Setpoint generator, position control system, platform apparatus, and exposure apparatus

Abstract

The invention provides a setpoint generator for a position control system comprising a locator of a master module and a slave module, the locator being configured to displace an object, the setpoint generator being configured to, during a displacement of the object:-determine a master setpoint trajectory of the master module; determining a slave setpoint trajectory of the slave module by means of an optimization algorithm; the optimization algorithm uses at least a portion of the primary setpoint trajectory, one or more boundary conditions, and an objective function associated with a performance characteristic of the locator.

Description

TECHNICAL FIELD

[0001] The present invention relates to a setpoint generator for a position control system of a positioner that can be applied for positioning a substrate or a patterning device in an exposure apparatus relative to a projection system in order to expose the substrate with a patterned beam of radiation. BACKGROUND

[0002] A lithographic apparatus is a machine constructed to apply a desired pattern to a substrate. For example, the lithographic apparatus can be used in the manufacture of integrated circuits (IC). For example, the lithographic apparatus can project a pattern (which can also be referred to as a design layout or design) from a patterning device (for example a mask) onto a layer of radiation- sensitive material (resist) provided on a substrate (for example a wafer).

[0003] As semiconductor manufacturing processes continue to advance, the dimensions of circuit elements have continually decreased while the number of circuit elements that have been successfully manufactured on a single device has continued to increase, following a trend commonly referred to as ‘Moore’s Law’. To keep up with Moore’s Law, the industry has continued to develop new tools and techniques to create increasingly smaller features. To project a pattern on a substrate, a lithographic apparatus can use electromagnetic radiation. The wavelength of this radiation determines the minimum size of features which can be formed on the substrate. Typical wavelengths are 365 nm (i-line), 248 nm, 193 nm and 13.5 nm. A lithographic apparatus that uses extreme ultraviolet (EUV) radiation, having a wavelength within a range of 4-20 nm, for example 6.7 nm or 13.5 nm, can be used to form smaller features on a substrate than is possible with a lithographic apparatus that uses, for example, radiation with a wavelength of 193 nm.

[0004] To ensure accurate projection of the pattern on the substrate, a positioner is used to position the substrate relative to the patterning device. Typically, such a positioner comprises a short stroke module that can achieve accurate positioning of the substrate over a relatively short distance and a long stroke module that can displace the substrate and the short stroke module over a relatively long distance. Typically, the position of the short stroke module and the long stroke module are controlled by a master slave controller, in which the short stroke module is considered the master and the long stroke module is used as a slave after the short stroke module.

[0005] In addition to accurate positioning of the substrate relative to the radiation beam comprising the pattern, it has been a desire to increase or improve the throughput of the lithographic apparatus, which typically requires increasing the power of the positioner to achieve higher accelerations and velocities. When the performance of a positioner having a master slave configuration is to be improved, it has been found that the application of known master slave control schemes imposes a limit on the improvements that can be achieved. SUMMARY

[0006] It is an object of the present invention to be able to improve the performance of a positioner having a master-slave configuration.

[0007] According to an aspect of the present invention, there is provided a setpoint generator for a position control system of a positioner comprising a master module and a slave module, the positioner being configured to displace an object, the setpoint generator being configured to, during displacement of the object: - determine a master setpoint trajectory for the master module; - determine a slave setpoint trajectory for the slave module by means of an optimization algorithm; the optimization algorithm using at least a part of the master setpoint trajectory, one or more boundary conditions and an objective function, the objective function being associated with a performance characteristic of the positioner.

[0008] According to another aspect of the present invention, there is provided a position control system comprising a setpoint generator according to the present invention.

[0009] According to another aspect of the present invention, there is provided a stage apparatus comprising a position control system according to the present invention.

[0010] According to another aspect of the present invention, there is provided an exposure apparatus comprising a stage apparatus according to the present invention. BRIEF DESCRIPTION OF DRAWINGS

[0011] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which:

[0012] Figure 1 a schematic overview of a lithographic apparatus is depicted;

[0013] Figure 2 a detailed view of a part of the lithographic apparatus of Figure 1 is depicted;

[0014] Figure 3 a position control system is schematically depicted;

[0015] Figure 4 a process that can be performed by a setpoint generator according to the present invention is depicted;

[0016] Figure 5 and 6 a positioner according to an embodiment of the present invention is schematically depicted.

[0017] Figure 7 a position control system according to the present invention is schematically depicted.

[0018] Figure 8 and 9 a trajectory that can be applied to a positioner module of the present invention is schematically depicted.

[0019] Figure 10a and10b The positions of a set of alignment marks on a substrate and wiring along the set of alignment marks are schematically shown. DETAILED DESCRIPTION

[0020] In the present document, the terms“radiation” and“beam” are used synonymously to encompass all types of electromagnetic radiation, including ultraviolet radiation (e.g. with a wavelength of 365, 248, 193, 157 or 126 nm) and EUV (extreme ultra-violet radiation, e.g. having a wavelength in the range of about 5-100 nm).

[0021] The term“reticle”,“mask” or“patterning device” as used herein can be broadly interpreted to include any patterning device that can be used to impart a pattern to a beam of radiation, including a mask or a reticle, which terms are used synonymously herein, and which are equally applicable to binary, phase shift, hybrid and multi-layer masks or reticles. The terms“light valve” and“patterning device” can also be used in this context. Examples of other such patterning devices include programmable mirror arrays and programmable LCD arrays.

[0022] Figure 1 A lithographic apparatus LA is schematically depicted. The lithographic apparatus LA includes an illumination system (also referred to as illuminator) IL configured to condition radiation beam B (e.g., UV, DUV, or EUV radiation), a mask support (e.g., a mask table) MT constructed to support a patterning device (e.g., a mask) MA and connected to a first positioner PM configured to accurately position the patterning device MA in accordance with certain parameters, a substrate support (e.g., a wafer table) WT constructed to hold a substrate (e.g., a resist coated wafer) W and connected to a second positioner PW configured to accurately position the substrate support in accordance with certain parameters, and a projection system (e.g., a refractive projection lens system) PS configured to project a pattern imparted to the radiation beam B by patterning device MA onto a target portion C (e.g., comprising one or more dies) of the substrate W.

[0023] In embodiments, the first positioner PM and / or the second positioner PW can be configured to be controlled by a position control system according to the present invention.

[0024] In operation, the illumination system IL receives a radiation beam from a radiation source SO (e.g., via a beam delivery system BD). The illumination system IL can include various types of optical components, such as refractive, reflective, magnetic, electromagnetic, electrostatic, and / or other types of optical components, or any combination thereof, for directing, shaping, and / or controlling the radiation. The illuminator 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 patterning device MA.

[0025] As used herein, the term "projection system" (PS) should be interpreted broadly to encompass all types of projection systems, including refractive, reflective, refracting-reflective, distorting, magnetic, electromagnetic, and / or electrostatic optical systems or any combination thereof, as appropriate, depending on the exposure radiation and / or other factors used, such as the use of immersion or vacuum. Any use of the term "projection lens" herein may be considered synonymous with the more general term "projection system" (PS).

[0026] A lithography apparatus LA can be of the type in which 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; this is also known as immersion lithography. More information on immersion techniques is given in US6952253, which is incorporated herein by reference.

[0027] The lithography apparatus LA can also be of the type having two or more substrate supports WT (also known as "dual-platform"). In such a "multi-platform" machine, the substrate supports WT can be used in parallel, and / or the subsequent exposure steps for preparing the substrate W can be performed on the substrate W located on one of the substrate supports WT, while another substrate W on the other substrate support WT is used to expose a pattern on the other substrate W.

[0028] In addition to the substrate support WT, the lithography apparatus LA may include a measurement platform. The measurement platform is arranged to hold sensors and / or cleaning equipment. 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 equipment may be arranged to clean part of the lithography apparatus, such as part of the projection system PS or part of a system providing immersion liquid. The measurement platform may move below the projection system PS as the substrate support WT moves away from the projection system PS.

[0029] In operation, a radiation beam B is incident on a patterning apparatus (e.g., a mask) MA held on a mask support MT and patterned by a pattern (design layout) present on the patterning apparatus MA. After traversing the patterning 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 IF, the substrate support WT can be accurately moved, for example, to position different target portions C in the path of the radiation beam B at focused and aligned positions. Similarly, a first positioner PM and possibly another position sensor (not shown in the image)... 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, as illustrated, occupy dedicated target portions, they can be located in the space between the target portions. When the substrate alignment marks P1, P2 are located between the target portions C, these are referred to as scribing alignment marks.

[0030] To illustrate the 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 these three axes is orthogonal to the other two. 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 but is used only for illustration. Conversely, 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.

[0031] Figure 2 It shows Figure 1 A more detailed view of a portion of the lithography apparatus LA. The lithography apparatus LA may be provided with a base frame BF, a counterweight block 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 the transmission of vibration from the base frame BF to the measurement frame MF.

[0032] 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, the driving force is also applied to the balancing mass block BM with an equal magnitude, 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 portion of the second positioner PW and the mass of the substrate support WT.

[0033] 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 to cause the substrate support WT to float 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 a bearing (such as a gas bearing) to cause the substrate support WT to float above the base frame BF.

[0034] A position measurement system (PMS) can include any type of sensor suitable for determining the position of a substrate stage WT. A position measurement system (PMS) can include any type of sensor suitable for determining the position of a mask support MT. Sensors can be optical sensors, such as interferometers or encoders. A position measurement system (PMS) can include a combined system of interferometers and encoders. Sensors can be another type of sensor, such as magnetic sensors, capacitive sensors, or inductive sensors. A position measurement system (PMS) can determine the position relative to a reference (e.g., a measurement frame MF or a projection system PS). A position measurement system (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).

[0035] 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 readhead, a grating, and a sensor. The encoder system may 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 created by diffracting the original radiation beam using a grating. If both the primary and secondary radiation beams are created by diffracting the original radiation beam using a grating, the primary radiation beam needs to have a different diffraction order than 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 readhead determines the phase or phase difference of the combined radiation beam. The sensor generates a signal based on the phase or phase difference. This signal represents the position of the encoder readhead relative to the grating. One of the encoder readhead and the grating can be arranged on the substrate structure WT. The other of the encoder readhead and the grating can be arranged on the measurement frame MF or the base frame BF. For example, multiple encoder readheads 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 readhead is arranged below the substrate support WT.

[0036] 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. The reference beam propagates to the reference mirror and is reflected back to the beam splitter. 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 frequency. This 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.

[0037] 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 over 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 over a large range of motion. By using the combination of the long-stroke module and the short-stroke module, the first positioner PM can move the mask support MT relative to the projection system PS with high accuracy over a large range of motion.

[0038] Within the meaning of this invention, the short-stroke module of the first locator PM can be regarded as an example of the master module of the locator according to the invention, and the long-stroke module of the first locator PM can be regarded as an example of the slave module of the locator according to the invention.

[0039] Similarly, the second positioner PM may include a long-stroke module and a short-stroke module. The short-stroke module is arranged to move the substrate support WT with high accuracy relative to the long-stroke module within a small range of motion. The long-stroke module is arranged to move the short-stroke module with relatively low accuracy relative to the projection system PS within a large range of motion. By using the combination of the long-stroke module and the short-stroke module, the second positioner PM can move the substrate support WT with high accuracy relative to the projection system PS within a large range of motion.

[0040] Within the meaning of this invention, the short-stroke module of the second locator PM can be regarded as an example of the master module of the locator according to the invention, and the long-stroke module of the second locator PM can be regarded as an example of the slave module of the locator according to the invention.

[0041] The first positioner PM and the second positioner PW are each provided with one or more actuators to move the mask support MT and the substrate support WT, respectively. The one or more actuators may be linear actuators to provide a driving force along a single axis (e.g., the y-axis). Multiple linear actuators may be applied to provide driving forces along multiple axes. The actuator may be a planar actuator to provide a driving force along multiple axes. For example, a planar actuator may be arranged to move the substrate support WT in six degrees of freedom. The actuator may be an electromagnetic actuator comprising at least one coil and at least one magnet. The actuator is arranged to move at least one coil relative to at least one magnet by applying current to at least one coil. The actuator may be a moving magnet type actuator having at least one magnet respectively coupled to the substrate support WT (mask support MT). The actuator may be a moving coil type actuator having at least one coil respectively coupled to the substrate support WT (mask support MT). The actuator can be a voice coil actuator, a magnetoresistive actuator, a Lorentz actuator, or any other suitable actuator.

[0042] The lithography apparatus LA includes Figure 3 A position control system (PCS) is schematically depicted. The PCS includes a setpoint generator (SP) and a control unit (CU), the control unit including a feedforward controller (FF) and a feedback controller (FB). The PCS provides a drive signal to an actuator (ACT). The actuator (ACT) can 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 using 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 desired position quantity of the device (P). For example, the reference signal represents the desired trajectory of the substrate support (WT). The position signal and the reference signal are applied as inputs to the control unit (CU) of the PCS. The difference between the reference signal and the position signal forms the input to the feedback controller (FB) of the control unit (CU). Based on this input, the feedback controller (FB) provides at least a portion of the drive signal to the actuator (ACT). The reference signal can form the input of 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. The feedforward FF can utilize information about the dynamic characteristics of the device P, such as mass, stiffness, resonant modes, and eigenfrequency.

[0043] In an embodiment, the position control system PCS includes a position control system according to the invention, the position control system PCS including a setpoint generator SP according to the invention.

[0044] According to embodiments of the present invention, a setpoint generator is provided that can provide setpoints for a locator with a master-slave configuration. Within the meaning of this invention, a locator with a master-slave configuration is a locator comprising multiple positioning modules that cooperate to achieve the positioning or displacement of an object.

[0045] As examples of such positioners, the first positioner PW and the second positioner PM described above can be mentioned. Such positioners may, for example, have a short-stroke module for accurately positioning and holding the stage of the pattern forming apparatus or substrate, and a long-stroke module for displacing the short-stroke module and the stage over a relatively large distance with more coarse accuracy.

[0046] As another example of such a positioner, a positioner with two long-stroke modules can be mentioned. Such a positioner may, for example, include a first long-stroke module for positioning or displacing an object along a desired trajectory and a second long-stroke module for following the first long-stroke module, for example, in essentially one degree of freedom. For example, in the case where the first long-stroke module comprises an electromagnet configured to displace the object in a plane (i.e., in two degrees of freedom), this arrangement can occur. In this arrangement, various cables and conduits may need to be connected to the mover of the long-stroke module, for example, for power supply and cooling. To facilitate two-dimensional movement of the first long-stroke module, a second long-stroke module is provided that holds the cables and conduits and follows the first long-stroke module, for example, in one degree of freedom. Further details regarding this arrangement will be described below.

[0047] In an embodiment, the present invention provides a setpoint generator for generating setpoints for a locator with a master-slave configuration, such as a master module and one or more slave modules. Therefore, this master-slave configuration means that the locator includes multiple positioning modules. The setpoint generator according to the invention is configured to determine a different setpoint for each of the multiple positioning modules, rather than copying the setpoint of one module and applying it to other modules, so that one or more slave modules substantially follow the master module.

[0048] exist Figure 4 The diagram schematically illustrates the process of applying the setpoint generator according to the present invention to achieve the setpoint trajectory of multiple positioning modules.

[0049] According to the present invention, a setpoint generator is configured to determine the setpoint trajectory of the master module of the locator in the first step 410. This setpoint trajectory of the master module may also be referred to as the master setpoint trajectory, or simply the master setpoint or master trajectory. This master setpoint trajectory may, for example, indicate the desired position of the master module or the object to be displaced by the locator, as a function of time. This trajectory may be expressed as a table or mathematical function, etc. For example, the setpoint trajectory may be expressed as a series of piecewise polynomials or a sequence of piecewise polynomials. In embodiments, the setpoint generator according to the present invention may determine the master setpoint trajectory based on a set of displacement parameters, which typically defines the displacement to be performed and any operating parameters or limitations of the locator to be considered. Therefore, the set of displacement parameters on which the trajectory is relied may include position information of the trajectory to be performed and the operating parameters of the locator. If the required displacement involves an exposure process of a substrate in an exposure apparatus, the position information may, for example, include position information of one or more fields on the substrate to be exposed during the exposure process. This position information may, for example, include the nominal position of the fields to be exposed, the length of the fields, the number of fields, etc. Operating parameters may include limitations of the locator, such as the maximum speed, maximum acceleration, maximum jerk, or maximum snap that need to be considered to determine the setpoint trajectory.

[0050] According to the invention, the setpoint generator is further configured to determine the setpoint trajectory of the slave module of the locator in the second step 420 by using an optimization algorithm. This setpoint trajectory of the slave module may also be referred to as a slave setpoint trajectory, or simply as a slave setpoint or slave trajectory. This slave setpoint trajectory may, for example, indicate the desired position of the slave module as a function of time. This trajectory can also be expressed as a table or mathematical function, etc. For example, the setpoint trajectory may be expressed as a series of piecewise polynomials or a sequence of piecewise polynomials.

[0051] Typically, an optimization algorithm is an algorithm designed to find a set of parameters that, when applied to a mathematical function or expression, leads to the optimal value of the mathematical function or expression, whether it is a maximum or minimum value, considering one or more boundary conditions. The mathematical function or expression can also be referred to as the objective function.

[0052] Over the past few decades, various methods or algorithms have been developed to achieve the optimal value of an objective function. For example, when the derivative of the objective function is available, such algorithms can utilize derivative information.

[0053] According to the present invention, based on the determined setpoint trajectory of the master module of the locator, an optimization algorithm is applied to find the setpoint trajectory of the slave module of the locator, which leads to the optimal value of the objective function, which describes, for example, the performance characteristics of the slave module of the locator.

[0054] According to the present invention, the objective function applied by the optimization algorithm is related to the performance characteristics of the locator. In particular, the objective function may, for example, include mathematical expressions that may be related to specific behaviors of the locator.

[0055] As a first example, the objective function may include a mathematical expression for the power consumption of the slave module of the positioner. For a given setpoint trajectory, the objective function derives the associated power consumption, which occurs if the slave module is controlled, for example, by a position control system to follow the given setpoint trajectory. The power consumption associated with the displacement along the setpoint trajectory can be obtained, for example, using a mathematical model of the slave module, particularly a mathematical model of the motor or actuator of the slave module. Such a mathematical model can, for example, determine the RMS value of the power supply current of the motor or actuator of the slave module, which follows the setpoint trajectory. Similar results can be obtained by applying an objective function that expresses the RMS value of the acceleration occurring during the setpoint trajectory, rather than a detailed motor model. In this respect, it can be noted that, generally, the power supply current of the motor or actuator will be proportional to the generated force, and thus proportional to the acceleration of the object on which the force is applied.

[0056] As a second example, the objective function may include a mathematical expression of the dynamic characteristics of the module. In this case, the objective function may, for example, include a mathematical function for the RMS value of the dynamic characteristics of the motor of the module when following a secondary setpoint trajectory. Examples of such dynamic characteristics may be, for example, speed, acceleration, jerk, or jerk-jerk. Compared to the latter, it has been observed that an objective function that minimizes the RMS value including jerk (jerk is the fourth derivative of position) provides a good trade-off between minimizing power consumption and desired dynamic behavior. As another dynamic characteristic, a specific spectrum, region, or range may be mentioned. For a given setpoint trajectory, the frequency content of the trajectory can be determined and evaluated or evaluated relative to the desired conditions or objective function. Thus, as an objective, the setpoint trajectory can be determined, for example, to avoid certain frequencies or specific frequency regions during application. By doing so, certain vibrations or other dynamic disturbances can be avoided or mitigated.

[0057] In embodiments of the invention, the objective function optimized by the optimization algorithm applied by the setpoint generator includes a combination of objectives. In this embodiment, the objective function may include a weighted combination of multiple objectives, such as a weighted combination of the RMS value of acceleration and the RMS value of the position difference between the master and slave modules. This weighted combination can then be minimized, for example. The optimization algorithm applied in the setpoint generator according to the invention may also consider one or more boundary conditions. As an example, a threshold for the allowable positional deviation between the master and slave setpoint trajectories may be such a boundary condition. In embodiments, this threshold may also be applied only to certain portions of the trajectory. In the case of a substrate exposure process, the maximum positional deviation between the master and slave setpoint trajectories can be set during the scanning portion of the setpoint trajectory. Figure 8 and 9 The process is described in more detail. The operating parameters of the module can also be used as boundary conditions. These parameters can be, for example, limits that can be generated from the module, such as maximum speed, maximum acceleration, or maximum jerk.

[0058] In embodiments of the invention, the setpoint generator is configured to perform [action] during locator operation, such as during object displacement. Figure 4 The illustrated process comprises at least a portion of determining the setpoint trajectory of the positioning module of the positioner. In advanced positioning processes, such as positioning a substrate during an exposure process in an exposure apparatus, the setpoint trajectory of the master module of the positioner, for example, holding the substrate, can be determined during the exposure process. In this case, the master setpoint trajectory to be followed may only be known in advance for a specific period (e.g., a few seconds). This period, or a portion thereof, can then be used to determine the secondary setpoint trajectory to be followed. More details about this process will be provided below.

[0059] Figure 5 and 6 A locator that can be controlled using a setpoint generator according to the invention is illustrated schematically.

[0060] Figure 5A side or front view schematically illustrates a first embodiment of a positioner 500, which includes multiple positioning modules for positioning an object. The positioner 500 includes a stage 510 configured to hold an object 520 (e.g., a substrate), a first positioning module 530, and a second positioning module 540. In the illustrated embodiment, the first positioning module 530, which can be considered a main module, is connected to the stage 510 and configured to position the stage 510. As shown, the first positioning module 530 includes an actuator assembly 532 for positioning the stage 510. In this embodiment, the first positioning module 530 may include the actuator assembly 532 configured to position the stage in six degrees of freedom (6 DOF) over a relatively short distance, for example, with high accuracy. In this respect, the first positioning module 530 can be considered an example of the short-stroke module discussed above. The actuator 532 shown may be, for example, an electromagnetic actuator, such as a Lorentz actuator or a magnetoresistive actuator. Such an actuator may include, for example, a first component 532.1, such as a magnetic or ferromagnetic component, which is configured to cooperate with a second component 532.2 (such as a coil component) to generate a force in a predetermined direction.

[0061] Figure 5 The second positioning module 540 of the positioner 500 shown includes a mover 540.1, which is displaceable relative to the stator 540.2 of the second positioning module 540. The second positioning module 540 may, for example, include a linear motor or a planar motor. In this arrangement, the mover 540.1 may, for example, include an array of coils that can be supplied with current, while the stator 540.2 may, for example, include an array of permanent magnets (or vice versa). The second positioning module 540 may, for example, be configured to displace the first positioning module 530 and the stage 510 over a relatively large distance. Therefore, the second positioning module 540 can be considered as an example of the long-stroke module discussed above.

[0062] The locator 500 also includes a position control system (PCS) according to the invention, configured to generate a position control signal 550 for controlling the positioning modules 530 and 540 of the locator. In the illustrated embodiment, the position control system PCS includes a setpoint generator SG configured to generate setpoints or setpoint trajectories for the positioning modules 530 and 540 of the locator 500. The position control system PCS may have... Figure 3The position control system (PCS) shown has a similar structure, including a setpoint generator (SG) and a control unit (CU). Note that the two components of the position control system according to the invention (i.e., the setpoint generator (SG) and the control unit (CU)) do not need to be integrated into a single module or structure. As an example, the setpoint generator can be, for instance, part of a main control system that is remote from the control unit (CU) of the position control system (PCS). In this case, the setpoint trajectory determined by the setpoint generator (SG) can be transmitted to the control unit (CU) via any suitable communication method (e.g., via a network).

[0063] Figure 6 A top view schematically illustrates a second embodiment of a positioner 600 according to the invention, which includes a first positioning module 610 and a second positioning module 620 for displacing and positioning an object. In the illustrated embodiment, the first positioning module 610 includes a mover 610.1 configured to move a stage in a plane extending along indicated X and Y directions. The stage may, for example, accommodate an object 630, such as a substrate. The mover 610.1 can be moved in the indicated XY plane by means of interaction with the stator 610.2 of the first positioning module 610. The first positioning module 610 may, for example, be an electromagnetic planar motor, wherein the mover 610.1 includes one or more coil arrays that can be supplied with current, and the stator 610.2 includes a two-dimensional spatially alternating pattern of permanent magnets. In an alternative embodiment, the mover 610.1 includes permanent magnets, and the stator 610.2 includes a coil array that, in use, forms a two-dimensional spatially alternating magnetic field. In the illustrated embodiment, the second positioning module 620 includes a mover 620.1, which is movable relative to the stator 620.2 along the indicated Y direction. The second positioning module 620 may, for example, include a linear motor, such as a linear electromagnetic motor. In the illustrated arrangement, both the first positioning module 610 and the second positioning module 620 can be considered examples of long-stroke modules.

[0064] In the illustrated embodiment, the purpose of the second positioning module 620 is to displace the cable assembly 640 of the positioner 600. The cable assembly 640, connected between the mover 610.1 of the first positioning module 610 and the mover 620.1 of the second positioning module 620, may include, for example, a cable for supplying power current to the mover 610.1. The cable assembly 640 may also include one or more conduits for supplying cooling fluid to the mover 610.1, for example, cooling the mover and / or the stage holding the object 630. The second positioning module 620 may also be referred to as a follower stage and assists in the movement of the first positioning module 610 holding the object 630. During operation, the second positioning module 620 will generally follow the movement of the first positioning module 610 along the Y direction. In known arrangements of the positioner 600, the second positioning module 620 thus applies the Y-direction setpoint or setpoint trajectory of the first positioning module 610. However, according to the invention, the position of the second positioning module 620 is controlled by a position control system PCS having a setpoint generator SG according to the invention. Therefore, the setpoint generator SG according to the present invention can determine the setpoint trajectories of the first positioning module 610 and the second positioning module 620. In particular, the setpoint generator SG can determine the first setpoint trajectory of the first positioning module 610 (which serves as the master module) and the second setpoint trajectory of the second positioning module 620 (which serves as the slave module), thereby determining the second setpoint trajectory by means of an optimization algorithm, as mentioned above.

[0065] As a third embodiment of the locator according to the invention, a combination of locators 500 and 600 can be considered. In this combined locator, a locator is obtained comprising: - The first positioning module is similar to Figure 5 The short-stroke module 530 is a short-stroke module that serves as the main module. - The second positioning module is similar to Figure 5 Long stroke module 540 or Figure 6 The long-stroke module 610, - The third positioning module is also similar to... Figure 6 The long stroke module 620 is a long stroke module and is used as a follower stage to the second positioning module.

[0066] In this arrangement, both the second and third positioning modules can be considered as slave modules of the first positioning module. Therefore, in this embodiment, the setpoint trajectories of the second and third positioning modules can be determined by the setpoint generator according to the invention using an optimization algorithm. In this embodiment, the optimization algorithm can apply at least a portion of the master setpoint trajectory, i.e., the setpoint trajectory of the first positioning module, one or more boundary conditions, and a first objective function, to determine the setpoint trajectory of the second positioning module. Further, the optimization algorithm can apply at least a portion of the master setpoint trajectory, i.e., the setpoint trajectory of the first positioning module, one or more boundary conditions, and a second objective function, to determine the setpoint trajectory of the third positioning module. Note that in this arrangement, the optimization algorithms applied may also be different for determining the setpoint trajectories of the second and third positioning modules.

[0067] Alternatively, in this arrangement with three positioning modules, the second positioning module can be a slave module relative to the first positioning module and a master module relative to the third positioning module. In this arrangement, the setpoint trajectory of the second positioning module will therefore be based on the setpoint trajectory of the first positioning module, while the setpoint trajectory of the third positioning module will be based on the setpoint trajectory of the second positioning module. A setpoint generator constructed in this way is as follows: Figure 7 The schematic diagram is shown below and will be described in detail.

[0068] In another embodiment, the locator according to the invention includes more than three modules, such as four modules. Typically, the invention can be implemented in a locator comprising multiple modules that cooperate to move a specific object or platform. Reference Figure 6 In the illustrated embodiment, the stator 610.2 of the first positioning module 610 may be a balancing mass block rather than a fixed structure. In this arrangement, the position of the stator 610.2 may also need to be controlled, for example by means of one or more actuators arranged to position the stator 610.2. In this arrangement, these one or more actuators may also receive a setpoint or setpoint trajectory, which may be derived, for example, using a setpoint generator according to the invention.

[0069] Figure 7 A position control system (PCS) including a setpoint generator according to the invention is schematically illustrated, wherein the setpoint generator (SG) is configured to determine the setpoint trajectories of three positioning modules of the positioner, which cooperate to displace the object. Figure 7 In this process, the generation of the three setpoint trajectories ST1, ST2 and ST3 is performed by the modules or routines SG1, OA1 and OA2 of the setpoint generator SG.

[0070] Figure 7The position control system PCS shown includes a setpoint generator SG and a control unit or controller CU, which uses the setpoint trajectories ST1, ST2 and ST3 of the setpoint generator to generate control signals CS to control the positioner.

[0071] Figure 7 The setpoint generator SG shown is configured to determine a first setpoint trajectory ST1, which is the setpoint trajectory of the locator's main module. This main module may, for example, correspond to... Figure 5 This is a short-stroke module similar to the short-stroke module 530. In the illustrated embodiment, the setpoint trajectory ST1 is generated by the module or routine SG1 of the setpoint generator SG based on an input parameter set, which may include, for example, the displacement parameters described above. Such parameters typically define the displacement to be performed and any operating parameters or limitations of the locator that need to be considered. Therefore, the dependent set of displacement parameters may include the position information of the trajectory to be performed and the operating parameters of the locator.

[0072] The setpoint generator SG shown is also configured to use an optimization algorithm indicated by OA1 to determine the setpoint trajectory ST2 of the locator's slave module. This slave module can, for example, correspond to... Figure 5 The long-stroke module 540 is similar to a long-stroke module. In the illustrated embodiment, the optimization algorithm OA1 of the setpoint generator SG generates the setpoint trajectory ST2 based on the setpoint trajectory ST1 of the main module, and considers one or more boundary conditions, such as... Figure 7 The boundary condition 1 indicates this. These boundary conditions 1 may, for example, express restrictions on the operating parameters of the module and / or restrictions on the positional relationship between the master and slave modules.

[0073] The setpoint generator SG shown is also configured to use an optimization algorithm indicated by OA2 to determine the setpoint trajectory ST3 of another slave module of the locator. This other slave module can, for example, correspond to... Figure 6 The long-stroke module 620 is similar to a long-stroke module. In the illustrated embodiment, the optimized algorithm OA2 of the setpoint generator SG generates the setpoint trajectory ST3 based on the setpoint trajectory ST2 from the module, and takes into account one or more boundary conditions, such as... Figure 7 The boundary condition 2 indicates this. These boundary conditions 2 may, for example, express restrictions on the operating parameters of another slave module and / or restrictions on the positional relationship between the master module and the slave module.

[0074] As mentioned above, the setpoint trajectories (e.g., trajectories ST1, ST2, and ST3) of the setpoint generator SG according to the present invention can be expressed as tables or mathematical functions, etc. For example, one or more setpoint trajectories can be expressed as a series of piecewise polynomials or a sequence of piecewise polynomials. If the control unit of the position control system according to the present invention requires a more suitable format, the conversion to this form can be implemented in the setpoint generator SG or the control unit CU.

[0075] The setpoint generator according to the invention can be advantageously applied to the position control system of a locator for positioning a substrate stage in a lithography or exposure apparatus, such as the locator PW for the substrate stage WT discussed above. In particular, substrates comprising multiple fields requiring exposure to a radiation beam having a patterned cross-section need to be accurately positioned relative to the projection system of the apparatus in order to project a pattern onto the substrate. Typically, the substrate stage (e.g., stage WT) holding the substrate W follows a curved pattern to expose the various fields to the radiation beam. The setpoint generator according to the invention can also be applied in substantially a similar manner to determine the setpoint trajectory for other processes performed in a lithography apparatus. Such processes, for example, involve the position measurement or determination of multiple marks on the substrate. Such position measurement of multiple marks on the substrate (e.g., alignment marks) may require the substrate to follow a similar trajectory, which necessitates that the substrate be positioned at different locations to perform the position measurement on the marks.

[0076] Figure 8 The diagram schematically illustrates the possible trajectories followed by the substrate stage in the XY plane when exposing three consecutive fields on a substrate during an exposure process. As can be seen, the curved trajectories to be followed consist of an alternating sequence of straight-line movements 810 and curves 820 in the horizontal direction of the figure. Arrows in the trajectory indicate the direction of movement of the substrate / substrate stage. During the straight-line movement 810, also known as the scan movement or scan trajectory, the fields on the substrate are exposed to a patterned radiation beam, while during the curve 820, also known as the preparation movement or preparation trajectory, the substrate is displaced to begin scanning the next field. Typically, the scan trajectory is a trajectory in which the substrate moves at a substantially constant speed, for example, in the Y or -Y direction. During the preparation movement or trajectory, the substrate is displaced to begin the next scan of the next field on the substrate.

[0077] Typically, a known setpoint generator determines the trajectory to be followed and provides it to the control unit of the position control system, for example, to control the positioning of the short-stroke module, thereby providing accurate positioning of the substrate along the drawn trajectory. In the known setpoint generator, the same setpoint trajectory can then be applied to control the position of the long-stroke module, which is configured to displace the short-stroke module and the substrate stage holding the substrate. In this arrangement, the long-stroke module will follow the exact same trajectory as the short-stroke module.

[0078] According to an embodiment of the invention, a setpoint generator is provided to determine an alternative setpoint trajectory for a slave module of a positioner for a positioning substrate. This alternative setpoint trajectory is determined by means of an optimization algorithm that uses at least a portion of the determined setpoint trajectory of a master module or short-stroke module. Typically, a setpoint generator for an exposure process of a semiconductor substrate does not determine the setpoint trajectory for the entire substrate at once. Instead, the setpoint generator ensures that the setpoints or setpoint trajectories to be followed are known several (e.g., 5) fields ahead or ahead of time. By doing so, the setpoint generator can still adjust the setpoint trajectory during the exposure process itself. This is relative to a slave module or long-stroke module (e.g., Figure 5 The determination of the setpoint trajectory in module 540 can also be noted, and this setpoint trajectory can be determined using an optimization algorithm based on information from only a portion of the master setpoint trajectory. In particular, the inventors have devised a method to determine the slave setpoint trajectory of a specific field on the substrate, given that the master setpoint trajectories of the field and the continuous field have been determined. Note that the setpoint trajectory of the field on the substrate can be considered as a combination of a preparation trajectory and a scan trajectory.

[0079] Figure 9 The process of determining the trajectory of the set point is illustrated in more detail. Figure 9 It schematically shows the relationship with Figure 8 The following is a similar master setpoint trajectory, where: - The movement P(N) corresponds to the preparation trajectory of field N. - The movement S(N) corresponds to the scan trajectory of field N. - The movement P(N+1) corresponds to the preparation trajectory of field N+1. - The movement S(N+1) corresponds to the scan trajectory of field N+1. - The movement P(N+2) corresponds to the preparation trajectory of field N+2, and - The movement S(N+2) corresponds to the scan trajectory of field N+2.

[0080] Given the indicated master setpoint trajectory, the setpoint generator according to the invention can determine the slave setpoint trajectory of field N based on the movement or trajectory P(N), S(N), P(N+1), and S(N+1), that is, the movement of the slave module to be followed when the master module performs movement P(N) and S(N).

[0081] Similarly, the setpoint generator according to the invention can determine the setpoint trajectory of field N+1 based on the movement or trajectory P(N+1), S(N+1), P(N+2) and S(N+2), that is, the movement of the slave module to be followed when the master module performs the movement P(N+1) and S(N+1).

[0082] Once the master setpoint trajectory and slave setpoint trajectory of the field are known, the exposure process of the field can be performed.

[0083] By employing the optimization algorithm applied to the setpoint generator according to the present invention, a more favorable setpoint trajectory for the positioner's slave module can be obtained, resulting in more favorable power consumption or dynamic behavior. (For illustrative purposes only.) Figure 9 A possible setpoint trajectory 900 is further illustrated, which the slave module can follow when executing trajectory P(N)-S(N)-P(N+1)-…-S(N+2). It is assumed that the slave setpoint trajectory starts from the same initial position (Xi, Yi) as the master setpoint trajectory. Note that in the given example, the slave module following setpoint trajectory 900 follows a shorter trajectory. It can also be noted that the slave module also undergoes displacement in the X direction during the scanning of trajectories S(N), S(N+1), and S(N+2).

[0084] By optimizing the trajectory of the slave module of the locator for locating an object, it may become possible for the slave module to cease to be a limiting factor in the locator's performance. As a result, when using the setpoint generator according to the invention, an improvement in the overall performance of the locator can be achieved. Alternatively or additionally, optimization of the trajectory followed by the slave module can create design freedom for the slave module, which can be used, for example, to reduce the rated power required by the module, or to reduce the weight, volume, or cost of the module.

[0085] In embodiments of the invention, optimization algorithms can also be applied to determine the setpoint trajectory of the locator's main module. Typically, optimization algorithms can also be applied if this main module is the only positioning module of the locator. In particular, optimization algorithms have been found to be advantageous for determining the preparation trajectory of exposure processes involving multiple fields or measurement processes involving multiple markers (such as alignment markers).

[0086] In this embodiment, the applied setpoint generator can perform the initial steps of determining the setpoint trajectory of the main module or unique positioning module in a conventional manner, such as generating a table or set of polynomials describing the initial setpoint trajectory as a function of time. In the case of an exposure process, this trajectory may be related to... Figure 8 The trajectories shown are similar. In the case of alignment measurement processes, it may be necessary to determine the positions of multiple alignment marks distributed on the substrate surface. Figure 10a The positions of these multiple alignment marks 1010 on the substrate 1000 are schematically shown. Figure 10bWiring 1020, i.e., the trajectory the substrate is to follow, is schematically illustrated to bring each alignment mark in the alignment markers close to the alignment position measurement tool. The required trajectory to be followed for measuring the positions of multiple alignment marks can be considered to have similar characteristics to the exposure process trajectory. In this respect, it can be noted that the alignment mark position measurement may require keeping the substrate platform moving at a relatively slow speed, or stopping when the alignment mark is within the capture range of the measurement tool. Between measurements of two marks, the platform then accelerates and decelerates to execute the measurement sequence as quickly as possible. Thus, such a trajectory performed between two consecutive measurements of the alignment marks can also be considered a preparation trajectory. Therefore, the alignment measurement process can also be considered as an alternating sequence of preparation and scan trajectories. Those skilled in the art will also understand that the overall power consumption and dynamic excitation caused by the platform will occur primarily during the execution of the preparation trajectory, rather than during the scan trajectory, which typically occurs at low or zero acceleration or deceleration. Therefore, to focus on optimizing the specific behavior of the platform, the preparation trajectory of the process (e.g., the exposure process or the alignment measurement process) can be optimized. - Therefore, in an embodiment, the present invention provides a setpoint generator for a position control system of a positioning module of a locator, wherein the setpoint generator is configured to: determine the initial setpoint trajectory of the positioning module of the locator. - The modified setpoint trajectory of the locator's positioning module is determined by means of an optimization algorithm; the optimization algorithm uses at least a portion of the initial setpoint trajectory, one or more boundary conditions, and an objective function that is related to the performance characteristics of the locator.

[0087] In an embodiment, in a manner similar to that discussed above, the setpoint generator can be configured to determine initial setpoint trajectories and / or modified setpoint trajectories during process execution. In this case, initial setpoint trajectories for multiple fields (e.g., the field to be exposed) or multiple locations requiring access to measure alignment marks can be calculated. Once initial setpoint trajectories for, for example, 5 to 10 fields or locations have been determined, modified setpoint trajectories can be determined based on the initial setpoint trajectories or a portion thereof using an optimization algorithm. Once the modified setpoint trajectories for one or more fields or locations are known, the process can begin; that is, the modified setpoint trajectories can be executed by the positioner. During positioning, the initial setpoint trajectories are then extended to other fields or locations, along with the modified setpoint trajectories, so that the desired setpoint can be provided to the position control system when needed.

[0088] Such a setpoint generator can be applied, for example, in a locator in a photolithography apparatus for positioning a substrate, wherein the locator is configured to displace the substrate in order to perform various processes on the substrate. As mentioned, such processes can include, for example, an exposure process (in which various fields on the substrate are exposed to a patterned radiation beam) or an alignment measurement process (in which the positions of various alignment marks on the substrate need to be determined).

[0089] In this embodiment, the step of determining the trajectory of the initial set point may include: - Obtain the positioner's operating parameters, such as maximum speed, maximum acceleration, or maximum jerk. - Obtain location information of one or more locations or fields on the substrate that the process needs to apply to the substrate; - Based on operating parameters and location information, determine the initial setpoint trajectory of the positioning module.

[0090] In this embodiment, the initial setpoint trajectory can therefore take into account the fundamental limitations of the positioner. According to embodiments of the invention, the initial setpoint trajectory can be further optimized into a modified setpoint trajectory using an optimization algorithm in a manner similar to that discussed above. For the described lithography processes, i.e., exposure and alignment measurement processes, the setpoint trajectory to be followed for each of one or more locations or fields on the substrate typically spans a preparation trajectory and a scan trajectory. Of these two trajectory components, the preparation trajectory is most correlated with positioner performance, such as dynamic behavior or power consumption. Therefore, in embodiments, optimization of the setpoint trajectory is performed only on the preparation trajectory. Thus, in embodiments, the setpoint generator according to the invention is configured to determine, by means of an optimization algorithm, a modified setpoint trajectory of the preparation trajectory of the positioner's positioning module, which determines the modified setpoint trajectory of the preparation trajectory of one or more locations or fields.

[0091] In embodiments of the invention, the trajectory of the positioning module or the setpoint from the module can be considered a substantially continuous function; that is, the displacement required by the module in the XY plane, as a function of time, is called a continuous function. This makes it easier and possible to determine the time derivative of the function. Examples already mentioned above are velocity (first time derivative of position), acceleration (second time derivative of position), jerk (third time derivative of position), and jerk (fourth time derivative of position).

[0092] Therefore, the objective function can also be expressed as a substantially continuous function whose derivative can be determined. This may help optimize the process to achieve the optimal value of the objective function. In particular, in embodiments of the present invention, the optimization process utilizes quadratic programming to achieve the optimal value of the objective function.

[0093] In an embodiment, the setpoint generator according to the invention is applied in a position control system according to the invention, which may be used, for example, to control a positioner having multiple positioning modules.

[0094] In one embodiment, a platform device is provided, comprising a position control system and a positioner according to the invention. In this embodiment, the positioner may, for example, comprise a short-stroke module as a master module and a long-stroke module as a slave module. In this embodiment, the platform device may also include an object stage for holding a substrate, wherein the short-stroke module is configured to position the object stage.

[0095] In one embodiment, the present invention also provides an exposure apparatus comprising a platform device according to the present invention.

[0096] While specific applications of photolithography apparatus in IC manufacturing are discussed in this article, it should be understood that the photolithography apparatus described herein can have other applications. Possible other applications include the fabrication of integrated optical systems, guiding and detecting patterns for magnetic domain memories, flat panel displays, liquid crystal displays (LCDs), thin-film magnetic heads, etc.

[0097] Although embodiments of the invention may be specifically referred to herein in the context of a lithography apparatus, embodiments of the invention can be used in other apparatuses. Embodiments of the invention may form part of a mask inspection apparatus, a measurement apparatus, or any apparatus for measuring or processing objects such as wafers (or other substrates) or masks (or other patterning equipment). These apparatuses may generally be referred to as lithography tools. Such lithography tools may use vacuum conditions or ambient (non-vacuum) conditions.

[0098] Although references to embodiments of the invention may have been made above in the context of optical lithography, it is to be understood that the invention is not limited to optical lithography and may be used in other applications, such as imprint lithography, where the context permits.

[0099] Where the context permits, embodiments of the invention may be implemented using hardware, firmware, software, or any combination thereof. Embodiments of the invention may also be implemented as instructions stored on a machine-readable medium that can be read and executed by one or more processors. A machine-readable medium may include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computing device). For example, a machine-readable medium may include read-only memory (ROM); random access memory (RAM); magnetic storage media; optical storage media; flash memory devices; electrical, optical, acoustic, or other forms of propagation signals (e.g., carrier waves, infrared signals, digital signals, etc.); and others. Further, firmware, software, routines, and instructions may be described herein as performing certain actions. However, it should be understood that this description is merely for convenience, and such actions are in fact produced by a computing device, processor, controller, or other device executing firmware, software, routines, instructions, etc., and doing so enables actuators or other devices to interact with the physical world.

[0100] While specific embodiments of the invention have been described above, it should 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, it will be apparent to those skilled in the art that modifications can be made to the described invention without departing from the scope of the claims set forth below. Other aspects of the invention are set forth in the following numbered clauses: 1. A setpoint generator for a position control system including a master module and a slave module, the master module being configured to cause displacement of an object, the setpoint generator being configured to: - Determine the main setpoint trajectory of the main module; - The setpoint trajectory of the slave module is determined by means of an optimization algorithm; the optimization algorithm uses at least a portion of the master setpoint trajectory, one or more boundary conditions, and an objective function that is related to the performance characteristics of the locator. 2. The setpoint generator according to Clause 1, wherein the performance characteristics of the positioner include the power consumption of the positioner and / or the dynamic characteristics of the positioner. 3. A setpoint generator according to any of the foregoing clauses, wherein the main setpoint trajectory comprises a piecewise polynomial sequence. 4. A setpoint generator according to any of the preceding clauses, wherein the optimization algorithm is configured to determine a setpoint trajectory that minimizes the objective function within one or more boundary conditions. 5. A setpoint generator according to Clause 4, wherein one or more boundary conditions include a threshold for the permissible deviation between the master setpoint trajectory and the slave setpoint trajectory. 6. A setpoint generator according to any one of clauses 4 to 5, wherein the setpoint trajectory is determined by means of quadratic programming. 7. A setpoint generator according to any one of clauses 4 to 6 above, wherein the objective function includes a mathematical expression of the power consumption of the main module as a function of the setpoint trajectory. 8. A setpoint generator according to any one of clauses 4 to 6, wherein the objective function includes a mathematical expression relating to the RMS value of the acceleration of the primary module while following the secondary setpoint trajectory. 9. A setpoint generator according to any one of Clauses 4 to 6, wherein the objective function includes a mathematical expression relating to the RMS value of the dynamic characteristics of the motor of the primary module following the secondary setpoint trajectory, the dynamic characteristics including at least one of velocity, acceleration, jerk, or jerk-jerk. 10. A setpoint generator according to any of the preceding clauses, wherein the object is a substrate, and wherein the displacement of the substrate is part of an exposure process or inspection process of the substrate. 11. The setpoint generator according to Clause 10, wherein determining the master setpoint trajectory includes: - Obtain the positioner's operating parameters, such as maximum speed, maximum acceleration, or maximum jerk. - Obtain location information for one or more fields on a substrate that need to be exposed during the exposure process or inspected during the contact process; - Based on operating parameters and location information, determine the primary setpoint trajectory of one or more fields or a subset thereof. 12. A setpoint generator according to Clause 10 or 11, wherein for each of one or more fields on the substrate, the primary setpoint trajectory spans the preparation trajectory and the scan trajectory. 13. A setpoint generator according to Clause 11 or 12, wherein the setpoint generator is configured to determine the master setpoint trajectory during the exposure process. 14. A setpoint generator according to Clause 13, wherein the setpoint generator is configured to determine a secondary setpoint trajectory for exposure of field N based on the primary setpoint trajectory of exposures of field N and field N+1. 15. A position control system comprising a setpoint generator according to any one of clauses 1 to 14. 16. A platform device including a position control system according to Clause 15, the platform device including a short-stroke module as a master module and a long-stroke module as a slave module. 17. The platform apparatus according to Clause 16 further includes a stage for holding the substrate, wherein the short-stroke module is configured to position the stage. 18. An exposure apparatus comprising a platform device according to Clause 16 or 17. 19. A setpoint generator for a position control system of a positioning module for a positioner, wherein the setpoint generator is configured to: - Determine the initial setpoint trajectory of the positioning module of the locator; - The modified setpoint trajectory of the locator's positioning module is determined by means of an optimization algorithm; the optimization algorithm uses at least a portion of the initial setpoint trajectory, one or more boundary conditions, and an objective function that is related to the performance characteristics of the locator. 20. A setpoint generator according to Clause 19, wherein the object is a substrate, and wherein the displacement of the substrate is part of a process applied to the substrate. 21. The setpoint generator according to Clause 19 or 20, wherein determining the initial setpoint trajectory includes: - Obtain the positioner's operating parameters, such as maximum speed, maximum acceleration, or maximum jerk. - Obtain location information of one or more locations or fields on the substrate that the process needs to apply to the substrate; - Based on operating parameters and location information, determine the initial setpoint trajectory of the positioning module. 22. A setpoint generator according to Clause 21, wherein for each of one or more locations or fields on the substrate, an initial setpoint trajectory spans a preparation trajectory and a scan trajectory. 23. The setpoint generator according to Clause 22, wherein determining the modified setpoint trajectory of the positioning module of the locator by means of an optimization algorithm includes determining the modified setpoint trajectory of a preparation trajectory for one or more locations or fields. 24. A setpoint generator according to Clause 21, wherein the process is an exposure process, alignment measurement, or inspection process. 25. A position control system comprising a setpoint generator according to any one of clauses 19 to 24. 26. A platform device including a position control system according to Clause 25, the platform device including a short-stroke module as a positioning module and a long-stroke module as a slave module.

Claims

1. A setpoint generator for a position control system of a locator, the locator including a master module and a slave module, the locator being configured to cause displacement of an object, the setpoint generator being configured to: Determine the main setpoint trajectory of the main module; The slave module's master setpoint trajectory is determined using an optimization algorithm; the optimization algorithm uses at least a portion of the master setpoint trajectory, one or more boundary conditions, and an objective function that is associated with the performance characteristics of the locator.

2. The setpoint generator according to claim 1, wherein the performance characteristics of the locator include: The power consumption and / or dynamic characteristics of the locator.

3. The setpoint generator according to any one of the preceding claims, wherein the main setpoint trajectory comprises a piecewise polynomial sequence.

4. The setpoint generator according to any one of the preceding claims, wherein the optimization algorithm is configured to: determine, within the one or more boundary conditions, the trajectory from the setpoint that minimizes the objective function.

5. The setpoint generator according to claim 4, wherein the one or more boundary conditions include: The threshold for the allowable deviation between the master setpoint trajectory and the slave setpoint trajectory.

6. The setpoint generator according to any one of claims 4 to 5, wherein the trajectory from the setpoint is determined by means of quadratic programming.

7. The setpoint generator according to any one of claims 4 to 6, wherein the objective function includes a mathematical expression of the power consumption of the main module as a function of the setpoint trajectory.

8. The setpoint generator according to any one of claims 4 to 6, wherein the objective function comprises a mathematical expression associated with the RMS value of the acceleration of the primary module while following the secondary setpoint trajectory.

9. The setpoint generator according to any one of claims 4 to 6, wherein the objective function comprises a mathematical expression associated with the following: the RMS value of the dynamic characteristics of the motor of the main module following the secondary setpoint trajectory, the dynamic characteristics including at least one of velocity, acceleration, jerk, or jerk-jerk.

10. A setpoint generator according to any one of the preceding claims, wherein the object is a substrate, and wherein the displacement of the substrate is part of an exposure process or an inspection process of the substrate.

11. The setpoint generator according to claim 10, wherein determining the main setpoint trajectory includes: Obtain the operating parameters of the positioner, such as maximum speed, maximum acceleration, or maximum jerk. Obtain location information of one or more fields on the substrate that need to be exposed during the exposure process or inspected during the inspection process; Based on the operating parameters and the location information, the primary setpoint trajectory of the one or more fields or a subset thereof is determined.

12. The setpoint generator of claim 10 or 11, wherein for each of the one or more fields on the substrate, the primary setpoint trajectory spans a preparation trajectory and a scan trajectory.

13. A position control system comprising a setpoint generator according to any one of claims 1 to 12.

14. A platform device comprising the position control system according to claim 13, the platform device comprising: The short-stroke module serves as the main module; And a long-stroke module, as the slave module.

15. The platform apparatus of claim 14, further comprising a stage for holding a substrate, the short-stroke module being configured to position the stage.

16. An exposure apparatus comprising the platform apparatus according to claim 14 or 15.

17. A setpoint generator for a position control system of a positioning module of a locator, wherein the setpoint generator is configured to: Determine the initial setpoint trajectory of the positioning module of the locator; The modified setpoint trajectory of the positioning module of the locator is determined by means of an optimization algorithm; the optimization algorithm uses at least a portion of the initial setpoint trajectory, one or more boundary conditions, and an objective function, the objective function being associated with the performance characteristics of the locator.

18. The setpoint generator of claim 17, wherein the object is a substrate, and wherein the displacement of the substrate is part of a process applied to the substrate.

19. The setpoint generator according to claim 17 or 18, wherein determining the initial setpoint trajectory comprises: Obtain the operating parameters of the positioner, such as maximum speed, maximum acceleration, or maximum jerk. To obtain location information of one or more positions or fields on the substrate, which the process needs to be applied to the substrate; Based on the operating parameters and the location information, the initial set point trajectory of the positioning module is determined.

20. A position control system comprising a setpoint generator according to any one of claims 17 to 19.

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