Vertical movement axis for an imaging optical head

Abstract

A translation stage can include a first plate and a second plate movable relative to the first plate along a vertical direction. The stage can also include one or more magnetic counterweights to counteract the weight of the second plate, wherein at least one of the one or more magnetic counterweights comprises a tunable magnetic counterweight. A tunable magnetic counterweight can include a first portion including one or more magnets and a second portion including one or more ferromagnetic materials, wherein the one or more ferromagnetic materials at least partially enclose the one or more magnets in a horizontal plane. The balance force can be adjusted by controlling at least one of a relative angle of rotation or a gap between the first portion and the second portion in the horizontal plane along a length of at least one direction. The stage can also include an actuator to position the second plate.

Description

Technical Field

[0001] This disclosure generally relates to a head assembly for a metering system, and more specifically, to a head assembly with a magnetic balance block. Background Technology

[0002] Metrological systems that provide optical imaging of samples typically require precise control of the distance between the sample and imaging optics (e.g., objectives) that can be positioned along the optical axis of the metrology system. This distance may be related to the focal height and / or depth of focus for a particular application. Furthermore, many applications require sample movement in a plane transverse to the optical axis. Therefore, adjustments to the imaging optics and / or the sample may be necessary to maintain the desired distance between them. However, such adjustments can be challenging in cases involving heavy mass and / or high tracking frequencies. Therefore, there is a need to develop systems and methods that address these shortcomings. Summary of the Invention

[0003] According to one or more illustrative embodiments of this disclosure, a translation stage is disclosed. In one illustrative embodiment, the stage includes a first plate. In another illustrative embodiment, the stage includes a second plate, wherein the second plate is movable relative to the first plate along a vertical direction associated with the weight of the second plate. In another illustrative embodiment, the stage includes one or more magnetic balancing blocks coupled to the first and second plates to provide a balancing force on the second plate in the vertical direction opposite to the weight of the second plate, wherein at least one of the one or more magnetic balancing blocks includes a tunable magnetic balancing block. In another illustrative embodiment, the tunable magnetic balancing block includes a first portion containing one or more magnets, the first portion being attached to one of the first or second plates. In another illustrative embodiment, the tunable magnetic balancing block includes a second portion containing one or more ferromagnetic materials, wherein the second portion is attached to one of the first or second plates different from the first portion. In another illustrative embodiment, the one or more ferromagnetic materials at least partially surround the one or more magnets in a horizontal plane orthogonal to the vertical direction. In another illustrative embodiment, the first portion and the second portion are separated by a gap. In another illustrative embodiment, the balancing force can be adjusted by controlling at least one of the relative rotation angle between the first portion and the second portion in the horizontal plane or the length of the gap along at least one direction. In another illustrative embodiment, the system includes an actuator configured to position the second plate relative to the first plate along the vertical direction.

[0004] According to one or more illustrative embodiments of this disclosure, a system is disclosed. In one illustrative embodiment, the system includes a first plate. In another illustrative embodiment, the system includes a second plate, wherein the second plate is movable relative to the first plate in a vertical direction associated with the weight of the second plate. In another illustrative embodiment, the second plate is configured to be attached to one or more objects. In another illustrative embodiment, the system includes one or more magnetic balancing blocks coupled to the first and second plates to provide a balancing force on the second plate in the vertical direction opposite to the weight of the second plate. In another illustrative embodiment, at least one of the one or more magnetic balancing blocks includes a tunable magnetic balancing block. In another illustrative embodiment, the tunable magnetic balancing block includes a first portion containing one or more magnets, wherein the first portion is attached to one of the first or second plates. In another illustrative embodiment, the tunable magnetic balancing block includes a second portion containing one or more ferromagnetic materials, wherein the second portion is attached to one of the first or second plates different from the first portion. In another illustrative embodiment, the one or more ferromagnetic materials at least partially surround the one or more magnets in a horizontal plane orthogonal to the vertical direction. In another illustrative embodiment, the first portion and the second portion are separated by a gap. In another illustrative embodiment, the balancing force can be adjusted by controlling at least one of the relative rotation angle between the first portion and the second portion in the horizontal plane or the size of the gap along at least one direction. In another illustrative embodiment, the system includes a translation stage for positioning a sample in at least the horizontal plane. In another illustrative embodiment, the system includes an actuator configured to position the second plate relative to the first plate along the vertical direction. In another illustrative embodiment, the system includes a controller for guiding the actuator via one or more drive signals to provide a selected distance between the sample and one of the one or more objects on the second plate in the vertical direction.

[0005] According to one or more illustrative embodiments of this disclosure, a method is disclosed. In one illustrative embodiment, the method includes placing a sample at a selected distance in a vertical direction from one of one or more objects, wherein the objects are connected to a translation stage. In another illustrative embodiment, the translation stage includes a first plate. In another illustrative embodiment, the stage includes a second plate, wherein the second plate is movable relative to the first plate along the vertical direction, and wherein the vertical direction is associated with the weight of the second plate. In one illustrative embodiment, one or more objects are connected to the second plate. In another illustrative embodiment, the stage includes one or more magnetic balancing blocks coupled to the first plate and the second plate to provide a balancing force on the second plate in the vertical direction opposite to the weight of the second plate, wherein at least one of the one or more magnetic balancing blocks includes a tunable magnetic balancing block, wherein the tunable magnetic balancing block includes a first portion containing one or more magnets, wherein the first portion is attached to one of the first plate or the second plate. In another illustrative embodiment, the tunable magnetic balance block includes a second portion containing one or more ferromagnetic materials, wherein the second portion is attached to one of the first plate or the second plate, different from the first portion. In another illustrative embodiment, the one or more ferromagnetic materials at least partially surround the one or more magnets in a horizontal plane orthogonal to the vertical direction. In another illustrative embodiment, the first portion and the second portion are separated by a gap. In another illustrative embodiment, the balancing force can be adjusted by controlling at least one of the relative rotation angle between the first portion and the second portion in the horizontal plane or the size of the gap along at least one direction. In another illustrative embodiment, the stage includes an actuator configured to position the second plate relative to the first plate along the vertical direction. In another illustrative embodiment, the method includes adjusting the balancing force to be equal to the combined weight of the second plate and the one or more objects. In another illustrative embodiment, the method includes generating a measurement of at least one of the position of the sample along the vertical direction or the distance between the sample and at least one of the one or more objects on the second plate in the vertical direction. In another illustrative embodiment, the method includes maintaining, via the actuator, the selected distance between the sample and one of one or more objects in the vertical direction based on the measurement.

[0006] It should be understood that both the foregoing general description and the following "Detailed Description" are exemplary and illustrative only, and do not necessarily limit the invention as claimed. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the general description, serve to explain the principles of the invention. Attached Figure Description

[0007] Those skilled in the art will better understand the many advantages of this disclosure by referring to the accompanying drawings.

[0008] Figure 1A This is a block diagram of a translation stage according to one or more embodiments of the present disclosure.

[0009] Figure 1B This is a simplified schematic diagram of a translation stage according to one or more embodiments of the present disclosure.

[0010] Figure 1C This is a partial perspective view of a translation stage comprising a plurality of magnetic balance blocks according to one or more embodiments of the present disclosure.

[0011] Figure 2A This is a top view of a magnetic balance block according to one or more embodiments of the present disclosure.

[0012] Figure 2B According to one or more embodiments of this disclosure Figure 2A A side view of the magnetic balance block in the image.

[0013] Figure 3 It is a plot of the balancing forces provided by a magnetic balance block according to one or more embodiments of the present disclosure, which vary based on the relative positions between the magnet and the ferromagnetic material.

[0014] Figure 4A This is a top view of a magnetic balance block comprising a ferromagnetic material with slits and a radially polarized magnet, according to one or more embodiments of the present disclosure.

[0015] Figure 4B According to one or more embodiments of this disclosure Figure 4A Side view of the magnetic balance block.

[0016] Figure 4C It is a plot of the balancing forces provided by a magnetic balance block according to one or more embodiments of the present disclosure, which vary based on the relative positions between the magnet and the ferromagnetic material.

[0017] Figure 5A This is a top view of a magnetic balance block comprising a first portion formed as a radially polarized magnet and a second portion formed as two separate ferromagnetic materials that can be individually positioned, according to one or more embodiments of the present disclosure.

[0018] Figure 5B It is based on one or more embodiments of this disclosure, as such Figure 5A The magnetic balance block depicted in the figure provides a plot of the balancing forces that vary according to the gap distance.

[0019] Figure 6AThis is a top view of a magnetic balance block comprising a first portion having a magnet and ferromagnetic material and a second portion having a single U-shaped ferromagnetic material, according to one or more embodiments of the present disclosure.

[0020] Figure 6B This is a top view of a magnetic balance block comprising a first portion having two magnets attached to a U-shaped ferromagnetic material and a second portion having a single ferromagnetic material, according to one or more embodiments of the present disclosure.

[0021] Figure 6C This is a top view of a magnetic balance block comprising a first portion having two separately positionable magnets attached to separate ferromagnetic materials and a second portion having two ferromagnetic materials, according to one or more embodiments of the present disclosure.

[0022] Figure 7A This is a simplified schematic diagram of a system comprising a vertically oriented translation stage and an additional translation stage for fixing and / or positioning samples, according to one or more embodiments of the present disclosure.

[0023] Figure 7B This is a simplified schematic diagram of an optical metrology system according to one or more embodiments of the present disclosure.

[0024] Figure 8 This is a flowchart illustrating the steps performed in a method according to one or more embodiments of the present disclosure. Detailed Implementation

[0025] The disclosed object will now be described in detail with reference to the accompanying drawings. This disclosure has been specifically shown and described with respect to particular embodiments and their specific features. The embodiments set forth herein should be considered explanatory and not restrictive. Those skilled in the art will readily understand that various changes and modifications in form and detail can be made without departing from the spirit and scope of this disclosure.

[0026] Embodiments of this disclosure relate to systems and methods for providing an adjustable counterweight for orienting a stage in a vertical direction, such that balancing forces counteract the weight of movable elements of the stage. As used herein, the term vertical direction refers to the direction associated with the weight of an object (e.g., the direction of gravity).

[0027] In some embodiments, the translation stage includes two plates movable relative to each other and an actuator (e.g., a stage positioning actuator) for controlling the relative position of the two plates. For example, a translation stage having a first plate and a second plate may have a second plate movable relative to the first plate. For example, the first plate may be fixed to a worktable or other support structure, while the second plate may contain an object to be positioned.

[0028] In the case of a linear translation stage oriented to provide linear motion in the vertical direction, the stage positioning actuator must typically bear the weight of the movable plate (e.g., a second plate) and any objects on it, which can induce excessive heat and increase the demand on the stage positioning actuator. For the purposes of this disclosure, the term load is used to refer to the movable plate of the translation stage and any objects attached to it. Furthermore, the term load weight is used to refer to the weight of this load. For example, the size and load requirements of the stage positioning actuator must typically be sufficient to fully support the load weight of the vertical translation stage. As an illustration, a stage positioning actuator configured as a lead screw attached to an electric motor may require a large amount of electric motor power to simply offset the load weight, which can result in significant heat generation and require an appropriately sized motor and associated components. Additionally, this configuration may suffer from relatively high inertia, low acceleration, significant friction, and variable pitch.

[0029] To mitigate strain on the actuators in a vertical configuration, counterweights can be used to at least partially offset the load weight, thus reducing or eliminating the need for stage positioning actuators to support the load weight. Therefore, the size and load requirements of the stage positioning actuators can be similar to those required for a translation stage configured for horizontal motion.

[0030] In some embodiments, the translation stage includes one or more magnetic counterweights to at least partially offset the weight of the movable plate and any mounted components.

[0031] In some embodiments, the magnetic balance block is formed as two parts configured to move relative to each other along a direction of motion (e.g., a vertical direction), wherein the first part comprises one or more magnets and the second part comprises one or more ferromagnetic materials arranged to at least partially surround the one or more magnets in a plane orthogonal to the direction of motion (e.g., a horizontal plane). As an illustrative example, the first part may be formed as a rod and the second part may be formed as a ferromagnetic sleeve that at least partially surrounds the rod. Furthermore, the first and second parts of the magnetic balance block may be connected to fixed and movable plates of a translation stage. In a general sense, either part of the magnetic balance block may be attached to either the movable plate or the fixed plate of the translation stage.

[0032] In this configuration, the magnetic attraction between the first and second portions can vary based on their relative positions along the direction of motion. Specifically, this force can be constant (or substantially constant) within the operating range (e.g., stroke length) when the first and second portions deviate from their equilibrium positions. In some embodiments, the translation stage includes one or more magnetic balancing blocks oriented such that this magnetic attraction operates against a balancing force against the load weight associated with the movable plate and any connected objects. Thus, the operating range of the magnetic balancing blocks defines the range of motion of the translation stage.

[0033] In some embodiments, the magnetic balance block as disclosed herein is formed to have a gap (e.g., an air gap) between the first and second portions to prevent friction between the first and second portions and to avoid hysteresis. This gap may be uniform or non-uniform in all directions within a plane (e.g., a horizontal plane).

[0034] In some embodiments, the translation stage includes at least one magnetic balancing block that provides a tunable balancing force. This magnetic balancing block is referred to herein as a tunable magnetic balancing block. It is envisioned herein that the tunable magnetic balancing block can be used to tune the balancing force to precisely counteract the load weight. Thus, the stage positioning actuator can adjust the position of the movable plate within the operating range of the magnetic balancing block without bearing the load weight.

[0035] Within the spirit and scope of this disclosure, various techniques can be used to tune the balancing force of a tunable magnetic balance block. In some embodiments, the balancing force is tuned by adjusting the relative rotation angle between the first and second portions (e.g., the relative rotation angle between one or more magnets and one or more ferromagnetic materials). For example, the first portion of the magnetic balance block may include at least one magnet arranged in a magnetic polarization direction in a horizontal plane, and the second portion may include an asymmetrical distribution of ferromagnetic material, such that the balancing force can vary according to the relative rotation angle between the first and second portions. In some embodiments, the balancing force is tuned by adjusting the gap distance between the first and second portions of the magnetic balance block. For example, the ferromagnetic sleeve may be formed as two or more adjustable sections, the positions of which can be adjusted relative to the magnets using one or more actuators.

[0036] This paper envisions that magnetic balance blocks are highly suitable for balancing loads in vertical translational states. For example, a magnetic balance block can provide a constant (or substantially constant) force within its operating range without introducing any friction and thus avoiding hysteresis. As another example, a magnetic balance block can provide near-zero stiffness and therefore avoid resonance (e.g., localized spring / mass resonance). As yet another example, a magnetic balance block can be relatively low-cost and highly reliable. For example, the operation of the balance block does not require the application of any power. Therefore, a magnetic balance block can achieve high-precision control of the vertical position of movable plates and connected objects at fast tracking rates (e.g., 5 to 10 Hz or higher) for a wide range of load weights.

[0037] This paper further envisions that magnetic counterweights could offer various advantages over alternative balancing techniques, at least in part, due to these benefits. For example, the mass of the counterweight can double the inertia of the system, which can limit tracking speed, acceleration, and / or accuracy. As another example, the preloaded springs providing the balancing force may suffer from parasitic resonance. Furthermore, this configuration fully offsets the load weight only at a single location, meaning that when the position of the movable platform deviates from this position, the linear actuator must bear the increased portion of the load weight. As yet another example, cylinders may require strict control of air pressure and temperature to maintain performance. Additionally, cylinders may be subject to frictional forces, which can adversely affect the accuracy of motion.

[0038] Additional embodiments of this disclosure relate to a system comprising a vertical translation stage having one or more magnetic counterweights. For example, the system may include one or more objects on a movable plate. In this way, the magnetic counterweights can counteract the weight of the movable plate and the objects. The position of these objects (e.g., relative to a sample) can then be controlled using one or more controllers. In some embodiments, the objects include at least one lens, such that the working distance between the lens and the sample can be controlled based on the position of the movable plate.

[0039] In some embodiments, the system is an optical system. For example, the system may include one or more optical components (e.g., one or more lenses, one or more mirrors, one or more detectors, one or more illumination sources, or the like) attached to a movable plate of a translation stage as disclosed herein. In this configuration, the relative position between the sample and at least one of the optical components can be controlled based on the position of the movable plate. As an illustration, in the case of an imaging system, one or more lenses may be connected to the movable plate such that the working distance between the lenses and the sample can be controlled based on the position of the movable plate. Furthermore, one or more additional components, such as, but not limited to, detectors or illumination sources (e.g., laser sources, light-emitting diodes (LEDs), or any other light source suitable for imaging), may be connected to the movable plate. As another illustration, a system including an optical head having optical components suitable for illuminating a sample and / or collecting light from the sample may be configured to have at least a portion of the optical head connected to a movable plate of a translation stage as disclosed herein. The optical head may include any type of optical head known in the art suitable for any application. For example, the optical head may include components suitable for, but not limited to, imaging (e.g., laser imaging, broadband imaging, or the like) or reading. In some embodiments, the optical system includes an optical metrology system, wherein at least some components for illuminating the sample or collecting light from the sample are connected to a movable plate.

[0040] For reference Figures 1A to 8 A system and method for providing an adjustable counterweight for oriented translational stage in the vertical direction are described in more detail according to one or more embodiments of the present disclosure.

[0041] Figure 1A This is a block diagram of a translation stage 100 according to one or more embodiments of the present disclosure. Figure 1B This is a simplified schematic diagram of a translation stage 100 according to one or more embodiments of the present disclosure.

[0042] In some embodiments, the translation stage 100 includes a fixed plate 102, a movable plate 104 (e.g., a first and a second plate), and at least one stage positioning actuator 106 (e.g., a linear actuator) for adjusting the position of the movable plate 104 relative to the fixed plate 102 in at least one translational direction.

[0043] For example, a translation stage 100 configured for unidirectional (1D) movement along a single translation direction may include a single stage positioning actuator 106. Various techniques can be used to achieve bidirectional (2D) movement. For example, two 1D translation stages 100 may be coupled to provide 2D movement. As an illustration, a fixed plate 102 of the first translation stage 100 may be mounted to a movable plate 104 of the second translation stage 100. As another example, a single translation stage 100 may include two stage positioning actuators 106 configured to adjust the position of the movable plate 104 in both directions.

[0044] The translation stage 100 may include any type of stage positioning actuator 106 known in the art. For example, the stage positioning actuator 106 may include a motor 108 coupled to a drive assembly 110 (e.g., but not limited to bearings (e.g., mechanical bearings, air bearings, magnetic bearings, or the like), gears, belts, screws, or pins). As an illustration, Figure 1B A stage positioning actuator 106 is depicted having a motor 108 coupled to a fixed plate 102 and a drive assembly 110 contacting and / or coupled to a movable plate 104. In some embodiments, the stage positioning actuator 106 includes a direct-drive linear actuator (e.g., a direct-drive motor), such as, but not limited to, a magnetic actuator or a piezoelectric actuator. In some embodiments, the stage positioning actuator 106 includes a voice coil actuator.

[0045] In some embodiments, the translation stage 100 includes one or more encoders 112 for providing measurements of the relative position of the movable plate 104 relative to the fixed plate 102. The translation stage 100 may include any type of encoder 112 known in the art, including, but not limited to, optical encoders 112, capacitive encoders 112, inductive encoders 112, or magnetic encoders 112. In this way, the measurements provided by the encoders 112 can be used as feedback to the stage positioning actuator 106 for controlling the relative position of the movable plate 104. This stage positioning actuator 106 may utilize any type of control technique for controlling the relative position of the movable plate 104, including, but not limited to, proportional-integral-derivative (PID) technology.

[0046] In some embodiments, the translation stage 100 includes one or more guides 114 (e.g., linear guides) for constraining the movement of the movable plate 104 relative to the fixed plate 102, such as, but not limited to, tracks or bearings (e.g., mechanical bearings, air bearings, magnetic bearings, or the like). For example, a translation stage 100 suitable for 1D linear motion may include guides formed as linear tracks, wherein the fixed plate 102 and / or the movable plate 104 are connected to the tracks via one or more bearings.

[0047] In some embodiments, at least the movable plate 104 includes one or more connectors 116 adapted to connect to and / or secure the object 118 to be translated. For example, the connector 116 may include one or more threaded or non-threaded holes adapted to establish a connection with the object 118 to be translated. As another example, the connector 116 may include clamps or other fastening devices for securing the object 118 to be translated.

[0048] In some embodiments, a translation stage 100 having a movable plate 104 suitable for movement in a vertical direction may include one or more magnetic balancing blocks 120, which are designed to provide balancing forces that at least partially offset the weight (e.g., load weight) of the movable plate 104 and any attached objects 118. Therefore, the size and load requirements of the stage positioning actuator 106 can be significantly reduced relative to configurations where the stage positioning actuator 106 must bear the weight of the movable plate 104 and any attached objects 118.

[0049] The translation stage 100 may contain any number of magnetic balancing blocks 120, wherein the magnetic balancing blocks 120 may be distributed in any manner and provide the same or different balancing forces.

[0050] In some embodiments, the translation stage 100 includes a single magnetic counterweight 120 to counteract the weight of the movable plate 104 and any attached objects 118. In this configuration, the single magnetic counterweight 120 can counteract the entire load weight.

[0051] In some embodiments, the translation stage 100 includes a plurality of magnetic balancing blocks 120 for distributing balancing forces. Figure 1C This is a partial perspective view of a translation stage 100 comprising a plurality of magnetic balancing blocks 120 according to one or more embodiments of the present disclosure. Specifically, Figure 1C A view depicting a portion of the movable plate 104. For example, Figure 1C Seven magnetic balancing blocks 120 are depicted to balance the movable plate 104, the stage positioning actuator 106, and the encoder 112. It should be noted that... Figure 1C The portion of the fixing plate 102 and the connection between the fixing plate 102 and various internal components are not depicted.

[0052] The use of multiple magnetic balancing blocks 120 offers various benefits. For example, distributing the balancing force among several magnetic balancing blocks 120 reduces the size and / or load requirements of each of the magnetic balancing blocks 120 compared to an alternative configuration having a single magnetic balancing block 120 suitable for balancing the entire load weight. As an illustration, Figure 1C The seven magnetic balancing blocks 120 depicted can distribute balancing forces along the X direction. As another example, distributing balancing forces among several magnetic balancing blocks 120 can facilitate balancing unevenly distributed load weights. For example, uneven distribution of load weights around the balancing blocks can introduce unwanted friction on the guide 114 and / or rotation of the movable plate 104. However, multiple magnetic balancing blocks 120 that potentially provide different balancing forces can counteract this uneven weight distribution. As an illustration, Figure 1C An asymmetric distribution of magnetic balancing blocks 120 suitable for balancing uneven load weights is depicted. Specifically, Figure 1C The translation stage 100 includes a platform 122 offset along the positive X direction, four magnetic balance blocks 120 close to the platform 122, and three magnetic balance blocks 120 on opposite sides of the translation stage 100.

[0053] In some embodiments, the translation stage 100 includes at least one magnetic balancing block 120 (e.g., an adjustable magnetic balancing block 120) that provides an adjustable balancing force. In a general sense, the translation stage 100 may include any combination of one or more magnetic balancing blocks 120 having a fixed and / or adjustable balancing force.

[0054] Within the spirit and scope of this disclosure, the adjustable magnetic balance block 120 can be used in a variety of applications. For example, one or more adjustable magnetic balance blocks 120 can achieve balanced forces (F). counterbalance Fine-tuning is used to precisely counteract the load weight, making...

[0055] F counterbalance =m·g (1)

[0056] Where m is the load mass (e.g., the combined mass of the movable plate 104 and any connected objects 118) and g is the acceleration due to gravity. Furthermore, this fine-tuning can be repeated as needed when the mass of the object 118 connected to the movable plate 104 is changed. As another example, one or more adjustable magnetic balance blocks 120 at different positions along the translation stage 100 can achieve fine-tuning of the distribution of the balancing force in the presence of unevenly distributed load weight. For illustration, Figure 1C The magnetic balance blocks 120a and 120b are adjustable.

[0057] For reference Figures 2A to 8 The magnetic balance block 120 is described in more detail according to one or more embodiments of the present disclosure.

[0058] Figure 2A This is a top view of a magnetic balance block 120 according to one or more embodiments of the present disclosure. Figure 2B According to one or more embodiments of this disclosure Figure 2A Side view of the magnetic balance block 120.

[0059] In some embodiments, the magnetic balancing block 120 includes a first portion 202 and a second portion 204 that at least partially surrounds the first portion 202 in a plane orthogonal to the direction of motion. Figure 2A and 2B In this configuration, the direction of motion is along the Z-direction (e.g., the vertical direction), and the second portion 204 of the magnetic balancing block 120 completely surrounds the first portion 202 in the XY plane (e.g., the horizontal plane). In this configuration, the first portion 202 can slide at least partially through the second portion 204 along the direction of motion.

[0060] In some embodiments, the first portion 202 includes at least one or more magnets 206, while the second portion 204 includes one or more ferromagnetic materials 208.

[0061] In this configuration, the magnetic attraction between at least one magnet 206 in the first portion 202 and at least one ferromagnetic material 208 in the second portion 204 provides a magnetic force that attracts the first portion 202 and the second portion 204 to each other. This magnetic force can be utilized in any suitable manner to counteract the load weight. In some embodiments, one of the magnet 206 or the ferromagnetic material 208 is attached to the fixed plate 102, while the other is attached to the movable plate 104. Furthermore, the relative positions of the magnet 206 and the ferromagnetic material 208 can be adjusted such that the magnetic attraction counteracts the load weight.

[0062] For example, Figure 2A and 2B The illustration depicts a configuration in which a first portion 202 comprises a single magnet 206 and a second portion 204 comprises a single ferromagnetic material 208 (e.g., a ferromagnetic sleeve). Specifically, the single magnet 206 is shaped as a rod having a long axis along the direction of motion (e.g., vertical or Z-direction), and the single ferromagnetic material 208 is shaped as a ring (or a portion thereof). Furthermore, a movable plate 104 may be connected to the magnet 206, and a fixed plate 102 may be connected to the ferromagnetic material 208. Therefore, the load weight associated with the movable plate 104 and any connected objects 118 may be associated with a force in the -Z direction, while the magnetic attraction between the magnet 206 and the ferromagnetic material 208 may be associated with a balanced force in the +Z direction. However, it should be understood that... Figure 2B The configurations provided are for illustrative purposes only and should not be construed as limiting this disclosure. Rather, alternative configurations in which the movable plate 104 is connected to the ferromagnetic material 208 and the fixed plate 102 is connected to the magnet 206 are within the spirit and scope of this disclosure.

[0063] Figure 3 This is a diagram showing the balancing force (F[N]) provided by the magnetic balancing block 120, varying according to the relative position between the magnet 206 and the ferromagnetic material 208, according to one or more embodiments of this disclosure. Specifically, Figure 3 The X-axis is related to the relative position between the top edge of magnet 206 and the bottom edge of ferromagnetic material 208, where a negative number indicates the gap between magnet 206 and sleeve in the Z direction, and a positive number indicates that magnet 206 is at least partially within ferromagnetic material 208. Figure 3 As explained, the magnetic balance block 120 can provide a substantially linear balancing force within the operating range 302. Therefore, the stage positioning actuator 106 can adjust the relative position of the movable plate 104 with respect to the fixed plate 102 across this range without changing the balancing force and therefore without changing the load on the stage positioning actuator 106.

[0064] In some embodiments, the first portion 202 and the second portion 204 of the magnetic balance block 120 are separated by a gap 210 in a plane orthogonal to the direction of motion (e.g., in...). Figure 2A and 2B In the XY plane, the gap 210 may be, but is not required to be, uniform. This gap 210 can be filled with any suitable material. In some embodiments, the gap 210 is an air gap and is filled with the ambient atmosphere. It is envisioned herein that the air gap 210 between the magnet 206 and the ferromagnetic material 208 provides frictionless operation and thus avoids hysteresis and other negative effects.

[0065] It should be understood that Figures 2A to 3 The associated descriptions are provided for illustrative purposes only and should not be construed as limiting this disclosure. For example, magnet 206 may have substantially any cross-sectional shape (e.g., in a configuration such as...). Figures 2A to 2B The shape in the XY plane depicted may be, for example, but not limited to, a circle, a rectangle, or a square. Furthermore, the ferromagnetic material 208 may be shaped to provide a uniform gap 210 or may have a non-uniform gap 210. Additionally, the first portion 202 and / or the second portion 204 may have a combination of magnets 206 arranged to provide balancing forces along the direction of motion and the ferromagnetic material 208.

[0066] For reference Figures 4A to 6C Various designs and techniques of the magnet balance block 120 are described in more detail according to one or more embodiments of the present disclosure.

[0067] Magnet 206 may be formed of any material suitable for being formed as a permanent magnet, such as, but not limited to, ferromagnetic materials, rare-earth magnetic materials (e.g., neodymium-based magnetic materials or the like), or composite materials. Magnet 206 may further have any magnetic polarization direction. In some embodiments, magnet 206 has axial magnetic polarization along the direction of motion (e.g., the Z-direction). In some embodiments, magnet 206 has a magnetic polarization direction in a plane orthogonal to the direction of motion (e.g., in the XY plane). Magnet 206 with this configuration may be referred to as radially polarized.

[0068] The ferromagnetic material 208 can be formed from any suitable ferromagnetic or composite material having non-zero magnetic permeability. Furthermore, the ferromagnetic material 208 may, but is not required to, be permanently magnetized (e.g., a permanent magnet).

[0069] This document envisions that, within the spirit and scope of this disclosure, the balancing force provided by the magnetic balance block 120 can be adjusted or otherwise controlled in various ways.

[0070] In some embodiments, the magnetic balancing block 120 includes one or more force adjustment actuators 124 for performing at least one of adjusting the gap 210 distance between a first portion 202 and a second portion 204 of the magnetic balancing block 120 in at least one direction in a horizontal plane or adjusting the magnetic polarization direction of the magnet 206 relative to the relative orientation between the ferromagnetic materials 208.

[0071] In some embodiments, the ferromagnetic material 208 is asymmetric in a plane orthogonal to the direction of motion (e.g., the XY plane), and the magnet 206 has at least a partial magnetic polarization direction in the XY plane. Therefore, the strength of the balancing force can be controlled by the relative rotation between the magnet 206 and the ferromagnetic material 208.

[0072] For example, the ferromagnetic material 208 may contain one or more slits in a plane orthogonal to the direction of motion (e.g., the XY plane), which can weaken the magnetic field flow. As an illustration, Figure 4A This is a top view of a magnetic balance block 120 comprising a ferromagnetic material 208 having a slit 402 and a radially polarized magnet 206, according to one or more embodiments of the present disclosure. Figure 4B According to one or more embodiments of this disclosure Figure 4A A side view of the magnetic balancing block 120. In this way, the ferromagnetic material 208 can be shaped into a ring-like portion in a horizontal plane (e.g., the XY plane). Furthermore, Figure 4A and 4B The magnet 206 is oriented along the magnetic polarization direction of the X-axis.

[0073] In some embodiments, the force-adjusting actuator 124 includes a rotary actuator configured to adjust the relative rotation between the magnet 206 and / or the ferromagnetic material 208 in a horizontal plane (e.g., the XY plane). For example, connected to the magnet 206 (e.g., as shown in the image). Figure 4B The rotational force adjustment actuator 124 (as depicted) can rotate the magnet 206 relative to the ferromagnetic material 208, which may have, but is not required to have, a fixed rotational position. As another example, the rotational force adjustment actuator 124 connected to the ferromagnetic material 208 can rotate the ferromagnetic material 208 relative to the magnet 206, which may have, but is not required to have, a fixed rotational position.

[0074] Figure 4C It is based on one or more embodiments of this disclosure, as such Figure 4A and 4B The magnetic balancing block 120 depicted provides a diagram showing the balancing forces that vary according to the relative rotational angle between the magnet 206 and the ferromagnetic material 208. (See diagram for reference.) Figure 4C As shown, the balancing force can be adjusted within the force range 404 by adjusting the relative rotation angle between the magnet 206 and the ferromagnetic material 208.

[0075] In some embodiments, the force adjustment actuator 124 includes at least one linear actuator configured to modify the gap 210 distance between the magnet 206 and the ferromagnetic material 208 along at least one direction. For example, the second portion 204 of the magnetic balance block 120 may include two or more types of ferromagnetic materials 208, such that one or more force adjustment actuators 124 can be used to adjust the position of any of these ferromagnetic materials 208 relative to the first portion 202 (or at least one of the magnets 206).

[0076] Figure 5A A non-limiting configuration of a magnetic balancing block 120 (e.g., an adjustable magnetic balancing block 120) providing an adjustable balancing force is depicted according to one or more embodiments of the present disclosure.

[0077] Figure 5A This is a top view of a magnetic balance block 120 comprising a first portion 202 of a radially polarized magnet 206 and a second portion 204 of two individually positionable ferromagnetic materials 208, according to one or more embodiments of the present disclosure.

[0078] For example, Figure 5A The second portion 204 of the magnetic balancing block 120 includes a first ferromagnetic material 208-1 and a second ferromagnetic material 208-2 positioned to at least partially surround the magnet 206. Furthermore, the first ferromagnetic material 208-1 and the second ferromagnetic material 208-2 can be attached to a force-adjusting actuator 124 (not explicitly shown) to adjust the gap 210 distance between the corresponding ferromagnetic materials 208-1, 208-2 and the magnet 206. In some embodiments, the force-adjusting actuator 124 is located radially (e.g., along...). Figure 5A The first ferromagnetic material 208-1 and the second ferromagnetic material 208-2 are adjusted symmetrically along the X-axis.

[0079] Figure 5B It is based on one or more embodiments of this disclosure, as such Figure 5A The magnetic balancing block 120 depicted provides a plot of the balancing forces that vary according to the distance of the gap 210. For example, the force adjusting actuator 124 adjusts the positions of the first ferromagnetic material 208-1 and the second ferromagnetic material 208-2 to correspond to their respective positions. Figure 5B The X-axis in the model has the same gap of 210. For example... Figure 5B As described, the balanced force can be adjusted within the force range 502 by adjusting the gap 210.

[0080] It should be understood that Figures 5A to 5BThe associated descriptions are provided for illustrative purposes only and should not be construed as limiting. For example, the magnetic counterweight 120 may comprise any number of ferromagnetic materials 208 having positions adjustable using any number of force-adjusting actuators 124. As another example, various ferromagnetic materials 208 may be shaped to, for example, Figure 5A All values ​​of the gap 210 depicted have a slit 504 (e.g., an opening, space, or the like) or can be shaped to contact at least one value of the gap 210 (not shown).

[0081] For reference Figures 6A to 6C In some embodiments, at least one of the first portion 202 or the second portion 204 of the magnetic balancing block 120 includes both a magnet 206 and a ferromagnetic material 208.

[0082] Figure 6A This is a top view of a magnetic balance block 120 comprising a first portion 202 having a magnet 206 and ferromagnetic material 208-3, and a second portion 204 having a single U-shaped ferromagnetic material 208-4, according to one or more embodiments of the present disclosure. In this configuration, the first portion 202 and / or the second portion 204 may be mounted on one or more force-adjusting actuators 124 to adjust their relative separation in the XY plane. For example, the magnet 206 may be sized to at least partially fit within a cavity 602 associated with the U-shaped ferromagnetic material 208-4.

[0083] Figure 6B This is a top view of a magnetic balance block 120 comprising a first portion 202 having two magnets 206 attached to U-shaped ferromagnetic material 208-5 and a second portion 204 having a single ferromagnetic material 208-6, according to one or more embodiments of the present disclosure. Furthermore, the second portion 204 may be fitted within an internal cavity 604 formed by the first portion 202. In this configuration, the first portion 202 and / or the second portion 204 may be mounted on one or more force-adjusting actuators 124 to adjust relative separation in the XY plane.

[0084] Figure 6C This is a top view of a magnetic balance block 120 comprising a first portion 202 having two individually positionable magnets 206 attached to individual ferromagnetic materials 208-7, 208-8, and a second portion 204 having two ferromagnetic materials 208-9, 208-10, according to one or more embodiments of the present disclosure. Furthermore, the second portion 204 can be fitted into an internal cavity 606 formed by the first portion 202. In this configuration, the first portion 202 and / or the second portion 204 can be mounted on one or more force-adjusting actuators 124 to adjust their relative separation in the XY plane.

[0085] It should be understood that Figures 6A to 6CThe associated descriptions are provided for illustrative purposes only and should not be construed as limiting. For example, the magnetic balancing block 120 may include any combination of magnets 206 and ferromagnetic materials 208 suitable for providing balancing forces on the first portion 202 and / or the second portion 204. Furthermore, any number of force-adjusting actuators 124 may be used to position any portion of the first portion 202 and the second portion 204 of the magnetic balancing block 120.

[0086] Refer again Figure 1A Various additional aspects of the translation stage 100 are described in more detail according to one or more embodiments of the present disclosure.

[0087] In some embodiments, the translation stage 100 includes a controller 126 having one or more processors 128 configured to execute a set of program instructions held in a memory 130 (e.g., a memory device).

[0088] One or more processors 128 of controller 126 may comprise any processor or processing element known in the art. In this sense, one or more processors 128 may comprise any microprocessor-type device configured to execute algorithms and / or instructions. For the purposes of this disclosure, the terms “processor” or “processing element” may be broadly defined to encompass any device having one or more processing or logic elements (e.g., one or more microprocessor devices, one or more application-specific integrated circuit (ASIC) devices, one or more field-programmable gate arrays (FPGAs), or one or more digital signal processors (DSPs)). In this sense, one or more processors 128 may comprise any device configured to execute algorithms and / or instructions (e.g., program instructions stored in memory). In some embodiments, one or more processors 128 may embody a desktop computer, a mainframe computer system, a workstation, a graphics computer, a parallel processor, a networked computer, or any other computer system configured to execute a program configured to operate or in conjunction with the translation stage 100, as described throughout this disclosure. Furthermore, different subsystems of the translation stage 100 may include processors or logic elements suitable for performing at least a portion of the steps described in this disclosure. Therefore, the above description should not be construed as limiting the embodiments of this disclosure, but is merely illustrative. Additionally, the steps described throughout this disclosure may be performed by a single controller or alternatively, multiple controllers. Furthermore, controller 126 may include one or more controllers housed in a common housing or within multiple housings. In this manner, any controller or combination of controllers may be individually packaged as a module suitable for integration into the translation stage 100.

[0089] Memory 130 may comprise any storage medium known in the art suitable for storing program instructions executable by one or more associated processors 128. For example, memory 130 may comprise a non-transitory memory medium. By another example, memory 130 may comprise, but is not limited to, read-only memory (ROM), random access memory (RAM), magnetic or optical storage devices (e.g., magnetic disks), magnetic tape, solid-state drives, and the like. It should be further noted that memory 130 may be housed together with one or more processors 128 within a common controller housing. In some embodiments, memory 130 may be remotely located relative to the physical location of one or more processors 128 and controller 126. For example, one or more processors 128 of controller 126 may access remote memory (e.g., a server) accessible via a network (e.g., the Internet, intranet, and the like).

[0090] Controller 126 may include or be coupled to any component or combination of components in the translation stage 100. Furthermore, controller 126 may receive data from any component in the translation stage 100 and / or control any component in the translation stage 100 via drive signals. For example, controller 126 may be coupled to force adjustment actuator 124 and thus generate drive signals to adjust the position of a first portion 202 or a second portion 204 of the magnetic balance block 120 (or any component thereof). In this way, controller 126 may be communicatively coupled to the translation stage 100 or any component thereof.

[0091] For reference Figures 7A to 7B The integration of the translation stage 100 within a larger system is described in more detail according to one or more embodiments of the present disclosure.

[0092] Figure 7A This is a simplified schematic diagram of a system 702 comprising a vertically oriented translation stage 100 and an additional translation stage 704 for fixing and / or positioning a sample 706, according to one or more embodiments of the present disclosure.

[0093] In some embodiments, various components of system 702 are movable plates 104 (e.g., as object 118) mounted to translation stage 100. In this configuration, the load weight may include the combined weight of the movable plate 104 and any attached components. Precise balancing using one or more magnetic balance blocks 120, and optionally one or more tunable magnetic balance blocks 120, provides precise, tunable control over the position of the components relative to sample 706.

[0094] This document envisions a system 702 having at least some components mounted to a translation stage 100 as disclosed herein, which may be well-suited, but not limited to, metrological applications in which the distance between a sample 706 and one or more components of the metrology system is measured. For example, system 702 may include an optical system, such as, but not limited to, an optical metrology system or an imager. As another example, system 702 may include a non-optical metrology system.

[0095] Figure 7B This is a simplified schematic diagram of an optical metrology system 702 according to one or more embodiments of the present disclosure.

[0096] In some embodiments, system 702 may be configured according to a metrology recipe to generate metrological measurements associated with sample 706 based on the metrology recipe. For example, system 702 may direct an illumination beam 708 from illumination source 710 to sample 706 (e.g., via illumination path 712), collect light or other radiation emitted from sample 706 in response to illumination beam 708 (referred herein to as measurement light 714) (e.g., via light-collecting path 716), and generate metrological data from at least one detector 718 based on measurement light 714. For example, the metrological data may be associated with diffraction of illumination beam 708 from sample 706. Illumination path 712 and light-collecting path 716 may further include additional optical elements at any suitable location, such as, but not limited to, lens 720 and beam manipulation assembly 722 (e.g., polarizer, spectral filter, spatial filter, beam blocker, aperture, or the like). In some embodiments, such as Figure 7B As described herein, system 702 includes one or more beam splitters 724 to allow simultaneous illumination and light collection through common objective lens 726 or other focusing elements.

[0097] System 702 may include one or more detectors 718 at any suitable location for collecting metrological data. For example, system 702 may include at least one detector 718 at a field plane (e.g., a plane conjugate to sample 706), which in Figure 7B As described below. As another example, although not described, system 702 may include at least one detector 718 at the pupil plane (e.g., the diffraction plane corresponding to the angular distribution of light from sample 706). Furthermore, although not described, system 702 may include multiple channels, each having a separate detector 718. System 702 may further include optical components for modifying the properties of the measurement light 714 within each channel, such as, but not limited to, polarizers, polarization rotators, spectral filters, spatial filters, or pupil filters (e.g., beam deflectors or apertures in the pupil plane for blocking or allowing selected diffraction orders to pass through).

[0098] General reference Figure 7A and 7BAny component of system 702 can be mounted to the movable plate 104 of the translation stage 100 (e.g., as object 118). For example, such object 118 mounted to the movable plate 104 may include at least one lens (e.g., objective lens 726 and detector 718). In this way, the system can operate as an imaging system and adjustment of the position of the movable plate 104 (e.g., via controller 126) provides control over the separation distance 728 (e.g., working distance) between the lens and the sample 706. In some embodiments, such as Figure 7B As depicted, such an object 118 mounted to the movable plate 104 may further include an illumination source 710. In some embodiments, such an object 118 mounted to the movable plate 104 may include a photomask, wherein the photomask and lenses are configured to project an image of the photomask onto the sample 706. In this way, the system 702 can operate as an optical projection system, a photolithography system (e.g., a scanner or stepper), or the like.

[0099] In some embodiments, system 702 includes one or more sensors 730 for monitoring the position of sample 706. For example, sensor 730 may measure, track, or otherwise monitor the position of sample 706 along a vertical direction. As another example, sensor 730 may measure, track, or otherwise monitor the separation distance 728 between sample 706 and at least one of one or more objects 118 (e.g., a lens or the like) on movable plate 104.

[0100] Sensor 730 may include any type of device known in the art suitable for determining the position of sample 706 or its change over time, such as, but not limited to, proximity sensors or distance sensors. Furthermore, sensor 730 may utilize any technology, such as, but not limited to, optical or capacitive technologies.

[0101] In some embodiments, system 702 may maintain (e.g., via drive signals from controller 126 to stage positioning actuator 106) a selected distance between sample 706 and one or more objects 118 on translation stage 100. For example, system 702 may maintain this selected distance when sample 706 is translated (e.g., along a horizontal plane) by an additional translation stage 704.

[0102] This document envisions that relatively high-frequency height control can be achieved by balancing a translation stage 100 using one or more magnetic balance blocks 120 as disclosed herein (wherein at least one tunable magnetic balance block 120 as disclosed herein is used to fine-tune the balancing force to match the load weight). Specifically, the stage positioning actuator 106 for controlling the position of the movable plate 104 does not need to bear the load weight. In some applications, height control can be achieved at frequencies on the order of 10 Hz or higher (e.g., hundreds of Hz, kHz, or higher).

[0103] Figure 8 This is a flowchart illustrating the steps performed in method 800 according to one or more embodiments of this disclosure. The applicant mentions that the embodiments and implementation techniques previously described herein in the background description of the translation stage 100 should be interpreted as extended to method 800. However, it should be further noted that method 800 is not limited to the architecture of the translation stage 100.

[0104] In some embodiments, method 800 includes step 802 of placing sample 706 in the vertical direction at a selected distance from one of one or more objects 118 connected to the translation stage 100. For example, in the case of an optical system, the selected distance may correspond to the working distance of a lens. In some embodiments, method 800 includes step 804 of adjusting the balancing force of one or more magnetic balance blocks 120 on the translation stage 100 to be equal to the combined weight of the movable plate 104 and the one or more objects 118. For example, at least one of the magnetic balance blocks 120 may have an adjustable balancing force. In this way, the stage positioning actuator 106 for controlling the position of the movable plate 104 and therefore the associated objects 118 connected thereto does not need to bear the associated load weight. Thus, high-frequency dynamic height control with minimal heat is achieved. In some embodiments, method 800 includes a step 806 of generating a measurement of at least one of the following: the position of sample 706 along a vertical direction or the distance between sample 706 and at least one of one or more objects 118 on movable plate 104 in the vertical direction. For example, one or more sensors 730 may be used to generate the measurement. In some embodiments, method 800 includes a step 808 of maintaining a selected distance between sample 706 and one of one or more objects 118 in the vertical direction based on the measurement. For example, the selected distance may be maintained while translating sample 706 along a horizontal plane.

[0105] The objects described herein sometimes refer to different components contained within or connected to other components. It should be understood that such depicted architectures are merely exemplary, and many other architectures can in fact be implemented to achieve the same functionality. Conceptually, any arrangement of components used to achieve the same functionality is effectively “associated” to achieve the desired functionality. Therefore, any two components combined herein to achieve a particular functionality can be considered “associated” with each other to achieve the desired functionality, regardless of the architecture or intermediate components. Similarly, any two such associated components can also be considered “connected” or “coupled” with each other to achieve the desired functionality, and any two components that can be suchly associated can also be considered “coupleable” with each other to achieve the desired functionality. Specific examples of coupleability include, but are not limited to, physically interactive and / or physically interactive components, and / or wirelessly interactive and / or logically interactive components.

[0106] It is believed that this disclosure and its many accompanying advantages will be understood from the foregoing description, and it will be appreciated that various changes can be made in the form, construction, and arrangement of the components without departing from the disclosed object or sacrificing all its material advantages. The forms described are merely illustrative, and the appended claims are intended to cover and encompass such changes. Furthermore, it should be understood that the invention is defined by the appended claims.

Claims

1. A translation stage, comprising: First board; A second plate, wherein the second plate is movable relative to the first plate in a vertical direction associated with the weight of the second plate; One or more magnetic balancing blocks coupled to the first plate and the second plate and providing a balancing force on the second plate in the vertical direction opposite to the weight of the second plate, wherein at least one of the one or more magnetic balancing blocks includes a tunable magnetic balancing block, wherein the tunable magnetic balancing block comprises: A first portion comprising one or more magnets, wherein the first portion is attached to one of the first plate or the second plate; and The second part comprises one or more ferromagnetic materials, wherein the second part is attached to one of the first plate or the second plate that is different from the first part, wherein the one or more ferromagnetic materials at least partially surround the one or more magnets in a horizontal plane orthogonal to the vertical direction, wherein the first part and the second part are separated by a gap, wherein the balancing force can be adjusted by controlling at least one of the relative rotation angle between the first part and the second part in the horizontal plane or the length of the gap along at least one direction; One or more additional actuators, connected to at least one of the first or second portions, adjust, based on one or more drive signals from a controller, at least one of the relative rotation angle between the first and second portions in the horizontal plane or the length of the gap in at least one direction, such that the balancing force is equal to the load weight of the second plate and one or more objects connected to the second plate, wherein the one or more ferromagnetic materials comprise two or more ferromagnetic materials, and wherein the one or more additional actuators adjust the gap distance between at least one of the two or more ferromagnetic materials and at least one of the one or more magnets; and An actuator configured to position the second plate relative to the first plate along the vertical direction without bearing the load weight, and to control a selected distance in the vertical direction between a sample located on an additional translation stage and one of the one or more objects on the second plate.

2. The translation stage according to claim 1, wherein at least one of the one or more magnets has at least a portion having a magnetic polarization direction in the horizontal plane, wherein the one or more ferromagnetic materials are distributed in the horizontal plane with at least one slit, wherein the balancing force can be adjusted by controlling the relative rotation angle between the first portion and the second portion in the horizontal plane.

3. The translation stage according to claim 2, wherein the one or more magnets comprise: A single magnet having at least a portion of the magnetic polarization direction in the horizontal plane.

4. The translation stage according to claim 3, wherein the individual magnet is shaped as a rod having a long axis along the vertical direction.

5. The translation platform according to claim 4, wherein the rod has a circular cross-section in the horizontal plane.

6. The translation stage according to claim 4, wherein the rod has a rectangular cross-section in the horizontal plane.

7. The translation stage according to claim 3, wherein the one or more ferromagnetic materials include: A single ferromagnetic material, which is shaped into a ring-shaped portion in the horizontal plane.

8. The translation stage according to claim 1, further comprising: One or more guide elements are used to constrain the movement between the first plate and the second plate to the vertical direction.

9. The translation stage of claim 1, wherein the first portion comprises one or more additional ferromagnetic materials, wherein the one or more ferromagnetic materials and the one or more additional ferromagnetic materials at least partially surround the one or more magnets.

10. The translation stage according to claim 1, wherein the actuator comprises a linear direct drive actuator.

11. A translation stage system, comprising: First board; A second plate, wherein the second plate is movable relative to the first plate in a vertical direction associated with the weight of the second plate, wherein the second plate is configured to be attached to one or more objects; One or more magnetic balancing blocks coupled to the first plate and the second plate and providing a balancing force on the second plate in the vertical direction opposite to the weight of the second plate, wherein at least one of the one or more magnetic balancing blocks includes a tunable magnetic balancing block, wherein the tunable magnetic balancing block comprises: A first portion comprising one or more magnets, the first portion being attached to one of the first plate or the second plate; and The second part comprises one or more ferromagnetic materials, the second part being attached to one of the first plate or the second plate that is different from the first part, wherein the one or more ferromagnetic materials at least partially surround the one or more magnets in a horizontal plane orthogonal to the vertical direction, wherein the first part and the second part are separated by a gap, wherein the balancing force can be adjusted by controlling at least one of the relative rotation angle between the first part and the second part in the horizontal plane or the length of the gap along at least one direction; One or more additional actuators connected to at least one of the first portion or the second portion to adjust, based on one or more drive signals from a controller, at least one of the relative rotation angle between the first portion and the second portion in the horizontal plane or the length of the gap in at least one direction, such that the balancing force is equal to the load weight of the second plate and the one or more objects, wherein the one or more ferromagnetic materials include two or more types of ferromagnetic materials, and wherein the one or more additional actuators adjust the gap distance between at least one of the two or more ferromagnetic materials and at least one of the one or more magnets; An additional translation stage that positions the sample in at least the horizontal plane; An actuator configured to position the second plate relative to the first plate along the vertical direction without bearing the load weight; and The controller, communicatively coupled to the at least one adjustable magnetic balance block, includes one or more processors configured to execute program instructions that cause the one or more processors to: The actuator is guided by one or more drive signals to control the sample at a selected distance in the vertical direction from one of the one or more objects on the second plate at a tracking rate of 5 Hz or higher.

12. The translation stage system of claim 11, wherein the one or more processors are further configured to execute program instructions that cause the one or more processors to guide the at least one tunable magnetic balance block via one or more additional drive signals to adjust the balancing force to be equal to the combined weight of the second plate and the one or more objects.

13. The translation stage system of claim 11, wherein positioning the second plate relative to the first plate along the vertical direction positions at least one of the one or more objects on the second plate relative to the sample.

14. The translation stage system according to claim 11, further comprising: A sensor for measuring at least one of the position of the sample along the vertical direction or the distance between the sample and at least one of the one or more objects on the second plate in the vertical direction, wherein the one or more processors are further configured to execute program instructions that cause the one or more processors to maintain the selected distance between the sample and the one or more objects on the second plate in the vertical direction via the one or more drive signals sent to the actuator.

15. The translation stage system of claim 11, wherein at least one of the one or more magnets has at least a portion having a magnetic polarization direction in the horizontal plane, wherein the one or more ferromagnetic materials are distributed in the horizontal plane with at least one slit, wherein the balancing force can be adjusted by controlling the relative rotation angle between the first portion and the second portion in the horizontal plane.

16. The translation stage system of claim 15, wherein the one or more magnets comprise: A single magnet having at least a portion of the magnetic polarization direction in the horizontal plane.

17. The translation stage system of claim 16, wherein the individual magnet is shaped as a rod having a long axis along the vertical direction.

18. The translation platform system of claim 17, wherein the rod has a circular cross-section in the horizontal plane.

19. The translation platform system of claim 17, wherein the rod has a rectangular cross-section in the horizontal plane.

20. The translation stage system according to claim 16, wherein the one or more ferromagnetic materials comprise: A single ferromagnetic material, which is shaped into a ring-shaped portion in the horizontal plane.

21. The translation stage system according to claim 11, further comprising: One or more guide elements are used to constrain the movement between the first plate and the second plate to the vertical direction.

22. The translation stage system of claim 11, wherein the one or more objects connected to the second plate include a lens, wherein the selected distance between the sample and one of the one or more objects on the second plate in the vertical direction corresponds to the distance between the sample and the lens.

23. The translation stage system of claim 22, wherein the one or more objects further comprises a detector configured to image at least a portion of the sample through the lens.

24. The translation stage system of claim 23, wherein the one or more objects further comprises an illumination source for illuminating at least the portion thereof of the sample.

25. The translation stage system according to claim 23, wherein the translation stage system includes a metering system.

26. The translation stage system of claim 23, wherein the translation stage system includes an imaging system.

27. The translation stage system of claim 22, wherein the one or more objects further comprises a photomask, wherein the photomask and the lens are configured to project an image of the photomask onto the sample.

28. A method for operating a translation stage, comprising: The sample is placed at a selected distance in the vertical direction from one of one or more objects, wherein the objects are connected to the translation stage, wherein the translation stage comprises: First board; A second plate, wherein the second plate is movable relative to the first plate along the vertical direction, wherein the vertical direction is associated with the weight of the second plate, wherein one or more objects are connected to the second plate; One or more magnetic balancing blocks coupled to the first plate and the second plate and providing a balancing force on the second plate in the vertical direction opposite to the weight of the second plate, wherein at least one of the one or more magnetic balancing blocks includes a tunable magnetic balancing block, wherein the tunable magnetic balancing block comprises: A first portion comprising one or more magnets, the first portion being attached to one of the first plate or the second plate; and The second part comprises one or more ferromagnetic materials, the second part being attached to one of the first plate or the second plate that is different from the first part, wherein the one or more ferromagnetic materials at least partially surround the one or more magnets in a horizontal plane orthogonal to the vertical direction, wherein the first part and the second part are separated by a gap, wherein the balancing force can be adjusted by controlling at least one of the relative rotation angle between the first part and the second part in the horizontal plane or the length of the gap along at least one direction; One or more additional actuators, connected to at least one of the first or second portions, adjust, based on one or more drive signals from a controller, at least one of the relative rotation angle or the length of the gap between the first and second portions in the horizontal plane in at least one direction, such that the balancing force is equal to the load weight of the second plate and the one or more objects, wherein the one or more ferromagnetic materials comprise two or more ferromagnetic materials, and wherein the one or more additional actuators adjust the gap distance between at least one of the two or more ferromagnetic materials and at least one of the one or more magnets; and An actuator configured to position the second plate relative to the first plate along the vertical direction without bearing the load weight; Generate a measurement of at least one of the positions of the sample along the vertical direction or the distances between the sample and at least one of the one or more objects on the second plate in the vertical direction; The selected distance between the sample and one of one or more objects in the vertical direction is maintained based on the measurement value via the actuator at a tracking rate of 5 Hz or higher.

29. The method of claim 28, wherein maintaining the selected distance between the sample and one of one or more objects in the vertical direction via the actuator based on the measurement comprises: When the sample is translated in the horizontal plane, the actuator maintains the selected distance between the sample and one of the one or more objects in the vertical direction based on the measurement value.

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