JP2007122181A - Driving stage device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving stage device for highly precisely controlling the temperature of a movable section. <P>SOLUTION: A driving stage device 1 is provided with a base plate 2; a stage 3 moving on the upper surface of the base plate 2; a driving part 4 for driving the stage 3; a heat transferring means 5 for transferring heat between the base plate 2 and the stage 3; and a control means 6 for controlling the temperature of the stage 3. The control means 6 uses the proportionality coefficients of heat conduction functions preliminarily calculated on the basis of actual measurement in order to make the heat conduction functions approximate to heat radiation functions for obtaining heat to be transferred according to heat radiation in a determined use temperature range, so that the heat conduction functions including the proportionality coefficients can be made to approximate to the heat radiation functions. Thus, it is possible to substitute the heat radiation functions proportional to the 4th power of an absolute temperature with heat conduction functions proportional to temperature, and to control the temperature of a movable section with high precision. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a drive stage apparatus having a driven stage.

As a conventional driving stage device, for example, as described in Patent Document 1, a stage, a radiation plate for radiation cooling, a Peltier element for controlling the temperature of the radiation plate, and a radiation amount of the radiation plate are changed. What is provided with the radiation shutter of this is known.
JP-A-2005-33179

  By the way, in a drive stage apparatus applied to a semiconductor or liquid crystal exposure apparatus or inspection apparatus, high drive accuracy of a movable part is required with the recent high performance of semiconductors and liquid crystals. In such a drive stage device, for example, the temperature of the movable portion changes due to exposure light or heat generation of the cable, and the drive accuracy of the drive stage or the semiconductor Si wafer expands and contracts, resulting in a decrease in positioning accuracy. It is necessary to control the temperature at a constant.

  However, in the above prior art, the control becomes non-linear because the thermal radiation is proportional to the fourth power of the absolute temperature, and therefore it is difficult to accurately determine the optimal control value. For this reason, there existed a problem that the temperature of a movable part could not be controlled accurately.

  Therefore, the present invention has been made in view of such circumstances, and an object thereof is to provide a drive stage device capable of controlling the temperature of the movable portion with high accuracy.

  In order to achieve the above object, a drive stage apparatus according to the present invention is a drive stage apparatus used in a vacuum atmosphere or a reduced pressure atmosphere, and includes a fixed part, a guide part provided in the fixed part, and a guide A movable part provided so as to move along the part, a heat transfer means provided between the fixed part and the movable part, and configured to move heat between the fixed part and the movable part, Control means for controlling the temperature so as to be the temperature, and the heat transfer means is controlled by the control means by means of a heat radiation heat radiating part that radiates heat by heat radiation, a heat radiation heat receiving part that receives heat by heat radiation, A heat transfer element that variably moves heat from a cooling part provided on the surface to a heat radiating part provided on the other surface, and the control means moves by heat radiation within a determined temperature range Heat radiation and heat dissipation for seeking heat So that the heat transfer function proportional to the temperature of the heat radiation heat receiving part and the temperature of the heat radiation heat receiving part approximates the heat radiation function proportional to the fourth power of the absolute temperature and the absolute temperature of the heat radiation receiving part. The proportional coefficient is a proportional coefficient of the heat transfer function obtained in advance based on actual measurement within the determined temperature range, and the heat transfer function including the proportional coefficient, information on the temperature of the movable part, and information on the temperature of the heat radiation heat radiating part Based on the information regarding the temperature of the heat radiation heat receiving part, the heat transfer element is controlled so that the movable part has a predetermined temperature.

  In such a drive stage apparatus of the present invention, the heat conduction obtained in advance based on actual measurements is so approximated that the heat conduction function approximates the heat radiation function for obtaining the heat transferred by heat radiation in the determined operating temperature range. Since the proportional coefficient of the function is used, the heat transfer function including this proportional coefficient is approximated to the heat radiation function in the above temperature range, and the heat transfer function proportional to the fourth power of the absolute temperature is proportional to the temperature. Replaced with a function. This eliminates non-linear elements from the temperature control of the movable part. As a result, it is possible to perform temperature control that is simple and realistic in comparison with temperature control based on theoretically obtained heat radiation. Therefore, the temperature of the movable part can be controlled with high accuracy.

  Here, the movable part is preferably a non-contact movable part having a gap between the movable part and the fixed part.

  In this case, the movable part and the fixed part are not in contact with each other, and heat transfer due to heat conduction is eliminated between the movable part and the fixed part. Therefore, temperature control by the control means is effective.

  The heat transfer element is preferably attached to the movable part.

  Since the movable part moves along the guide part provided in the fixed part, it is necessary to attach a heat transfer element so as to correspond to the movement of the movable part. Therefore, for example, when a heat transfer element is attached to the fixed part, it is necessary to attach the heat transfer element to the entire area along the guide part. Just attach a thermal element. Therefore, a simple drive stage apparatus can be configured.

  Also, the heat radiation heat radiating part and the heat radiation heat receiving part are attached with a constant interval regardless of the position of the movable part, so that the radiant heat moved by the heat radiation is constant regardless of the position of the movable part. In addition, it is preferable that each has a predetermined length in a direction parallel to the guide portion.

  Thereby, it can prevent that the radiant heat moved by heat radiation changes because a movable part moves, and the calorie | heat amount of the radiant heat to move becomes uniform irrespective of the position of a movable part. Therefore, the temperature of the movable part can be controlled with high accuracy.

  Moreover, when the movable part is located at the extreme end position of the movable range in which the movable part moves, it is preferable that the heat radiation heat radiating part and the heat radiation heat receiving part are in contact.

  In the operating temperature range, it is necessary to obtain in advance a proportional coefficient of the heat transfer function corresponding to this range. Therefore, the proportional coefficient of the heat transfer function is obtained at the extreme end position of the movable range by contacting the thermal radiation heat radiating portion and the thermal radiation heat receiving portion with the movable portion located at the extreme end position of the movable range. Can do. Therefore, the above-described proportionality coefficient can be easily obtained in advance. Furthermore, since these proportional coefficients can be obtained for each drive stage device, temperature control can be performed in consideration of variations in individual devices, and the accuracy is further improved. Further, for example, by periodically obtaining the above-described proportionality coefficient, it is possible to calibrate the secular change.

  Furthermore, the heat transfer means may be controlled by the control means so as to reverse the heat transfer direction between the fixed portion and the movable portion.

  In this case, by reversing the direction of heat movement between the fixed part and the movable part, the movable part can be freely cooled or radiated. Therefore, it is possible to apply the drive table device to various installation locations and uses.

  ADVANTAGE OF THE INVENTION According to this invention, the drive stage apparatus which can control the temperature of a movable part with high precision can be provided.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same portions are denoted by the same reference numerals, and redundant descriptions are omitted.

  FIG. 1 is a schematic plan view showing a drive stage apparatus according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along line II-II in FIG. The drive stage apparatus 1 of this embodiment is applied to a semiconductor or liquid crystal exposure apparatus or inspection apparatus, and moves between a base plate (fixed portion) 2 and the upper surface of the base plate 2 as shown in each drawing. A stage (movable part) 3, a drive part 4 that drives the stage 3, a heat transfer means 5 that moves heat between the base plate 2 and the stage 3, and a control means 6 that controls the temperature of the stage 3. I have. In addition, the drive stage apparatus 1 is arrange | positioned and sealed, for example in a chamber, for example, the inside of a chamber is made into the substantially vacuum state with the vacuum pump etc., for example.

  The base plate 2 includes a guide portion 7 on its upper surface so as to extend in the longitudinal direction of the base plate 2. The stage 3 is movable along the guide portion 7 via the non-contact bearing 8. For example, an air ejection hole for non-contact is provided on the surface of the non-contact bearing 8 on the guide portion 7 side, and air is ejected from the air ejection hole toward the non-contact bearing 8. For example, an air film of about 10 μm is formed between 8 and the guide portion 7. Here, the position of the stage 3 from when the non-contact bearing 8 is located at one end of the guide portion 7 to when it is located at the other end becomes the movable range.

  The drive unit 4 is a linear motor that generates a driving thrust by changing the balance of magnetic force, and a mover 9 having a coil, for example, attached to the lower surface of the stage 3, and a base plate corresponding to the mover 9. The stator 10 is attached to the upper surface of 2 and extends in the longitudinal direction, for example, a stator 10 having a magnet. When driving the stage 3, a drive thrust is generated in the movable element 9 by energizing the coil constituting the movable element 9, and the stage 3 moves on the base plate 2 while being supported and guided in a non-contact manner with the guide portion 7. .

  The heat transfer means 5 includes a Peltier element (heat transfer element) 11, a heat radiation heat radiating plate (heat radiation heat radiating portion) 12 that radiates heat by heat radiation, a heat radiation heat receiving plate (heat radiation heat receiving portion) 13 that receives heat, and a drive And a chiller 14 for exhausting heat to the outside of the stage apparatus 1. Here, the Peltier element is a heat dissipation surface (cooling part) 15 provided on the other surface from a cooling surface (cooling part) 15 provided on one surface by passing an electric current to generate an amount of heat proportional to the magnitude of the current. It is moved toward the heat radiating portion 16. Moreover, the cooling surface 15 and the heat radiating surface 16 can be switched by changing the direction of the flowing current. The Peltier element 11 is provided such that its cooling surface 15 abuts on an end surface orthogonal to the extending direction of the guide portion 7 in the stage 3, and actually, as shown in FIG. 3, the longitudinal direction of the base plate 2 (vertical direction in the figure) ) Along the line. These Peltier elements 11 are connected in series by lead wires 22 so that a direct current flows from a power source 21.

  Returning to FIG. 1 and FIG. 2, the thermal radiation heat dissipation plate 12 is provided on the stage 3 via the Peltier element 11. Specifically, the heat radiation heat radiating plate 12 is provided in contact with the heat radiating surface 16 of the Peltier element 11. The stage 3 and the heat radiation heat radiating plate 12 are thermally insulated except for the heat transfer by the Peltier element 11.

  The heat radiation heat receiving plate 13 extends in the longitudinal direction of the base plate 2 and is provided on the upper surface thereof. The heat receiving surface is adjacent to the heat radiation surface of the heat radiation heat sink plate 12 with a certain distance. The heat radiation heat receiving plate 13 has a length equal to or longer than the moving distance of the heat radiation heat radiating plate 12 when the stage 3 moves from one end of the movable range along the guide portion 7 toward the other end. As described above, the heat radiation heat sink 12 and the heat radiation heat sink 13 have a certain distance over the movable range of the stage 3 and the heat radiation heat sink 13 has a sufficient length. The amount of heat moving from the radiation heat radiating plate 12 toward the heat radiation heat receiving plate 13 becomes uniform regardless of the position of the stage 3.

  The heat radiation surface of the heat radiation heat dissipation plate 12 and the heat reception surface of the heat radiation heat reception plate 13 are each formed into a bellows-like curved surface so as to increase the surface area and increase the amount of heat transfer due to heat radiation. The chiller 14 is provided on the base plate 2 and is kept constant so that the temperature of the base plate 2 becomes 23 ° C., for example.

  The control means 6 includes a temperature sensor 17 for acquiring the temperature of the stage 3 and a temperature sensor 18 for acquiring the temperature of the heat radiation radiator plate 12. The control means 6 performs PID control of the Peltier element 11 to adjust the amount of heat that moves from the cooling surface 15 toward the heat radiating surface 16 so as to control the temperature of the stage 3 so as to reach a predetermined temperature. Note that the PID control is feedback control in which control is performed by three elements: a deviation between a current value (stage 3 temperature) and a target value (predetermined temperature), its integration, and differentiation. This is a control that suppresses the phenomenon of overshooting the value or oscillating before and after the target value, and can stabilize the current value as the target value in a shorter time compared to normal feedback control.

  In the drive stage apparatus 1 configured as described above, the base plate 2 and the stage 3 are brought into non-contact by the non-contact bearing 8 and the drive unit 4, and the stage 3 is driven to move to a desired position. A predetermined process is performed on the processed object. And in this drive stage apparatus 1, the following temperature control is performed by the control means 6. FIG.

First, general temperature control based on the thermal radiation of the stage 3 will be described. In this temperature control, the heat radiation heat radiation plate 12 and the heat radiation heat reception plate 13 are based on the temperature (temperature on the high temperature side) T ₁ of the heat radiation heat radiation plate and the temperature (temperature on the low temperature side) T ₂ of the heat radiation heat reception plate. A heat transfer amount Q that is moved by heat radiation between the two is obtained. Then, determine the heat movement amount Q, and the temperature of the stage 3 obtained by the temperature sensor 17, based on the predetermined temperature T _0, the PID control value for the PID control.

Next, based on the obtained PID control value, the amount of current to be supplied to the Peltier element 11 is acquired, and the current of this amount of current is supplied to the Peltier element 11. As a result, the Peltier element 11 moves the amount of heat corresponding to the supplied current amount from the cooling surface 15 toward the heat radiation surface 16. As a result, the temperature of the stage 3 is controlled so as to approach the predetermined temperature T _0. Then, such a temperature control of the stage 3 are repeated, the temperature of the stage 3 is controlled to a predetermined temperature T _0.

Here, heat transfer amount Q due to heat radiation is calculated according to the following equation (1) which is proportional to the absolute temperature of the temperature T ₂ of the temperature T ₁ and the heat radiation heat receiving plate 13 of the heat radiation radiating plate 12.

_{Q = ε · F G · σ} · A ((T 1 +273) 4 - (T 2 +273) 4) ... (1)
However,
ε: emissivity of the radiation surface,
F _G : form factor of the radiation surface,
σ: Stefan-Boltzmann constant W / (m ² · K ⁴ ),
A: Radiation surface area m ² ,
T ₁ : temperature of the heat radiation heat sink 12 ° C.
T ₂ : temperature of the heat radiation heat receiving plate 13 ° C,

  However, in the equation (1), the heat transfer amount Q is nonlinear that is proportional to the fourth power of the absolute temperature. Therefore, it is difficult to obtain the heat transfer amount Q and the PID control value with high accuracy.

  Therefore, in the present embodiment, the temperature of the heat radiation heat radiating plate 12 and the temperature of the heat radiation heat receiving plate 13 (hereinafter referred to as “use temperature range”) when using the drive stage device 1 are expressed by the following formula (1): 2) The heat transfer function proportional to the temperature shown in the equation is approximated, and the heat transfer amount Q is obtained by the approximated heat transfer function. Note that the proportionality coefficient (thermal conductance) h included in the equation (2) is a proportionality constant obtained in advance based on actual measurement so that the equation (2) approximates the equation (1) in the operating temperature range.

Q = h (T ₁ −T ₂ ) (2)
However,
h: Proportional constant (thermal conductance) W / K,
T ₁ : temperature of the heat radiation heat sink 12 ° C.
T ₂ : temperature of the heat radiation heat receiving plate 13 ° C,

  In order to obtain the proportionality coefficient h included in the equation (2) in advance, first, a function B (solid line in FIG. 4) of the heat transfer amount Q due to thermal radiation in the operating temperature range A is obtained based on actual measurement. Then, the heat radiation heat radiating plate 12 and the heat radiation heat receiving plate 13 are brought into contact with each other, and the function C (broken line in FIG. 4) of the heat transfer amount Q due to heat conduction in the operating temperature range A that approximates the function B is measured. Ask based on. As a result, the slope of the function C in the operating temperature range A becomes the proportional coefficient h in the operating temperature range A.

  Here, in the present embodiment, the stage 3 is moved to a position that is outside the use range and at the end of the movable range. In this state, as shown in FIG. 5, the heat radiation heat radiating plate 12 and the heat radiation heat receiving plate 13 are configured to be in contact with each other. Thereby, in a state where the stage 3 is located at the extreme end position of the movable range, for example, the heat radiation heat sink 12 is inserted into the heat radiation heat receiving plate 13 deeply and shallowly so that the contact area (area, length) can be varied. The function C is approximated to the function B by making contact, etc., and the proportionality coefficient h in the operating temperature range A can be obtained. Therefore, the proportionality coefficient h in the operating temperature range A is easily obtained in advance. In addition, between the heat radiation heat radiation plate 12 and the heat radiation heat reception plate 13, for example, by providing a heat transfer body, both are brought into contact, and the length, contact area, heat conduction coefficient, etc. of the heat transfer body are changed, The function C may be approximated to the function B. By the way, this heat transfer body is removed during use.

  As described above, in the drive stage apparatus 1 of the present embodiment, the heat transfer amount Q obtained by the equation (2) by heat conduction including the proportionality coefficient h is the heat transfer amount Q obtained by the equation (1) by heat radiation. And match with accuracy. That is, it is possible to control the temperature of the stage 3 by replacing the heat radiation function proportional to the fourth power of the absolute temperature with a heat transfer function proportional to the temperature. This eliminates non-linear elements from the temperature control and prevents the stage 3 from being rapidly cooled or not cooled at all because the amount of heat transfer Q cannot be determined with high accuracy, for example. . Therefore, compared with temperature control based on theoretically obtained heat radiation, temperature control that is simple and realistic can be performed, and the temperature of the stage 3 can be controlled with high accuracy.

  In the present embodiment, since the heat radiation heat sink 12 and the heat radiation heat sink 13 are in contact with each other at the extreme end position of the movable range, the proportional coefficient in the operating temperature range is obtained for each drive stage device. It is possible to perform temperature control in consideration of variations of individual devices, and the accuracy is further improved. Furthermore, secular change can also be calibrated by, for example, periodically obtaining a proportional coefficient in the operating temperature range. In addition, due to the contact configuration, an effect as a stopper that suppresses the stage 3 from moving out of the movable range from the guide portion 7 is also achieved.

  Further, in the present embodiment, the base plate 2 and the stage 3 are brought into non-contact by the non-contact bearing 8 and the drive unit 4, and heat transfer due to heat conduction between the base plate 2 and the stage 3 is eliminated. Therefore, temperature control based on the heat radiation of the control means 6 is more effective.

  Further, in the present embodiment, since the Peltier element 11 is attached to the stage 3, it is only necessary to attach the Peltier element 11 to the stage 3 shorter than the base plate 2, and the drive stage device 1 can have a simple configuration. . When attaching the Peltier element 11 to the base plate 2, it is necessary to attach the Peltier element 11 to the entire region along the guide portion 7.

  As described above, with respect to the drive stage apparatus 1 described above, the temperature of the heat radiation heat receiving plate 13 is maintained at 23 ° C., and the temperature is controlled by the control means 6 so that the stage 3 has a desired temperature. It was ± 0.01 ° C., and the effect of temperature control with high accuracy could be confirmed.

  Note that it is conceivable that the function B, which is a heat radiation function, is obtained, and the heat transfer function approximated to the function B is obtained, for example, by a computer or the like. The accuracy of temperature control is inferior compared with the method of this embodiment.

  The present invention is not limited to the embodiment described above. For example, in the above embodiment, the temperature is controlled so as to cool the stage 3, but the stage 3 may be heated by reversing the flow of the current supplied to the Peltier element 11. The cooling surface 15 of the Peltier element 11 serves as a heat radiation surface, the heat radiation surface 16 serves as a cooling surface, the heat radiation heat radiation plate 12 serves as a heat radiation heat reception plate, and the heat radiation heat reception plate 13 serves as a heat radiation heat radiation plate.

  Moreover, in the said embodiment, although the stage 3 is attached to the base plate 2 through the non-contact bearing 8, it is applicable also to the contact type through a roller bearing or a ball bearing.

  Moreover, in the said embodiment, although the guide part 7 and the drive part 4 are each comprised by one, two or more may be provided. Furthermore, the present invention can be applied to a so-called XY drive stage apparatus in which the other stage and the guide unit are provided along the direction orthogonal to the one stage and the guide unit and the stage is movable in both directions orthogonal to each other. .

Further, in the above embodiment, the temperature T ₂ of the heat radiation heat receiving plate 13 is kept constant, not be constant, the temperature of the thermal radiation heat receiving plate 13 may be a possible acquisition. In this case, the proportional coefficient takes into consideration the use temperature range of the heat radiation heat receiving plate 13 as well as the use temperature range of the heat radiation heat sink plate 12. In addition, a plurality of proportional coefficients in the operating temperature range may exist corresponding to the temperatures in the operating temperature range.

  Furthermore, in the above embodiment, the drive stage apparatus 1 is used in a substantially vacuum, but may be used in a reduced pressure.

It is a schematic plan view which shows the drive stage apparatus which concerns on one Embodiment of this invention. It is sectional drawing which follows the II-II line | wire in FIG. It is a schematic plan view which shows the wiring of a Peltier device. It is a diagram which shows the amount of heat transfer between a heat radiation heat sink and a heat radiation heat receiving plate. It is sectional drawing which shows the state in which a stage is located in the edge part of a movable range.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Drive stage apparatus, 2 ... Base plate (fixed part), 3 ... Stage (movable part), 5 ... Heat transfer means, 6 ... Control means, 7 ... Guide part, 11 ... Peltier element (heat transfer element), 12 ... Thermal radiation heat radiation plate (thermal radiation heat radiation portion), 13 ... Thermal radiation heat radiation plate (thermal radiation heat reception portion), 15 ... Cooling surface (cooling portion), 16 ... Radiation surface (heat radiation portion), A ... Operating temperature range, h ... Proportional coefficient, T ₀ ... predetermined temperature.

Claims (6)

A drive stage device used in a vacuum atmosphere or a reduced pressure atmosphere,
A fixed part;
A guide portion provided in the fixed portion;
A movable part provided to move along the guide part;
A heat transfer means that is provided between the fixed portion and the movable portion and moves heat between the fixed portion and the movable portion;
Control means for controlling the temperature so that the movable part has a predetermined temperature,
The heat transfer means is
A heat radiation heat dissipating part that dissipates heat by heat radiation;
A heat radiation receiving part that receives heat by radiation;
A heat transfer element that is controlled by the control means and moves heat from a cooling part provided on one surface to a heat radiating part provided on the other surface in a variable amount of heat;
The control means includes
The temperature and heat radiation of the heat radiation heat radiating section are proportional to the absolute temperature of the heat radiation heat radiating section and the fourth power of the absolute temperature of the heat radiation heat receiving section for obtaining the heat transferred by the heat radiation within the determined temperature range. The proportional coefficient of the heat transfer function is set as the proportional coefficient of the heat transfer function determined in advance based on actual measurement within the determined temperature range so that the heat transfer function proportional to the temperature of the heat receiving unit is approximated.
Based on the heat transfer function including the proportional coefficient, the information on the temperature of the movable part, the information on the temperature of the heat radiation heat radiating part, and the information on the temperature of the heat radiation heat receiving part, the movable part is at the predetermined temperature. The drive stage device is characterized in that the heat transfer element is controlled so that   The drive stage apparatus according to claim 1, wherein the movable portion is a non-contact movable portion having a gap between the movable portion and the fixed portion.   The drive stage device according to claim 1, wherein the heat transfer element is attached to the movable part.   The heat radiation heat radiating part and the heat radiation heat receiving part are attached with a constant interval regardless of the position of the movable part, and the radiant heat moved by the heat radiation is constant regardless of the position of the movable part. The drive stage device according to any one of claims 1 to 3, wherein each of the drive stage devices has a predetermined length in a direction parallel to the guide portion.   The heat radiation heat radiating part and the heat radiation heat receiving part are in contact with each other when the movable part is positioned at the extreme end position of the movable range in which the movable part moves. The drive stage apparatus of any one of Claims.   The said heat transfer means is controlled by the said control means so that the moving direction of the heat between the said fixed part and the said movable part may be reversed, The any one of Claims 1-5 characterized by the above-mentioned. The drive stage device according to the item.

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