws, nuts, bolts, clips, clamps, adhesive, etc.), and / or other operations. Operation 902 may comprise providing a body the same as or similar to body 406 shown in Fig. 4, and / or other components described above.

[0102] At operation 904, one or more heaters configured to heat the body are coupled. The one or more heaters are configured to heat the (e.g., stainless steel) body, the heat transfer portion, and / or other components. The one or more heaters may comprise one or more (e.g., radiative) heat sources and / orother heaters. Operation 904 may comprise configuring a heater the same as or similar to heater 420 shown in Fig. 4, and / or other components described above.

[0103] At operation 906, the heat transfer portion is directly bonded to the body. The heat transfer portion is configured to facilitate heat transfer through one or more areas and / or an entirety of the (e.g., stainless steel) body. The heat transfer portion may comprise copper, copper and diamond, copper and aluminum oxide, copper and silicon carbide, and / or other heat conductive materials, for example.

[0104] The heat transfer portion (e.g., a copper portion) is directly bonded to the (stainless steel) body. Direct bonding comprises a chemical, mechanical, heat based, and / or pressure based connection between surfaces, and / or portions of surfaces, of the heat transfer portion and the body, without intervening or intermediary materials and / or other components. Direct bonding ensures that heat transfer portion 404 and body 406 touch and / or are otherwise in contact with each other.

[0105] The heat transfer portion may be directly bonded to the body using cold spray technology, for example. A grain structure of the (e.g., copper) heat transfer portion and / or the (e.g., stainless steel) body may show effects of cold spraying at sharp angles in the grain structure, and / or may include detectable Al Ox abrasives in the (e.g., copper) heat transfer portion caused by cold spraying, for example, among other possible effects. The (e.g., copper) heat transfer portion may be directly bonded to the (e.g., stainless steel) body using brazing with braze detectable in a stainless steel - copper interface; using melting; using plating; and / or using other methods.

[0106] The (e.g., stainless steel) body may comprise one or more cavities configured to accommodate one or more heaters. The one or more cavities may comprise one or more grooves, slots, channels, depressions, pockets, orifices, and / or other structures. The heat transfer portion (e.g., a copper portion) may be configured to cover one or more heaters and / or cavities, and couple one or more heaters to the (e.g., stainless steel) body. For example, the heat transfer portion may cover over one or more heaters and fill in some or all of any additional available space in grooves that form cavities. This may ensure effective heat transfer as described herein, and / or have other purposes.

[0107] Operation 906 may be performed employing a heat transfer portion the same as or similar to heat transfer portion 404 shown in Fig. 4, and / or other components described above.

[0108] The heat transfer portion (e.g., a copper portion) may comprise one or more pockets within the (e.g., stainless steel) body. The one or more pockets may be located directly adjacent to the one or more heaters, for example. Grooves may be formed in the pockets, and heaters may be placed into the grooves (e.g., before being covered with the heat transfer portion (e.g., as shown in Fig. 7 and described above).

[0109] Method 900 may comprise capping or more pockets with a layer. The layer may be a stainless steel layer, for example, and / or may be formed from other materials. The layer may be deposited using cold spray technology (e.g., such that a grain structure of the stainless steel layer shows effects of cold spraying at sharp angles in the grain structure caused by cold spraying) and / or other technologies. Thelayer may encase the (e.g., copper) heat transfer portion, for example, as shown in Fig. 7. The (e.g., stainless steel) layer may be welded to the (e.g., stainless steel) body and / or coupled to the body using other techniques.

[0110] A first side of the (e.g., stainless steel) body, that is opposite a second side comprising the (e.g., copper) heat transfer portion, may be configured to face a tin rich environment in an EUV source. Method 900 may optionally comprise coating the first side and / or the second side with titanium nitride (TiN) coating on the first side and / or the second side of the body. Method 900 may for example comprise forming an electroless nickel (Ni) layer and / or an electroplated tin (Sn) layer on first side of body (e.g., as shown in Fig. 7 and described above). Instead or in addition, method 900 may comprise forming a layer of molybdenum and / or other materials on the first side and / or the second side.

[0111] Fig. 10 is a diagram of an example computer system CS that may be used for, or to control one or more of the operations described herein (e.g., a cold spraying operation). Computer system CS includes a bus BS or other communication mechanism for communicating information, and a processor PRO coupled with bus BS for processing information. Computer system CS also includes a main memory MM, such as a random access memory (RAM) or other dynamic storage device, coupled to bus BS for storing information and instructions to be executed by processor PRO. Main memory MM also may be used for storing temporary variables or other intermediate information during execution of instructions by processor PRO. Computer system CS further includes a read only memory (ROM) ROM or other static storage device coupled to bus BS for storing static information and instructions for processor PRO. A storage device SD, such as a magnetic disk or optical disk, is provided and coupled to bus BS for storing information and instructions.

[0112] Computer system CS may be coupled via bus BS to a display DS, such as a flat panel or touch panel display or a cathode ray tube (CRT) for displaying information to a computer user. An input device ID, including alphanumeric and other keys, is coupled to bus BS for communicating information and command selections to processor PRO. Another type of user input device is cursor control CC, such as a mouse, a trackball, or cursor direction keys for communicating direction information and command selections to processor PRO and for controlling cursor movement on display DS. This input device typically has two degrees of freedom in two axes, a first axis (e.g., x) and a second axis (e.g., y), that allows the device to specify positions in a plane. A touch panel (screen) display may also be used as an input device.

[0113] All or some of one or more operations described herein may be performed by computer system CS in response to processor PRO executing one or more sequences of one or more instructions contained in main memory MM. Such instructions may be read into main memory MM from another computer-readable medium, such as storage device SD. Execution of the sequences of instructions included in main memory MM causes processor PRO to perform the process steps (operations) described herein. One or more processors in a multi-processing arrangement may also be employed toexecute the sequences of instructions contained in main memory MM. Hard-wired circuitry may be used in place of or in combination with software instructions. Thus, the description herein is not limited to any specific combination of hardware circuitry and software.

[0114] The term “computer-readable medium” or “machine-readable medium” as used herein refers to any medium that participates in providing instructions to processor PRO for execution. Such a medium may take many forms, including but not limited to, non-volatile media, volatile media, and transmission media. Non-volatile media include, for example, optical or magnetic disks, such as storage device SD. Volatile media include dynamic memory, such as main memory MM. Transmission media include coaxial cables, copper wire and fiber optics, including the wires that comprise bus BS. Transmission media can also take the form of acoustic or light waves, such as those generated during radio frequency (RF) and infrared (IR) data communications. Computer-readable media can be non- transitory, for example, a floppy disk, a flexible disk, hard disk, magnetic tape, any other magnetic medium, a CD-ROM, DVD, any other optical medium, punch cards, paper tape, any other physical medium with patterns of holes, a RAM, a PROM, and EPROM, a FLASH-EPROM, any other memory chip or cartridge. Non-transitory computer readable media can have instructions recorded thereon. The instructions, when executed by a computer, can implement any of the operations described herein. Transitory computer-readable media can include a carrier wave or other propagating electromagnetic signal, for example.

[0115] Various forms of computer readable media may be involved in carrying one or more sequences of one or more instructions to processor PRO for execution. For example, the instructions may initially be borne on a magnetic disk of a remote computer. The remote computer can load the instructions into its dynamic memory and send the instructions over a network. Computer system CS can receive the data and place the data on bus BS. Bus BS carries the data to main memory MM, from which processor PRO retrieves and executes the instructions. The instructions received by main memory MM may optionally be stored on storage device SD either before or after execution by processor PRO.

[0116] Computer system CS may also include a communication interface CI coupled to bus BS. Communication interface CI provides a two-way data communication coupling to a network link NDL that is connected to a local network LAN. For example, communication interface CI may be an integrated services digital network (ISDN) card or a modem to provide a data communication connection to a corresponding type of telephone line. As another example, communication interface CI may be a local area network (LAN) card to provide a data communication connection to a compatible LAN. Wireless links may also be implemented. In any such implementation, communication interface CI sends and receives electrical, electromagnetic or optical signals that carry digital data streams representing various types of information.

[0117] Network link NDL typically provides data communication through one or more networks toother data devices. For example, network link NDL may provide a connection through local network LAN to a host computer HC. This can include data communication services provided through the worldwide packet data communication network, now commonly referred to as the “Internet” INT. Local network LAN (Internet) may use electrical, electromagnetic or optical signals that carry digital data streams. The signals through the various networks and the signals on network data link NDL and through communication interface CI, which carry the digital data to and from computer system CS, are exemplary forms of carrier waves transporting the information.

[0118] Computer system CS can send messages and receive data, including program code, through the network(s), network data link NDL, and communication interface CL In the Internet example, host computer HC might transmit a requested code for an application program through Internet INT, network data link NDL, local network LAN, and communication interface CL One such downloaded application may provide all or part of a method described herein, for example. The received code may be executed by processor PRO as it is received, and / or stored in storage device SD, or other non-volatile storage for later execution. In this manner, computer system CS may obtain application code in the form of a carrier wave.

[0119] Various embodiments of the present systems and methods are disclosed in the subsequent list of numbered clauses. In the following, further features, characteristics, and exemplary technical solutions of the present disclosure will be described in terms of clauses that may be optionally claimed in any combination:1. A heat transfer system for an extreme ultraviolet (EUV) radiation utilization apparatus, comprising: an EUV radiation utilization apparatus housing comprising a stainless steel body; and a copper portion directly bonded to the stainless steel body, the copper portion configured to facilitate heat transfer through the stainless steel body.2. The system of clause 1, wherein the copper portion is directly bonded to the stainless steel body using cold spray technology.3. The system of any of the previous clauses, wherein a grain structure of the copper portion and / or the stainless steel body shows effects of cold spraying at sharp angles in the grain structure, and / or includes detectable Al Ox abrasives in the copper portion caused by cold spraying.4. The system of any of the previous clauses, wherein the copper portion is directly bonded to the stainless steel body using brazing with braze detectable in a stainless steel - copper interface; using melting; or using plating.5. The system of any of the previous clauses, further comprising one or more heaters configured to heat the stainless steel body and the copper portion.6. The system of any of the previous clauses, wherein the one or more heaters comprise one or more heat sources.7. The system of any of the previous clauses, wherein the stainless steel body comprises one or morecavities configured to accommodate the one or more heaters.8. The system of any of the previous clauses, wherein the one or more cavities comprise one or more grooves.9. The system of any of the previous clauses, wherein the copper portion is configured to cover the one or more heaters, and couple the one or more heaters to the stainless steel body.10. The system of any of the previous clauses, wherein the copper portion comprises one or more pockets within the stainless steel body.11. The system of any of the previous clauses, wherein the one or more pockets are located directly adjacent to the one or more heaters.12. The system of any of the previous clauses, wherein the one or more pockets are capped with a stainless steel layer deposited using cold spray technology to encase the copper portion.13. The system of any of the previous clauses, wherein a grain structure of the stainless steel layer shows effects of cold spraying at sharp angles in the grain structure caused by cold spraying.14. The system of any of the previous clauses, wherein the stainless steel layer is welded to the stainless steel body.15. The system of any of the previous clauses, wherein the one or more pockets are located between the one or more heaters.16. The system of any of the previous clauses, wherein the one or more heaters are brazed to the stainless steel body.17. The system of any of the previous clauses, wherein the stainless steel body is formed by cold spraying, additive manufacturing, and / or machining.18. The system of any of the previous clauses, wherein a first side of the stainless steel body, that is opposite a second side comprising the copper portion, is configured to face a tin rich environment in the EUV radiation utilization apparatus.19. The system of any of the previous clauses, further comprising: a titanium nitride (TiN) coating on the first side and / or the second side of the stainless steel body; an electroless nickel (Ni) layer and / or an electroplated tin (Sn) layer formed on the first side of the stainless steel body; and / or a layer of molybdenum formed on the first side and / or the second side.20. The system of any of the previous clauses, wherein the radiation utilization apparatus comprises an EUV radiation source, an inspection tool, or a lithography apparatus.21. A heat transfer system for an extreme ultraviolet (EUV) radiation utilization apparatus, comprising: a body; one or more heaters configured to heat the body; and a heat transfer portion directly bonded to the body using cold spray technology, the heat transfer portion configured to couple the one or more heaters to the body, and facilitate heat transfer through the body.22. The system of any of the previous clauses, wherein a grain structure of the body and / or the heat transfer portion shows effects of cold spraying at sharp angles in the grain structure, and / or includesdetectable abrasives in the heat transfer portion caused by cold spraying.23. The system of any of the previous clauses, wherein the body comprises stainless steel or mild steel; and the heat transfer portion comprises copper, copper and diamond, copper and aluminum oxide, or copper and silicon carbide.24. The system of any of the previous clauses, wherein the one or more heaters comprise one or more heat sources.25. The system of any of the previous clauses, wherein the body comprises one or more cavities configured to accommodate the one or more heaters.26. The system of any of the previous clauses, wherein the one or more cavities comprise one or more grooves.27. The system of any of the previous clauses, wherein the heat transfer portion is configured to cover the one or more heaters, and couple the one or more heaters to the body.28. The system of any of the previous clauses, wherein the heat transfer portion comprises one or more pockets within the body.29. The system of any of the previous clauses, wherein the one or more pockets contact the one or more heaters.30. The system of any of the previous clauses, wherein the one or more pockets are encased with a layer deposited using cold spray technology.31. The system of any of the previous clauses, wherein a grain structure of the layer shows effects of cold spraying at sharp angles in the grain structure caused by cold spraying.32. The system of any of the previous clauses, wherein the one or more pockets are encased with a layer welded to the body.33. The system of any of the previous clauses, wherein the one or more pockets are located between the one or more heaters.34. The system of any of the previous clauses, wherein the one or more heaters are brazed to the body.35. The system of any of the previous clauses, wherein the body is formed by cold spraying, additive manufacturing, and / or machining.36. The system of any of the previous clauses, wherein a first side of the body, that is opposite a second side comprising the heat transfer portion, is configured to face a tin rich environment in the EUV radiation utilization apparatus.37. The system of any of the previous clauses, further comprising a titanium nitride (TiN) coating on the first side and / or the second side of the body.38. The system of any of the previous clauses, further comprising an electroless nickel (Ni) layer formed on the first side of the body.39. The system of any of the previous clauses, further comprising an electroplated tin (Sn) layer formed on the first side of the body; and / or a layer of molybdenum formed on the first side of the body.40. The system of any of the previous clauses, wherein the radiation utilization apparatus comprises an EUV radiation source, an inspection tool, or a lithography apparatus.41. A heat transfer method for an extreme ultraviolet (EUV) radiation utilization apparatus, comprising: providing an EUV radiation utilization apparatus housing comprising a stainless steel body; and directly bonding a copper portion to the stainless steel body, the copper portion configured to facilitate heat transfer through the stainless steel body.42. A method of method of manufacturing a heat transfer system for an extreme ultraviolet (EUV) radiation utilization apparatus, said method comprising: providing an EUV radiation utilization apparatus housing comprising a stainless steel body; and directly bonding a copper portion to the stainless steel body, the copper portion configured to facilitate heat transfer through the stainless steel body.43. The method of clause 41 or 42, wherein the copper portion is directly bonded to the stainless steel body using cold spray technology.44. The method of any of clauses 41-43, wherein a grain structure of the copper portion and / or the stainless steel body shows effects of cold spraying at sharp angles in the grain structure, and / or includes detectable Al Ox abrasives in the copper portion caused by cold spraying.45. The method of any of clauses 41-44, wherein the copper portion is directly bonded to the stainless steel body using brazing with braze detectable in a stainless steel - copper interface; using melting; or using plating.46. The method of any of clauses 41-45, further comprising heating the stainless steel body and the copper portion with one or more heaters.47. The method of any of clauses 41-46, wherein the one or more heaters comprise one or more heat sources.48. The method of any of clauses 41-47, wherein the stainless steel body comprises one or more cavities configured to accommodate the one or more heaters.49. The method of any of clauses 41-48, wherein the one or more cavities comprise one or more grooves.50. The method of any of clauses 41-49, wherein the copper portion is configured to cover the one or more heaters, and couple the one or more heaters to the stainless steel body.51. The method of any of clauses 41-50, wherein the copper portion comprises one or more pockets within the stainless steel body.52. The method of any of clauses 41-51, wherein the one or more pockets are located directly adjacent to the one or more heaters.53. The method of any of clauses 41-52, wherein the one or more pockets are capped with a stainless steel layer deposited using cold spray technology to encase the copper portion.54. The method of any of clauses 41-53, wherein a grain structure of the stainless steel layer shows effects of cold spraying at sharp angles in the grain structure caused by cold spraying.55. The method of any of clauses 41-54, wherein the stainless steel layer is welded to the stainless steel body.56. The method of any of clauses 41-55, wherein the one or more pockets are located between the one or more heaters.57. The method of any of clauses 41-56, wherein the one or more heaters are brazed to the stainless steel body.58. The method of any of clauses 41-57, wherein the stainless steel body is formed by cold spraying, additive manufacturing, and / or machining.59. The method of any of clauses 41-58, wherein a first side of the stainless steel body, that is opposite a second side comprising the copper portion, is configured to face a tin rich environment in the EUV radiation utilization apparatus.60. The method of any of clauses 41-59, further comprising: coating a titanium nitride (TiN) coating on the first side and / or the second side of the stainless steel body; forming an electroless nickel (Ni) layer and / or an electroplated tin (Sn) layer on the first side of the stainless steel body; and / or forming a layer of molybdenum on the first side and / or the second side .61. The method of any of clauses 41-60, wherein the radiation utilization apparatus comprises an EUV radiation source, an inspection tool, or a lithography apparatus.62. A heat transfer method for an extreme ultraviolet (EUV) radiation utilization apparatus, comprising: providing a body; coupling one or more heaters configured to heat the body; and directly bonding a heat transfer portion to the body using cold spray technology, the heat transfer portion configured to couple the one or more heaters to the body, and facilitate heat transfer through the body.63. A method of manufacturing a heat transfer system for an extreme ultraviolet (EUV) radiation utilization apparatus, said method comprising: providing a body; coupling one or more heaters configured to heat the body; and directly bonding a heat transfer portion to the body using cold spray technology, the heat transfer portion configured to couple the one or more heaters to the body, and facilitate heat transfer through the body.64. The method of any of clauses 62 or 63, wherein a grain structure of the body and / or the heat transfer portion shows effects of cold spraying at sharp angles in the grain structure, and / or includes detectable abrasives in the heat transfer portion caused by cold spraying.65. The method of any of clauses 62-64, wherein the body comprises stainless steel or mild steel; and the heat transfer portion comprises copper, copper and diamond, copper and aluminum oxide, or copper and silicon carbide.66. The method of any of clauses 62-65, wherein the one or more heaters comprise one or more heat sources.67. The method of any of clauses 62-66, wherein the body comprises one or more cavities configured to accommodate the one or more heaters.68. The method of any of clauses 62-67, wherein the one or more cavities comprise one or more grooves.69. The method of any of clauses 62-68, wherein the heat transfer portion is configured to cover the one or more heaters, and couple the one or more heaters to the body.70. The method of any of clauses 62-69, wherein the heat transfer portion comprises one or more pockets within the body.71. The method of any of clauses 62-70, wherein the one or more pockets contact the one or more heaters.72. The method of any of clauses 62-71, wherein the one or more pockets are encased with a layer deposited using cold spray technology.73. The method of any of clauses 62-72, wherein a grain structure of the layer shows effects of cold spraying at sharp angles in the grain structure caused by cold spraying.74. The method of any of clauses 62-73, wherein the one or more pockets are encased with a layer welded to the body.75. The method of any of clauses 62-74, wherein the one or more pockets are located between the one or more heaters.76. The method of any of clauses 62-75, wherein the one or more heaters are brazed to the body.77. The method of any of clauses 62-76, wherein the body is formed by cold spraying, additive manufacturing, and / or machining.78. The method of any of clauses 62-77, wherein a first side of the body, that is opposite a second side comprising the heat transfer portion, is configured to face a tin rich environment in the EUV radiation utilization apparatus.79. The method of any of clauses 62-78, further comprising coating a titanium nitride (TiN) coating on the first side and / or the second side of the body.80. The method of any of clauses 62-79, further comprising forming an electroless nickel (Ni) layer on the first side of the body.81. The method of any of clauses 62-80, further comprising forming an electroplated tin (Sn) layer on the first side of the body; and / or forming a layer of molybdenum on the first side of the body.82. The method of any of clauses 62-81, wherein the radiation utilization apparatus comprises an EUV radiation source, an inspection tool, or a lithography apparatus.

[0120] The concepts disclosed herein may be associated with any generic patterning system for patterning sub wavelength features, and may be especially useful with emerging patterning technologies capable of producing increasingly shorter wavelengths. Emerging technologies already in use include EUV (extreme ultra violet), DUV lithography that is capable of producing a 193nm wavelength with the use of an ArF laser, and even a 157nm wavelength with the use of a Fluorine laser. Moreover, EUV lithography is capable of producing wavelengths within a range of 20-5nm by hitting a material (either solid or a plasma) with high energy electrons in order to produce photons within this range.

[0121] While the concepts disclosed herein may be used for patterning on a substrate such as a silicon wafer, it shall be understood that the disclosed concepts may be used with any type of lithographic patterning systems, e.g., those used for patterning on substrates other than silicon wafers. In addition, the combination and sub-combinations of disclosed elements may comprise separate embodiments.

[0122] The descriptions above are intended to be illustrative, not limiting. Thus, it will be apparent to one skilled in the art that modifications may be made as described without departing from the scope of the claims set out below.

Claims

CLAIMS1. A heat transfer system for an extreme ultraviolet (EUV) radiation utilization apparatus, comprising: an EUV radiation utilization apparatus housing comprising a stainless steel body; and a copper portion directly bonded to the stainless steel body, the copper portion configured to facilitate heat transfer through the stainless steel body.

2. The system of claim 1, wherein the copper portion is directly bonded to the stainless steel body using cold spray technology.

3. The system of claim 2, wherein a grain structure of the copper portion and / or the stainless steel body shows effects of cold spraying at sharp angles in the grain structure, and / or includes detectable A1OXabrasives in the copper portion caused by cold spraying.

4. The system of claim 1, wherein the copper portion is directly bonded to the stainless steel body using brazing with braze detectable in a stainless steel - copper interface; using melting; or using plating.

5. The system of any of claims 1 -4, further comprising one or more heaters configured to heat the stainless steel body and the copper portion.

6. The system of claim 5, wherein the stainless steel body comprises one or more cavities configured to accommodate the one or more heaters, said one or more cavities optionally comprising one or more grooves.

7. The system of any of claims 5-6, wherein the copper portion is configured to cover the one or more heaters, and couple the one or more heaters to the stainless steel body.

8. The system of any of claims 5-7, wherein the copper portion comprises one or more pockets within the stainless steel body.

9. The system of claim 8, wherein the one or more pockets are located directly adjacent to the one or more heaters.

10. The system of claim 9, wherein the one or more pockets are capped with a stainless steel layer deposited using cold spray technology to encase the copper portion.

11. The system of claim 10, wherein a grain structure of the stainless steel layer shows effects of cold spraying at sharp angles in the grain structure caused by cold spraying.

12. The system of claim 10, wherein the stainless steel layer is welded to the stainless steel body.

13. The system of claim 8 or 9, wherein the one or more pockets are located between the one or more heaters.

14. The system of claim 13, wherein the one or more heaters are brazed to the stainless steel body.

15. The system of any of claims 1-14, wherein the stainless steel body is formed by cold spraying, additive manufacturing, and / or machining.

16. The system of any of claims 1-15, wherein a first side of the stainless steel body, that is opposite a second side comprising the copper portion, is configured to face a tin rich environment in the EUV radiation utilization apparatus.

17. The system of claim 16, further comprising: a titanium nitride (TiN) coating on the first side and / or the second side of the stainless steel body; an electroless nickel (Ni) layer and / or an electroplated tin (Sn) layer formed on the first side of the stainless steel body; and / or a layer of molybdenum formed on the first side and / or the second side.

18. The system of any one of claims 1-17, wherein the radiation utilization apparatus comprises an EUV radiation source, an inspection tool, or a lithography apparatus.

19. A heat transfer method for an extreme ultraviolet (EUV) radiation utilization apparatus, comprising: providing an EUV radiation utilization apparatus housing comprising a stainless steel body; and directly bonding a copper portion to the stainless steel body, the copper portion configured to facilitate heat transfer through the stainless steel body.

20. A method of manufacturing a heat transfer system for an extreme ultraviolet (EUV) radiation utilization apparatus, said method comprising:providing an EUV radiation utilization apparatus housing comprising a stainless steel body; and directly bonding a copper portion to the stainless steel body, the copper portion configured to facilitate heat transfer through the stainless steel body.

21. A heat transfer system for an extreme ultraviolet (EUV) radiation utilization apparatus, comprising: a body; one or more heaters configured to heat the body; and a heat transfer portion directly bonded to the body using cold spray technology, the heat transfer portion configured to couple the one or more heaters to the body, and facilitate heat transfer through the body.

22. A heat transfer method for an extreme ultraviolet (EUV) radiation utilization apparatus, comprising: providing a body; coupling one or more heaters configured to heat the body; and directly bonding a heat transfer portion to the body using cold spray technology, the heat transfer portion configured to couple the one or more heaters to the body, and facilitate heat transfer through the body.

23. A method of manufacturing a heat transfer system for an extreme ultraviolet (EUV) radiation utilization apparatus, said method comprising: providing a body; coupling one or more heaters configured to heat the body; and directly bonding a heat transfer portion to the body using cold spray technology, the heat transfer portion configured to couple the one or more heaters to the body, and facilitate heat transfer through the body.

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