High force low vibration cylindrical linear motor

Abstract

A cylindrical linear motor is described that reduces or eliminates cogging and can provide more efficient cooling to achieve higher acceleration. The cylindrical linear motor includes a novel structure for efficient cooling. In some embodiments, there is a cylindrical linear mover that includes magnets, such as Halbach magnets, arranged in a radial structure such that the orientation of the magnets is radially uniform. Surrounding the cylindrical mover are a series of circular (disc-shaped) coils, circular cooling plates, and circular backiron armatures stacked repeatedly in sets of three. In other embodiments, the new linear motor includes cylindrical cooling plates of different radial sizes, each concentrically spaced around the cylindrical mover.

Description

HIGH FORCE LOW VIBRATION CYLINDRICAL LINEAR MOTORCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority of US application 63 / 674,267 which was filed on July 22, 2024 and which is incorporated herein in its entirety by reference.TECHNICAL FIELD

[0002] This description relates generally to high force cylindrical linear motors with low vibration.BACKGROUND

[0003] Linear actuators are known. Also known as permanent magnet linear synchronous motors (PMSMs), multi-phase electromagnetic linear actuators have been used as long stroke actuators in lithography apparatuses, metrology systems, and other devices, for example. A lithography (e.g., projection) apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In such a case, a patterning device (e.g., a mask) may contain 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. In general, a single substrate contains a plurality of adjacent target portions to which the pattern is transferred successively by the lithographic projection 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. Various movements of the lithography apparatus may be facilitated by one or more linear actuators.

[0004] There are various kinds of linear actuators, including Lorentz actuators, Linear Motor Motion Systems (LiMMS), and cylindrical linear drive motors. Existing motors each have some drawbacks, while the overall goal may be to improve acceleration capabilities while minimizing unwanted effects. It is desirable to develop new kinds of forcers with higher force densities while reducing negative characteristics. It is also desirable to use less energy to create more efficient performance.SUMMARY

[0005] A high force, low vibration cylindrical linear motor is described.

[0006] According to an embodiment, there is provided a cylindrical linear motor configured to actuate proximally and distally in an axial direction. The cylindrical linear motor comprises a cylindrical mover comprising a plurality of permanent magnets positioned radially on an outside edge of the cylindrical mover; a plurality of disc-shaped electrical coils; a plurality of disc-shaped cooling plates; and a plurality of disc-shaped backiron armatures; wherein each of the plurality of disc-shaped electrical coils, disc-shaped cooling plates and disc-shaped backiron armatures are stacked and revolve around the cylindrical mover.

[0007] In some embodiments, each one of the plurality of disc-shaped electrical coils, disc-shaped cooling plate, and disc-shaped backiron armatures are stacked around the cylindrical mover in a repeating pattern comprising one of the disc-shaped cooling plates being sandwiched between one of the plurality of electrical coils and one of the plurality of backiron armatures.

[0008] In some embodiments, the cylindrical mover comprises a plurality of rings of permanent magnets, each of the plurality of rings positioned radially on the outside edge of the cylindrical mover.

[0009] In some embodiments, an orientation of the plurality of magnets in one of the plurality of rings is uniformly facing radially outward.

[0010] In some embodiments, an orientation of the plurality of magnets in one of the plurality of rings is uniformly facing radially inward.

[0011] In some embodiments, each of the plurality of disc-shaped cooling plates comprises a plurality of cooling channels, each oriented in the axial direction of the cylindrical linear motor and each positioned toward an outer edge of the disc-shaped cooling plates, the plurality of cooling channels configured to allow coolant to flow through each of the plurality of cooling plates. In some embodiments, the plurality of cooling channels is a first plurality of cooling channels, and each of the plurality of cooling plates comprises a second plurality of cooling channels, each oriented in the radial direction of the cylindrical linear motor and flowing across the each of their respective disc-shaped cooling plates, the plurality of second cooling channels configured to allow coolant to flow into each of the plurality of cooling plates.

[0012] In some embodiments, the cylindrical linear motor further comprises a plurality of gaskets, where a pair of the plurality of gaskets are positioned between cooling channels of successive adjacent disc-shaped cooling plates.

[0013] In some embodiments, each of the plurality of disc-shaped electrical coils comprises an inner lead and outer lead, the inner lead and the outer lead positioned on an outer edge of their respective disc-shaped electrical coil.

[0014] In some embodiments, each of the plurality of disc-shaped backiron armatures comprises an inner slot configured to fit a respective one of the plurality of disc-shaped cooling plates and a respective one of the plurality of disc-shaped electrical coils.

[0015] In some embodiments, the plurality of disc-shaped electrical coils are arranged in a repeating pattern to provide a distributed phase current to power the cylindrical linear motor.

[0016] In some embodiments, the plurality of disc-shaped electrical coils are arranged in a repeating pattern to provide a concentrated phase current to power the cylindrical linear motor.

[0017] In some embodiments, the cylindrical linear motor is configured to provide linear actuation in a deep ultraviolet (DUV) lithography system or an extreme ultraviolet (EUV) lithography system.

[0018] In some embodiments, a second cylindrical linear motor configured to actuate proximally and distally in an axial direction is disclosed. The cylindrical linear motor comprises: a cylindrical mover comprising a plurality of permanent magnets positioned radially on an outside edge of the cylindrical mover; a cylindrical backiron armature concentrically encasing the cylindrical mover and comprising a plurality of disc-shaped iron teeth oriented radially inward toward a center of the cylindrical mover, each adjacent pair of the plurality of disc-shaped iron teeth defining a disc-shaped slot therebetween; a first plurality of ring-shaped cooling plates having a first circumference defined by a first radius, each of the first plurality of ring-shaped cooling plates fitted into a respective discshaped slot defined by the adjacent pairs of disc-shaped iron teeth; a second plurality of ring-shaped cooling plates having a second circumference defined by a second radius smaller than the first radius, each of the second plurality of ring-shaped cooling plates fitted into the respective disc-shaped slot defined by the adjacent pairs of disc-shaped iron teeth, wherein the first plurality and second plurality of ring-shaped cooling plates concentrically enclose the cylindrical mover; and a plurality of discshaped electrical coils, each of the plurality of disc-shaped electrical coils fitted into the respective disc-shaped slot and sandwiched between a respective one of the first plurality of ring-shaped cooling plates and a respective one of the second plurality of ring-shaped cooling plates.

[0019] In some embodiments, the cylindrical mover comprises a plurality of rings of permanent magnets, each of the plurality of rings positioned radially on the outside edge of the cylindrical mover.

[0020] In some embodiments, an orientation of the plurality of magnets in one of the plurality of rings is uniformly facing radially outward.

[0021] In some embodiments, an orientation of the plurality of magnets in one of the plurality of rings is uniformly facing radially inward.

[0022] In some embodiments, each of the plurality of disc-shaped electrical coils comprises an inner lead and outer lead, the inner lead and the outer lead positioned on an outer edge of their respective disc-shaped electrical coil.

[0023] In some embodiments, the plurality of disc-shaped electrical coils are arranged in a repeating pattern to provide a distributed phase current to power the cylindrical linear motor.

[0024] In some embodiments, the plurality of disc-shaped electrical coils are arranged in a repeating pattern to provide a concentrated phase current to power the cylindrical linear motor.

[0025] In some embodiments, the cylindrical linear motor is configured to provide linear actuation in a deep ultraviolet (DUV) lithography system or an extreme ultraviolet (EUV) lithography system.

[0026] In some embodiments, a semiconductor device manufacturing method is disclosed. The method may include: receiving a substrate with a photoresist layer; directing radiation from a radiation source to transfer a pattern from a reticle onto the photoresist layer; actuating the reticle using a cylindrical linear motor; and removing a portion of the photoresist layer to form a pattern over the substrate. The cylindrical motor may include: a cylindrical mover comprising a plurality of permanent magnets positioned radially on an outside edge of the cylindrical mover; a plurality of discshaped electrical coils; a plurality of disc-shaped cooling plates; and a plurality of disc-shaped backiron armatures. Each of the plurality of disc-shaped electrical coils, disc-shaped cooling plates and disc-shaped backiron armatures are stacked and revolve around the cylindrical mover.BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate one or more embodiments and, together with the description, explain these embodiments. Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which:

[0028] FIG. 1 schematically depicts a lithography apparatus, which may include a linear actuator with the present cooling system, according to an embodiment.

[0029] FIG. 2 schematically depicts an embodiment of a lithographic cell or cluster, which may include a linear actuator with the present cooling system in one or more apparatuses of the lithographic cell or cluster, according to an embodiment.

[0030] FIG. 3 shows an example placement of cylindrical linear motors in an apparatus.

[0031] FIGS. 4A and 4B show example structures of the cylindrical linear motor of the present disclosure, according to some embodiments.

[0032] FIGS. 5A and 5B show illustrations of different configurations of the phase currents of the magnets in the linear mover, according to some embodiments.

[0033] FIGS. 6A and 6B shows an alternative example implementation for generating the series of circular coils, circular cooling plates, and circular iron armature, according to some embodiments.

[0034] FIG. 7 shows several alternative structural designs for a cylindrical linear motor with cooling plates, according to some embodiments.

[0035] FIGS. 8A and 8B provide additional example illustrations for the structures of alternative design 700, according to some embodiments.

[0036] FIGS. 9 A and 9B provide additional example illustrations for the structures of alternative design 710, according to some embodiments.

[0037] FIGS. 10A and 10B provide additional example illustrations for the structures of alternativedesign 720, according to some embodiments.DETAILED DESCRIPTION

[0038] Multi-phase electromagnetic linear actuators have been used as long stroke actuators in lithography apparatuses, metrology systems, and other devices. For example, Lorentz actuators, linear actuators with magnetic materials present in their armatures with or without slots or magnetic teeth in the armature, and / or other motion systems are used in lithography apparatuses. Some of these systems, such as linear motors with slotted iron armatures, produce unwanted vibrations. In particular, there is a periodic reluctance force / attraction force with the iron armature that oscillates as a function of velocity, tooth pitch and any harmonics present in the force applied. This causes an unwanted vibration known to those with skill in the art, as cogging. It is desirable to reduce or even eliminate the cogging from linear accelerations, while achieving higher lithography apparatus stage accelerations. Eliminating or reducing cogging allows for more precise movement in the linear motor and reduces degradation in the motor over time.

[0039] In addition, higher stage accelerations increase productivity of a lithography apparatus, resulting in a lower cost per die (or per microchip). To reduce the cost per die, future high-NA systems will require higher throughput (e.g. 220 [wph] to >300 [wph]), which can partially be achieved by increasing the acceleration of the stages to reduce prep time between exposures of each die, for example, from 32G to 100G. To achieve higher accelerations, higher force density actuators are needed, e.g. at least 2000 [N / kg] are needed. Additionally, future systems are expected to use less energy than is used today (e.g., >7 [kWh / waf| to <5 [kWh / waf| per system), and therefore more efficient motors are also desirable for all actuated components.

[0040] However, higher stage accelerations cause increased dynamic loading and increased thermal loading in current linear actuators used in lithography apparatuses. The increased dynamic and thermal loading can cause a catastrophic temperature increase in linear actuator coils and / or an overall failure of an actuator motor, increased demand on amplifiers, and, depending on the design, a greater degree of saturation of soft-magnetic materials present in a magnetic circuit of the linear actuator. Increased thermal loading is known to reduce the efficiency or actuators due to the thermal runaway effect (resistance increases at higher temperature, at higher resistance more power is dissipated, thus more heat is generated by the coils which further raises their temperature). Failure of the coil windings is widely recognized to occur when the coil temperature exceeds the wire insulation rating. These factors limit an achievable force density (in [N / kg]) by the linear actuator, and therefore limit an achievable peak acceleration of a lithography apparatus stage ([N / kg] = [m / s2]). Three-phase Lorentz actuators, for example, using moving magnets or moving coils are presently used in many lithography apparatuses. Lorentz actuators are sometimes favored because they produce less vibration and produce less prevalent nonlinear behavior compared to other linear actuators. However, Lorentz actuators are relatively inefficient compared to the other linear actuators, requiring more averagepower from amplifiers.

[0041] A new linear motor that addresses the cogging issues and can provide more efficient cooling to achieve higher acceleration is described below. The new linear motor is cylindrically shaped and includes a novel structure for efficient cooling. In some embodiments, a linear mover is cylindrical and includes magnets, such as Halbach magnets, arranged in a radial structure such that the orientation of the magnets faces radially outward. Surrounding the cylindrical mover are a series of circular (disc-shaped) coils, circular cooling plates, and circular backiron armatures stacked repeatedly in sets of three. In other embodiments, the new linear motor includes cylindrical cooling plates of different radial sizes, each concentrically spaced around the cylindrical mover. The positioning of the magnets in the cylindrical mover being in a radial design structure reduces the cogging that would occur in a rectangular arrangement traditional in slotted iron armatures. The circular cooling plates sandwiched between each coil and circular iron armature provides efficient cooling. Thus, a linear actuator having the new cooling system described below is more efficient compared to prior linear actuators, requiring reduced average power from amplifiers compared to prior linear actuators. This allows such a linear actuator to achieve a higher force density (limited by coil temperature or amplifier limits) compared to prior linear actuators, and reduced cogging, and therefore achieve a higher peak acceleration of a lithography apparatus stage. The various designs of the linear actuator of the present disclosures may therefore be used in a deep ultraviolet (DUV) lithography system or an extreme ultraviolet (EUV) lithography system, among other types of lithography systems.

[0042] In some embodiments, the cylindrical linear motor includes a cooling system that includes circular (disc-shaped) cooling plates repeatedly sandwiched between a circular electrical coil and a circular backiron armature. The electrical coils are configured to be energized to provide an electromagnetic force for the linear actuator. The cooling plates are in thermal contact with the electrical coils and configured to cool the electrical coils. Among other advantages, the electrical coils and the cooling plates are configured to be assembled piece by piece. The radial orientation of the electrical coils and the cooling plates relative to the length of the armature, and / or the separate piece by piece nature of electrical coils and the cooling plates, is configured to provide sufficient cooling to allow for higher force densities. Also, an orientation of the electrical coils and the cooling plates in a plane perpendicular to the length of the armature may be configured to resist unwanted motion or deformation of the linear actuator.

[0043] The following introductory paragraphs describe general lithography system functionality - as one of many possible use case examples for the linear actuator(s) described herein. Note that although specific reference may be made in this text to the manufacture of integrated circuits (ICs), it should be understood that the described cooling system 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.

[0044] As an introduction, prior to transferring a pattern from a patterning device such as a mask to a 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 and / or other 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, chemical mechanical polishing, etc., all intended to finish an individual layer of the device. If several layers are required in the device, then the whole procedure, or a variant thereof, is repeated for 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, and then the individual devices can be mounted on a carrier, connected to pins, etc.

[0045] 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, chemical mechanical polishing, ion implantation, and / or other processes. 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, etc. One or more metrology processes are typically involved in the patterning process. Lithography apparatuses, metrology systems, and other equipment used to fabricate semiconductor devices may use one or more linear actuators having the described cooling system.

[0046] Lithography is a step in the manufacturing of device 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.

[0047] FIG. 1 schematically depicts an embodiment of a lithographic apparatus LA that may include and / or be associated with one or more linear actuators and corresponding cooling systems. The apparatus comprises: an illumination system (illuminator) IL configured to condition a radiation beam B (e.g. UV radiation, DUV radiation, or 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. aresist-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 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 of a type as referred to above, or employing a reflective mask).

[0048] The illuminator IL receives a beam of radiation from a radiation source SO. The source and the lithographic apparatus may be separate entities, for example when the source is an excimer laser. In such cases, the source is not considered to form part of the lithographic apparatus 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 may be an integral part of the apparatus, for example when the source is a mercury lamp. The source SO and the illuminator IL, together with the beam delivery system BD if required, may be referred to as a radiation system.

[0049] 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.

[0050] 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-inncr. 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 the beam. 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.

[0051] 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 beamacross 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.

[0052] 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.

[0053] 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 support structure 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.

[0054] The lithographic apparatus may be of a type 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 carried out 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 bemade.

[0055] In operation of the lithographic apparatus, a radiation beam 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. 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 the aid of a long-stroke module (coarse positioning) and a short-stroke module (fine positioning), which form part of the first positioner PM. Similarly, movement of the substrate table WT may be 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 short-stroke 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.

[0056] The depicted apparatus may be used in at least one of the following modes: 1. 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. 2. 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. 3. 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. Combinations and / or variations on the above-described modes of use or entirely different modes of use may also be employed.

[0057] A 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. Any or all of these tools may include linear actuators with corresponding cooling systems. 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 includes multiple processed layers.

[0058] The terms “radiation” and “beam” used herein encompass all types of electromagnetic radiation, including ultraviolet (UV) or deep ultraviolet (DUV) radiation (e.g. having a wavelength of 365, 248, 193, 157 or 126 nm) and extreme ultra-violet (EUV) radiation (e.g. having a wavelength in the range of 5-20 nm), as well as particle beams, such as ion beams or electron beams.

[0059] 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, critical dimension (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.

[0060] As shown in FIG. 2, the lithographic apparatus LA may form part of a lithographic cell LC, also sometimes referred to a lithocell or cluster, which also includes apparatuses to perform pre- and post-exposure processes on a substrate. Conventionally these include one or more spin coaters SC to deposit one or more resist layers, one or more developers to develop exposed resist, one or more chill plates CH and / or one or more bake plates BK. A substrate handler, or robot, RO picks up one or more substrates from input / output port I / Ol, I / O2, moves them between the different process apparatuses and delivers them to the loading bay LB of the lithographic apparatus. These apparatuses, which are often collectively referred to as the track, are under the control of a track control unit TCU which is itself controlled by the supervisory control system SCS, which also controls the lithographic apparatus via lithography control unit LACU. Thus, the different apparatuses can be operated to maximize throughput and processing efficiency.

[0061] In order that a substrate that is exposed by the lithographic apparatus is exposed correctly and consistently and / or in order to monitor a part of the patterning process (e.g., a device manufacturing process) that includes at least one pattern transfer step (e.g., an optical lithography step), it is desirable to inspect a substrate or other object to measure or determine one or more properties such as alignment, overlay (which can be, for example, between structures in overlying layers or between structures in a same layer that have been provided separately to the layer by, for example, a double patterning process), line thickness, critical dimension (CD), focus offset, a material property, etc.

[0062] The one or more measured parameters may include, for example, alignment, overlay between successive layers formed in or on the patterned substrate, critical dimension (CD) (e.g., critical linewidth) of, for example, features formed in or on the patterned substrate, focus or focus error of an optical lithography step, dose or dose error of an optical lithography step, optical aberrations of an optical lithography step, etc. This measurement may be performed on a target of the product substrate itself and / or on a dedicated metrology target provided on the substrate. The measurement can be performed after-development of a resist but before etching, after-etching, after deposition, and / or at other times.

[0063] There are various techniques for making measurements of the structures formed in the patterning process, including the use of a scanning electron microscope, an image-based measurement tool and / or various specialized tools. Any or all of these tools may include linear actuators with corresponding cooling systems. A fast and non-invasive form of specialized metrology tool is one in which a beam of radiation is directed onto a target on the surface of the substrate and properties of the scattered (diffracted / reflected) beam are measured. By evaluating one or more properties of the radiation scattered by the substrate, one or more properties of the substrate can be determined. This may be termed diffraction-based metrology. One such application of this diffraction-based metrology is in the measurement of feature asymmetry within a target. This can be used as a measure of overlay, for example, but other applications are also known. For example, asymmetry can be measured by comparing opposite parts of the diffraction spectrum (for example, comparing the -1st and +lstorders in the diffraction spectrum of a periodic grating).

[0064] Metrology results may be provided directly or indirectly to the supervisory control system SCS. If an error is detected, an adjustment may be made to exposure of a subsequent substrate (especially if the inspection can be done soon and fast enough that one or more other substrates of the batch are still to be exposed) and / or to subsequent exposure of the exposed substrate. Also, an already exposed substrate may be stripped and reworked to improve yield, or discarded, thereby avoiding performing further processing on a substrate known to be faulty. In a case where only some target portions of a substrate are faulty, further exposures may be performed only on those target portions which meet specifications.

[0065] Referring to FIG. 3, shown is an example placement of cylindrical linear motors in anapparatus. Illustration 300 shows an example module 305 that may be included in a lithography apparatus such as what is described in FIG. 1. Cylindrical linear drive motors may be used for actuating reticle masking blades during exposure. The linear motors 310 move linearly in the y- direction in this example. A tubular mover 315 is shown with Halbach magnets affixed over the cylindrical surface. These movers 315 would be placed where the linear motors 310 are, for example.

[0066] The present cylindrical linear motor system(s), and / or method(s) may be used as standalone tools and / or techniques, and / or or used in conjunction with semiconductor manufacturing apparatuses and / or processes, to enhance the accurate transfer of complex designs to physical wafers. For example, the present cylindrical linear motor system may be included in the lithography apparatus shown in FIG. 1, included in one or more apparatuses of the lithographic cell shown in FIG. 2, included in a module as part of a lithography apparatus as shown in FIG. 3, and / or included in other apparatuses (semiconductor or non-semiconductor related). As described above, the present cylindrical linear motor includes a cylindrical mover with radially oriented magnets surrounded by repeating stacks of a circular coil, a circular cooling plate, and a circular backiron armature. The electrical coils are configured to be energized to provide an electromagnetic force for the linear actuator. The cooling plates are in thermal contact with the electrical coils and configured to cool the electrical coils.

[0067] The lithographic apparatus LA and radiation source SO described herein can be used in a method for manufacturing a semiconductor device. A semiconductor device manufacturing method comprises receiving a substrate W with a photoresist layer. The method further comprises directing a radiation beam from radiation source SO to transfer a pattern from a mask onto the photoresist layer. This could be achieved by a patterning device which is configured to form a patterned radiation beam, imparting the patterned radiation beam onto the photoresist layer. The method for manufacturing a semiconductor device further comprises the step of removing a portion of the photoresist layer to form the pattern over the substrate W.

[0068] The substrate W may be made of silicon or other semiconductor materials. Alternatively or additionally, the substrate W may include other semiconductor materials such as germanium (Ge) or carbon (C). In some embodiments, the semiconductor substrate is made of a compound semiconductor such as III-V compound semiconductors, II- V compound semiconductors, and / or any suitable integration of Group IV materials. In some embodiments, the substrate W may be a silicon-on- insulator (SOI) or a germanium-on-insulator (GOI) substrate.

[0069] The semiconductor device made from the substrate W may have various device elements. Examples of semiconductor device elements that are formed over the substrate W include transistors (e.g., planar or non-planar metal oxide semiconductor field effect transistors (MOSFET), bipolar junction transistors (BJT), high-voltage transistors, high-frequency transistors, etc.), diodes, CMOS image sensors, passive devices, and / or other applicable elements. Various processes may be performed to form the semiconductor device elements, such as deposition, etching, implantation,epitaxial growth, polishing, thermal treatment, and / or other suitable processes. In some embodiments, the substrate W is coated with a photoresist layer sensitive to the EUV light.

[0070] Referring to FIGS. 4A and 4B, shown are example structures of the cylindrical linear motor of the present disclosure, according to some embodiments. Referring to FIG. 4A, illustration 400 shows an exploded view of a set of three pieces, circular (disc-shaped) electrical coil 402, circular cooling plate 404, and circular backiron armature 410 with teeth or slots 408, that would stack and surround a linear mover that includes magnets. In between the circular cooling plate 404 and the backiron armature 410 are a pair of gaskets 406 for providing sealing of the coolant through channels present in the top and bottom of the cooling plate 404. As shown, the disc-shaped structures would stack along the linear direction of the mover while being oriented radially outward.

[0071] Illustration 415 shows an example of how the repeating set of three pieces may be stacked around the linear mover, which is shown in the center. The mover would be driven back and forth in the y-axis direction, while each of the circular pieces, e.g., the circular (disc-shaped) electrical coil 402, circular cooling plate 404, and circular backiron armature 410, surround the mover and are oriented radially outward in the x-z plane.

[0072] Illustration 420 shows a zoomed-in cross-sectional area of layers of the repeating set of three pieces, according to some embodiments. For clarity, the viewpoint of this illustration is a flat cross-sectional area in the y-z plane, consistent with the three-dimensional viewpoints of illustrations 400 and 415. As shown, there is a repeating set of three pieces, the circular coil 430 that is consistent with coil 402, the backiron armature 428 that is consistent with the backiron armature 410, and the circular cooling plate 426 that is consistent with the circular cooling plate 404. Each circular electrical coil 430 may include an outer lead 422 and an inner lead 424 that provide electrical connection to drive the linear motor. These are all stacked to surround the cylindrical mover 432.

[0073] Illustration 440 shows a closer view of just a single set of the three pieces surrounding the cylindrical linear motor. The cooling surface 442 of the cooling plate 426 that is shaped like a disc (along the x-z plane) may be in physical contact with one whole surface of the electrical coil 430. Within the electrical coil 430, the electrical wires 444 may be stacked along the x-z plane (as indicated by the arrow), in lines running in the y-axis direction, as shown. This may provide very dense electrical connection to produce high acceleration. The cooling surface touches all of the stacked coils, and therefore provides the most cooling to enable maximal acceleration.

[0074] Referring to FIG. 4B, shown are additional example details and viewpoints of the cylindrical linear motor, according to some embodiments. Illustration 450 shows example coolant routing through the circular cooling plate 404. The handle-like ends of the cooling plates include holes that are inlets / outlets 452, 454, 456, and 458. From there, the coolant may travel along the periphery, both along the outer ring edge 453 and the inner ring edge 455, of the cooling plate and out to the opposite inlet / outlet 452, 454, 456, and 458.

[0075] Illustration 460 shows a cross-sectional view of the coolant channels. Here, the mover 462is surrounded by the stacks of cooling plates, coils, and backiron armatures. A zoomed in view of a section 464 of the cross-sectional area is shown in illustration 470. Here, the coolant channels 472 are more clearly visible. A coolant bus may run through each of the inlets / outlets 452, 454, 456, and 458, such as illustrated by the flow path 474. The coolant section 472 may represent the available volume for coolant to flow along the adjacent coils. End caps, not shown, may close the bus volumes at one end of the linear motor to hold pressure.

[0076] Referring to FIGS. 5A and 5B, shown are illustrations of different configurations of the phase currents of the magnets in the linear mover, according to some embodiments. The top row shows how the phase currents may be oriented in a cylindrical structure with a smooth coil armature, while the bottom row shows how the phase currents may be oriented in a cylindrical structure with a slotted armature having iron teeth to separate the repeating sets of cooling plate and electrical coil.

[0077] Illustration 500 in FIG. 5A shows a cross-sectional view in the x-z plane of an example with smooth coil armature. The electrical coil 502 is stacked next to the coil armature 504 (see illustration 400) and the cooling plate, shown here with just the coolant channel edge 506. Inside the linear mover are magnets 508, such as Halbach magnets, oriented radially outward in this initial phase. In other layers of the mover that are not shown because the orientation of the mover is in the y- axis direction and the layers would therefore be in or out of the page, the orientation of the magnets may all be oriented radially toward the center. The radial symmetry of the orientation of the magnets of these phases allows for cogging to be minimized or even eliminated, because there are no periodic reluctance or attraction forces created by the radial symmetry. In addition, for phase currents of a layer of magnets oriented in or out of the page, the orientation of each magnet would alternate. That is, if a first magnet in the wheel of eight magnets is oriented out of the page, then the adjacent magnet is oriented going into the page, and so on. This alternating pattern also reduces the cogging forces since the alternating directionality of the magnets cancels out the attraction / reluctance forces.

[0078] Illustration 510 in FIG. 5 A shows a side cross-sectional view (cutting through the middle down the y-axis) of the smooth coil armature example to show the layers of magnets and the coils in a concentrated phase current arrangement, according to some embodiments. Here, the stacks of the circular coils, circular cooling plates, and circular iron armatures are combined and surround the mover having the magnets. In this view, the iron coil armature 512 appears as a solid line of material, although one can understand that the coil armature 512 effectively envelopes the rest of the materials cylindrically. Within this casing, each coil 502 in the stack may be assigned a phase current, in this case arranged in three concentrated phases: -a, +a; -b, +b; and -c, +c and repeating thereafter. Thus, the actuator pitch 520 is the length of the unique set of phase currents, before it repeats. In between each coil 502 would be the cooling plate, such as cooling plate 514 to illustrate where each cooling plate is positioned. The coils appear above and below the mover 522, due to the circular orientation of the coils and due to showing just the cross-sectional viewpoint. This view makes it easier to see how the magnets 516 in the mover 522 are oriented in each layer. Again, while envisioning that themagnets are arranged radially around the mover 522 (in the x-z plane), the orientation of the magnets repeat in a pattern of four layers. Therefore, the magnet pitch 518 is the length as shown. To be clear, this means that the pitch ratio of coil to magnet in this example is 2: 1.

[0079] Illustration 530 in FIG. 5A shows a similar arrangement as illustration 510, except there is now shown a distributed phase current for the same smooth coil armature example, according to some embodiments. Here, the phase currents of the stacks of coils being distributed leads to a repeating distributed phase current pattern 534 as the following: -a, -b, -c; +a, +b, +c, and so on. The depth of the magnets are now larger, so that the repeating magnet orientation pattern 536 matches the length of the distributed phase current pattern. The magnet pattern still is a repeating pattern of four layers, which is now equal in depth to the distributed phase current pattern. That is, the magnet pitch 532 now equals the actuator pitch.

[0080] Illustration 550 in FIG. 5B shows a cross-sectional view in the x-z plane of an example with a slotted coil armature, meaning the iron armature has “teeth.” The electrical coil 552 is stacked next to the slotted coil armature 554 (see illustration 400) and the cooling plate, shown here with just the coolant channel edge 556. A portion of the slots or “teeth” 560 is shown that represents the slots or teeth being slightly longer than the coils and cooling plates that are slotted between the slots or teeth. Like in illustration 500, inside the linear mover are magnets 558, such as Halbach magnets, oriented radially outward in this initial phase. In other layers of the mover that are not shown because the orientation of the mover is in the y-axis direction and the layers would therefore be in or out of the page, the orientation of the magnets may all be oriented radially toward the center. The radial symmetry of the orientation of the magnets of these phases allows for cogging to be minimized or even eliminated, because there are no periodic reluctance or attraction forces created by the radial symmetry. In addition, for phase currents of a layer of magnets oriented in or out of the page, the orientation of each magnet would alternate. That is, if a first magnet in the wheel of eight magnets is oriented out of the page, then the adjacent magnet is oriented going into the page, and so on. This alternating pattern also reduces the cogging forces since the alternating directionality of the magnets cancels out the attraction / reluctance forces.

[0081] Similar to illustration 510, illustration 560 in FIG. 5B shows a side cross-sectional view (cutting through the middle down the y-axis) of the slotted coil armature example to show the layers of magnets and the coils in a concentrated phase current arrangement, according to some embodiments. Here, the stacks of the circular coils, circular cooling plates, and circular iron armatures are combined and surround the mover having the magnets. In this view, the slotted iron coil armature 562 appears as a solid line of material with slots or “teeth,” such as 561, although one can understand that the coil armature 562 effectively envelopes the rest of the materials cylindrically. Within this casing, each coil 552 in the stack may be assigned a phase current, in this case arranged in three concentrated phases: -a, +a; -b, +b; and -c, +c and repeating thereafter. In this example, the + / - phases are assigned on opposite sides of each slot. The actuator pitch 566 is the length of the unique set ofphase currents, before it repeats. In between each coil 552 would be the cooling plate, such as cooling plate 554 to illustrate where each cooling plate is positioned. The coils appear above and below the mover 572, due to the circular orientation of the coils and due to showing just the cross-sectional viewpoint. This view makes it easier to see how the magnets 574 in the mover 572 are oriented in each layer. Again, while envisioning that the magnets are arranged radially around the mover 572 (in the x-z plane), the orientation of the magnets repeat in a pattern of four layers. Therefore, the magnet pitch 564 is the length as shown. To be clear, this means that the pitch ratio of coil to magnet in this example is 2:1.

[0082] Illustration 570 in FIG. 5B shows a similar arrangement as illustration 560, except there is now shown a distributed phase current for the same slotted coil armature example, according to some embodiments. Here, the phase currents of the stacks of coils being distributed leads to a repeating distributed phase current pattern 574 as the following: -a, -b, -c; +a, +b, +c, and so on. Each coil with a different phase is positioned between successive slots in this example. The depth of the magnets are now larger, so that the repeating magnet orientation pattern 576 matches the length of the distributed phase current pattern. The magnet pattern still is a repeating pattern of four layers, which is now equal in depth to the distributed phase current pattern. That is, the magnet pitch 568 now equals the actuator pitch.

[0083] Referring to FIGS. 6A and 6B, shown is an alternative example implementation for generating the series of circular coils, circular cooling plates, and circular iron armature, according to some embodiments. In illustration 600 in FIG. 6A, rather build modular discs of each material that can be stacked, pairs of half subcomponents of each type may be constructed and then pieced together. Shown is an exploded view of these subcomponents. The backiron armature 602 with slotted teeth is shown built in two halves, along with two halves of the cooling plates 604. The entire column of coils 606 may be formed as a single piece or stacked from individual discs. Then the mover 608 that contains the magnets, such as Halbach magnets, may be formed into a single piece and placed inside the cylindrical ring of coils 606. The positioning of each disc of the cooling plates and coils may still be consistent with the order as shown in FIG. 4, except the subcomponents that form them are now made up of halves of the entire set.

[0084] Illustration 610 in FIG. 6B shows are more distinct angle of one half of the slotted iron armature with teeth for the coil slots. Illustration 615 shows a more distinct angle of one half of the cooling plate structure. Illustration 625 shows a cross-sectional view of the half cooling plate structure, showing where the inlet and outlet 627 and 629 are for this half. The other half is symmetric to this, so there would be two inlet / outlet pairs for the cooling plate apparatus. Illustration 620 shows a semi-transparent view of how the half-pieces may look when pieced together. The leads 622 to the electrical coils are shown extending out of the structure when the pieces are connected. This structure may include four actuators with five distributed phases each and a magnetic mover, although embodiments are not limited to the number of actuators or number of phases, or even if the phases aredistributed or concentrated.

[0085] Referring to FIG. 7, shown are several alternative structural designs for a cylindrical linear motor with cooling plates, according to some embodiments. These alternative designs may include different orientations for the cooling plates and coils within the structure of a cylindrical iron armature. In these three examples of FIG. 7, the illustrations are shown from the viewpoint of a side cross-sectional area, like in illustrations 510, 530, 560 and 570 of FIG. 5. The rotational axis 730, which would be the center of the mover, makes clear that the three examples shown here include the top and bottom of a side cross-sectional area of a cylindrical section. In other words, these illustrations show a cross section of the various components in a radial direction out from the center of the rotational axis.

[0086] Illustration 700 shows a side cross-sectional view of a slotted iron armature 702, which is shown radially symmetrical on the bottom. In each slot, there are three flat rings of cooling plates 706, with two sets of electrical coils 704 also formed in a ring or disc shape. The flat rings of cooling plates 706 are flattened in the axial direction. The electrical coils 704 are edge wound coils based on the direction of the layers of coils as shown. The three flat rings of cooling plates within each slot have different radii that varies the size of the rings as shown, allowing them to be positioned concentrically. This structure may repeat within each slot of the slotted iron armature 702. In this case of edge wound coils, the easy direction - meaning the direction having a lower thermal resistance - is in the radial direction.

[0087] Illustration 710 shows another alternative, in this case a side cross-sectional view of a slotted iron armature 702, which is shown radially symmetrical on the bottom. In each slot, there are two cylindrical pairs of electrical coils 714 and a disc-shaped cooling plate 716 sandwiched in between. Each disc-shaped cooling plate 716 is flattened in the radial direction. The electrical coils 714 are traditionally wound, which is to say in the axial direction as shown. The easy direction with a lower thermal resistance for these traditionally wound coils is in the axial direction.

[0088] Illustration 720 shows yet another example alternative design. The cooling apparatuses 722 are cylindrical or tubular in this case, each with different radii, such that each smaller cooling cylinder 722 can be positioned concentrically within the larger ones. In each space between the concentrically positioned cooling cylinders 722, there are edge wound electrical coils 724 surrounding slots or teeth 726 of the iron armature. The electrical coils 724 and slots 726 are formed in discs that revolve around the rotational axis, like the other examples shown throughout this disclosure.

[0089] FIGS. 8A and 8B provide additional example illustrations for the structures of alternative design 700, according to some embodiments. While illustration 700 provides a cross-sectional view along the y-plane, various other views are shown in FIGS. 8A and 8B. Illustration 802 shows a perspective view of the same design, with a cross-sectional cutout along the z-plane. On the outside is the cylindrical backiron armature, and inside that are three concentric rings of cylindrical cooling plates 816, in the shape of rings. Between these three rings are two concentric cylinders of electriccoils 818. Their electrical conduits 820 are shown protruding out beyond the backiron armature. Illustration 804 shows a front view of the cross-sectional area in the z-plane. The three rings of cylindrical cooling plates 816 are shown, along with the two rings of electric coils 818 sandwiched in between. For additional detail, two cross sections 810 and 812 are provided to show a linear slice of what the design looks like. Illustration 806 provides a linear cross-sectional view along the axis 810. Since this cuts right through the electrical conduits 820, they are apparent at the top. The rings of cooling plates 816 are shown, with the smallest ring on the innermost position shown to span the most area from this view, due to the innermost cylindrical space being hollowed at based on these illustrations. In practice, the cylindrical mover would be placed in the center there. The electric coils 818 are also shown sandwiched between the three cooling plates 816. Illustration 808 provides a linear cross-sectional view along the axis 812. Since this does not cut right through the electrical conduits 820, the electrical conduits are not shown in this view. Illustration 814 provides a closer view of just the top section, so the rings of cooling plates 816 and the electrical coils 818 are more easily seen.

[0090] Referring to FIG. 8B, additional views of the alternative design of illustration 700 are shown. Illustration 852 shows a perspective view of just the collection of electric coils and cylindrical cooling plates. It may be apparent that the cooling plates do not fully wrap around the electric coils but instead provide space for the electrical conduits. Illustration 854 provides an exploded view of the components for clearer visibility. The three concentric cylindrical cooling plates 858 can be more clearly seen as cylindrical rings that do not fully wrap all the way around. This provides space for the electrical conduits. Instead, at the edge right next to the electrical conduits, the cooling plates 858 are connected together to provide maximal cooling surface area next to the electrical conduits. The electric coils 866 are shown as constructed in a single piece, where the space near the electrical conduits actually connects the two rings together. The cooling plates 858 may be fitted around the electric coils 866 as structured as a single piece. The cooling plates 858 may be placed inside and around the electric coils 866 by sliding them in the direction of 864, and / or the electric coils 866 are moved in the direction of 820. Direction 872 provides an example of the direction of the coolant that would uniformly flow out of the cooling plates 858, while direction 874 provides an example direction of the coolant flowing into the cooling plates 858.

[0091] After the cooling plates 858 are positioned in and around the electric coils 866, two half- cylindrical pieces 860 that form the back iron armature may be fitted over the composition of the cooling plates and electric coils. The two half cylinders may be fitted in the direction of 870 and 868. It can be seen that the top piece includes slots for the electrical conduits to protrude out of.

[0092] Illustration 856 provides a front view of a cross-sectional area of the direction of fluid passages, according to some embodiments. The coolant flows into the cooling plates in direction 874, on one side of the cooling plates with respect to the position of the electrical conduits. The coolant would then flow around the cooling plates in the clockwise direction, and then flow out of the coolingplates at direction 872, consistent with the descriptions of illustration 854.

[0093] FIGS. 9A and 9B provide additional example illustrations for the structures of alternative design 710, according to some embodiments. While illustration 710 provides a cross-sectional view along the y-plane, various other views are shown in FIGS. 9A and 9B. Illustration 902 provides a cross-sectional view of this alternative design of illustration 710 in the x-plane, meaning the cylindrical structure is viewed as it is cut horizontally. This shows the backiron armature 906, the cooling plates 908 and the electric coils 910. Illustration 904 provides a cross-sectional view of the alternative design of illustration 710 in the y-plane, meaning the cylindrical structure is viewed as it is cut vertically. The cooling plates 908 are shown, along with the electric coils 910. The main difference here is the presence of the entrance of the coolant at the top of the structure. This is consistent with the cooling channels visible in cooling plates 404 of FIG. 4A, as well as the cooling channels shown in FIG. 9B, below.

[0094] Referring to FIG. 9B, shown are additional views of the alternative design of illustration 710, according to some embodiments. Illustration 952 shows a perspective view of the structure including the backiron armature, the cooling plates and the electric coils. The alternative design of illustration 710 and FIGS. 9A and 9B are similar to the initial embodiment in FIGS. 4A and 4B, except with the variant that there are two sets of electric coils within each slot between the teeth of the backiron armature, with a cooling plate sandwiched in between. Therefore, the views shown in FIGS. 4 A and 4B can be analogously applied to this design as would be apparent to those with skill in the art. Illustration 954 shows a perspective view with a cross-sectional cutout in the y-plane. This shows example flows of the coolant through the cooling plates. Direction 956 shows the position and the direction of where the coolant may enter the cooling plates, that is through the top cooling channels, while direction 958 shows the direction and position of where the coolant may exit the cooling plates, that is through the bottom set of cooling channels.

[0095] FIGS. 10A and 10B provide additional example illustrations for the structures of alternative design 720, according to some embodiments. While illustration 720 provides a cross-sectional view along the y-plane, various other views are shown in FIGS. 10A and 10B. The alternative design of illustration 720 is similar to the alternative design of illustration 700. The main difference is that the iron armature is made up of separate cylindrical sections with different radii, and the cooling plates are now connected as one piece, whereas in the design of illustration 700, these structures were built essentially opposite of this. Illustration 1002 shows a perspective view of the assembled components, including the iron armatures, the electric coils, and the cooling plates. Illustration 1004 shows an exploded perspective view of the components, more readily showing the differences. While the electric coil structure 1010 is substantially the same as in FIGS. 8A and 8B and illustration 700, the iron armature 1012 is now made up of three separate cylindrical pieces with different radii that slot into the electric coils 1010. The cooling plates 1014 are now made up of a single piece having three concentric cylinders of cooling rings. They are connected by a cooling disc 1020 at a backend, whichincludes two cooling channels to allow coolant to flow into via direction 1018 and coolant to flow out of via direction 1016. Illustration 1006 shows a front view cross sectional area along the z-plane that illustrates the positions of the inflow 1018 and outflow 1016. The coolant reaches the three rings via spreading along the backplane disc 1020.

[0096] Referring to FIG. 10B, shown are various additional views of the alternative design of illustration 720. Illustration 1052 shows the positions of the cooling plates 1014 with the backplane disc 1020, and the electric coils 1010 sandwiched in between. This view is similar to illustration 804, with the main difference being that the cooling plates are connected via the backplane disc 1020. For additional views, cross-sectional views along axes 1060 and 1062 are shown as well. Illustration 1054 shows the linear cross-sectional view along axis 1060. The electrical conduits are apparent, as axis 1060 cuts right in between them. The cooling plate rings 1014 are shown, along with the electric coils 1010. The backplane disc 1020 is also shown. Illustration 1056 shows the linear cross section along axis 1062. The main difference here is that axis 1062 does not cut through the electrical conduits, so those are not shown. The cooling plates 1014 and the electric coils 1010 are visible still. The backplane disc 1020 is also still visible. Illustration 1058 shows a closer view of the positions of the cooling plates 1014, backplane disc 1020, and the electric coils 1010 in between the separate iron armatures that are the signature features of this design.

[0097] 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 cylindrical linear motor configured to actuate proximally and distally in an axial direction, the cylindrical linear motor comprising: a cylindrical mover comprising a plurality of permanent magnets positioned radially on an outside edge of the cylindrical mover; a plurality of disc-shaped electrical coils; a plurality of disc-shaped cooling plates; and a plurality of disc-shaped backiron armatures; wherein each of the plurality of disc-shaped electrical coils, disc-shaped cooling plates and discshaped backiron armatures are stacked and revolve around the cylindrical mover.2. The cylindrical linear motor of clause 1, wherein each one of the plurality of disc-shaped electrical coils, disc-shaped cooling plate, and disc-shaped backiron armatures are stacked around the cylindrical mover in a repeating pattern comprising one of the disc-shaped cooling plates being sandwiched between one of the plurality of electrical coils and one of the plurality of backiron armatures.3. The cylindrical linear motor of any of the previous clauses, wherein the cylindrical mover comprises a plurality of rings of permanent magnets, each of the plurality of rings positioned radially on the outside edge of the cylindrical mover.4. The cylindrical linear motor of any of the previous clauses, wherein an orientation of the plurality of magnets in one of the plurality of rings is uniformly facing radially outward.5. The cylindrical linear motor of any of the previous clauses, wherein an orientation of the plurality of magnets in one of the plurality of rings is uniformly facing radially inward.6. The cylindrical linear motor of any of the previous clauses, wherein each of the plurality of discshaped cooling plates comprises a plurality of cooling channels, each oriented in the axial direction of the cylindrical linear motor and each positioned toward an outer edge of the disc-shaped cooling plates, the plurality of cooling channels configured to allow coolant to flow through each of the plurality of cooling plates.7. The cylindrical linear motor of any of the previous clauses, wherein the plurality of cooling channels is a first plurality of cooling channels, and each of the plurality of cooling plates comprises a second plurality of cooling channels, each oriented in the radial direction of the cylindrical linear motor and flowing across the each of their respective disc-shaped cooling plates, the plurality of second cooling channels configured to allow coolant to flow into each of the plurality of cooling plates.8. The cylindrical linear motor of any of the previous clauses, further comprising a plurality of gaskets, where a pair of the plurality of gaskets are positioned between cooling channels of successive adjacent disc-shaped cooling plates.9. The cylindrical linear motor of any of the previous clauses, wherein each of the plurality of discshaped electrical coils comprises an inner lead and outer lead, the inner lead and the outer lead positioned on an outer edge of their respective disc-shaped electrical coil.10. The cylindrical linear motor of any of the previous clauses, wherein each of the plurality of discshaped backiron armatures comprises an inner slot configured to fit a respective one of the plurality of disc-shaped cooling plates and a respective one of the plurality of disc-shaped electrical coils.11. The cylindrical linear motor of any of the previous clauses, wherein the plurality of disc-shaped electrical coils are arranged in a repeating pattern to provide a distributed phase current to power the cylindrical linear motor.12. The cylindrical linear motor of any of the previous clauses, wherein the plurality of disc-shaped electrical coils are arranged in a repeating pattern to provide a concentrated phase current to power the cylindrical linear motor.13. The cylindrical linear motor of any of the previous clauses, configured to provide linear actuation in a deep ultraviolet (DUV) lithography system or an extreme ultraviolet (EUV) lithography system.14. A cylindrical linear motor configured to actuate proximally and distally in an axial direction, the cylindrical linear motor comprising: a cylindrical mover comprising a plurality of permanent magnets positioned radially on an outside edge of the cylindrical mover; a cylindrical backiron armature concentrically encasing the cylindrical mover and comprising a plurality of disc-shaped iron teeth oriented radially inward toward a center of the cylindrical mover, each adjacent pair of the plurality of disc-shaped iron teeth defining a disc-shaped slot therebetween; a first plurality of ring-shaped cooling plates having a first circumference defined by a first radius, each of the first plurality of ring-shaped cooling plates fitted into a respective disc-shaped slot defined by the adjacent pairs of discshaped iron teeth; a second plurality of ring-shaped cooling plates having a second circumference defined by a second radius smaller than the first radius, each of the second plurality of ring-shaped cooling plates fitted into the respective disc-shaped slot defined by the adjacent pairs of disc-shaped iron teeth, wherein the first plurality and second plurality of ring-shaped cooling plates concentrically enclose the cylindrical mover; and a plurality of disc-shaped electrical coils, each of the plurality of disc-shaped electrical coils fitted into the respective disc-shaped slot and sandwiched between a respective one of the first plurality of ring-shaped cooling plates and a respective one of the second plurality of ring-shaped cooling plates.15. The cylindrical linear motor of any of the previous clauses, wherein the cylindrical mover comprises a plurality of rings of permanent magnets, each of the plurality of rings positioned radially on the outside edge of the cylindrical mover.16. The cylindrical linear motor of any of the previous clauses, wherein an orientation of the plurality of magnets in one of the plurality of rings is uniformly facing radially outward.17. The cylindrical linear motor of any of the previous clauses, wherein an orientation of the plurality of magnets in one of the plurality of rings is uniformly facing radially inward.18. The cylindrical linear motor of any of the previous clauses, wherein each of the plurality of discshaped electrical coils comprises an inner lead and outer lead, the inner lead and the outer lead positioned on an outer edge of their respective disc-shaped electrical coil.19. The cylindrical linear motor of any of the previous clauses, wherein the plurality of disc-shaped electrical coils are arranged in a repeating pattern to provide a distributed phase current to power the cylindrical linear motor.20. The cylindrical linear motor of any of the previous clauses, wherein the plurality of disc-shaped electrical coils are arranged in a repeating pattern to provide a concentrated phase current to power the cylindrical linear motor.21. The cylindrical linear motor of any of the previous clauses, configured to provide linear actuation in a deep ultraviolet (DUV) lithography system or an extreme ultraviolet (EUV) lithography system.22. A semiconductor device manufacturing method, the method comprising: receiving a substrate with a photoresist layer; directing radiation from a radiation source to transfer a pattern from a reticle onto the photoresist layer; actuating the reticle using a cylindrical linear motor comprising: a cylindrical mover comprising a plurality of permanent magnets positioned radially on an outside edge of the cylindrical mover; a plurality of disc-shaped electrical coils; a plurality of disc-shaped cooling plates; and a plurality of disc-shaped backiron armatures; wherein each of the plurality of disc-shaped electrical coils, disc-shaped cooling plates and disc-shaped backiron armatures are stacked and revolve around the cylindrical mover; and removing a portion of the photoresist layer to form a pattern over the substrate.

[0098] While the concepts disclosed herein may be used for a linear actuator associated with wafermanufacturing on a substrate such as a silicon wafer, it shall be understood that the disclosed concepts may be used with any type of manufacturing system that may include a linear actuator, e.g., those used for manufacturing on substrates other than silicon wafers. In addition, the combination and subcombinations of disclosed elements may comprise separate embodiments. For example, the cooling system, and an associated lithography apparatus that includes the cooling system may comprise separate embodiments, and / or these features may be used together in the same embodiment.

[0099] 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 cylindrical linear motor configured to actuate proximally and distally in an axial direction, the cylindrical linear motor comprising: a cylindrical mover comprising a plurality of permanent magnets positioned radially on an outside edge of the cylindrical mover; a plurality of disc-shaped electrical coils; a plurality of disc-shaped cooling plates; and a plurality of disc-shaped backiron armatures; wherein each of the plurality of disc-shaped electrical coils, disc-shaped cooling plates and disc-shaped backiron armatures are stacked and revolve around the cylindrical mover.

2. The cylindrical linear motor of claim 1, wherein each one of the plurality of disc-shaped electrical coils, disc-shaped cooling plate, and disc-shaped backiron armatures are stacked around the cylindrical mover in a repeating pattern comprising one of the disc-shaped cooling plates being sandwiched between one of the plurality of electrical coils and one of the plurality of backiron armatures.

3. The cylindrical linear motor of claim 1, wherein: the cylindrical mover comprises a plurality of rings of permanent magnets, each of the plurality of rings positioned radially on the outside edge of the cylindrical mover; an orientation of the plurality of magnets in one of the plurality of rings is uniformly facing radially outward or is uniformly facing radially inward.

4. The cylindrical linear motor of claim 1, wherein each of the plurality of disc-shaped cooling plates comprises a plurality of cooling channels, each oriented in the axial direction of the cylindrical linear motor and each positioned toward an outer edge of the disc-shaped cooling plates, the plurality of cooling channels configured to allow coolant to flow through each of the plurality of cooling plates.

5. The cylindrical linear motor of claim 4, further comprising a plurality of gaskets, where a pair of the plurality of gaskets are positioned between cooling channels of successive adjacent disc-shaped cooling plates; wherein the plurality of cooling channels is a first plurality of cooling channels, and each of the plurality of cooling plates comprises a second plurality of cooling channels, each oriented in the radial direction of the cylindrical linear motor and flowing across the each of their respective discshaped cooling plates, the plurality of second cooling channels configured to allow coolant to flow into each of the plurality of cooling plates.

6. The cylindrical linear motor of claim 1, wherein each of the plurality of disc-shaped electrical coils comprises an inner lead and outer lead, the inner lead and the outer lead positioned on an outer edge of their respective disc-shaped electrical coil.

7. The cylindrical linear motor of claim 1, wherein each of the plurality of disc-shaped backiron armatures comprises an inner slot configured to fit a respective one of the plurality of disc-shaped cooling plates and a respective one of the plurality of disc-shaped electrical coils.

8. The cylindrical linear motor of claim 1, wherein the plurality of disc-shaped electrical coils are arranged in a repeating pattern to provide a distributed phase current to power the cylindrical linear motor or to provide a concentrated phase current to power the cylindrical linear motor.

9. The cylindrical linear motor of claim 1, configured to provide linear actuation in a deep ultraviolet (DUV) lithography system or an extreme ultraviolet (EUV) lithography system.

10. A cylindrical linear motor configured to actuate proximally and distally in an axial direction, the cylindrical linear motor comprising: a cylindrical mover comprising a plurality of permanent magnets positioned radially on an outside edge of the cylindrical mover; a cylindrical backiron armature concentrically encasing the cylindrical mover and comprising a plurality of disc -shaped iron teeth oriented radially inward toward a center of the cylindrical mover, each adjacent pair of the plurality of disc-shaped iron teeth defining a disc-shaped slot therebetween; a first plurality of ring-shaped cooling plates having a first circumference defined by a first radius, each of the first plurality of ring-shaped cooling plates fitted into a respective disc-shaped slot defined by the adjacent pairs of disc-shaped iron teeth; a second plurality of ring-shaped cooling plates having a second circumference defined by a second radius smaller than the first radius, each of the second plurality of ring-shaped cooling plates fitted into the respective disc-shaped slot defined by the adjacent pairs of disc-shaped iron teeth, wherein the first plurality and second plurality of ring-shaped cooling plates concentrically enclose the cylindrical mover; and a plurality of disc-shaped electrical coils, each of the plurality of disc-shaped electrical coils fitted into the respective disc-shaped slot and sandwiched between a respective one of the first plurality of ring-shaped cooling plates and a respective one of the second plurality of ring-shaped cooling plates.

11. The cylindrical linear motor of claim 10, wherein:the cylindrical mover comprises a plurality of rings of permanent magnets, each of the plurality of rings positioned radially on the outside edge of the cylindrical mover; an orientation of the plurality of magnets in one of the plurality of rings is uniformly facing radially outward or is uniformly facing radially inward.

12. The cylindrical linear motor of claim 10, wherein each of the plurality of disc-shaped electrical coils comprises an inner lead and outer lead, the inner lead and the outer lead positioned on an outer edge of their respective disc-shaped electrical coil.

13. The cylindrical linear motor of claim 10, wherein the plurality of disc-shaped electrical coils are arranged in a repeating pattern to provide a distributed phase current to power the cylindrical linear motor.

14. The cylindrical linear motor of claim 10, wherein the plurality of disc-shaped electrical coils are arranged in a repeating pattern to provide a concentrated phase current to power the cylindrical linear motor.

15. A semiconductor device manufacturing method, the method comprising: receiving a substrate with a photoresist layer; directing radiation from a radiation source to transfer a pattern from a reticle onto the photoresist layer; actuating the reticle using a cylindrical linear motor comprising: a cylindrical mover comprising a plurality of permanent magnets positioned radially on an outside edge of the cylindrical mover; a plurality of disc-shaped electrical coils; a plurality of disc-shaped cooling plates; and a plurality of disc-shaped backiron armatures; wherein each of the plurality of disc-shaped electrical coils, disc-shaped cooling plates and disc-shaped backiron armatures are stacked and revolve around the cylindrical mover; and removing a portion of the photoresist layer to form a pattern over the substrate.

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