3D lorentz-type permanent magnet motor

Abstract

A Lorentz-type permanent magnet motor including a permanent magnet motor including at least one coil assembly and at least one magnet assembly. The at least one magnet assembly includes a first magnet group including two or more primary magnets extending in a first direction, and a second magnet group including two secondary magnets extending in a second direction perpendicular to the first direction. The two or more primary magnets are placed adjacent to each other in the second direction with alternating polarization directions. A secondary magnet is arranged on each end of the first magnet group with respect to the first direction. From a third direction perpendicular to the first direction and the second direction, the secondary magnets of the second magnet group overlap at least a portion of a turn section of the at least one coil assembly.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to European application 24163768.5, filed on March 15, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to a Lorentz-type permanent magnet motor capable of providing force in two or more directions. The invention also relates to a positioning system for positioning a movable object, a photolithography tool, and a method for applying force and / or torque to the movable object. Background Technology

[0004] A lithography apparatus is a machine configured to apply a desired pattern onto a substrate. Lithography apparatus can be used, for example, in the manufacture of integrated circuits (ICs). A lithography apparatus can project a pattern (often referred to as a “design layout” or “design”) from a patterning apparatus (e.g., a mask) onto a layer of radiation-sensitive material (resist) disposed on a substrate (e.g., a wafer).

[0005] As semiconductor manufacturing processes have advanced, the size of circuit elements has shrunk over the decades, while the number of functional elements, such as transistors, per device has steadily increased, following a trend commonly known as Moore's Law. To keep pace with Moore's Law, the semiconductor industry is pursuing technologies that enable the creation of increasingly smaller features. To project patterns onto a substrate, photolithography equipment can use electromagnetic radiation. The wavelength of this radiation determines the minimum size of the feature patterned on the substrate. Typical wavelengths currently used are 365 nm (i-line), 248 nm, 193 nm, and 13.5 nm. Compared to photolithography equipment using radiation with a wavelength, for example, 193 nm, photolithography equipment using extreme ultraviolet (EUV) radiation with wavelengths in the range of 4 nm to 20 nm (e.g., 6.7 nm or 13.5 nm) can be used to form smaller features on a substrate.

[0006] In photolithography equipment, motors such as planar motors are used to position wafers and other movable objects. These motors typically provide movement in one or two directions. When movement in three directions (X, Y, Z, where X, Y, and Z are orthogonal to each other, X and Y lie in the plane of the wafer, and Z is perpendicular to the wafer) is required, multiple motors are used to extend the number of degrees of freedom to the desired number. These motors / actuators are typically Lorentz type. The forces generated by these motors can be divided into in-plane driving forces (i.e., forces in the plane of the wafer (X, Y plane)) and out-of-plane levitation forces (in the Z direction).

[0007] These planar motors include coil assemblies comprising multiple coils arranged side-by-side in a direction along the plane of the coils. The motor also includes a magnet assembly comprising multiple magnets, which are also arranged side-by-side in the same direction as the coils. The motor can apply an in-plane driving force along this direction. The magnets have alternating polarities, such as up-down-up-down or a Halbach array. One of the magnet assembly and the coil assembly is connected to a generally stationary environment, while the other is connected to an object to be moved relative to the generally stationary environment.

[0008] The drawback of these planar motors is that they can only generate force in one in-plane direction (i.e., in the X and Y planes) and in the out-of-plane direction Z. Therefore, multiple motors are needed to allow force to be applied in both in-plane directions. This increases the required space and the mass of the motors. Summary of the Invention

[0009] The objective of this invention is to provide a Lorentz-type permanent magnet motor that is more compact than current permanent magnet motors, capable of providing force in three directions and / or torque about three axes. Another objective of this invention is to provide a positioning system that is more compact than current positioning systems for positioning movable objects in three directions. Another objective of this invention is to provide a lithography tool that is more compact than current lithography tools. A further objective of this invention is to provide a method for applying force and / or torque to a movable object.

[0010] According to one aspect of the present invention, a Lorentz-type permanent magnet motor is provided, comprising:

[0011] - At least one coil assembly arranged in a coil plane defined by a first direction and a second direction perpendicular to the first direction, the at least one coil assembly having a plurality of coils, each coil including two or more main segments extending along the first direction and a turning segment transitioning between two adjacent main segments.

[0012] - At least one magnet assembly arranged parallel to and close to the at least one coil assembly, the at least one magnet assembly having a first magnet group comprising two or more primary magnets extending along a first direction, the two or more primary magnets being placed adjacent to each other along a second direction, the two or more primary magnets having alternating polarization directions.

[0013] in:

[0014] - The at least one magnet assembly further includes a second magnet group comprising two secondary magnets extending along the second direction, wherein a first secondary magnet is disposed at a first end of the first magnet group, and a second secondary magnet is disposed at a second end of the first magnet group, wherein the second end of the first magnet group is opposite to the first end of the first magnet group relative to the first direction.

[0015] - Viewed from a third direction perpendicular to the first direction, the second direction, and the coil plane, the secondary magnet of the second magnet group overlaps with at least a portion of the turning section of the at least one coil assembly.

[0016] According to one aspect of the present invention, a positioning system for locating a movable object is provided, wherein the positioning system includes a permanent magnet motor as described in any one of claims 1 to 12, wherein one of the coil assembly and the magnet assembly is connected to the movable object, and the other of the coil assembly and the magnet assembly is connected to the environment.

[0017] According to one aspect of the invention, a lithography tool, such as a lithography apparatus, is provided, the lithography tool including the positioning system as claimed in claim 13.

[0018] According to one aspect of the present invention, a method for applying force and / or torque to a movable object is provided, the method comprising:

[0019] - Provide a permanent magnet motor as claimed in any one of claims 1 to 12, a positioning system as claimed in claim 13, or a photolithography tool as claimed in claim 14.

[0020] - Connect one of the coil assembly and the magnet assembly to the movable object, and connect the other of the coil assembly and the magnet assembly to the environment, preferably connecting the magnet assembly to the movable object and the coil assembly to the environment.

[0021] - Providing current to the coils of the coil assembly, wherein the current supplied to each coil of the coil assembly varies relative to at least one other coil of the coil assembly in order to apply force or torque to the movable object through the interaction of the coil assembly with the magnetic field generated by the magnet assembly, wherein the current supplied to each coil depends on the position of the coil in the coil assembly and the position of the movable object when measured along the second direction.

[0022] According to one aspect of the present invention, a Lorentz-type permanent magnet motor is provided, comprising:

[0023] - At least one coil assembly, said at least one coil assembly being arranged in a coil plane defined by a first direction and a second direction perpendicular to the first direction, said at least one coil assembly having a plurality of coils.

[0024] - At least one magnet assembly arranged parallel to and close to the at least one coil assembly, the at least one magnet assembly comprising two or more magnets extending along a first direction, the two or more primary magnets being placed adjacent to each other along a second direction, the two or more primary magnets having alternating polarization directions.

[0025] The coil assembly includes four or more even-numbered coils, each of which can be controlled to generate a first force in the second direction using a first current component and a second force in a third direction perpendicular to the first and second directions using a second current component. Attached Figure Description

[0026] Embodiments of the invention will now be described by way of example only, with reference to the accompanying schematic diagrams, in which:

[0027] - Figure 1 A schematic schematic diagram depicting a photolithography apparatus;

[0028] - Figure 2 Depicting Figure 1 Detailed view of a portion of the lithography equipment;

[0029] - Figure 3 A schematic depiction of the position control system;

[0030] - Figure 4 A schematic side view of a prior art permanent magnet motor is depicted.

[0031] - Figure 5 schematic depiction Figure 4 A perspective view of a prior art permanent magnet motor;

[0032] - Figure 6 A perspective view schematically depicting a first embodiment of the permanent magnet motor according to the present invention;

[0033] - Figure 7 A perspective view schematically depicting a second embodiment of the permanent magnet motor according to the present invention;

[0034] - Figure 8 schematic depiction Figure 7 A side view of a permanent magnet motor, with some parts removed for clarity;

[0035] - Figure 9A schematic depiction of the Halbach array;

[0036] - Figure 10 A top view schematically depicting a third embodiment of the permanent magnet motor according to the present invention;

[0037] - Figure 11 schematic depiction Figure 10 A perspective view of a permanent magnet motor;

[0038] - Figure 12 A side view of a fourth embodiment of a permanent magnet motor according to the present invention is schematically depicted, wherein some parts are removed for clarity;

[0039] - Figure 13 From different Figure 12 The perspective in the illustration is depicted Figure 12 Side view of a permanent magnet motor;

[0040] - Figure 14 A perspective view schematically depicting a fifth embodiment of the permanent magnet motor according to the present invention;

[0041] - Figure 15 A top view schematically depicting a sixth embodiment of the permanent magnet motor according to the present invention is shown.

[0042] - Figure 16 A perspective view schematically depicting another embodiment of the permanent magnet motor according to the present invention is shown.

[0043] - Figure 17 A perspective view schematically depicting another embodiment of the permanent magnet motor according to the present invention is shown.

[0044] - Figure 18 and Figure 19 A top view and a perspective view of yet another embodiment of the permanent magnet motor according to the present invention are schematically depicted.

[0045] - Figure 20 and Figure 21 A side view and a perspective view of yet another embodiment of the permanent magnet motor according to the present invention are schematically depicted.

[0046] - Figure 22 A top view schematically depicting another embodiment of the permanent magnet motor according to the present invention is shown. Detailed Implementation

[0047] In this document, the terms “radiation” and “beam” are used to cover all types of electromagnetic radiation, including ultraviolet radiation (e.g., having wavelengths of 365 nm, 248 nm, 193 nm, 157 nm, or 126 nm) and EUV (extreme ultraviolet radiation, e.g., having wavelengths in the range of about 5 nm to 100 nm).

[0048] As used herein, the terms “mask,” “mask,” or “patterning apparatus” can be broadly interpreted to refer to a general patterning apparatus that can be used to impart a patterned cross-section to an incident radiation beam, the patterned cross-section corresponding to a pattern to be generated in a target portion of a substrate. In such contexts, the term “optical valve” may also be used. Examples of these patterning apparatuses, in addition to classic masks (transmissive or reflective, binary, phase-shifting, hybrid, etc.), include programmable mirror arrays and programmable LCD arrays.

[0049] Figure 1 A lithography apparatus LA is schematically depicted. The lithography apparatus LA includes: an irradiation system (also called an irradiator) IL configured to modulate a radiation beam B (e.g., UV radiation, DUV radiation, or EUV radiation); a mask support (e.g., a mask stage) MT configured to support a patterning apparatus (e.g., a mask) MA; and a positioning system 31 for positioning the patterning apparatus MA and a substrate (e.g., a wafer coated with resist) W. The positioning system 31 includes a first positioner PM and a second positioner PW. The first positioner PM is configured to accurately position the patterning apparatus MA according to certain parameters. The mask support MT is connected to the first positioner PM. The second positioner PW is configured to accurately position the substrate support according to certain parameters. The second positioner PW is connected to a substrate support (e.g., a wafer stage) WT configured to hold the substrate W. The lithography apparatus LA also includes a projection system (e.g., a refractive projection lens system) PS, which is configured to project a pattern, provided by the patterning apparatus MA to the radiation beam B, onto a target portion C (e.g., comprising one or more dies) of the substrate W.

[0050] In operation, the irradiation system IL receives a radiation beam from the radiation source SO, for example, via a beam delivery system BD. The irradiation system IL may include various types of optical components for guiding, shaping, and / or controlling the radiation, such as refractive, reflective, magnetic, electromagnetic, electrostatic, and / or other types of optical components or any combination thereof. The irradiator IL can be used to adjust the radiation beam B to have a desired spatial and angular intensity distribution in its cross-section at the plane of the pattern forming apparatus MA.

[0051] The term “projection system” PS as used herein should be broadly interpreted to encompass any type of projection system suitable for the exposure radiation used and / or for other factors such as immersion in liquids or vacuum, including refractive, reflective, reflective-refractive, distorting, magnetic, electromagnetic, and / or electrostatic optical systems or any combination thereof. Any use of the term “projection lens” herein may be considered synonymous with the more general term “projection system” PS.

[0052] Photolithography equipment (LA) can fall into the following categories: at least a portion of the substrate can be covered by a liquid (e.g., water) with a relatively high refractive index to fill the space between the projection system (PS) and the substrate (W), also known as immersion lithography. Further information on immersion techniques is given in US6952253, which is incorporated herein by reference.

[0053] Photolithography equipment (LA) can also be of the type with two or more substrate supports (WT) (also known as "dual platforms"). In such a "multi-platform" machine, substrate supports (WT) can be used in parallel, and / or a subsequent exposure step for preparing substrate W on one substrate support (WT) can be performed, while another substrate W on another substrate support (WT) is used to expose a pattern on the other substrate W.

[0054] In addition to the substrate support WT, the lithography apparatus LA may also include a measurement platform. The measurement platform is arranged to hold sensors and / or cleaning devices. The sensors may be arranged to measure the properties of the projection system PS or the properties of the radiation beam B. The measurement platform may hold multiple sensors. The cleaning devices may be arranged to clean parts of the lithography apparatus, such as parts of the projection system PS or parts of the system providing the immersion liquid. The measurement platform can move below the projection system PS when the substrate support WT is away from the projection system PS.

[0055] In operation, a radiation beam B is incident on a pattern forming apparatus (e.g., a mask) MA held on a mask support MT and patterned by a pattern (design layout) presented on the pattern forming apparatus MA. Having traversed the pattern forming apparatus MA, the radiation beam B passes through a projection system PS, which focuses the beam onto a target portion C of the substrate W. With the aid of a second positioner PW and a position measurement system PMS, the substrate support WT can be accurately moved, for example, to position different target portions C at focused and aligned locations along the path of the radiation beam B. Similarly, a first positioner PM and possibly another position sensor (the other position sensor is not in...) Figure 1(As clearly depicted in the diagram) can be used to accurately position the patterning apparatus MA relative to the path of the radiation beam B. The patterning apparatus MA and the substrate W can be aligned using mask alignment marks M1, M2 and substrate alignment marks P1, P2. Although the substrate alignment marks P1, P2 occupy dedicated target portions as illustrated, they can also be located in the space between target portions. When the substrate alignment marks P1, P2 are located between target portions C, these substrate alignment marks are referred to as scribing alignment marks.

[0056] For the purpose of illustrating this invention, a Cartesian coordinate system is used. A Cartesian coordinate system has three axes: the x-axis, the y-axis, and the z-axis. Each of the three axes is orthogonal to the other two axes. A rotation about the x-axis is called an Rx rotation. A rotation about the y-axis is called an Ry rotation. A rotation about the z-axis is called an Rz rotation. The x-axis and y-axis define a horizontal plane, while the z-axis is in the vertical direction. The Cartesian coordinate system is not limiting of the invention and is only used for illustration. Alternatively, another coordinate system, such as a cylindrical coordinate system, can be used to illustrate the invention. The orientation of the Cartesian coordinate system can be different, for example, such that the z-axis has a component along the horizontal plane.

[0057] Figure 2 Show Figure 1 A more detailed view of a portion of a lithography apparatus LA. The lithography apparatus LA may include a base frame BF, a counterweight BM, a measurement frame MF, and a vibration isolation system IS. The measurement frame MF supports the projection system PS. Additionally, the measurement frame MF may support a portion of the position measurement system PMS. The measurement frame MF is supported by the base frame BF via the vibration isolation system IS. The vibration isolation system IS is arranged to prevent or reduce vibrations propagating from the base frame BF to the measurement frame MF.

[0058] The second positioner PW is arranged to accelerate the substrate support WT by providing a driving force between the substrate support WT and the balancing mass block BM. The driving force accelerates the substrate support WT in the desired direction. Due to the conservation of momentum, an equal driving force is also applied to the balancing mass block BM, but in the opposite direction to the desired direction. Typically, the mass of the balancing mass block BM is significantly greater than the mass of the moving portions of the second positioner PW and the substrate support WT.

[0059] In one embodiment, the second positioner PW is supported by a balancing mass block BM. For example, the second positioner PW includes a planar motor for suspending the substrate support WT above the balancing mass block BM. In another embodiment, the second positioner PW is supported by a base frame BF. For example, the second positioner PW includes a linear motor and includes a bearing, such as a gas bearing, for suspending the substrate support WT above the base frame BF.

[0060] A position measurement system (PMS) can include any type of sensor adapted to determine the position of a substrate support WT. A PMS can also include any type of sensor adapted to determine the position of a mask support MT. The sensor can be an optical sensor, such as an interferometer or encoder. A PMS can include a combined system of interferometers and encoders. The sensor can also be another type of sensor, such as a magnetic sensor, a capacitive sensor, or an inductive sensor. A PMS can determine the position relative to a reference object, such as a measurement frame MF or a projection system PS. A PMS can determine the position of the substrate stage WT and / or the mask support MT by measuring the position or by measuring the time derivative of the position (such as velocity or acceleration).

[0061] A position measurement system (PMS) may include an encoder system. Encoder systems are known, for example, from U.S. Patent Application US2007 / 0058173A1, filed September 7, 2006, which is incorporated herein by reference. The encoder system includes an encoder head, a grating, and a sensor. The encoder system can receive a primary radiation beam and a secondary radiation beam. Both the primary and secondary radiation beams originate from the same radiation beam, i.e., the original radiation beam. At least one of the primary and secondary radiation beams is generated by diffracting the original radiation beam using a grating. If both the primary and secondary radiation beams are generated by diffracting the original radiation beam using a grating, the primary radiation beam needs to have a different diffraction order compared to the secondary radiation beam. Different diffraction orders are, for example, +1, -1, +2, and -2. The encoder system optically combines the primary and secondary radiation beams into a combined radiation beam. A sensor in the encoder head determines the phase or phase difference of the combined radiation beam. The sensor generates a signal based on the phase or phase difference. The signal represents the position of the encoder head relative to the grating. One of the encoder head and the grating can be arranged on the substrate structure WT. The other of the encoder head and the grating can be arranged on the measurement frame MF or the base frame BF. For example, multiple encoder heads are arranged on the measurement frame MF, while the grating is arranged on the top surface of the substrate support WT. In another example, the grating is arranged on the bottom surface of the substrate support WT, and the encoder head is arranged below the substrate support WT.

[0062] A position measurement system (PMS) may include an interferometer system. Interferometer systems are known, for example, from U.S. Patent 6,020,964, filed July 13, 1998, which is incorporated herein by reference. An interferometer system may include a beam splitter, a mirror, a reference mirror, and a sensor. A radiation beam is split into a reference beam and a measurement beam by the beam splitter. The measurement beam propagates to the mirror and is reflected back to the beam splitter by the mirror surface. The reference beam propagates to the reference mirror and is reflected back to the beam splitter by the reference mirror surface. At the beam splitter, the measurement beam and the reference beam are combined into a combined radiation beam. The combined radiation beam is incident on the sensor. The sensor determines the phase or frequency of the combined radiation beam. The sensor generates a signal based on the phase or the frequency. The signal represents the displacement of the mirror. In an embodiment, the mirror is connected to a substrate support WT. The reference mirror may be connected to a measurement frame MF. In an embodiment, the measurement beam and the reference beam are combined into a combined radiation beam by additional optical components instead of a beam splitter.

[0063] The first positioner PM may include a long-stroke module and a short-stroke module. The short-stroke module is arranged to move the mask support MT relative to the long-stroke module with high accuracy within a small range of motion. The long-stroke module is arranged to move the short-stroke module relative to the projection system PS with relatively low accuracy within a large range of motion. In the combination of the long-stroke module and the short-stroke module, the first positioner PM is able to move the mask support MT relative to the projection system PS with high accuracy within a large range of motion. Similarly, the second positioner PW may include a long-stroke module and a short-stroke module. The short-stroke module is arranged to move the substrate support WT relative to the long-stroke module with high accuracy within a small range of motion. The long-stroke module is arranged to move the short-stroke module relative to the projection system PS with relatively low accuracy within a large range of motion. In the combination of the long-stroke module and the short-stroke module, the second positioner PW is able to move the substrate support WT relative to the projection system PS with high accuracy within a large range of motion.

[0064] The first positioner PM and the second positioner PW are each equipped with actuators to move the mask support MT and the substrate support WT, respectively. The actuators include planar actuators to provide driving force along multiple axes. For example, the planar actuators can be arranged to move the substrate support WT in six degrees of freedom (i.e., move the substrate support WT along three spatial axes and rotate the substrate support WT about the three spatial axes). The actuators can be electromagnetic actuators comprising at least one coil and at least one magnet. The actuators are arranged to move at least one coil relative to at least one magnet by applying current to at least one coil. The actuators can be moving magnet type actuators having at least one magnet respectively connected to the substrate support WT or the mask support MT. The actuators can be moving coil type actuators having at least one coil respectively connected to the substrate support WT or the mask support MT. The actuators can be voice coil actuators, magnetoresistive actuators, Lorentz actuators, or piezoelectric actuators, or any other suitable actuators.

[0065] Photolithography equipment (LA) includes, for example Figure 3 A position control system (PCS) is schematically depicted. The PCS includes a setpoint generator (SP), a feedforward controller (FF), and a feedback controller (FB). The PCS provides a drive signal to an actuator (ACT). The actuator (ACT) may be an actuator of a first positioner (PM) or a second positioner (PW). The actuator (ACT) drives a device (P), which may include a substrate support (WT) or a mask support (MT). The output of the device (P) is a position quantity, such as position, velocity, or acceleration. The position quantity is measured by a position measurement system (PMS). The PMS generates a signal representing the position quantity of the device (P). The setpoint generator (SP) generates a signal representing a reference signal representing the ideal position quantity of the device (P). For example, the reference signal represents the desired trajectory of the substrate support (WT). The difference between the reference signal and the position signal forms the input to the feedback controller (FB). Based on this input, the feedback controller (FB) provides at least a portion of the drive signal to the actuator (ACT). The reference signal may form the input to the feedforward controller (FF). Based on this input, the feedforward controller (FF) provides at least a portion of the drive signal to the actuator (ACT). Feedforward FF can use information about the dynamic characteristics of device P, such as mass, stiffness, resonant modes, and intrinsic frequencies.

[0066] Figure 4 A schematic side view of a prior art permanent magnet motor 1 is depicted. Figure 5This same permanent magnet motor 1 is schematically depicted in perspective view. The permanent magnet motor 1 includes two coil assemblies 3, each having multiple coils 7, namely, a first coil assembly 27 and a second coil assembly 28. Systems with a single coil assembly 3 are also well known. The permanent magnet motor 1 also includes a magnet assembly 10.

[0067] Each coil assembly 3 is arranged in a coil plane 4 defined by a first direction 5 and a second direction 6, wherein the third direction 20 is perpendicular to the coil plane 4. The coil plane 4 is a plane that intersects each coil 7 of the coil assembly 3 at the same position relative to the axis of the coil 7. Each coil 7 includes two main sections 8 extending along the first direction 5 and two turning sections 9 transitioning between two adjacent main sections 8. This is, for example, Figure 10 This is even more evident in the middle. In Figure 10 In the middle, the turning section 9 of coil 7 is visible.

[0068] The magnet assembly 10 of the permanent magnet motor 1 is arranged parallel to and close to the coil assembly 3, such that the magnet assembly 10 is also positioned substantially parallel to the coil plane 4. The magnet assembly 10 includes a first magnet group 11, which includes a plurality of primary magnets 12 extending along a first direction 5. The primary magnets 12 are placed adjacent to each other along a second direction 6 and have alternating polarization directions 13. Each primary magnet 12 has a polarization direction opposite to that of its adjacent primary magnet 12. Halbach arrays with periodic polarization (see also...) are also known to be used. Figure 9 (or other types or magnet arrays).

[0069] Figure 6 A perspective view schematically depicting a first embodiment of a permanent magnet motor 1 according to the present invention is shown. The permanent magnet motor 1 includes the same components described above with respect to prior art permanent magnet motors, wherein a second magnet assembly 14 is added, comprising two secondary magnets 15 extending along a second direction 6. A first primary magnet 16 is arranged at a first end 17 of the first magnet assembly 11, and a second secondary magnet 18 is arranged at a second end 19 of the first magnet assembly 11. The second end 19 of the first magnet assembly 11 is opposite to the first end 17 of the first magnet assembly 11 relative to a first direction 5. Therefore, the secondary magnets 15 are arranged perpendicular to the primary magnets 12, and the secondary magnets 15 preferably extend along all the primary magnets 12. Viewed from a third direction 20 perpendicular to the first direction 5, the second direction 6, and therefore perpendicular to the coil plane 4, the secondary magnets 15 of the second magnet assembly 14 overlap with at least a portion of the turning section 9 of the coil assembly 3. This is, for example... Figure 10 It is more visible in the middle.

[0070] Similar to Figure 4 and Figure 5 The prior art permanent magnet motor shown in the figure, Figure 6The permanent magnet motor 1 also includes two back irons 21 extending in a plane parallel to the coil plane 4. The back irons 21 are arranged adjacent to the coil assembly 3. The back irons 21 can provide a return path for the magnetic flux, so that the magnetic field in the permanent magnet motor 1 can be enhanced.

[0071] The polarization directions 13 of the primary magnets 12 and secondary magnets 15 are oriented along a third direction 20, and each primary magnet 12 has a polarization direction 13 opposite to that of its adjacent primary magnet 12. However, as discussed above, the primary magnets 12 can alternatively be arranged in a Halbach array (see...). Figure 9 The polarization direction 13 of the first-stage magnet 16 is opposite to that of the second-stage magnet 18.

[0072] The second magnet assembly 14 allows the permanent magnet motor 1 to provide force not only in the second direction 6 (similar to that in the prior art permanent magnet motor 1) but also in the first direction 5. Therefore, it may no longer be necessary to use multiple motors to allow force to be applied in two plane directions 5 and 6, thereby reducing the size, weight, and complexity of the permanent magnet motor 1.

[0073] The permanent magnet motor 1 can be controlled by using a current controller to control the current in each coil of coil 7 in a three-phase system. The current in coil 7 depends at least on the position of coil 7 within the coil assembly and the movable object 32 (e.g., substrate support WT or mask support MT, see below) via the following equation. Figure 1 Position 6 along the second direction:

[0074]

[0075] Among them, i n Let n be the current passing through coil n. Let y be the common amplitude of all coils, y be the position of the movable object 32 in the second direction 6, and s be the spatial period of the primary magnet 12 (i.e., the distance between two magnets 12 with the same polarity 13). This is the phase angle. The number of coils, n, starts counting from 1 for each coil 7 along the second direction 6. Note that n = 1 produces the same i as n = 4. n This is because the phase difference of the cosines is 2π and cos(β) = cos(β + 2π). Therefore, it can be concluded that there are three distinct current phases, making this a three-phase system, where the current i in each coil 7 is... n The phase relative to the adjacent coil 7 at the phase angle (i.e., a change of 120 degrees), where each phase is via The term is separated into two sub-phases: an upper coil portion 29 and a lower coil portion 30. Other numbers of phases are also possible; in this case, for m phases, the term... quilt Replacement, where m is an integer. The number of phases depends on the distance cs between adjacent coils 7 (see...). Figure 4 The ratio between the CS:S ratio and the spatial period s of the primary magnets 12. In the imaged embodiment, the CS:S ratio is 2:3, that is, there are 3 coils 7 along the second direction 6 across the width of the 4 primary magnets 12 (2 for each polarity 13). Figure 4 And a 3-phase system is used. If the ratio is, for example, 2:5 (5 coils 7 exist on the width of 4 primary magnets 12), a 5-phase system is used. If the ratio is, for example, 3:4 (4 coils 7 exist on the width of 6 primary magnets 12), a 4-phase system is used, and for 2:7, a 7-phase system is used, and so on. Generally, the number of phases is preferably equal to the minimum integer number of coils, which is adapted to a width that is an integer multiple of the spatial period s of the primary magnets. In the case of alternating up-down-up-down magnets, this means that the number of phases is equal to the minimum number of coils that are first in a width that is the same as the even integer number of primary magnets, because there are two primary magnets in one spatial period s of the primary magnets. The above is also described in U.S. Patent Application US 2018 / 0224756 A1, which is incorporated herein by reference.

[0076] The upper coil portion 29 and the lower coil portion 30 have the same number of coils n. If the coil is not separated into the upper coil portion 29 and the lower coil portion 30, the phase angle is zero. If the coil is separated into the upper coil portion 29 and the lower coil portion 30, the operator ± represents addition for the upper coil portion 29 and subtraction for the lower coil portion 30. This is also described in US 2018 / 0224756 A1. and It can be rewritten as

[0077]

[0078] in, The force exerted on the movable object 32 by the permanent magnet motor 1 in the second direction 6, The force exerted on the movable object 32 by the permanent magnet motor 1 on the third direction 20, Let be the actuator constant of the permanent magnet motor in the second direction 6, and Let be the actuator constant of the permanent magnet motor in the third direction 20. Using this, the current in coil 7 can be rewritten into two parts: one part determining the driving force exerted by the permanent magnet motor 1 on the movable object 32 in the second direction 6 relative to the environment; and the other part determining the levitation force exerted by the permanent magnet motor 1 on the movable object 32 in the third direction 20 relative to the environment. This is derived below.

[0079]

[0080] use:

[0081]

[0082] In this article, the cosine term Determine the driving force and the sine term The levitation force is determined. To provide levitation for the movable object 32, the lower coil portion 30 repels the primary magnet 12 of the first magnet group 11, while the upper coil portion attracts the primary magnet 12 of the first magnet group 11. Therefore, the sign of the sine term of the upper coil portion 29 is opposite to the sign of the sine term of the lower coil portion 30.

[0083] Permanent magnet motors 1 using the above-described control are known from the prior art. In the permanent magnet motor 1 according to the invention, the secondary magnet 15 allows the permanent magnet motor 1 to apply force to the movable object 32 relative to the environment not only in the second direction 6 and the third direction 20 but also in the first direction 5. This can be achieved by directing the current component I... x Each addition to the coil current completes this process, such that:

[0084]

[0085] When I x When all coils 7 are identical (but may depend, for example, on the time or position of the movable object 32), all coils are attracted by one of the secondary magnets 15 and repelled by the other. This causes a force to be exerted on the movable object 32 relative to the environment in the first direction 5. x It can also be varied for each coil 7 to achieve other goals. Typically, if I... x If the distribution on coil 7 is symmetrical with respect to the center of mass of the movable object 32, then the permanent magnet motor 1 can apply a force to the movable object 32 in the first direction 5 relative to the environment. If I xIf the distribution on coil 7 is not symmetrical with respect to the center of mass of the movable object 32, then the permanent magnet motor can apply torque to the movable object 32 relative to the environment around a third direction 20. In such a case, it is preferable to use a permanent magnet motor 1 comprising at least two instances of each phase, wherein coil 7 is separated into at least two coil groups 41, 42, such that each coil group 41, 42 includes all phases (see...). Figure 15 ). You can then put an I x The coil 7 is applied to one group of coils 41 and 42, while another I can be applied simultaneously. x (For example, -I) x The I7 is applied to coils 7 in another set of 41, 42. All coils 7 in each corresponding set of 41, 42 then receive the same I7 as the other coils 7 in the corresponding set of 41, 42. x This prevents interference from the force exerted on the movable object 32 by the permanent magnet motor 1 in the second direction 6. Regarding... Figure 15 This situation will be discussed in more detail.

[0086] In such Figure 6 In a first embodiment of the permanent magnet motor 1 shown, the permanent magnet motor 1 includes a magnet assembly 10 arranged between two coil assemblies 3 (a first coil assembly 27 and a second coil assembly 28). Figure 7 A perspective view of a second embodiment of a permanent magnet motor 1 according to the present invention is schematically depicted, the permanent magnet motor including a coil assembly 3 disposed between two magnet assemblies 10 (a first magnet assembly 23 and a second magnet assembly 24).

[0087] The permanent magnet motor 1 according to the invention can be integrated into the positioning system 31, for example, a lithography apparatus LA or another lithography tool (see...). Figure 1 In a positioning system 31, one of the coil assembly 3 and the magnet assembly 10 is connected to a movable object 32, such as a substrate support WT or a mask support MT. The other of the coil assembly 3 and the magnet assembly 10 is connected to a substantially stationary environment. The permanent magnet motor 1 can then apply force and / or torque to the movable object 32 relative to the substantially stationary environment. Figure 6 In the first embodiment shown, preferably, the magnet assembly 10 is connected to the movable object 32, while the coil assembly 3 is connected to a substantially stationary environment. Such an embodiment is referred to as a mobile magnet motor. Figure 7 In the second embodiment shown, preferably, the coil assembly 3 is connected to the movable object 32, while the magnet assembly 10 is connected to a substantially stationary environment. Such an embodiment is referred to as a mobile coil motor.

[0088] Whether to use a moving coil motor or a moving magnet motor preferably depends on the specific application. The advantage of a moving magnet motor may be that the magnet does not need to be connected to any cables or wires for power supply and cooling. This can reduce the weight and size of the moving parts, thereby reducing reactive force and reactive torque when operating the permanent magnet motor 1. However, in some applications, if it is proven that a lighter moving part is due to other design parameters, then using a moving coil motor instead may be beneficial.

[0089] Because the positioning system 31 according to the invention no longer requires a separate motor to apply force in directions 5 and 6 in both planes, the size, weight, and complexity of the positioning system 31 can be reduced. This allows for a more compact construction of the lithography apparatus LA and / or allows more space in the lithography apparatus LA for other components. Furthermore, the reduced weight allows for faster acceleration and / or less vibration of the movable object 32, resulting in higher production throughput and / or higher accuracy and / or reduced wear of the lithography apparatus LA.

[0090] like Figure 6 The first embodiment of the permanent magnet motor 1 shown in the figure and as follows Figure 7 The second embodiment of the permanent magnet motor 1 shown includes two back irons 21, namely a first back iron 25 and a second back iron 26. In such a way... Figure 6 In the first embodiment of the permanent magnet motor 1 shown, a first back iron 25 is arranged adjacent to a first coil assembly 27, and a second back iron 26 is arranged adjacent to a second coil assembly 28. The coil 7 of the first coil assembly 27 is arranged between the magnet assembly 10 and the first back iron 25, while the coil 7 of the second coil assembly 28 is arranged between the magnet assembly 10 and the second back iron 26. Figure 7 In the second embodiment of the permanent magnet motor 1 shown, a first back iron 25 is arranged adjacent to a first magnet assembly 23, and a second back iron 26 is arranged adjacent to a second magnet assembly 24. A first magnet group 11 and a second magnet group 14 of the first magnet assembly 23 are arranged between the coil assembly 3 and the first back iron 25, while the first magnet group 11 and the second magnet group 14 of the second magnet assembly 24 are arranged between the coil assembly 3 and the second back iron 26.

[0091] Figure 8 schematic depiction Figure 7 A side view of a permanent magnet motor, in which the second magnet assembly 14 has been removed for clarity. Figure 8 In the first direction 5, the permanent magnet motor 1 is viewed. Each coil 7 is separated into an upper coil portion 29 and a lower coil portion 30 along a separation plane 44 parallel to the coil plane 4 at the middle of the coil 7.

[0092] When using separate coils 7, torque can be applied to the movable object 32 relative to the environment by varying the current in the upper coil portion 29 relative to each coil 7 or the lower coil portion 30 of a subset of coils 7.

[0093] A torque can be generated about a first direction by applying an electric current, the torque causing the upper coil portion 29 to be pulled along a second direction 6 in the opposite direction to the lower coil portion 30. To achieve this, the cosine term... For example, by making The upper coil portion 29 and the lower coil portion 30 are modified to differ from each other. For example:

[0094]

[0095] Here, in the lower coil section, the cosine term has a negative sign instead of a positive sign. In this way, instead of a net force being applied in the second direction 6, a torque is applied about the first direction 5 because the force pulling the upper coil section 29 along the second direction 6 is equal in magnitude but opposite in sign to the force pulling the associated lower coil section 30 along the second direction 6. Therefore, the force along the second direction 6 is canceled out, while a torque is generated about the first direction 5.

[0096] Similarly, a torque can be generated about a second direction by applying an electric current, the torque causing the upper coil portion 29 to be pulled along the first direction 5 in a direction opposite to that of the lower coil portion 30. To achieve this, the relevant items I of the upper coil portion 29 and the lower coil portion 30... x Modified. For example:

[0097]

[0098] In this way, instead of applying force in the first direction 5, torque is applied around the second direction 6.

[0099] Those skilled in the art will recognize that the generation of force and torque can be simultaneously combined by adding current components to achieve the respective objectives. For example, torque can be applied to the movable object 32 relative to the environment about a second direction, while force is applied in the first direction:

[0100]

[0101] Here, because of item I x,1 The upper coil portion 29 and the lower coil portion 30 have opposite signs, and item I x,2 Since the upper coil portion 29 and the lower coil portion 30 have the same sign, item I... x,1 This generates torque around the second direction 6, while term I...x,2 The force generated in the first direction 5.

[0102] Figure 9 A first magnet group 11 of the magnet assembly 10 of the permanent magnet motor 1 according to the invention is schematically depicted, wherein primary magnets 12 are arranged in a Halbach array 22. In the Halbach array, the polarization directions 13 of the magnets are arranged in a spatial rotational pattern. In the case of the permanent magnet motor 1 according to the invention, the axis of the rotational pattern extends along a first direction 5, and the polarization direction 13 is arranged on the axis of the rotational pattern. The Halbach array 22 can enhance the magnetic field inside the permanent magnet motor 1 while reducing the magnetic field outside the permanent magnet motor 1. Other types of periodically polarized magnet arrays (such as sinusoidally varying polarization 13) can also be used. When using the Halbach array 22 or another type of magnet array with a periodic polarization pattern, the distance between two primary magnets 12 with equal polarization 13 is maintained at the same value s as the values ​​used in the equations and discussion above.

[0103] Figure 10 A top view schematically depicting a third embodiment of the permanent magnet motor 1 according to the present invention is shown. Figure 10 In the middle, from a third party's perspective, we see permanent magnet motor 1. Figure 11 schematic depiction Figure 10 A perspective view of a permanent magnet motor 1. In this embodiment, the permanent magnet motor 1 includes exactly one coil assembly 3 and exactly one magnet assembly 10. A back iron 21 is arranged adjacent to either the coil assembly 3 or the magnet assembly 10. In the imaged embodiment, the back iron is arranged adjacent to the magnet assembly 10 such that the magnet assembly 10 is positioned between the coil assembly 3 and the back iron 21. In an alternative in which the back iron 21 is arranged adjacent to the coil assembly 3, the coil assembly 3 is positioned between the magnet assembly 10 and the back iron 21. The back iron 21 may also be omitted. This variant can be considered a “half-motor” variant, where the moving part of the motor is not enclosed by two stationary parts, or vice versa.

[0104] Figure 12 A side view of a fourth embodiment of the permanent magnet motor 1 according to the present invention is schematically depicted, wherein the second magnet assembly 14 is removed for clarity. Figure 13 To depict and schematically from different perspectives Figure 12 The same permanent magnet motor 1, Figure 13 A second magnet assembly 14, comprising a primary magnet 16 and a secondary magnet 18, is also shown. Figure 12 In the middle, looking at the permanent magnet motor 1 from the first direction, while... Figure 13 In the middle, the permanent magnet motor 1 is viewed from the second direction 6. The permanent magnet motor 1 according to the fourth embodiment is similar in that it is also a semi-motor design. Figure 10 and Figure 11The permanent magnet motor 1 according to the third embodiment is shown in the figure. One difference is that the permanent magnet motor 1 according to the fourth embodiment does not include one back iron 21 but includes two back irons 21, which is different from the third embodiment. Another difference is that, in the case of... Figure 10 and Figure 11 In the permanent magnet motor 1 according to the third embodiment shown in the figure, the back iron is arranged adjacent to the magnet assembly 10, while Figure 12 and Figure 13 In the fourth embodiment of the permanent magnet motor 1 according to the present invention shown, one of the back irons 21 is arranged adjacent to the coil assembly 3, and the other of the back irons 21 is arranged on the other side of the permanent magnet motor 1.

[0105] It is evident that minimizing the mass of the moving part of the permanent magnet motor 1 to reduce stress may be beneficial; therefore, it is preferable to use a motor such as... Figure 10 and Figure 11 The permanent magnet motor 1 according to the third embodiment shown is a moving coil motor, wherein the coil assembly 3 is connected to a movable object 32 such as a substrate support WT or a mask support MT, and the magnet assembly 10 is connected to a substantially stationary environment. Similarly, it is preferable to use a... Figure 12 and Figure 13 The permanent magnet motor 1 according to the fourth embodiment shown in the figure is a movable magnet motor, wherein the magnet assembly 10 is connected to a movable object 32 such as a substrate support WT or a mask support MT, and the coil assembly 3 and the back iron 21 are connected to a generally stationary environment.

[0106] Figure 14 A perspective view schematically depicting a fifth embodiment of the permanent magnet motor 1 according to the present invention is shown. This embodiment is similar to... Figure 12 and Figure 13 The fourth embodiment shown differs from the fifth embodiment of the permanent magnet motor 1 in that it does not have a back iron 21. This also reduces the size and weight of the permanent magnet motor 1.

[0107] Figure 15 A perspective view schematically depicting a sixth embodiment of the permanent magnet motor 1 according to the present invention is shown. This embodiment is similar to... Figure 14The fifth embodiment shown differs from the sixth embodiment of the permanent magnet motor 1 in that it has more coils 7 and more primary magnets 12. The coils 7 are separated into a first coil group 41 and a second coil group 42. The first coil group 41 and the second coil group 42 are arranged on opposite sides of a line 43 extending in a first direction 5. Providing a different current to the coils 7 in the first coil group 41 compared to the current in the second coil group 42 allows torque to be applied to the movable object 32 about a third direction 20. In particular, providing a second current component to the first coil group 41 and providing the negative value of the second current component to the second coil group 42 allows torque to be applied to the movable object 32 about a third direction 20, without potentially applying another linear force to the movable object 32. This is because in this case, in Figure 15 In this process, one of the first coil group 41 and the second coil group 42 will be forced upward relative to the magnet assembly 10 (i.e., attracted to the first stage magnet 16 and repelled by the second stage magnet 18), and the other of the first coil group 41 and the second coil group 42 will be forced downward relative to the magnet assembly 10 (i.e., attracted to the second stage magnet 18 and repelled by the first stage magnet 16).

[0108] Figure 15 Another embodiment of the permanent magnet motor 1 according to the invention is shown, wherein the coil assembly includes two coil groups 41 and 42. This is attributed to the secondary magnet and the current in each coil (specifically i...) y The interaction of these components can generate undesirable parasitic torques on a movable object in a third direction around 20. This is achieved by using the second current component + I. x The current is applied to the coil in the first coil group 41, and the negative value of the second current component - I x The coils applied to the second coil group 42 may not exert another linear force on the movable object. To at least partially compensate for or counteract the undesirable torque around the third-direction 20, I x It can be selected to have i that depends on the coil. y And the magnitude of physical dimensions (e.g., coil width and space along the second direction 6), and having relative to i y Phase shift.

[0109] Those skilled in the art will recognize that, Figure 15The core concept of the sixth embodiment of the permanent magnet motor shown, namely, separating the coils 7 into a first coil group 41 and a second coil group 42, can also be applied to other embodiments. Preferably, in that case, there should be an even number of coils 7, such that the two coil groups 41, 42 can have an equal number of coils 7 to provide symmetry. This can help to provide rotational torque about a third direction 20 without generating undesirable linear forces in the first direction 5 or the second direction 6. It is also feasible, and in some cases may be preferred, that not all coils 7 are used to apply torque about a third direction 20, i.e., not all coils belong to the first coil group 41 or the second coil group 42. For example, only the outer coil 7 can be used in this case. As an example, in Figure 15 In this configuration, the second current component can be supplied only to the leftmost coil, while the negative value of the second current component can be supplied only to the rightmost coil. In this case, the first coil group 41 includes only the leftmost coil 7, and the second coil group 42 includes only the rightmost coil 7. This specialization of specific coils 7 in the permanent magnet motor facilitates overall control of the permanent magnet motor 1, potentially yielding benefits in hardware connections and control logic.

[0110] Figure 16 and Figure 17 A further embodiment of the permanent magnet motor 1 according to the invention is schematically shown, wherein the coil assembly 3 includes four coils 9. This is attributed to the primary magnet and the current in each coil (specifically i... z The interaction of these forces can generate unwanted parasitic torques on the movable object around the first direction 5. Figure 16 Similar to Figure 7 and Figure 8 The design includes a coil assembly located between two magnet assemblies 10, and Figure 17 Similar to Figure 10 and Figure 11 The "half-motor" comprises exactly one coil assembly and exactly one magnet assembly. Note that more even numbers of coils can be included in the coil assembly to achieve the same effect, provided that the amplitude and phase of the coil current are chosen accordingly to generate the desired force and to at least partially compensate for or counteract any undesired torque around the first direction 5. In this example with four coils, the current phase difference between adjacent coils can be... Each of coil 9 (i.e., the nth coil) is controllable to use the first current component. A first force is generated in the second direction and a second current component is used. A second force is generated in a third direction perpendicular to the first and second directions. When the second current component is configured such that... At least partially compensated or offset attributable to Undesirable parasitic torque generated around the first direction 5. In the equation, R2 is the distance from the center of the two inner coils to the center of the coil assembly, and similarly, R1 is the distance from the center of the two outer coils to the center of the coil assembly. Coil 9 can be separated into an upper portion and a lower portion along a separation plane parallel to the coil plane, and the current in the upper and lower portions can be controlled independently, having, for example, opposite second current components, i.e. This ensures that at least part of the compensation or offset is due to Undesirable parasitic torque generated on the movable object around the first direction 5.

[0111] Figure 18 and Figure 19 Another embodiment of a permanent magnet motor 1 according to the present invention is shown. In this embodiment, the permanent magnet motor 1 includes a coil assembly 3 arranged in a coil plane defined by a first direction 5 and a second direction 6 perpendicular to the first direction, the coil assembly 3 having a plurality of coils 9. The permanent magnet motor 1 also includes a magnet assembly 10 arranged parallel to and close to the coil assembly, the magnet assembly including two or more magnets extending along the first direction, the two or more magnets being placed adjacent to each other along the second direction 6, the two or more primary magnets having alternating polarization directions. The coil assembly 3 includes four or more even-numbered adjacent coils 9, each coil being controllable to generate a first force in the second direction 6 using a first current component and a second force in a third direction 20 perpendicular to the first and second directions using a second current component. Similar to the previous embodiment, when the second current component is configured such that At least partially compensated or offset attributable to Undesirable parasitic torque generated on the movable object around the first direction 5.

[0112] Figure 18 and Figure 19 An embodiment according to a "half-motor" design is shown, which includes exactly one coil assembly and exactly one magnet assembly. However... Figure 20 and Figure 21 The image shows another embodiment with a coil assembly 3 between two magnet assemblies 10. In this embodiment, each coil is separated into an upper coil portion 29 and a lower coil portion 30 along a separation plane 44 parallel to the coil plane 4 at the middle of the coil, thereby allowing for individual control. Similarly, when the second current component of the coil is configured to

[0113] hour,

[0114] It can at least partially compensate for or offset the reasons attributable to Undesirable parasitic torque generated on the movable object about the first direction 5. Note that... Figure 18 and Figure 19 The diagram shows a moving coil motor configuration, and it should be understood that a moving magnet motor will function similarly.

[0115] It should be understood that two or more permanent magnet motors in the described embodiments can be combined to achieve greater flexibility in actuating movable objects. For example, in... Figure 22 In the embodiment shown, four such motors (motors 1, 2, 3, and 4) are arranged in a 2×2 matrix. By individually controlling the current components of the coils in the coil assembly, linear forces in a first direction, a second direction, and a third direction, as well as torques about the first direction, the second direction, and the third direction, can be generated, and the torques about the directions can be at least partially compensated for or counteracted. It should be understood that the design of each of the motors, the number of motors combined, and the manner in which the motors are arranged can be otherwise selected for the intended purpose and application.

[0116] While specific references can be made to the use of lithography equipment in IC manufacturing within this document, it should be understood that the lithography equipment described herein can have other applications. Possible other applications include manufacturing integrated optical systems, guiding and detecting patterns for magnetic domain memories, flat panel displays, liquid crystal displays (LCDs), thin-film magnetic heads, etc.

[0117] While specific reference is made herein to embodiments of the invention within the context of a photolithography apparatus, these embodiments can be used with other apparatuses. Embodiments of the invention can form components of any apparatus that performs mask inspection, measurement, or measurement or processing of objects such as wafers (or other substrates) or masks (or other patterning apparatuses). These apparatuses are generally referred to as photolithography tools. Such photolithography tools can be used under vacuum conditions or ambient (non-vacuum) conditions.

[0118] Although specific reference has been made above to the use of embodiments of the present invention in the context of optical lithography, it will be understood that the present invention is not limited to optical lithography and can be used in other applications, such as imprint lithography, where circumstances permit.

[0119] Other aspects of the invention are set forth in the following numbered aspects.

[0120] 1. A Lorentz-type permanent magnet motor, comprising:

[0121] - At least one coil assembly arranged in a coil plane defined by a first direction and a second direction perpendicular to the first direction, the at least one coil assembly having a plurality of coils, each coil including two or more main segments extending along the first direction and a turning segment transitioning between two adjacent main segments.

[0122] - At least one magnet assembly arranged parallel to and close to the at least one coil assembly, the at least one magnet assembly having a first magnet group comprising two or more primary magnets extending along a first direction, the two or more primary magnets being placed adjacent to each other along a second direction, the two or more primary magnets having alternating polarization directions.

[0123] in:

[0124] - The at least one magnet assembly further includes a second magnet group comprising two secondary magnets extending along the second direction, wherein a first secondary magnet is disposed at a first end of the first magnet group, and a second secondary magnet is disposed at a second end of the first magnet group, wherein the second end of the first magnet group is opposite to the first end of the first magnet group relative to the first direction.

[0125] - Viewed from a third direction perpendicular to the first direction, the second direction, and the coil plane, the secondary magnet of the second magnet group overlaps with at least a portion of the turning section of the at least one coil assembly.

[0126] 2. The permanent magnet motor according to aspect 1 further includes a back iron extending in a plane parallel to the plane of the coil, wherein the back iron is arranged adjacent to the at least one coil assembly or the at least one magnet assembly.

[0127] 3. The permanent magnet motor according to aspect 1 or 2, wherein the polarization direction of the primary magnet and / or the secondary magnet is oriented along the third direction.

[0128] 4. The permanent magnet motor according to any one of aspects 1 to 3, wherein the polarization direction of the first-stage magnet is opposite to the polarization direction of the second-stage magnet.

[0129] 5. The permanent magnet motor according to any one of aspects 1 to 4, wherein each primary magnet has a different polarization direction from at least one adjacent primary magnet, wherein, preferably, the two or more primary magnets are arranged in a Halbach array.

[0130] 6. The permanent magnet motor according to any one of aspects 1 to 4, wherein each primary magnet has a polarization direction opposite to that of at least one adjacent primary magnet.

[0131] 7. The permanent magnet motor according to any one of aspects 1 to 6, wherein the coil assembly is arranged between two magnet assemblies, the two magnet assemblies comprising a first magnet assembly and a second magnet assembly.

[0132] 8. The permanent magnet motor according to aspect 7, wherein:

[0133] - The permanent magnet motor includes a first back iron arranged adjacent to the first magnet assembly and a second back iron arranged adjacent to the second magnet assembly.

[0134] - The first magnet group and the second magnet group of the first magnet assembly are arranged between the coil assembly and the first back iron.

[0135] - The first magnet group and the second magnet group of the second magnet assembly are arranged between the coil assembly and the second back iron.

[0136] 9. The permanent magnet motor according to any one of aspects 1 to 6, comprising a magnet assembly disposed between two coil assemblies, the two coil assemblies including a first coil assembly and a second coil assembly.

[0137] 10. The permanent magnet motor according to aspect 9, wherein:

[0138] - The permanent magnet motor includes a first back iron arranged adjacent to the first coil assembly and a second back iron arranged adjacent to the second coil assembly.

[0139] - At least one coil of the first coil assembly is arranged between the magnet assembly and the first back iron.

[0140] - At least one coil of the second coil assembly is arranged between the magnet assembly and the second back iron.

[0141] 11. A permanent magnet motor according to any one of aspects 1 to 6, comprising exactly one coil assembly and exactly one magnet assembly, wherein:

[0142] - The magnet assembly is arranged between the coil assembly and the back iron, wherein the back iron is arranged adjacent to the magnet assembly, or

[0143] - The coil assembly is arranged between the magnet assembly and the back iron, wherein the back iron is arranged adjacent to the coil assembly.

[0144] 12. The permanent magnet motor according to any one of aspects 1 to 11, wherein each coil is separated into an upper coil portion and a lower coil portion along a separation plane parallel to the plane of the coil at the middle of the coil.

[0145] 13. The permanent magnet motor according to any one of aspects 1 to 12, wherein the coil assembly comprises four or more even-numbered coils, each coil being controllable to generate a first force in the second direction using a first current component and a second force in a third direction perpendicular to the first and second directions using a second current component, wherein the amplitudes of the second current components of at least two of the coils are different to at least partially compensate for or counteract the torque about the first direction.

[0146] 14. A positioning system for locating a movable object, wherein the positioning system includes a permanent magnet motor according to any one of aspects 1 to 13, wherein one of the coil assembly and the magnet assembly is connected to the movable object, and the other of the coil assembly and the magnet assembly is connected to the environment.

[0147] 15. A lithography tool, such as a lithography apparatus, comprising the positioning system according to aspect 14.

[0148] 16. A method for applying force and / or torque to a movable object, the method comprising:

[0149] - Provide a permanent magnet motor according to any one of aspects 1 to 13, a positioning system according to aspect 14, or a photolithography tool according to aspect 15.

[0150] - Connect one of the coil assembly and the magnet assembly to the movable object, and connect the other of the coil assembly and the magnet assembly to the environment, preferably connecting the magnet assembly to the movable object and the coil assembly to the environment.

[0151] - Providing current to the coils of the coil assembly, wherein the current supplied to each coil of the coil assembly varies relative to at least one other coil of the coil assembly in order to apply force or torque to the movable object through the interaction of the coil assembly with the magnetic field generated by the magnet assembly, wherein the current supplied to each coil depends on the position of the coil in the coil assembly and the position of the movable object when measured along the second direction.

[0152] 17. The method according to aspect 16, wherein the current supplied to each coil of the coil assembly includes a first current component that is equal for each coil of the coil assembly, so as to apply a force on the movable object along the first direction.

[0153] 18. The method according to aspect 16 or 17, comprising the steps of providing a second current component to a first coil group and providing the negative value of the second current component to a second coil group, wherein the first coil group and the second coil are arranged on opposite sides of a line extending in the first direction to apply a torque about the third direction on the movable object or at least partially compensate for or counteract a torque about the third direction on the movable object.

[0154] 19. The method according to any one of aspects 16 to 18, wherein each coil is separated into an upper coil portion and a lower coil portion along a separation plane parallel to the plane of the coil at the middle of the coil, the method comprising controlling the relationship between the current supplied to each upper coil portion and the current supplied to its corresponding lower coil portion, such that:

[0155] - Apply a torque about the first direction to the movable object, and / or

[0156] - Apply torque about the second direction to the movable object.

[0157] 20. A Lorentz-type permanent magnet motor, comprising:

[0158] - At least one coil assembly, said at least one coil assembly being arranged in a coil plane defined by a first direction and a second direction perpendicular to the first direction, said at least one coil assembly having a plurality of coils.

[0159] - At least one magnet assembly arranged parallel to and close to the at least one coil assembly, the at least one magnet assembly comprising two or more magnets extending along a first direction, the two or more primary magnets being placed adjacent to each other along a second direction, the two or more primary magnets having alternating polarization directions.

[0160] in,

[0161] The coil assembly includes four or more even-numbered coils, each coil being controllable to generate a first force in the second direction using a first current component and a second force in a third direction perpendicular to the first and second directions using a second current component.

[0162] 21. The permanent magnet motor according to aspect 20, comprising exactly one coil assembly and exactly one magnet assembly, wherein:

[0163] - The magnet assembly is arranged between the coil assembly and the back iron, wherein the back iron is arranged adjacent to the magnet assembly, or

[0164] - The coil assembly is arranged between the magnet assembly and the back iron, wherein the back iron is arranged adjacent to the coil assembly.

[0165] 22. The permanent magnet motor according to aspect 20, wherein the coil assembly is arranged between two magnet assemblies.

[0166] 23. The permanent magnet motor according to aspect 22, wherein each coil is separated into an upper coil portion and a lower coil portion along a separation plane parallel to the plane of the coil at the middle of the coil.

[0167] 24. A permanent magnet motor according to any one of aspects 20 to 23, wherein the second current components of at least two coils of the coils have different amplitudes to at least partially compensate for or counteract parasitic torque about the first direction.

[0168] 25. The permanent magnet motor according to any one of aspects 20 to 24, wherein the different amplitudes have a linear relationship depending on the size of the coil assembly.

[0169] 26. A lithography tool, such as a lithography apparatus, comprising a permanent magnet motor according to any one of aspects 20 to 25.

[0170] 27. A method for applying a first force along a second direction and a second force along a third direction perpendicular to the first and second directions on a movable object, the method comprising:

[0171] - Provide a permanent magnet motor according to any one of aspects 20 to 25 or a photolithography tool according to aspect 26.

[0172] Connect one of the coil assembly and the magnet assembly to the movable object, and connect the other of the coil assembly and the magnet assembly to the environment.

[0173] - A first current component is provided to each coil of the coil assembly to generate a first force in the second direction, and a second current component is provided to each coil of the coil assembly to generate a second force in the third direction, wherein the second current components of at least two coils of the coils have different amplitudes to at least partially compensate for or counteract parasitic torques about the first direction.

[0174] 28. The method according to aspect 27, wherein the amplitude has a linear relationship depending on the size of the coil assembly.

[0175] While specific embodiments of the invention have been described above, it will be understood that the invention can be practiced in other ways than those described. The above description is intended to be illustrative and not restrictive. Therefore, those skilled in the art will understand that modifications can be made to the described invention without departing from the scope of the claims set forth below.

Claims

1. A Lorentz-type permanent magnet motor, comprising: - At least one coil assembly arranged in a coil plane defined by a first direction and a second direction perpendicular to the first direction, the at least one coil assembly having a plurality of coils, each coil including two or more main segments extending along the first direction and a turning segment transitioning between two adjacent main segments. - At least one magnet assembly, the at least one magnet assembly being arranged parallel to and close to the at least one coil assembly, the at least one magnet assembly having a first magnet group, the first magnet group comprising two or more primary magnets extending along a first direction, the two or more primary magnets being placed adjacent to each other along a second direction, the two or more primary magnets having alternating polarization directions. in: The at least one magnet assembly further includes a second magnet group comprising two secondary magnets extending along the second direction, wherein a first secondary magnet is disposed at a first end of the first magnet group, and a second secondary magnet is disposed at a second end of the first magnet group, wherein the second end of the first magnet group is opposite to the first end of the first magnet group relative to the first direction. - Viewed from a third direction perpendicular to the first direction, the second direction, and the coil plane, the secondary magnet of the second magnet group overlaps with at least a portion of the turning section of the at least one coil assembly.

2. The permanent magnet motor according to claim 1 further includes a back iron extending in a plane parallel to the coil plane, wherein, The back iron is arranged adjacent to the at least one coil assembly or the at least one magnet assembly.

3. The permanent magnet motor according to claim 1 or 2, wherein, The polarization direction of the primary magnet and / or the secondary magnet is oriented along the third direction.

4. The permanent magnet motor according to any one of claims 1 to 3, wherein, The polarization direction of the first-stage magnet is opposite to that of the second-stage magnet.

5. The permanent magnet motor according to any one of claims 1 to 4, wherein, The coil assembly is arranged between two magnet assemblies, the two magnet assemblies including a first magnet assembly and a second magnet assembly.

6. The permanent magnet motor according to any one of claims 1 to 4, comprising a magnet assembly disposed between two coil assemblies, the two coil assemblies comprising a first coil assembly and a second coil assembly.

7. The permanent magnet motor according to any one of claims 1 to 4, comprising exactly one coil assembly and exactly one magnet assembly, wherein: - The magnet assembly is arranged between the coil assembly and the back iron, wherein the back iron is arranged adjacent to the magnet assembly, or - The coil assembly is arranged between the magnet assembly and the back iron, wherein the back iron is arranged adjacent to the coil assembly.

8. The permanent magnet motor according to any one of claims 1 to 7, wherein, Each coil is separated into an upper coil portion and a lower coil portion along a separation plane parallel to the coil plane in the middle of the coil.

9. The permanent magnet motor according to any one of claims 1 to 8, wherein, The coil assembly includes four or more even-numbered coils, each coil being controllable to generate a first force in the second direction using a first current component and a second force in a third direction perpendicular to the first and second directions using a second current component, wherein the amplitudes of the second current components of at least two of the coils are different to at least partially compensate for or counteract the torque about the first direction.

10. A positioning system comprising a permanent magnet motor and a current controller according to any one of claims 1 to 9, wherein, The permanent magnet motor includes a first coil group and a second coil group arranged on opposite sides of a line extending along the first direction. The current controller is configured to provide a second current component to the first coil group and a negative value of the second current component to the second coil group in order to apply a torque about the third direction on the movable object or at least partially compensate for or counteract the torque about the third direction on the movable object.

11. A lithography tool, such as a lithography apparatus, comprising the positioning system according to claim 10.

12. A method for applying force and / or torque to a movable object, the method comprising: - Provide a permanent magnet motor according to any one of claims 1 to 9, a positioning system according to claim 10, or a photolithography tool according to claim 11. Connect one of the coil assembly and the magnet assembly to the movable object, and connect the other of the coil assembly and the magnet assembly to the environment. Preferably, connect the magnet assembly to the movable object and the coil assembly to the environment. - Providing current to the coils of the coil assembly, wherein the current supplied to each coil of the coil assembly varies relative to at least one other coil of the coil assembly in order to apply force or torque to the movable object through the interaction of the coil assembly with the magnetic field generated by the magnet assembly, wherein the current supplied to each coil depends on the position of the coil in the coil assembly and the position of the movable object when measured along the second direction.

13. The method according to claim 12, wherein, The current supplied to each coil of the coil assembly includes a first current component that is equal for each coil of the coil assembly, so as to apply a force to the movable object along the first direction.

14. The method of claim 12 or 13, further comprising the steps of providing a second current component to a first coil group and providing the negative value of the second current component to a second coil group, wherein, The first coil group and the second coil are arranged on opposite sides of a line extending in the first direction to apply a torque about the third direction to the movable object or at least partially compensate for or counteract the torque about the third direction on the movable object.

15. The method according to any one of claims 12 to 14, wherein, Each coil is separated into an upper coil portion and a lower coil portion along a separation plane parallel to the coil plane at the middle of the coil, the method comprising controlling the relationship between the current supplied to each upper coil portion and the current supplied to its corresponding lower coil portion, so as to: - Apply torque about the first direction to the movable object, and / or - Apply torque about the second direction to the movable object.

16. A Lorentz-type permanent magnet motor, comprising: - At least one coil assembly, said at least one coil assembly being arranged in a coil plane defined by a first direction and a second direction perpendicular to the first direction, said at least one coil assembly having a plurality of coils. - At least one magnet assembly, the at least one magnet assembly being arranged parallel to and close to the at least one coil assembly, the at least one magnet assembly comprising two or more magnets extending along the first direction, the two or more primary magnets being placed adjacent to each other along the second direction, the two or more primary magnets having alternating polarization directions. in, The coil assembly includes four or more even-numbered coils, each coil being controllable to generate a first force in the second direction using a first current component and a second force in a third direction perpendicular to the first and second directions using a second current component.

17. The permanent magnet motor of claim 16, comprising exactly one coil assembly and exactly one magnet assembly, wherein: - The magnet assembly is arranged between the coil assembly and the back iron, wherein the back iron is arranged adjacent to the magnet assembly, or - The coil assembly is arranged between the magnet assembly and the back iron, wherein the back iron is arranged adjacent to the coil assembly.

18. The permanent magnet motor according to claim 16, wherein, The coil assembly is arranged between the two magnet assemblies.

19. The permanent magnet motor according to claim 18, wherein, Each coil is separated into an upper coil portion and a lower coil portion along a separation plane parallel to the coil plane in the middle of the coil.

20. The permanent magnet motor according to any one of claims 16 to 19, wherein, The second current components of at least two of the coils have different amplitudes to at least partially compensate for or counteract the parasitic torque around the first direction.

21. The permanent magnet motor according to any one of claims 16 to 20, wherein, The different amplitudes have a linear relationship depending on the size of the coil assembly.

22. A lithography tool, such as a lithography apparatus, comprising a permanent magnet motor according to any one of claims 16 to 21.

23. A method for applying a first force along a second direction and a second force along a third direction perpendicular to the first and second directions on a movable object, the method comprising: - Provide a permanent magnet motor according to any one of claims 16 to 21 or a photolithography tool according to claim 22. Connect one of the coil assembly and the magnet assembly to the movable object, and connect the other of the coil assembly and the magnet assembly to the environment. - A first current component is provided to each coil of the coil assembly to generate a first force in the second direction, and a second current component is provided to each coil of the coil assembly to generate a second force in the third direction, wherein the second current components of at least two coils of the coils have different amplitudes to at least partially compensate for or counteract the parasitic torque about the first direction.

24. The method according to claim 23, wherein, The amplitude has a linear relationship depending on the size of the coil assembly.

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