Stage apparatus, pattern forming apparatus, and method for manufacturing article

Abstract

To provide a stage device that can prevent a reduction in positioning accuracy while maintaining an improvement in throughput.SOLUTION: A stage device according to the present invention comprises: a stage; a driving unit that drives the stage; first and second amplifiers that output output signals obtained by amplifying input signals through pulse width modulation control and linear control, respectively; a switcher that turns on or off first and second connections between the first and second amplifiers and the driving unit; and a control unit that calculates the input signals from a command value for driving the stage and outputs the signals to the first and second amplifiers. The control unit determines a switching condition for the switcher based on parameters of the stage and the driving unit and the command value so that an output voltage of the second amplifier falls within the maximum output voltage, and controls the switcher based on the determined switching condition.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a stage apparatus, a pattern forming apparatus, and a method for manufacturing an article. [Background technology]

[0002] In a stage device used in a pattern forming apparatus, improvements in both throughput and positioning accuracy are required. Patent Document 1 discloses a stage device that improves throughput by applying a large thrust using a large current from a PWM amplifier during non-exposure periods, and improves positioning accuracy by applying a stable thrust using a high-quality current from a linear amplifier during exposure periods. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-128488 Summary of the Invention [Problem to be solved by the invention]

[0004] The stage device disclosed in Patent Document 1 is provided with a selector that selects to use a PWM amplifier when the output current is equal to or greater than a predetermined value, and selects to use a linear amplifier when the output current is less than the predetermined value. In this case, if a motor, which is an inductive load, is used as the stage driver, the phase of the load current waveform and the phase of the load voltage waveform will shift depending on the frequency of the command value. As a result, depending on the current command value, the output current may exceed the maximum output voltage of the linear amplifier even if it is less than a predetermined value, which may result in a decrease in positioning accuracy. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a stage device that can suppress a decrease in positioning accuracy while maintaining an improvement in throughput. [Means for solving the problem]

[0005] The stage device according to the present invention comprises a stage and a stage driving device. motor for and the output signal obtained by amplifying the input signal using pulse width modulation control. motor and a first amplifier that amplifies the input signal by linear control and outputs the resulting output signal. motor a second amplifier outputting to motor a stage apparatus including a switcher that switches between a first amplifier and a second amplifier as an amplifier that outputs to a first input signal, and a control unit that controls the switcher, motor The switch is controlled so that the output voltage of the second amplifier is equal to or lower than the maximum output voltage, using a switching condition based on the parameters and a command value for driving the stage. The parameters include the resistance value, inductance value, and thrust constant of the motor, and the mass of the stage. It is characterized by: [Effects of the Invention]

[0006] According to the present invention, it is possible to provide a stage device that can suppress a decrease in positioning accuracy while maintaining an improvement in throughput. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 2 is a block diagram of a position control system and a speed control system provided in the stage device according to the first embodiment. [Figure 2] 10 is a flowchart showing a switching condition determination process in the stage device according to the first embodiment. [Figure 3] 3A to 3C are diagrams showing command waveforms, a block diagram, load current waveforms, and load voltage waveforms used in the switching condition determination process; [Figure 4] FIG. 10 is a block diagram of a position control system provided in a stage apparatus according to a second embodiment. [Figure 5] 3A and 3B are partially enlarged block diagrams of a position control system provided in the stage device and diagrams showing how switches are switched. [Figure 6]FIG. 10 is a diagram showing how a switch is switched in a position control system provided in a stage apparatus according to the second embodiment. [Figure 7] FIG. 11 is a block diagram of a position control system provided in a stage apparatus according to a third embodiment. [Figure 8] 10 is a flowchart showing a switching condition determination process in a stage apparatus according to a third embodiment. [Figure 9] 10A and 10B are diagrams showing load current waveforms, load voltage waveforms, and a switching condition table for determining switching conditions in a stage device according to a third embodiment. [Figure 10] FIG. 1 is a diagram showing the configuration of an exposure apparatus equipped with a stage apparatus according to the present embodiment. [Figure 11] 1A and 1B are a block diagram of a control system provided in a conventional stage device and diagrams showing examples of position waveforms, velocity waveforms, and acceleration waveforms. [Figure 12] 1A and 1B are a block diagram of a motor driver provided in a conventional stage device and diagrams showing examples of motor current waveforms and motor voltage waveforms. DETAILED DESCRIPTION OF THE INVENTION

[0008] The stage device according to this embodiment will be described in detail below with reference to the accompanying drawings. Note that the drawings shown below are drawn at a different scale than the actual scale in order to facilitate understanding of this embodiment.

[0009] The stage device according to this embodiment uses a motor driver that combines a PWM (Pulse Width Modulation) amplifier that can efficiently pass a large current and a linear amplifier that can pass a high-quality current with little distortion.

[0010] In a stage device used in a semiconductor exposure apparatus, improvements in both throughput and positioning accuracy are required. To improve both of these, a stage device has been proposed that is equipped with a motor driver that combines a PWM amplifier that amplifies and outputs an input signal using pulse width modulation control, and a linear amplifier that amplifies and outputs an input signal using linear control.

[0011] FIG. 11(a) shows a block diagram of a control system provided in a conventional stage device. FIG. 11(b) shows an example of a position waveform, a velocity waveform, and an acceleration waveform included in the drive command value 101 used in a conventional stage device.

[0012] In the conventional stage device shown in FIG. 11(a), position control is performed by inputting the difference between the position command included in the drive command value 101 and the stage position detected by a stage position detection means (not shown) into a position controller 102. Then, the position controller 102 outputs a current command value for the motor driver, and the difference between the output current command value and the motor current value detected by a current detection means (not shown) is input to the current controller 103 and processed for calculation, thereby performing constant current control.

[0013] Next, the current output from the current controller 103 is input to both the PWM amplifier 104 and the linear amplifier 105 . The output current from one of the PWM amplifier 104 and the linear amplifier 105 selected by a switch serving as a switching means 106 is input to a motor 107, and the motor 107, which is controlled to a constant current, drives a stage 108, thereby performing position control.

[0014] Here, the PWM amplifier 104 can pass a large current with high efficiency by controlling the switching of a FET (Field Effect Transistor) or the like at high speed. However, it is known that the PWM amplifier 104 generates ripple noise and nonlinear distortion due to switching.

[0015] On the other hand, the linear amplifier 105 has low efficiency because a large amount of heat is generated by the bias current generated in the output stage of the transistor, but it can pass a high-quality current with little distortion.

[0016] In a stage device used in an exposure apparatus, the stage is controlled by using a drive command waveform such as that shown in FIG. 11(b). For example, when performing exposure between positions C and D while moving the stage from a predetermined position A to position B, the stage is first accelerated by applying a positive acceleration that changes in a trapezoidal shape, and the stage is accelerated and moved to position C between times t0 and t'.

[0017] After that, the acceleration is set to 0, and the stage is moved at a constant velocity to position D between time t' and t''. Then, by applying an inverted trapezoidal negative acceleration to decelerate the stage, the stage is decelerated and moved to position B between time t'' and t1.

[0018] Here, in order to improve throughput, it is necessary to drive the stage 108 at high acceleration by passing a large current through the motor 107 during the acceleration period between times t0 and t' and the deceleration period between times t'' and t1. On the other hand, in order to perform high-precision exposure by controlling the movement speed of the stage 108 with high precision during the constant speed section between times t' and t'', it is required to pass a high-quality current with little distortion through the motor driver.

[0019] Therefore, in the stage device used in the exposure apparatus, drive control is performed using the PWM amplifier 104 during acceleration / deceleration sections where a large current is required, while drive control is switched to the linear amplifier 105 during constant speed sections and stop sections after time t1. This makes it possible to achieve an improvement in throughput and an improvement in positioning accuracy due to the increased acceleration.

[0020] In the conventional stage device shown in FIG. 11(a), a comparator 109 compares a current command value to the current controller 103 with a preset switching current setting value 110. This controls a switch as a switching means 106 for switching between the PWM amplifier 104 and the linear amplifier 105.

[0021] FIG. 12(a) shows a block diagram of a motor driver provided in a conventional stage device. 12(b) and 12(c) show examples of a motor current waveform I(R) and a motor voltage waveform V(vtg) when constant current driving is performed by a motor driver provided in a conventional stage device.

[0022] In the motor driver shown in FIG. 12(a), constant current control is performed by a current controller 103 calculating the difference between a current command value 111 and the motor current detected by a current detection means (not shown). Here, the maximum output voltage of the PWM amplifier 104 is ±200V, the maximum output voltage of the linear amplifier 105 is ±40V, and the switching current setting value 110 is ±1A.

[0023] The current command value 111 is compared with a switching current set value 110 by a comparator 109 . If the current command value 111 is a small current less than ±1 A, which is the switching current setting value 110, the linear amplifier 105 is selected by switching the switch as the switching means . On the other hand, when the current command value 111 is a large current equal to or greater than ±1 A, which is the switching current setting value 110, the PWM amplifier 104 is selected by switching the switch as the switching means .

[0024] Here, the motor 107 is an inductive load made of a wound coil, and can be equivalently represented by an RL circuit consisting of a resistance value R and an inductance value L, where R=13Ω and L=28 mH as an example.

[0025] Examples of the motor current waveform I(R) and motor voltage waveform V(vtg) when such a motor 107 is driven at a constant current are shown in FIGS. 12(b) and (c). Here, Figure 12(b) shows the case where a current command value 111 with a frequency of 30 Hz and an amplitude of ±5 A is input, and Figure 12(c) shows the case where a current command value 111 with a frequency of 50 Hz and an amplitude of ±5 A is input. As described above, since the motor 107 is an inductive load, the phase of the motor current waveform I(R) and the phase of the motor voltage waveform V(vtg) shift from each other depending on the frequency of the current command value 111.

[0026] In the example shown in FIG. 12(b), even if the PWM amplifier 104 is switched to the linear amplifier 105 when the current command value 111 is ±1 A, the motor voltage remains within the maximum output voltage of the linear amplifier 105, ±40 V, as shown by the white circle. Therefore, switching between the PWM amplifier 104 and the linear amplifier 105 can be performed smoothly.

[0027] However, in the example shown in Figure 12(c), when switching from the PWM amplifier 104 to the linear amplifier 105 occurs when the current command value 111 is ±1 A, the motor voltage may exceed the maximum output voltage of the linear amplifier 105, ±40 V, as shown by the black circle. Therefore, switching between the PWM amplifier 104 and the linear amplifier 105 cannot be performed appropriately.

[0028] In this way, in the conventional method of switching amplifiers by comparing the current command value to the motor driver with a preset switching current setting value, depending on the switching current setting value, there is a possibility that the maximum output voltage of the linear amplifier will be exceeded when switching the amplifier. In this case, there is a risk that current fluctuations will occur in the motor driver, which may reduce the control accuracy of the stage.

[0029] Therefore, in order to solve the above problems, the stage device according to this embodiment employs the following configuration. Specifically, the stage device according to this embodiment is provided with a calculation unit that determines in advance the conditions for switching between the PWM amplifier and the linear amplifier by referencing the motor parameters and drive command values. The motor parameters include the resistance value, inductance value, thrust constant, and payload of the motor.

[0030] The calculation unit then generates a velocity waveform and an acceleration waveform by, for example, differentiating the position command value included in the drive command value. Next, a load current waveform is generated by referencing the values ​​of the motor's transportable mass and thrust constant, and the generated load current waveform is then input into a load model calculated from the motor's resistance and inductance values ​​to calculate the load voltage waveform.

[0031] Then, the load voltage waveform is corrected by determining the back electromotive force with reference to the velocity waveform and the thrust constant of the motor. Finally, by referring to the load current waveform and the corrected load voltage waveform, a switching condition setting value is determined such that the motor voltage falls within the maximum output voltage of the linear amplifier when switching between the PWM amplifier and the linear amplifier. Then, based on the determined switching condition setting value, a switching means for switching between the PWM amplifier and the linear amplifier is controlled.

[0032] In this way, in the stage device according to this embodiment, the optimum switching conditions between the PWM amplifier and the linear amplifier are calculated in accordance with the drive command value. This makes it possible to reduce the current fluctuations that occur when switching between the PWM amplifier and the linear amplifier, thereby achieving the effects of suppressing vibrations in the stage device and improving control precision.

[0033] [First embodiment] 1(a) and 1(b) are block diagrams of a position control system and a speed control system, respectively, used in a stage device according to the first embodiment. In the stage device according to this embodiment, the stage is controlled by using either a position control system or a speed control system.

[0034] 1(a), in the position control system provided in the stage device according to this embodiment, the difference between the position command value included in the drive command value 1 (command value) and the value indicating the stage position detected by a stage position detection means (not shown) is input to a position controller 2. In this way, position control is performed. Here, as the stage position detection means, an encoder, a laser interferometer, or the like can be used, selected depending on the required accuracy.

[0035] Then, the position controller 2 (control unit) outputs a current command value for the motor driver, and the difference between the output current command value and the motor current value detected by a current detection means (not shown) is input to the current controller 3 (control unit) and processed for calculation, thereby performing constant current control. As the current detection means, a current probe, a shunt resistor, or the like is generally used.

[0036] Next, the current (input current) output from the current controller 3 is input to both the PWM amplifier 4 (first amplifier) ​​and the linear amplifier 5 (second amplifier). The output current (output signal) from either the PWM amplifier 4 or the linear amplifier 5 selected by the switch S (switching device) serving as the switching means 6 is input to the motor 7 (drive unit), and the motor 7, which is controlled to a constant current, drives the stage 8, thereby performing position control. In other words, the switch S as the switching means 6 turns on or off the first connection between the PWM amplifier 4 and the motor 7, and turns on or off the second connection between the linear amplifier 5 and the motor 7.

[0037] 1(b), in the velocity control system provided in the stage device according to this embodiment, the difference between the velocity command value included in the drive command value 1 and the value indicating the stage velocity detected by a stage velocity detection means (not shown) is input to a velocity controller 12 (control unit), thereby performing velocity control. Here, the stage speed detection means can use a method of differentiating position outputs from an encoder or a laser interferometer.

[0038] Then, the speed controller 12 outputs a current command value for the motor driver, and the difference between the output current command value and the motor current value detected by a current detection means (not shown) is input to the current controller 3 and processed for calculation, thereby performing constant current control. As the current detection means, a current probe, a shunt resistor, or the like is generally used.

[0039] Next, the current output from the current controller 3 is input to both the PWM amplifier 4 and the linear amplifier 5 . The output current from either the PWM amplifier 4 or the linear amplifier 5 selected by the switch S as a switching means 6 is input to the motor 7, and the motor 7, which is controlled to a constant current, drives the stage 8, thereby controlling the speed.

[0040] The stage device according to this embodiment is provided with a calculation unit 10 (control unit) that determines in advance the switching conditions for the PWM amplifier 4 and the linear amplifier 5 by referring to the motor parameters 11 and the position command value, speed command value, etc. included in the drive command value 1. In other words, in the stage device according to this embodiment, the calculation unit 10 determines the switching conditions for the PWM amplifier 4 and the linear amplifier 5 before driving of the stage 8 based on the position command value, the speed command value, etc., starts. Then, a comparator 9 (control unit) compares the output from the calculation unit 10 with the output from the position controller 2 or the speed controller 12, whereby the switching control of the switch S is performed. Here, the motor parameters 11 (parameters) include the resistance value, inductance value, thrust constant, and payload of the motor 7.

[0041] FIG. 2 is a flowchart showing the switching condition determination process in the calculation unit 10 provided in the stage device according to this embodiment. 3(a), (b), and (c) respectively show the command waveform used in the switching condition determination process, a block diagram showing the switching condition determination process, and the load current waveform and load voltage waveform used in the switching condition determination process.

[0042] As shown in FIG. 2, in the switching condition determination process, first, a velocity command waveform vel(t) and an acceleration command waveform acc(t) are acquired (step S11). Specifically, as shown in Figure 1(a), when a position command waveform pos(t) is given as the drive command value 1, a velocity command waveform vel(t) can be generated by performing a first differentiation operation on the position command waveform pos(t). Also, an acceleration command waveform acc(t) can be generated by performing a second differentiation operation on the position command waveform pos(t). On the other hand, when a velocity command waveform vel(t) is given as the drive command value 1 as shown in FIG. 1(b), an acceleration command waveform acc(t) can be generated by performing a single differentiation operation.

[0043] An example of the position command waveform pos(t), velocity command waveform vel(t), and acceleration command waveform acc(t) obtained as described above is shown in FIG. 3(a).

[0044] Next, a load current waveform i(t) in the motor 7 is generated (step S12). Specifically, when the transportable mass of the motor 7 is M, the thrust F(t) required to drive the motor 7 is expressed as the following equation (1) using the acceleration command waveform acc(t). F(t)=M×acc(t) (1) In the stage device according to this embodiment, the mass of the stage 8 can be used as the transportable mass M of the motor 7.

[0045] Next, when the thrust constant of the motor 7 is Kf, the load current waveform i(t) in the motor 7 is expressed as the following equation (2) using the thrust F(t). i(t)=F(t) / Kf (2)

[0046] Therefore, the load current waveform i(t) in the motor 7 can be generated from the equations (1) and (2) as shown in the following equation (3). i(t)=M×acc(t) / Kf (3)

[0047] Next, a load model is generated for generating a load voltage waveform v(t) from the load current waveform i(t) (step S13). Specifically, since the motor 7 used in the stage device according to this embodiment is an inductive load consisting of a wound coil, an RL circuit consisting of the resistance value R and inductance value L of the coil of the motor 7 is used as the load model, as shown in FIG. 3(b).

[0048] Next, the load current waveform i(t) generated in step S12 is input to the load model generated in step S13, thereby generating a load voltage waveform v(t) (step S14). Specifically, since the load model generated in step S13 is equivalent to an RL circuit as described above, the generated load voltage waveform v(t) can be expressed as in the following equation (4). v(t)=i(t)×(R+jωL) (4)

[0049] Next, since the motor 7 is represented by an RL circuit as described above, a back electromotive force is generated in a direction that opposes the coil current. Therefore, the load voltage waveform v(t) is corrected based on this, and a corrected load voltage waveform vc(t) is generated (step S15). Specifically, the back electromotive force waveform vb(t) can be expressed as the following equation (5) using the back electromotive force coefficient and the speed command waveform vel(t). vb(t)=Kf×vel(t) (5) It should be noted that since it is known that the back electromotive force coefficient is the same value as the thrust constant Kf of the motor 7, the thrust constant Kf of the motor 7 is substituted into equation (5).

[0050] Then, as shown in the following equation (6), the corrected load voltage waveform vc(t) can be obtained from the difference between the load voltage waveform v(t) generated in step S14 and the back electromotive force waveform vb(t). vc(t)=v(t)-vb(t) (6)

[0051] A block diagram showing the processing from step S13 to step S15 described here is shown in FIG. 3(b).

[0052] Next, by referring to the load current waveform i(t) generated in step S12 and the corrected load voltage waveform vc(t) generated in step S15, a switching condition is determined such that the output voltage of the linear amplifier 5 falls within the maximum output voltage ±40 V (step S16). For example, in the load current waveform i(t) and load voltage waveform vc(t) shown in Figure 3(c), when the load current becomes ±0.5 A, the linear amplifier 5 is switched to the PWM amplifier 4. This allows the output voltage of the linear amplifier 5 to be kept within the maximum output voltage of ±40 V, as shown by the white circles.

[0053] That is, in step S16, comparator 9 compares ±0.5 A, which is the switching condition determined by calculation unit 10, with the current command value output from position controller 2 or speed controller 12. Then, based on the comparison by comparator 9, switch S is controlled so that linear amplifier 5 is selected when the load current is less than ±0.5 A. In this way, the stage device according to this embodiment can switch between the linear amplifier 5 and the PWM amplifier 4 in an excellent manner.

[0054] As described above, the stage device according to this embodiment is provided with a calculation unit 10 that determines in advance the conditions for switching between the PWM amplifier 4 and the linear amplifier 5 by the switching means 6 by referring to the motor parameters 11 and the drive command value 1. This allows for smooth switching between the PWM amplifier 4 and the linear amplifier 5, and provides a stage device that further improves positioning accuracy by suppressing a decrease in positioning accuracy while maintaining improved throughput.

[0055] [Second embodiment] FIG. 4 shows a block diagram of a position control system provided in a stage device according to the second embodiment.

[0056] As shown in FIG. 4, in the stage device according to this embodiment, position control is performed by inputting the position difference between the position command value included in the drive command value 1 and the stage position detected by a stage position detection means (not shown) into a position controller 2. As the stage position detection means, an encoder, a laser interferometer, or the like can be used, selected depending on the required accuracy.

[0057] Next, the position controller 2 outputs a current command value for the motor driver, and the difference between the output current command value and the motor current value detected by a current detection means (not shown) is calculated by the current controller 3, thereby performing constant current control. As the current detection means, a current probe, a shunt resistor, or the like is generally used.

[0058] Next, the current output from the current controller 3 is input to both the PWM amplifier 4 and the linear amplifier 5 . Then, switches S1 (first switch) and S2 (second switch) serving as switching means 6 select the current output from either the PWM amplifier 4 or the linear amplifier 5, and the constant current controlled motor 7 drives the stage 8, thereby performing position control. In other words, the switch S1 as the switching means 6 turns on or off the first connection between the PWM amplifier 4 and the motor 7. On the other hand, the switch S2 as the switching means 6 turns on or off the second connection between the linear amplifier 5 and the motor 7.

[0059] The stage device according to this embodiment may use a velocity control system based on the velocity command value included in the drive command value 1, similar to the stage device according to the first embodiment. The processing in the speed control system provided in the stage device according to this embodiment is also the same as that in the stage device according to the first embodiment, and therefore a description thereof will be omitted here.

[0060] Furthermore, the stage device according to this embodiment is provided with a calculation unit 10 that determines in advance the switching conditions between the PWM amplifier 4 and the linear amplifier 5 by referring to the motor parameters 11 and the drive command values ​​1 that include the position command value, the speed command value, etc. Here, the motor parameters 11 include the resistance value, inductance value, thrust constant, and payload of the motor 7.

[0061] As shown in FIG. 4, in the stage device according to this embodiment, switches S1 and S2 serving as switching means 6 are provided independently at the output stages of the PWM amplifier 4 and the linear amplifier 5, respectively. Moreover, similar to the stage device according to the first embodiment described above, the switching conditions are determined by the calculation unit 10. Then, a comparator 9 compares a threshold value based on the determined switching conditions with the current command value, and switches between the output of the PWM amplifier 4 and the output of the linear amplifier 5 by independently controlling the switches S1 and S2.

[0062] 5(a) and 5(b) are a partially enlarged block diagram of a position control system provided in the stage device and a view showing the state when the switch S is switched, respectively. The stage device shown here has the same configuration as the stage device according to this embodiment, except that a single switch S is provided as the switching means 6 instead of the switches S1 and S2.

[0063] As shown in FIG. 5(a), consider the case where the switch S operates at time T1, causing a transition from a state in which the PWM amplifier 4 is selected (contact C1) to a state in which the linear amplifier 5 is selected (contact C2). At this time, if there is a delay in the operation of the switch S, there will be a period in which both the contacts C1 and C2 are OFF until the linear amplifier 5 is selected at time T2. In this case, since the motor 7 is an inductive load due to the wound coil, if the coil ends of the motor 7 are released while current is flowing, a large surge voltage will be generated across both ends of the coil of the motor 7, as shown in Figure 5(b).

[0064] 6(a), (b), (c) and (d) show how the switches S1 and S2 are switched in the position control system provided in the stage device according to this embodiment.

[0065] As shown in FIG. 6(a), in the stage device according to this embodiment, at a predetermined time before time T1, switch S1 is on while switch S2 is off, thereby selecting PWM amplifier 4 (state 1, FIG. 6(b)). Next, between times T1 and T2, the switches S1 and S2 are both on, and the PWM amplifier 4 and the linear amplifier 5 are selected (state 2, FIG. 6(c)). Then, for a predetermined time after time T2, the switch S1 is turned off while the switch S2 is turned on, thereby selecting the linear amplifier 5 (state 3, FIG. 6(d)).

[0066] In the stage device according to this embodiment, the switches S1 and S2 serving as the switching means 6 are provided independently at the output stages of the PWM amplifier 4 and the linear amplifier 5, respectively, as described above. When switching between the PWM amplifier 4 and the linear amplifier 5, a time is provided during which both the switches S1 and S2 are turned on so that the coil ends are not released. This makes it possible to prevent the occurrence of surge voltage across the coil of the motor 7, thereby improving the reliability of the positioning of the stage 8.

[0067] As described above, the stage device according to this embodiment is provided with a calculation unit 10 that determines in advance the conditions for switching between the PWM amplifier 4 and the linear amplifier 5 by the switching means 6 by referring to the motor parameters 11 and the drive command value 1. Furthermore, in the stage device according to this embodiment, the switching means 6 is configured by two switches S1 and S2, which makes it possible to prevent the occurrence of surge voltage across the coil of the motor 7 due to switching between the PWM amplifier 4 and the linear amplifier 5. This allows for even better switching between the PWM amplifier 4 and the linear amplifier 5, and makes it possible to provide a stage device that further improves positioning accuracy by suppressing a decrease in positioning accuracy while maintaining improved throughput.

[0068] [Third embodiment] FIG. 7 shows a block diagram of a position control system used in a stage device according to the third embodiment.

[0069] In the stage device according to the first embodiment, before driving of the stage 8 starts, the position command value or the speed command value included in the drive command value 1 is input to the calculation unit 10. Then, the calculation unit 10 refers to the motor parameters 11 and the input position command value or the speed command value to calculate and determine the switching conditions of the switching means 6. In this case, since it was necessary to calculate the load current waveform i(t) and the load voltage waveform vc(t) each time the stage 8 was driven, as described above, there was a possibility that a delay would occur before the driving of the stage 8 began.

[0070] Therefore, in the stage device according to this embodiment, the following configuration is adopted, making it possible to suppress the occurrence of such delays in driving the stage 8.

[0071] As shown in FIG. 7, in the position control system provided in the stage device according to this embodiment, the velocity command value or acceleration command value included in the drive command value 1 is input to a calculation unit 15 (control unit). Then, the calculation unit 15 obtains a position command value by integrating the input speed command value or acceleration command value, and then outputs the position command value to the position controller 2.

[0072] Next, the difference between the output position command value and a value indicating the stage position detected by a stage position detection means (not shown) is input to the position controller 2. In this way, position control is performed. Here, as the stage position detection means, an encoder, a laser interferometer, or the like can be used, selected depending on the required accuracy.

[0073] Then, the position controller 2 outputs a current command value for the motor driver, and the difference between the output current command value and the motor current value detected by a current detection means (not shown) is input to the current controller 3 and processed for calculation, thereby performing constant current control. As the current detection means, a current probe, a shunt resistor, or the like is generally used.

[0074] Next, the current output from the current controller 3 is input to both the PWM amplifier 4 and the linear amplifier 5 . The output current from either the PWM amplifier 4 or the linear amplifier 5 selected by the switch S as a switching means 6 is input to the motor 7, and the motor 7, which is controlled to a constant current, drives the stage 8, thereby performing position control. In other words, the switch S as the switching means 6 turns on or off the first connection between the PWM amplifier 4 and the motor 7, and turns on or off the second connection between the linear amplifier 5 and the motor 7.

[0075] It should be noted that the stage device according to this embodiment uses a position control system such as that shown in FIG. 7, but is not limited to this, and a speed control system such as that shown in FIG. 1(b) may also be used. In this case, the speed command value included in the drive command value 1 is output to the speed controller 12, so the calculation unit 15 can be omitted.

[0076] The stage device according to this embodiment is provided with a switching condition determination unit 13 (control unit) that determines the switching conditions of the PWM amplifier 4 and the linear amplifier 5 in advance by referring to the switching condition table 14 and the velocity command value and acceleration command value included in the drive command value 1. In other words, in the stage device according to this embodiment, the switching condition determination unit 13 determines the switching conditions for the PWM amplifier 4 and the linear amplifier 5 before driving of the stage 8 based on the position command value starts.

[0077] That is, in the stage device according to this embodiment, the switching condition table 14 is created in advance. Then, when driving the stage 8, the switching conditions for the PWM amplifier 4 and the linear amplifier 5 can be determined simply by referring to the switching condition table 14 and the velocity command value and acceleration command value included in the drive command value 1.

[0078] Then, the comparator 9 compares the output from the switching condition determining unit 13 with the output from the position controller 2, whereby the switching control of the switch S is performed.

[0079] FIG. 8A is a flowchart showing the process of creating the switching condition table 14 in the stage device according to this embodiment. This processing may be performed in the calculation unit 15 or in another calculation unit (not shown).

[0080] As shown in FIG. 8(a), in the switching condition table creation process, first, the amplitudes vel and acc (speed and acceleration data) of the speed command waveform vel(t) and acceleration command waveform acc(t) expected to drive the stage 8 are obtained (step S21). The amplitudes vel and acc assumed here may be input by the user, for example.

[0081] Also, examples of possible amplitudes vel and acc are shown in FIGS. 9(a) and (b). Next, a velocity command waveform vel(t) and an acceleration command waveform acc(t) are generated based on the input amplitudes vel and acc (step S22). Here, in the stage device according to this embodiment, it is assumed that the frequency and waveform of each of the velocity command waveform vel(t) and acceleration command waveform acc(t) do not change. That is, in the examples shown in Figures 9(a) and (b), the velocity command waveform vel(t) and the acceleration command waveform acc(t) each have a cycle of 24 ms and a trapezoidal waveform shape.

[0082] Next, a load current waveform i(t) for the motor 7 is generated (step S23). Specifically, when the transportable mass of the motor 7 is M, the thrust force F(t) required to drive the motor 7 is expressed as the following equation (7) using the acceleration command waveform acc(t). F(t)=M×acc(t) (7) In the stage device according to this embodiment, the mass of the stage 8 can be used as the transportable mass M of the motor 7.

[0083] Next, when the thrust constant of the motor 7 is Kf, the load current waveform i(t) in the motor 7 is expressed as the following equation (8) using the thrust F(t). i(t)=F(t) / Kf (8) Therefore, the load current waveform i(t) in the motor 7 can be generated from the equations (7) and (8) as shown in the following equation (9). i(t)=M×acc(t) / Kf (9)

[0084] Next, a load model is generated for generating a load voltage waveform v(t) from the load current waveform i(t) (step S24). Specifically, since the motor 7 used in the stage device according to this embodiment is an inductive load consisting of a wound coil, an RL circuit consisting of the resistance value R and inductance value L of the coil of the motor 7 is used as the load model, as shown in FIG. 3(b).

[0085] Next, the load current waveform i(t) generated in step S23 is input to the load model generated in step S24, thereby generating a load voltage waveform v(t) (step S25). Specifically, since the load model generated in step S24 is equivalent to an RL circuit as described above, the generated load voltage waveform v(t) can be expressed as in the following equation (10). v(t)=i(t)×(R+jωL) ···(10)

[0086] Next, since the motor 7 is represented by an RL circuit as described above, a back electromotive force is generated in a direction that opposes the coil current, and the load voltage waveform v(t) is corrected based on this to generate a corrected load voltage waveform vc(t) (step S26). Specifically, the back electromotive force waveform vb(t) can be expressed as the following equation (11) using the back electromotive force coefficient and the speed command waveform vel(t). vb(t)=Kf×vel(t) (11) It is known that the back electromotive force coefficient is the same as the thrust constant Kf of the motor 7, so the thrust constant Kf of the motor 7 is substituted into equation (11).

[0087] Then, as shown in the following equation (12), the corrected load voltage waveform vc(t) can be obtained from the difference between the load voltage waveform v(t) generated in step S25 and the back electromotive force waveform vb(t). vc(t)=v(t)-vb(t) (12)

[0088] Next, by referring to the load current waveform i(t) generated in step S23 and the corrected load voltage waveform vc(t) generated in step S26, a switching condition is determined such that the output voltage of the linear amplifier 5 falls within the maximum output voltage ±40 V (step S27).

[0089] For example, consider the case shown in FIG. 9(a) where the amplitude vel of the speed command waveform vel(t) is vel1 and the amplitude acc of the acceleration command waveform acc(t) is acc1 (the amplitude of the load current waveform i(t) is ±3 A). At this time, by referring to the load current waveform i(t) generated in step S23 and the corrected load voltage waveform vc(t) generated in step S26, the switching condition ±i is set so that the output voltage of the linear amplifier 5 falls within the maximum output voltage ±40V. 11 (A) is determined.

[0090] Also, as shown in FIG. 9(b), consider the case where the amplitude vel of the speed command waveform vel(t) is vel2 and the amplitude acc of the acceleration command waveform acc(t) is acc2 (the amplitude of the load current waveform i(t) is ±5 A). At this time, by referring to the load current waveform i(t) generated in step S23 and the corrected load voltage waveform vc(t) generated in step S26, the switching condition ±i is set so that the output voltage of the linear amplifier 5 falls within the maximum output voltage ±40V. 22 (A) is determined.

[0091] Then, it is determined whether the determination of the switching conditions as described above has been performed for all possible combinations of the amplitudes vel and acc (step S28). If it is determined that not all combinations have been performed (No in step S28), the process returns to step S21, and the process of determining the switching condition continues.

[0092] On the other hand, if it is determined that all combinations have been performed (Yes in step S28), the switching condition table 14 is created based on the obtained results (step S29), and the switching condition table creation process ends. FIG. 9(c) shows an example of the switching condition table 14 created in step S29.

[0093] FIG. 8B is a flowchart showing the switching condition determination process in the switching condition determination unit 13 provided in the stage device according to this embodiment.

[0094] As shown in FIG. 8(b), in the switching condition determination process, first, the amplitudes vel and acc of the velocity command waveform vel(t) and acceleration command waveform acc(t) included in the drive command value 1 are obtained (step S31). Then, the switching condition determination unit 13 determines the current values ​​corresponding to the switching conditions of the PWM amplifier 4 and the linear amplifier 5 using the switching condition table 14 based on the input amplitudes vel and acc (step S32).

[0095] As described above, in the stage device according to this embodiment, when driving the stage 8, the switching conditions can be instantly determined by referring to the amplitudes vel and acc contained in the drive command value 1 and the switching condition table 14.

[0096] Furthermore, by creating a switching condition table 14 so that the amplitudes vel and acc satisfy the relationships of the following equations (13) and (14), even if there are no values ​​corresponding to the input amplitudes vel and acc, the switching conditions can be determined by referring to nearby values. vel1 <vel2<vel3<vel4<vel5···(13) acc1 <acc2<acc3<acc4<acc5···(14)

[0097] For example, if a value between vel2 and vel3 is input for the amplitude vel, and a value between acc2 and acc3 is input for the amplitude acc, the switching conditions corresponding to the larger values, i.e., vel3 and acc3, respectively, may be determined. This makes the switching conditions stricter, that is, the current value corresponding to the switching conditions becomes smaller, so that the PWM amplifier 4 and the linear amplifier 5 can be switched safely.

[0098] As described above, the stage device according to this embodiment is provided with a switching condition determination unit 13 that determines in advance the switching conditions for the PWM amplifier 4 and the linear amplifier 5 by referring to the switching condition table 14 and the amplitudes vel and acc contained in the drive command value 1. That is, in the stage device according to this embodiment, the load current waveform i(t) and the load voltage waveform vc(t) are calculated for combinations of amplitudes vel and acc that are assumed in advance, and the switching conditions are determined, thereby creating the switching condition table 14.

[0099] When driving the stage 8, the switching conditions for the PWM amplifier 4 and the linear amplifier 5 can be determined simply by referring to the switching condition table 14 and the amplitudes vel and acc included in the drive command value 1. This allows for good switching between the PWM amplifier 4 and the linear amplifier 5, making it possible to provide a stage device that further improves throughput while suppressing a decrease in positioning accuracy.

[0100] Although the preferred embodiments have been described above, the present invention is not limited to these embodiments and various modifications and changes are possible within the scope of the gist thereof.

[0101] [Exposure equipment] FIG. 10 shows a configuration diagram of an exposure apparatus 900 equipped with a stage apparatus according to this embodiment.

[0102] The exposure apparatus 900 includes a lamp lighting device 401 (light source), an illumination optical system 402 , a slit 403 , an imaging optical system 404 , an original stage 405 , a projection optical system 406 , and a substrate stage 407 . The stage device according to this embodiment is used to control the driving of the original stage 405 and the substrate stage 407, for example.

[0103] The lamp lighting device 401 is a light source that emits ultraviolet light, such as a high-pressure mercury lamp. The illumination optical system 402 includes a first bending mirror 501 , a first condenser lens 502 , a fly's-eye lens 503 , a second condenser lens 504 , and a second bending mirror 505 . The original stage 405 is a mask stage that holds the original O, and can be driven in the Y-axis direction shown in FIG.

[0104] The projection optical system 406 is a projection optical system for projecting and transferring a pattern drawn on the original O onto a substrate P coated with a photosensitive agent. The exposure apparatus 900 uses a projection optical system 406 that is an Offner type optical system. In the case of an Offner optical system, the original O is illuminated with an arc-shaped light to ensure a good image area. The illumination shape of the exposure light that reaches the substrate P also has an arc-shaped light shape. The light that passes through the original O is reflected in this order by the trapezoidal mirror 601, the concave mirror 602, the convex mirror 603, the concave mirror 602, and the trapezoidal mirror 601, before reaching the substrate P, and the pattern on the original O is transferred onto the substrate P.

[0105] The substrate stage 407 is a wafer stage that holds the substrate P, and is driven in the Y direction in synchronization with the original stage 405 to expose the substrate P. The substrate stage 407 can be driven in the X direction as well as the Y direction, and when exposing multiple panels on the substrate P, the substrate stage 407 is driven in both the X and Y directions to perform exposure.

[0106] Exposure light emitted from a lamp lighting device 401 passes through an illumination optical system 402 , a slit 403 and an imaging optical system 404 , and then irradiates an original O placed on an original stage 405 . The exposure light transmitted through the original O passes through a projection optical system 406 and irradiates a substrate P placed on a substrate stage 407, and an exposure area on the substrate P is exposed.

[0107] Although the above describes an embodiment in which the stage device according to this embodiment is provided in an exposure apparatus, the stage device according to this embodiment can also be applied to pattern forming apparatuses such as imprint apparatuses and drawing apparatuses.

[0108] The imprinting device referred to here is a device that brings an imprinting material and a mold material supplied onto a substrate into contact with each other, and then applies energy to the imprinting material to harden it, thereby forming a pattern in the hardened material to which the mold pattern has been transferred. A drawing device is a device that forms a pattern (latent image pattern) on a substrate by drawing on the substrate with a charged particle beam (electron beam) or a laser beam.

[0109] [Production method] The method for manufacturing an article according to this embodiment is suitable for manufacturing articles such as microdevices, such as semiconductor devices, and elements having a microstructure. The method for manufacturing an article according to this embodiment includes a step of forming a latent image pattern in a photosensitive agent applied to a substrate using the exposure apparatus 900 described above (an exposure step of exposing the substrate). The method for manufacturing an article according to this embodiment also includes a development step (processing step) of developing the substrate on which the latent image pattern has been formed in the exposure step. Furthermore, the method for manufacturing an article according to this embodiment includes other well-known manufacturing steps (oxidation, film formation, deposition, doping, planarization, etching, resist stripping, dicing, bonding, packaging, etc.) performed on the substrate developed in the development step.

[0110] The method for manufacturing an article according to this embodiment is advantageous over conventional methods in at least one of the performance, quality, productivity, and production costs of the article. Furthermore, the method for manufacturing an article according to this embodiment is not limited to the above-described exposure apparatus 900, and may be performed using a pattern forming apparatus such as an imprint apparatus or a drawing apparatus that includes the stage apparatus according to this embodiment. [Explanation of symbols]

[0111] 1 Drive command value (command value) 2 Position controller (control unit) 3 Current controller (control section) 4 PWM amplifier (first amplifier) 5 Linear amplifier (second amplifier) 6. Switching means (switch) 7 Motor (drive unit) 8 Stages 9 Comparator (control unit) 11 Motor parameters (parameters) 12 Speed ​​controller (control unit) 13 Switching condition determination unit (control unit)

Claims

1. Stage and A motor for driving the stage; a first amplifier that amplifies an input signal by pulse width modulation control and outputs an output signal to the motor; a second amplifier that amplifies the input signal by linear control and outputs an output signal to the motor; a switch that switches an amplifier to be output to the motor between the first amplifier and the second amplifier; A control unit that controls the switch; A stage apparatus comprising: the control unit controls the switch using a switching condition based on a parameter of the motor and a command value for driving the stage so that the output voltage of the second amplifier is equal to or lower than a maximum output voltage; the parameters include a resistance value, an inductance value, and a thrust constant of the motor, and a mass of the stage; A stage apparatus comprising:

2. 2. The stage apparatus according to claim 1, wherein the control unit determines the switching condition before driving of the stage based on the command value starts.

3. 3. The stage apparatus according to claim 1, wherein the control unit determines the switching condition based on a load current waveform and a load voltage waveform in the motor.

4. 4. The stage apparatus according to claim 3, wherein the control unit generates a velocity command waveform and an acceleration command waveform from the command value, generates the load current waveform from the acceleration command waveform, a mass of the stage and a thrust constant of the motor, generates a load model from a resistance value and an inductance value of the motor, generates the load voltage waveform by inputting the load current waveform to the load model, and determines the load current waveform and the load voltage waveform by correcting the load voltage waveform using a back electromotive force waveform determined from the velocity command waveform and the thrust constant of the motor.

5. 4. The stage apparatus according to claim 3, wherein the control unit determines the switching condition based on a switching condition table created based on the parameters and the command value.

6. 6. The stage device according to claim 5, wherein the control unit generates a velocity command waveform and an acceleration command waveform for each of a plurality of velocity and acceleration data inputted, generates the load current waveform from the acceleration command waveform, a mass of the stage and a thrust constant of the motor, generates a load model from a resistance value and an inductance value of the motor, generates the load voltage waveform by inputting the load current waveform to the load model, obtains the load current waveform and the load voltage waveform by correcting the load voltage waveform using a back electromotive force waveform obtained from the velocity command waveform and the thrust constant of the motor, and creates the switching condition table by determining the switching condition based on the obtained load current waveform and load voltage waveform.

7. the switch includes a first switch that turns on or off a first connection between the first amplifier and the motor, and a second switch that turns on or off a second connection between the second amplifier and the motor, The stage device according to any one of claims 1 to 6, characterized in that the control unit controls the first switch and the second switch so as to transition from a state in which one of the first connection and the second connection is turned on and the other is turned off to a state in which both the first connection and the second connection are turned on, and then one of the connections is turned off and the other is turned on.

8. A pattern forming apparatus for forming a pattern on a substrate, comprising: A pattern forming apparatus comprising: the stage device according to claim 1 ; and a stage unit for controlling driving of the stage on which the substrate is placed.

9. forming a pattern on the substrate using the pattern forming apparatus according to claim 8; processing the patterned substrate to obtain an article; A method for producing an article, comprising the steps of:

10. A switching method for switching between a first amplifier that outputs an output signal obtained by amplifying an input signal by pulse width modulation control to a motor for driving a stage, and a second amplifier that outputs an output signal obtained by amplifying the input signal by linear control to the motor, comprising: determining a switching condition for causing the output voltage of the second amplifier to be equal to or lower than a maximum output voltage based on a parameter of the motor and a command value for driving the stage; switching between the first amplifier and the second amplifier based on the determined switching condition; Including, the parameters include a resistance value, an inductance value, and a thrust constant of the motor, and a mass of the stage; A switching method comprising:

11. The method according to claim 10 , wherein the step of determining includes the step of determining the switching condition before driving of the stage based on the command value starts.

12. 12. The method of claim 10 or 11, wherein the determining step includes determining the switching conditions based on load current and voltage waveforms at the motor.

13. The determining step includes: generating a velocity command waveform and an acceleration command waveform from the command values; generating the load current waveform from the acceleration command waveform, the mass of the stage, and the thrust constant of the motor; generating a load model from resistance and inductance values ​​of the motor; generating the load voltage waveform by inputting the load current waveform into the load model; correcting the load voltage waveform using a back electromotive force waveform calculated from the speed command waveform and a thrust constant of the motor; 13. The method of claim 12, comprising:

14. The method according to claim 12, wherein the step of determining includes a step of determining the switching condition based on a switching condition table created based on the parameters and the command value.

15. 15. The method of claim 14, further comprising the steps of: generating a velocity command waveform and an acceleration command waveform for each of a plurality of velocity and acceleration data inputted, generating the load current waveform from the acceleration command waveform, a mass of the stage and a thrust constant of the motor, generating a load model from a resistance value and an inductance value of the motor, generating the load voltage waveform by inputting the load current waveform to the load model, obtaining the load current waveform and the load voltage waveform by correcting the load voltage waveform using a back electromotive force waveform obtained from the velocity command waveform and the thrust constant of the motor, and determining the switching condition based on the obtained load current waveform and load voltage waveform, thereby creating the switching condition table.

16. 16. The method of claim 10, wherein the switching step includes a step of switching between the first amplifier and the second amplifier by transitioning from a state in which one of a first connection between the first amplifier and the motor and a second connection between the second amplifier and the motor is turned on and the other is turned off to a state in which both the first connection and the second connection are turned on and then one is turned off and the other is turned on.

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