CN113541532A

CN113541532A - Drive system, lithographic apparatus and method of manufacturing an article

Info

Publication number: CN113541532A
Application number: CN202110421529.0A
Authority: CN
Inventors: 北直树
Original assignee: Canon Inc
Current assignee: Canon Inc
Priority date: 2020-04-20
Filing date: 2021-04-20
Publication date: 2021-10-22
Also published as: JP2021175212A; KR20210129597A; JP7490436B2

Abstract

The invention relates to a drive system, a lithographic apparatus and an article manufacturing method. In order to provide a drive system capable of driving with high precision, the drive system is provided with: a motor including a stator and a mover; a position detection unit that detects a relative position between a stator and a mover of the motor; an acquisition unit that acquires reference magnetic flux density information corresponding to the relative position; a measuring unit that measures actual magnetic flux density information corresponding to the relative position; and a control unit configured to set the relative position when the magnitude of the reference magnetic flux density information matches a predetermined set value as a 1 st relative position, set the relative position when the magnitude of the magnetic flux density information measured by the measurement unit matches the predetermined set value as a 2 nd relative position, acquire a difference between the 1 st relative position and the 2 nd relative position a plurality of times while the measured magnetic flux density information changes for one cycle, and control the driving of the motor based on the difference for each of the plurality of times.

Description

Drive system, lithographic apparatus and method of manufacturing an article

Technical Field

The invention relates to a drive system, a lithographic apparatus and an article manufacturing method.

Background

In order to accurately drive the motor, it is necessary to provide a current command value that matches the spatial distribution of the magnetic flux density generated by the mover or the stator. However, an error occurs between the magnetic flux density calculated from the value of the position detection unit referenced by the current command value and the magnetic flux density actually generated by the mover or the stator.

In order to reduce this error, japanese patent No. 3765287 and japanese patent application laid-open No. 2008-178237 disclose a system that calculates a difference between a position where a calculated magnetic flux density becomes zero and a position where a measured magnetic flux density becomes zero, and corrects a value of a position detection unit or a current command value. In japanese patent No. 3765287 and japanese patent application laid-open No. 2008-178237, the value of the position detection unit or the current command value is corrected by measuring the back electromotive force of the motor proportional to the magnetic flux density instead of the magnetic flux density and calculating the position at which the magnetic flux density becomes zero.

Disclosure of Invention

That is, in japanese patent No. 3765287 and japanese patent application laid-open No. 2008-178237, the difference between the position where the calculated magnetic flux density becomes zero and the position where the measured magnetic flux density becomes zero is obtained over the entire drive range or during one period of magnetic flux change, and the value of the position detection unit or the current command value is corrected. However, in the conventional method, since only 1 difference occurs over the entire drive range or during one period of magnetic flux change, the accuracy is low, and even the deviation of the magnetic flux density in one period due to the mounting error of the plurality of magnets cannot be corrected. Therefore, it is not sufficient to be applied to, for example, a lithographic apparatus or the like.

The invention aims to provide a driving system capable of performing position control with high precision.

Means for solving the problems

To achieve the object, a drive system according to one aspect of the present invention includes:

a motor including a stator and a mover;

a position detection unit that detects a relative position between a stator and a mover of the motor;

an acquisition unit that acquires reference magnetic flux density information corresponding to the relative position;

a measuring unit that measures actual magnetic flux density information corresponding to the relative position; and

and a control unit configured to set the relative position when the magnitude of the reference magnetic flux density information matches a predetermined set value as a 1 st relative position, set the relative position when the magnitude of the magnetic flux density information measured by the measurement unit matches the predetermined set value as a 2 nd relative position, acquire a difference between the 1 st relative position and the 2 nd relative position a plurality of times while the measured magnetic flux density information changes for one cycle, and control driving of the motor based on the difference for each of the plurality of times.

ADVANTAGEOUS EFFECTS OF INVENTION

According to one aspect of the present invention, a drive system capable of performing highly accurate position control can be provided.

Drawings

Fig. 1 is a plan view showing a schematic structure of a positioning stage using a linear motor in the embodiment.

Fig. 2 is a structural view of the linear motor in the embodiment.

FIG. 3 is a graph showing the relationship between the arrangement of the origin points of the magnets, coils and position detectors and the magnetic flux density when all the positions are designed values in the example.

Fig. 4 is a diagram illustrating forces received by the mover from the coils 121a to 121c in the embodiment.

Fig. 5 is a diagram illustrating a relationship between an arrangement and a magnetic flux density when the original points of the magnets, the coils, and the position detectors are arranged offset in the example, fig. 5 a is a diagram when the

magnets

114, 119, and the coils 121 are arranged according to design values and only the original points of the position detectors are offset, and fig. 5B is a diagram when the original points of the position detectors are at positions according to design values and the

magnets

114, 119, and the coils 121 are arranged offset due to manufacturing errors, mounting errors, and the like.

Fig. 6 is a control block diagram of the drive system in the present embodiment.

Fig. 7 is a flowchart showing a correction method when the set value is 1 in the embodiment.

Fig. 8 is a graph showing the deviation of the actual magnetic flux density from the ideal magnetic flux density and 1 set value in the embodiment.

Fig. 9 is a flowchart showing a correction method when the set value is plural in the embodiment.

Fig. 10 is a diagram showing a deviation of an actual magnetic flux density from an ideal magnetic flux density and a plurality of set values in the embodiment.

Fig. 11 is a diagram showing an example of a scanning exposure apparatus in the embodiment.

Fig. 12 is a flowchart showing a sequence of the exposure apparatus in the embodiment.

Detailed Description

Hereinafter, preferred embodiments of the drive system according to the present invention will be described in detail with reference to the accompanying drawings and examples. In the drawings, the same components and elements are denoted by the same reference numerals, and redundant description is omitted or simplified.

[ example 1 ]

Fig. 1 is a plan view showing a schematic structure of a positioning stage using a linear motor in the embodiment. In the present embodiment, a stage on which a substrate of a lithography apparatus is mounted will be described as an example. In addition, in the present embodiment, a linear motor including a stator having a plurality of coils and a mover requiring a plurality of permanent magnets is used, but a linear motor including a mover having a plurality of coils and a stator requiring a plurality of permanent magnets may be used. Alternatively, instead of the linear motor, a general rotary type motor may be used.

In fig. 1, a pair of movers 31 is provided on the left and right sides of the mounting table 11 in the driving direction (Y-axis direction). These pair of movers 31 cooperate with the corresponding pair of stators 32 to constitute the linear motor 13A and the linear motor 13B. The structure of the linear motor will be described later.

The stage 11 is provided with a mirror 12, and the displacement amount in the Y-axis direction of the stage 11 or P1[ m ] which is the position is measured by reflecting the measurement light from a laser interferometer (measurement unit) not shown. Further, the

linear motors

13A and 13B are provided with encoders, not shown, to measure displacement amounts or positions P2[ m ] of the stators 32 of the

linear motors

13A and 13B in the Y axis direction.

At this time, C [ m ] as a relative position (hereinafter referred to as commutation position) of the mounting table 11 and the stator 32 is expressed by formula (1).

C＝P1-P2…(1)

Fig. 2 is a structural diagram of the linear motor in the embodiment, and shows a specific structural example of the linear motor 13A and the linear motor 13B.

The mover 31 of fig. 1 includes a magnet array 111A and a magnet array 111B configured as a magnet group including a plurality of permanent magnets. Further, the magnetic yoke 115 and the case 116 are attached to the table surface for holding the magnet array 111A and the magnet array 111B.

The magnet array 111A and the magnet array 111B are composed of a main pole magnet 114 whose magnetic pole is oriented in the Z direction and an auxiliary pole magnet 119 whose magnetic pole is oriented in the Y direction.

The main pole magnets 114 are arranged with their magnetic pole directions being opposite to each other with the auxiliary pole magnets 119 interposed therebetween every 1, and at equal intervals in the Y direction.

The auxiliary pole magnet 119 is disposed in such a direction that the polarity of the portion of the main pole magnet 114 facing the coil 121 is repelled from the auxiliary pole magnet 119.

The stator 32 of fig. 1 has coils 121 in the sheath 122 at equal intervals in the Y direction, and is disposed so as to be sandwiched between the stators 31 from above and below. Here, the relationship expressed by the following formula (2) exists between the pitch MP of the main pole magnet 114 and the pitch CP of the coil 121.

CP＝1.5*MP…(2)

Fig. 3 is a diagram showing the relationship between the arrangement and the magnetic flux density when the

magnets

114 and 119, the coil 121, and the position detector are arranged at their original points all according to the design values in the example. The ideal magnetic flux density is consistent with the actual magnetic flux density according to the design value. The ideal magnetic flux density here is a magnetic flux density determined by the commutation position C obtained from a sensor such as a laser interferometer or an encoder and the pitch MP on the design value of the main pole magnet 114. That is, the magnetic flux density information serving as a reference is a value obtained from the magnet pitch and the relative position of the mover or the stator.

The actual magnetic flux density is the magnetic flux density generated in the coil 121 of the stator 32 by the magnet of the mover 31.

Fig. 4 is a diagram illustrating forces received by the mover from the coils 121a to 121c in the embodiment. That is, the forces received by the mover 31 from the

coils

121a, 121b, and 121c shown in fig. 2 when the mover 31 is moved in the Y-axis direction by applying a constant current in the same direction are shown. In the coil 121a, a force having a sine wave between-2.5 MP and 0.5MP is reduced because only a part of the coil faces the magnet of the mover 13 at positions before and after-2.5 MP or less and at positions before and after 0.5MP or more. The coil 121b has a sinusoidal force at-1 MP to 2MP, and the phase is shifted by 90 degrees from the coil 121 a.

The coil 121c has a sinusoidal force at 0.5MP to 3.5MP, and the phase is shifted by 180 degrees from 121 a. Here, when a current of up to 0.5MP flows through the coil 121a and a current in the opposite direction to the current flows through the coil 121c at 0.5MP or more in the

coils

121a and 121c, a sinusoidal force can be continuously generated. In this case, if the direction of the coil is connected in the opposite direction to that of the

coils

121a and 121c using 1 current driver and a current is passed through only one of the coils using a selection switch according to the positional relationship between the coil and the magnet, the current driver does not have to be prepared for each coil.

Similarly, a sinusoidal force can be continuously generated by flowing current in the coil in alternating directions at intervals of 1MP at intervals of 3 MP. In a completely similar manner, a sinusoidal force can be continuously generated by passing a current in alternating directions through the coil represented by 121b and the coils 1 by 1. Here, the coil group represented by 121a is referred to as an a phase, and the coil group represented by 121B is referred to as a B phase.

The thrust F generated in the mover 31 is the sum of the thrust received from the a phase and the thrust received from the B phase, as shown in equation (3).

F＝L*Ba(C)’*Ia(C)+L*Bb(C)’*Ib(C)…(3)

L is the length of the conductor of the coil, which is the same in all coils.

Ba (c)' is an actual magnetic flux density generated by the magnet of the mover 31 in the a-phase coil of the stator 32, and ia (c) is a current flowing through the a-phase coil of the stator 32. Where bb (c)' is an actual magnetic flux density generated by the magnet of the mover 31 in the B-phase coil of the stator 32, and ib (c) is a current flowing through the B-phase coil of the stator 32. In this case, the ideal magnetic flux densities ba (c) and bb (c) are expressed by the following formulas (4) and (5).

Ba(C)＝B*sin(2×π×C/MP)…(4)

Bb(C)＝B*cos(2×π×C/MP)…(5)

B is the amplitude of the magnetic flux density and C is the commutation position. When the arrangement of the origin points of the

magnets

114 and 119, the coil 121, and the position detector are all designed values, the actual magnetic flux densities ba (c) ', and bb (c)' are equivalent to the ideal magnetic flux densities ba (c), and bb (c).

In order to make the thrust force F generated in the mover 31 constant, the currents ia (c), ib (c) flowing through the phases a and B of the coil 121 may be matched to ideal magnetic flux densities to obtain the equations (6) and (7).

Ia(C)＝I*sin(2×π×C/MP)…(6)

Ib(C)＝I*cos(2×π×C/MP)…(7)

When equations (4), (5), (6) and (7) are substituted into equation (3), the result is

F＝L*B*I*sin(2×π×C/MP)^2+L*B*I*cos(2×π×C/MP)^2

＝L*B*I…(8)

If the

magnets

114 and 119, the coil 121, and the position detector are arranged at their original points all according to the design values, B is constant in the amplitude of the magnetic flux density, and I is constant in the amplitude of the current, so the thrust force F is constant.

Fig. 5 is a diagram showing the relationship between the arrangement of the primary points of the magnet, the coil, and the position detector and the magnetic flux density when the primary points are displaced in the example. Fig. 5 a is a diagram when the

magnets

114 and 119 and the coil 121 are arranged according to design values and only the origin of the position detector is shifted. At this time, a deviation is generated between the ideal magnetic flux density and the actual magnetic flux density. This is because the ideal magnetic flux density calculated from the commutation position C and the pitch MP of the main pole magnet 114 is calculated from the commutation position output from the position detector whose origin is shifted.

Fig. 5B is a diagram when the origin of the position detector is at a position according to the design value and the

magnets

114 and 119 and the coil 121 are displaced due to manufacturing errors, mounting errors, and the like. Depending on the arrangement of the

magnets

114, 119 and the coil 121, the actual magnetic flux density deviates from the ideal magnetic flux density. This is because the pitch MP, which should be constant at an ideal magnetic flux density, differs depending on the position. In a real linear motor, the factors of fig. 5 a and 5B are combined, and a complex offset is generated between the ideal magnetic flux density and the actual magnetic flux density.

Therefore, even if the currents ia (c) and ib (c) are applied to the linear motor 13 so that the thrust force F becomes constant for a desired magnetic flux density, the thrust force generated in the linear motor 13 is not constant because the formula (8) does not hold. In order to make the thrust constant, in the present embodiment, the currents ia (c) and ib (c) are corrected in accordance with the actual magnetic flux density generated by the magnets of the mover 31.

Fig. 6 is a control block diagram of the drive system in the present embodiment. The

linear motors

13A and 13B are each configured by a current driver 42, a changeover switch 43, a back electromotive force acquisition port 48, a commutation position calculator 51, an ideal magnetic flux density calculator 52, an actual magnetic flux density calculator 53, and an offset calculator 54. The commutation position calculator 51, the ideal magnetic flux density calculator 52, the actual magnetic flux density calculator 53, and the offset calculator 54 constitute the processing unit 44.

EEPROM 45, controller 41, and mounting table 11 shown in a dashed line frame are shared by linear motor 13A and linear motor 13B. The control unit 41 incorporates a CPU as a computer, and functions as a control unit that executes various operations of the entire apparatus based on a computer program stored in a memory, not shown.

The commutation position calculator 51 calculates the commutation position C from the formula (1) using the position P1 of the stage 11 obtained by the laser interferometer and the position P2 of the stator 32 obtained by the encoder.

Here, the commutation position calculator 51 functions as a position detection unit that detects the relative position (commutation position) of the stator and the mover of the motor.

The ideal magnetic flux density calculator 52 calculates an ideal (reference) magnetic flux density according to equations (4) and (5). Here, the ideal magnetic flux density calculator 52 functions as an acquisition unit that acquires magnetic flux density information (voltage value corresponding to magnetic flux) serving as a reference corresponding to the relative position.

In addition, the actual magnetic flux density calculator 53 obtains the actual magnetic flux density from the counter electromotive force acquired from the counter electromotive force acquisition port 48. That is, the actual magnetic flux density calculator 53 functions as a measurement unit that measures actual magnetic flux density information (voltage value) corresponding to the relative position.

The offset calculator 54 compares the ideal magnetic flux density with the actual magnetic flux density, and calculates a difference (offset) between the commutation positions when the magnitude of the magnetic flux density becomes the set value H. The Δ C calculated by the offset calculator 54 is stored in a storage medium such as the EEPROM 45 in association with the commutation position.

The control unit 41 corrects the current command value based on the offset amount stored in the EEPROM 45, and sends the command to the current driver 42.

The current driver 42 drives the motor by causing a current having a command value to flow through the linear motor 13. Thereby, the mounting table 11 is driven.

The method of correcting the current command value by the control unit 41 (control means) will be described in detail below. The control unit 41 executes the processing shown in fig. 7 in accordance with a program stored in a memory, not shown.

Fig. 7 is a flowchart showing a correction method when the set value is 1 in the embodiment, and the correction method of the current command value is explained in detail according to the flowchart of fig. 7. In S101, the linear motor 13B is driven at a constant speed v.

In S102, counter electromotive forces va (c) and vb (c) generated in the a-phase and B-phase coils 121 of the linear motor 13A when the linear motor 13B is driven at the constant speed v are measured by connecting the changeover switch 43 of the linear motor 13A to the counter electromotive force acquisition port 48. That is, the measured magnetic flux density information is determined based on the back electromotive force obtained when the mover is operated.

Next, in S103, the actual magnetic flux density calculator 53 calculates the actual magnetic flux densities ba (c) 'and bb (c)', based on the measured back electromotive force.

Here, a method of calculating an actual magnetic flux density will be described. The counter electromotive forces va (c) and vb (c) when the mover 31 is operated are expressed by the following equations.

Va(C)＝v*Ba(C)’*L…(9)

Vb(C)＝v*Bb(C)’*L…(10)

At this time, if the mover 31 is operated at a constant speed v and L is the length of the conductor and is the same for all the coils, the counter electromotive forces va (c) and vb (c) are proportional to the actual magnetic flux densities ba (c) 'and bb (c)'. Therefore, the back electromotive forces va (c) and vb (c) obtained previously can be regarded as the actual magnetic flux densities ba (c) and bb (c) of the linear motor 13A.

In S104, the ideal magnetic flux density calculator 52 calculates the ideal magnetic flux density using the commutation position calculated by the commutation position calculator 51 and the pitch MP of the main pole magnets 114.

In S105, the actual magnetic flux density and the ideal magnetic flux density are normalized. That is, the relative position difference is obtained in a state where the amplitudes are aligned. Since the actual magnetic flux densities Ba (c) 'and Bb (c)' are equivalent to the back electromotive forces va (c) and vb (c), the normalized actual magnetic flux densities Ba _ nor (c) 'and Bb _ nor (c)' can be obtained by dividing Ba (c) 'and Bb (c)' by the amplitude V of the back electromotive force. Similarly, the normalized ideal magnetic flux densities Ba _ nor (c) and Bb _ nor (c) can be obtained by dividing the ideal magnetic flux densities Ba (c) and Bb (c) obtained in S104 by the amplitude B.

The normalization is performed to match the amplitudes when calculating the offset amounts between the ideal magnetic flux densities ba (c) and bb (c) and the actual magnetic flux densities ba (c) 'and bb (c)', and thus the offset amounts can be calculated by using arbitrary set values in-1 to 1 of fig. 8.

In S106, the offset amount is calculated using the normalized actual magnetic flux density Ba _ nor (c)' obtained previously and the normalized ideal magnetic flux density Ba _ nor (c).

As shown in FIG. 8, an arbitrary predetermined set value H is set within the range of-1 to 1, and the 1 st commutation position and the 2 nd commutation position are determined from the actual magnetic flux density Ba _ nor (C)' and the intersection of the ideal magnetic flux density Ba _ nor (C) and the set value H. Here, the set value H is a predetermined set value within the amplitude of the reference magnetic flux density information and the measured magnetic flux density information.

The 1 st commutation position and the 2 nd commutation position can be obtained in a plurality of periods during which the magnetic flux changes for one cycle.

The 1 st commutation position (1 st relative position) as the intersection of H and Ba _ nor (C) is C1, C2, C3, …, and the 2 nd commutation position (2 nd relative position) as the intersection of H and Ba _ nor (C) 'is C1', C2 ', C3', …. That is, the control means sets the relative position when the magnitude of the magnetic flux density information (voltage) serving as the reference coincides with a predetermined set value as the 1 st relative position, and sets the relative position when the magnitude of the magnetic flux density information measured by the measuring means coincides with the predetermined set value as the 2 nd relative position.

The commutation positions closest to the commutation position as in C1 and C1' are 1 pair.

ΔC1＝C1-C1’…(11)

The offset amount Δ C is calculated using each pair as in the above equation (11).

In S107, as shown in fig. 8, INT1 is set as the interval between the 2 nd commutation position C1 'and the next 2 nd commutation position C2', and the calculated shift amount Δ C1 is stored in a storage medium such as an EEPROM 45 in association with INT 1.

Similarly, INT2 is defined as the interval between the 2 nd commutation position C2 'and the next 2 nd commutation position C3', and the calculated shift amount Δ C2 is stored in association with INT 2. These actions are performed with all offsets. That is, the difference (offset amount Δ C) between the 1 st relative position and the 2 nd relative position is acquired and stored a plurality of times while the measured magnetic flux density information changes by one cycle.

In S108, it is confirmed that the offset amount has been calculated in the linear motor 13B. In a case where this is not done, in S109, the linear motor 13A is driven at the constant speed v this time. Thereafter, S102 to S108 are performed, and the process ends. Thereby, both the offset amount data of the linear motor 13A and the offset amount of the linear motor 13B are obtained.

As described above, the present embodiment is characterized in that the motor 13A and the other motor 13B are provided, and the control unit drives the other motor 13B to measure the counter electromotive force of the motor 13A. Further, by driving the motor 13A, the counter electromotive force of the other motor 13B is measured. Further, the present invention is characterized in that the stage (target object) can be moved in the same direction by driving both motors simultaneously.

Next, a method of correcting the current command value using these offsets will be described. At the commutation position in the section INT1, Δ C1 is substituted into Δ C in the following equations (12) and (13) to correct the current command value. Similarly, the current command value is corrected by substituting Δ C2 into Δ C in equations (12) and (13) at the commutation position in the section INT 2. That is, the control unit controls the drive current of the motor according to the difference at each of the plurality of times.

Ia(C)＝I*sin(2×π×(C-ΔC)/MP)…(12)

Ib(C)＝I*cos(2×π×(C-ΔC)/MP)…(13)

By thus finely correcting the current command value by adding the offset amounts associated with the sections including the commutation position at each commutation position, the fluctuation of the offset amount within 1 cycle can be finely corrected.

That is, the ideal magnetic flux density curve shown in B of fig. 5 can be matched with the actual magnetic flux density curve with high accuracy. Further, the section up to the calculation of the first offset amount is corrected using Δ C1 as the first offset amount.

The current driver 42 drives the motor by causing the current of the corrected command value to flow through the linear motor 13. This drives the mounting table 11 with high accuracy.

In the above description, a linear motor using a coil for the stator and a permanent magnet for the mover is used, but the configuration may be reversed.

[ example 2 ]

Fig. 9 is a flowchart showing a correction method in the case where a plurality of setting values are set in the embodiment, and the processing in the case where more detailed correction is performed will be described with reference to fig. 9.

S201 to S205 are the same as the processing of S101 to S105, so the description is omitted.

In S206, as shown in fig. 10, the number of setting values H of 1 in example 1 is set in plural. Fig. 10 is a diagram showing a deviation of an actual magnetic flux density from an ideal magnetic flux density and a plurality of set values in the embodiment.

In the present embodiment, the set value H is set to H1 and H2 from top to bottom. In S207, the offset amount is calculated using the setting value set in S206 in the same manner as in S106.

In S208, it is determined whether or not S207 has been performed using all the setting values set in S206, and if not, S207 is repeated using the next setting value H. When the number of offset amounts that can be calculated using 1 set value is N _ sh and the number of set values is N _ st, all of the N _ sh × N _ st offset amounts can be obtained.

In S209, the calculated Δ C is rearranged in order of the 2 nd commutation position C from small to large. Then, in S210, as shown in fig. 10, the section between the 2 nd commutation position C1 'and C2' which is the next 2 nd commutation position in the rearrangement order in S209 is set to INT 1. Then, the calculated shift amount Δ C1 is stored in a storage medium such as an EEPROM 45 in association with INT 1.

Similarly, INT2 is the section between the 2 nd commutation position C2 'and C5' which becomes the next 2 nd commutation position in the rearrangement sequence in S209, and the calculated shift amount Δ C2 is stored in association with INT 2.

These actions are performed with all offsets. In S211, it is confirmed that the offset amount has been calculated in the linear motor 13B. If not, the linear motor 13A is driven at a constant speed v in S212. Thereafter, S202 to S211 are performed, and the process ends. Thereby, both the offset amount data of the linear motor 13A and the offset amount of the linear motor 13B are obtained.

As for the correction, the correction is performed at each commutation position using the offset amount associated with the section to which the commutation position belongs, as in embodiment 1. This makes it possible to divide the correction into more detailed sections and perform the correction, and therefore, more accurate correction can be performed in sequence.

In the description, a linear motor using a coil for a stator and a permanent magnet for a mover is used, but the configuration may be reversed.

The offset amount obtained in the present embodiment can be used not only to correct the current command value (drive current), but also to correct the timing of switching the coil. As described above, the linear motor is driven by the coil that controls the flow of current. When switching the coils, it is desirable to switch in such a manner that the current observed in the entire phase becomes smooth.

The switching timing is determined according to the design value of the coil, but as shown in B of fig. 5, the

magnets

114 and 119 and the coil 121 are shifted due to manufacturing errors, mounting errors, and the like. When switching is performed at the commutation position of T1, which is the switching timing based on the design value, the corrected current command value cannot be smoothed. Therefore, by correcting the switching timing T1 using the offset amount obtained in the present embodiment and setting it to T2, the current can be switched smoothly.

Next, an example will be described in which a driving system that performs correction in consideration of the offset within one cycle of the magnetic flux density is applied to the scanning exposure apparatus 600.

Fig. 11 is a diagram showing an example of a scanning exposure apparatus in the embodiment, and the scanning exposure apparatus 600 is a step-and-scan (step-and-scan) type exposure apparatus that performs scanning exposure on the substrate 14 by using slit light shaped by a slit. The scanning exposure apparatus 600 includes an illumination optical system 23, an original plate mounting table 26, a projection optical system 27, a substrate mounting table 15, an original plate mounting table position measuring unit 17, a substrate mounting table position measuring unit 18, a substrate mark measuring unit 21, a substrate transfer unit 22, and a control unit 24.

The substrate mounting table 15 is a table that moves to hold a substrate, and is driven by the driving system of the embodiment.

The control unit 24 controls the illumination optical system 23, the original plate mounting table 26, the projection optical system 27, the substrate mounting table 15, the original plate mounting table position measuring unit 17, the substrate mounting table position measuring unit 18, the substrate mark measuring unit 21, and the substrate transfer unit 22.

The control unit 24 controls a process of transferring the pattern formed on the original plate to the substrate 14 (a process of scanning and exposing the substrate 14).

The control unit 24 is configured by, for example, a PLD (Programmable Logic Device) such as an FPGA (Field Programmable Gate Array).

Alternatively, the communication apparatus may be constituted by an ASIC (Application Specific Integrated Circuit), a general-purpose computer in which a program is embedded, or a combination of all or a part of them. In addition, the control section 24 includes a driver for controlling the actuator.

The illumination optical system 23 illuminates the original plate 25. The illumination optical system 23 shapes light emitted from a light source (not shown) into slit light having a long strip shape or an arc shape in the X direction, for example, by a light shielding member such as a masking blade (not shown), and illuminates a part of the original plate 25 with the slit light. The original plate 25 and the substrate 14 are held by the original plate stage 26 and the substrate stage 15, respectively, and are arranged at positions (an object plane and an image plane of the projection optical system 27) substantially optically conjugate with each other with the projection optical system 27 interposed therebetween.

The projection optical system 27 has a predetermined projection magnification (for example, 1/2 times or 1/4 times), and projects the pattern of the original plate 25 onto the substrate 14 by slit light. The area on the substrate 14 (the area to which the slit light is irradiated) on which the pattern of the original plate 25 is projected is referred to as an irradiation area. The original plate mounting table 26 and the substrate mounting table 15 are configured to be movable in a direction (Y direction) orthogonal to the optical axis direction (Z direction) of the projection optical system 27. The original plate mounting table 26 and the substrate mounting table 15 are relatively scanned at a speed ratio corresponding to the projection magnification of the projection optical system 27 while being synchronized with each other.

Thereby, the substrate 14 is scanned in the Y direction with respect to the irradiation region, and the pattern formed on the original plate 25 is transferred to shot (shot) regions on the substrate 14. Then, the scanning exposure is sequentially performed for each of the plurality of shot regions of the substrate 14 while moving the substrate mounting table 15, and the exposure process for 1 substrate 14 is completed.

The original plate stage position measuring unit 17 includes, for example, a laser interferometer, and measures the position of the original plate stage 26. The laser interferometer irradiates a laser beam toward a reflection plate (not shown) provided on the original plate mounting table 26, for example, and detects a displacement (a displacement from a reference position) of the original plate mounting table 26 by interference between the laser beam reflected by the reflection plate and the laser beam reflected by the reference surface.

The original plate stage position measuring unit 17 can acquire the current position of the original plate stage 26 from the displacement. Here, the original plate stage position measuring unit 17 measures the position of the original plate stage 26 by a laser interferometer using a laser beam, but the present invention is not limited thereto, and the position of the original plate stage 26 may be measured by an encoder, for example.

The substrate stage position measuring unit 18 includes, for example, a laser interferometer, and measures the position of the substrate stage 15. The laser interferometer irradiates a laser beam toward a reflecting plate (not shown) provided on the substrate mounting table 15, for example, and detects a displacement (displacement from a reference position) of the substrate mounting table 15 by interference between the laser beam reflected by the reflecting plate and the laser beam reflected by the reference surface. The substrate stage position measuring unit 18 can acquire the current position of the substrate stage 15 from the displacement.

Here, the substrate mounting table position measuring unit 18 measures the position of the substrate mounting table 15 by a laser interferometer using a laser beam, but the present invention is not limited thereto, and the position of the substrate mounting table 15 may be measured by an encoder, for example.

The substrate mark measuring section 21 includes, for example, an imaging element, and is capable of detecting the position of a mark provided on a substrate.

Here, the substrate mark measuring section 21 of the present embodiment detects the mark by the imaging element, but is not limited thereto, and for example, the mark may be detected by a transmission type sensor.

The substrate transfer unit 22 supplies and collects the substrate on the substrate mounting table 15.

A sequence of printing a pattern of an original plate of an exposure apparatus on a substrate will be described with reference to the flowchart of fig. 12. Fig. 12 is a flowchart showing a sequence of the exposure apparatus in the embodiment.

In step S700, an exposure sequence is started, and in step S701, the substrate transfer unit 22 supplies (loads) the substrate (wafer) 14 onto the substrate mounting table 15. Next, in step S702, the substrate mounting table 15 is driven so that the mark on the substrate 14 defined in the exposure recipe enters the measurement field of the substrate mark measuring section 21, and alignment of the substrate is performed.

Thereafter, in step S703, the original plate stage 26 and the substrate stage 15 are synchronized to perform scanning driving, and the pattern of the original plate is sequentially exposed on the substrate 14 by the projection optical system 27.

At this time, the exposure sequence, exposure viewing angle, are defined in the exposure recipe. Finally, in step S704, the substrate transfer unit 22 recovers (unloads) the substrate 14 from the substrate mounting table. This completes the process of exposing the pattern on the substrate.

Next, a case where the configuration of embodiment 1 is applied to the control of the substrate mounting table 15 of embodiment 2 will be described. The control section 41 in fig. 6 corresponds to the control section 24, the current driver 42 corresponds to the control section 24, the processing section 44 corresponds to the control section 24, the EEPROM 45 corresponds to the control section 24, the linear motor 13 corresponds to the substrate mounting table 15, and the mounting table 11 corresponds to the substrate mounting table 15.

By applying a drive system that takes into account the shift in the magnetic flux density within one cycle to the substrate mounting table 15, the thrust force of the mounting table can be made nearly constant, and therefore the accuracy of the exposure apparatus can be improved.

In addition, when the method is applied to the substrate mounting table 15 of the scanning exposure apparatus, any one of the application method of setting 1 set value as in embodiment 1 and the application method of setting a plurality of set values as in embodiment 2 can be applied.

The flow of saving the offset amount shown in fig. 7 and 9 is performed before the exposure operation shown in fig. 12 is performed. Then, the substrate mounting table 15 is driven using the offset amount stored in advance while applying the correction method of the current command value as described in embodiment 1 or embodiment 2.

In this way, when the substrate mounting table 15 is controlled, the driving system that stores a plurality of offset amounts and corrects the current command value using the offset amounts is applied, so that the effect that the exposure can be performed with high accuracy in the exposure sequence of S703 is obtained.

In addition, when the control of embodiment 1 or embodiment 2 is applied to the position control of the original plate mounting table 26, the control unit 41, the current driver 42, the processing unit 44, the EEPROM 45, and the like in fig. 6 are included in the control unit 24. The linear motor 13 corresponds to a motor for driving the original plate mounting table 26, and the mounting table 11 corresponds to the original plate mounting table 26.

The present embodiment can be applied to the original plate mounting table 26 that holds the original plate, as in the case of being applied to the substrate mounting table 15, and can store the offset amount and correct the current command value with high accuracy even when applied to the original plate mounting table 26.

That is, the original plate mounting table 26 also has the effect of being able to perform exposure with high accuracy in the exposure sequence of S703 by storing a plurality of offset amounts and correcting the current command value using them, as in the substrate mounting table 15.

Next, a method for manufacturing an article (semiconductor IC device, liquid crystal display device, MEMS, etc.) using the exposure apparatus will be described.

The article is manufactured, for example, by a process of exposing a substrate (wafer, glass substrate, or the like) coated with a photosensitive agent using the exposure apparatus, a process of developing the substrate (photosensitive agent), and a process of post-treating the developed substrate in a post-treatment process.

Alternatively, the imprint apparatus is manufactured by performing a post-processing step (a step of manufacturing an article from an imprinted substrate) using a mold as an original plate through a step of imprinting a substrate coated with an imprint material and a step of releasing the mold.

The post-processing steps include etching, resist stripping, dicing, bonding, and packaging.

According to the article manufacturing method of the present invention, since the position can be controlled with high accuracy, articles with higher quality than the conventional article can be manufactured.

The preferred embodiments of the present invention have been described above, but the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the gist thereof.

For example, although the stage control apparatus and the exposure apparatus have been described in the embodiments, the present invention can be applied to other lithography apparatuses.

For example, the lithography apparatus may be a flattening apparatus that shapes a substrate assembly by using a mold (flat template) having a flat surface portion without an uneven pattern so as to flatten the substrate assembly.

In addition, as another example of the lithography apparatus, a drawing apparatus or the like may be used which draws a pattern on a substrate by using a charged particle beam (an electron beam, an ion beam, or the like) through a charged particle optical system.

Further, a part or all of the control in the present embodiment may be realized by supplying a computer program that realizes the functions of the above-described embodiments to the drive system via a network or various storage media. The program may be read and executed by a computer (or a CPU, MPU, or the like) in the drive system. In this case, the program and the storage medium storing the program constitute the present invention.

The present application claims priority to Japanese patent application No. 2020-.

Claims

1. A drive system, comprising:

a motor including a stator and a mover;

2. The drive system of claim 1,

the stator includes a plurality of coils, and the mover includes a plurality of permanent magnets.

3. The drive system of claim 1,

the stator includes a plurality of permanent magnets, and the mover includes a plurality of coils.

4. The drive system according to any one of claims 1 to 3,

the reference magnetic flux density information is a value obtained from the magnet pitch and the relative position of the mover or the stator.

5. The drive system of claim 1,

the measured magnetic flux density information is determined based on the back electromotive force obtained when the mover is operated.

6. The drive system of claim 5,

the driving system further includes another motor for moving the mover, and the control unit moves a predetermined object in the same direction by driving the motor and the another motor at the same time.

7. The drive system of claim 6,

the control unit measures magnetic flux density information of the other motor based on a counter electromotive force obtained when the motor operates the mover of the other motor by driving the motor.

8. The drive system of claim 1,

the magnetic flux density information is a voltage value corresponding to a magnetic flux.

9. The drive system of claim 1,

the predetermined set value is a predetermined set value within the amplitude of the reference magnetic flux density information and the measured magnetic flux density information, which include 0.

10. The drive system of claim 1,

the control means acquires the difference in a state where the reference magnetic flux density information and the measured magnetic flux density information are aligned in amplitude.

11. The drive system of claim 1,

the setting value is set in plural, and the difference is obtained for each setting value.

12. The drive system of claim 1,

the control unit controls a drive current of the motor according to a difference at each of the plurality of times.

13. The drive system of claim 1,

the control unit controls a switching timing of the coil of the motor according to a difference of each of the plurality of times.

14. A lithographic apparatus for forming a pattern of a master on a substrate, comprising:

a stage for holding the substrate; and

a drive system for driving the placing table,

the drive system is provided with:

a motor including a stator and a mover;

15. A lithographic apparatus for forming a pattern of a master on a substrate, comprising:

a stage for holding the original plate; and

a drive system for driving the loading table holding the original plate,

the drive system is provided with:

a motor including a stator and a mover;

16. A method of manufacturing an article, in which a pattern of a master is formed on a substrate using a lithographic apparatus, the method comprising,

the lithographic apparatus has:

a substrate mounting table for holding the substrate;

a master plate mounting table for holding the master plate; and

a drive system for driving the substrate mounting table or the original plate mounting table,

the drive system is provided with:

a motor including a stator and a mover;

control means for setting the relative position when the magnitude of the reference magnetic flux density information coincides with a predetermined set value as a 1 st relative position, setting the relative position when the magnitude of the magnetic flux density information measured by the measurement means coincides with the predetermined set value as a 2 nd relative position, acquiring a difference between the 1 st relative position and the 2 nd relative position a plurality of times during a period in which the measured magnetic flux density information changes by one cycle, and controlling the driving of the motor based on the difference for each of the plurality of times,

the method for manufacturing the article comprises:

forming a pattern of the original plate on the substrate using the lithography apparatus; and

and a step of manufacturing an article from the substrate according to the pattern formed on the substrate.