JP3148512B2 - Drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates, XY table of a semiconductor exposure apparatus and the shape measuring apparatus, a driving device mounted on a position-decided Me apparatus such as a high-precision processing machine.

[0002]

2. Description of the Related Art Today, positioning accuracy on the order of nanometers (nm) is required.
m low thermal expansion material (coefficient of thermal expansion 1 × 10 ⁻⁶ ) is deformed by 100 nm with a temperature change of 1 ° C., and even if the change of air temperature in the optical path of the optical interferometer is 1 ° C. or less, Since the measured value may change by 100 nm, cooling of the drive unit for recovering heat released from the drive unit is indispensable as a measure for preventing these temperature changes.

Conventionally, a driving device generates heat during driving, and the generated heat causes a thermal deformation of a structure or an air fluctuation which causes an error of an optical interference type length measuring device. , Using a Peltier element or the like. That is, as shown in FIG. 7, the cooling control unit 3 controls the flow rate of the refrigerant and the heat so that the driving device 1 and the device on which the driving device 1 is mounted reach a predetermined temperature when the driving device (driving unit) 1 generates heat. Cooling is performed by presetting the cooling amount of the cooling means such as the temperature of the heat radiating portion of the pipe and the drive current of the Peltier element. For example, when flowing a coolant, the recovery heat capacity is increased by setting a large flow rate or using a coolant lower than a predetermined temperature, so that the driving device or the positioning device approaches the predetermined temperature during driving and the temperature becomes constant. Like that.

[0004]

However, in the above-mentioned conventional example, the following cooling method is used because cooling is always performed at a predetermined cooling amount based on an average heat generation amount during driving.

The amount of heat generated by the driving device is not constant, and the amount of heat generated varies depending on the driving pattern of the driving device, so that the temperature changes.

When the driving device is stopped and the heat generation is minute or zero, cooling is performed more than necessary, and the cooling device is operating wastefully.

Further, when the temperature of the refrigerant used is low when the driving device is stopped, or when the amount of heat recovery is always constant, the temperature of the driving device becomes too low.

Among the above disadvantages, those particularly related to temperature change, etc., cause a temperature change in the structure and atmosphere around the drive device, and cause thermal deformation of the structure, measurement error of the position caused by the temperature change, and the like. This had an adverse effect on positioning accuracy on the order of nanometers.

SUMMARY OF THE INVENTION In view of the above-mentioned problems of the prior art, it is an object of the present invention to more effectively remove the adverse effect on positioning accuracy due to heat generated by a driving device.

[0010]

A and operation for] To achieve this object, the driving device of the present invention used to position-decided Me apparatus,
A linear motor for performing position-decided Me, cooling circulating a refrigerant
Has a device, a cooling unit for recovering heat generated from the linear motor, the linear motor vicinity of the refrigerant or the
Temperature measurement to measure the temperature of refrigerant passing through a linear motor
Means, and cooling control means for controlling the amount of cooling of the cooling means in accordance with the temperature obtained by the temperature measuring means, thereby reducing the temperature change of the driving device, the structure around the driving device, the atmosphere, etc. In addition, the length measurement error caused by thermal deformation and temperature change of the structure is reduced, and positioning accuracy by the driving device is improved.

[0011] The cold却制control means for controlling the flow rate of the coolant. That is, when the amount of heat generated is high and the temperature rises, the flow rate of the refrigerant is increased to lower the temperature. Or, fluctuation of temperature such as atmosphere is prevented. If the flow rate of the refrigerant increases, the volume of the refrigerant flowing per unit time increases and the heat capacity increases, thereby increasing the cooling capacity. Therefore, the cooling amount is controlled by controlling the flow rate of the refrigerant.

If the temperature measuring means measures the temperature of the refrigerant near the linear motor , for example, if the temperature measurement point of the temperature measuring means is the temperature of the refrigerant passing through the linear motor , Is used as an index of the amount of heat generated or the temperature of the linear motor. Therefore, by keeping the measured temperature of the refrigerant constant, a change in the temperature of the driving device or the like is prevented.

Furthermore, prior Symbol temperature measuring means, the linear motor coil, when it is intended to measure the temperature of at least one portion of the permanent magnet or near thereof, coil or the like measuring point temperature is a heat source , The temperature change can be measured immediately, and since the heat source or the vicinity thereof is cooled, the amount of heat recovery can be accurately adjusted with respect to the heat generation amount. Further, the time delay of the temperature control and the cooling control due to the delay of the temperature rise at the temperature measurement point is suppressed to a minimum. Therefore, by optimizing the cooling amount and increasing the efficiency, the temperature of the device is kept constant, disturbance factors such as errors in length measurement due to thermal deformation and temperature change are reduced, and the positioning accuracy of the driving device is improved. . In particular, the linear motor
For a multi-pole linear motor with multiple coils
Has a temperature measurement means for each coil.
Preferably. Further, the present invention relates to a positioning device.
Particularly suitable for a drive that measures the position of an elephant with a laser interferometer.
It is applied well.

[0014]

【Example】

[Embodiment 1] FIG. 1 is a block diagram of a driving apparatus according to a first embodiment of the present invention, which best illustrates the features of the present invention. In the figure, 1 is a driving means for performing precise positioning, 2 is a temperature measuring means for measuring a temperature, 3 is a cooling means connected to or incorporated in the driving means 1 to recover heat of the driving means 1, and 4 is a temperature. Cooling control means for taking in the temperature data of the measuring means 2, determining the cooling amount according to the data, and controlling the cooling means 3, and 5 are temperature sensors for the temperature measuring means 2 to measure the temperature of the driving means 1. .

The driving means 1 is for driving and precisely positioning the object to be positioned, and when driven, generates heat and the temperature rises. This temperature is measured by the driving means 1 or a temperature sensor 5 arranged in the vicinity thereof, and the temperature measuring means 2 sends the temperature of the driving means 1 obtained by the temperature sensor 5 to the cooling control means 4 as temperature data. The cooling control unit 4 determines a cooling amount of the cooling unit 3 based on the temperature data obtained from the temperature measuring unit 2. For example, if the temperature rises with time, the cooling amount increases, and if the temperature decreases, the cooling amount decreases. Further, the cooling unit 3 cools the driving unit 1 according to the cooling amount determined by the cooling control unit 4. At this time, the cooling means 3 performs cooling in accordance with the amount of heat generated by the driving means 1, so that the cooling means 3
However, the amount of heat not recovered can be kept almost constant.
Accordingly, it is possible to prevent the positioning accuracy from deteriorating due to the thermal deformation of the driving means 1 and the structure around the driving means 1 and the temperature change of the atmosphere.

[Embodiment 2] FIG. 2 is a block diagram showing a second embodiment of the present invention. Reference numeral 4 denotes a cooling amount based on the temperature data obtained from the temperature measuring means 2 as in the first embodiment. Is a cooling device that cools the driving device 1 by using the cooling device 3. The cooling device 6 performs cooling according to the cooling amount determined by the cooling control means 4. In FIG. 1, the cooling control means 4 directly issues a cooling amount command to the cooling means 3, whereas in FIG. 2, the cooling control means 4 issues a cooling amount command to the cooling device 6, and the cooling device 6 responds accordingly. It is characterized in that the cooling means 3 performs cooling. For example, when cooling a drive device by flowing a refrigerant with a temperature controller,
The cooling means 3 is a refrigerant, and the cooling device 6 is a temperature controller for flowing a refrigerant at a certain temperature at a certain flow rate, which is applicable to this example.
In this case, the same effect as in the above embodiment can be obtained.

[Embodiment 3] FIG. 3 is a block diagram showing a third embodiment of the present invention, and shows an embodiment in which a refrigerant is used for cooling means. In the figure, 1a and 1b are a pair of driving means, 1a is a fixed-side driving means, 1b
Is a movable driving means movable in the left and right direction of the drawing, 5 is a temperature sensor disposed on the driving means 1a or 1b, 2
Is a temperature measuring means for outputting temperature data measured by the temperature sensor 5 to the outside, 3a is a supply-side refrigerant for cooling the driving means 1a and 1b, 3b is a return-side refrigerant for cooling the driving means 1a and 1b, and 4 is Cooling control means that receives temperature data from the temperature measuring means 2 and outputs a command signal for controlling the flow rate of the cooling amount of the cooling medium, 6a is a temperature regulator for flowing a cooling medium having a predetermined temperature, and 6b is a valve opening / closing or pump. A regulator for adjusting the refrigerant flow rate by adjusting the output, etc., 6c is a flow meter for measuring the refrigerant flow rate, 6d is a refrigerant flow rate indicated by a command signal from the cooling control means 4 and the refrigerant flow rate measured by the flow meter 6c match. The flow command means 10 controls the amount of adjustment of the adjuster 6b (the opening and closing amount of the valve, the output of the pump, and the like) so that the positioning target mounted on the movable drive means 1b, and the movable target drive means 1b. Loading The position reference of the positioning target 10 thus obtained, 12 is position measuring means for measuring the position of the positioning target 10 with reference to the position reference 11, 13 is the length measured by this, and 14 is the positioning obtained from the position measuring means 12. A controller for outputting a command signal for controlling the driving amount of the driving means 1a, 1b based on the position data of the object 10;
Reference numeral 15 denotes a driving unit 1 in accordance with a command from the controller 14.
a, 1b.

When the driving means 1b moves in the horizontal direction in the drawing with respect to the fixed driving means 1a, the positioning object 1 is moved.
0 moves in the same direction, and the position of the positioning target 10 is measured by the position measuring means 12 based on the position reference 11. For example, when the position reference 11 is a reflection mirror and the position measuring means 12 is a laser interferometer, the length 13 is an optical path length, and this is the position of the positioning target 10.
In general, the positioning target 10 and the position reference 11 are somewhat separated, and the position of the position reference 11 is
Since the position 2 is used, a change in the distance between the two results in a positioning error. The controller 14 is a position measuring means 1
A command is given to the driver 15 to position the positioning target 10 at a predetermined position using the position data of 2, and the driver 15 drives the driving means 1a and 1b. At that time, when the driving means 1a and 1b generate heat, the temperature tends to change. This temperature is measured by the temperature measuring means 2 using the temperature sensor 5, and based on the result, the cooling control means 4 makes the temperature controller 6a
The flow rates of the refrigerants 3a and 3b flowing through are adjusted using the controller 6b so that the temperature change of the driving means 1a and 1b is eliminated. When adjusting the controller 6b, the flow command means 6d issues a command so that the flow rate measured by the flow meter 6c reaches the command value of the flow rate of the cooling control means 4.

When the temperature change of the driving means 1b stops, the thermal deformation of the driving means 1b stops, and the distance between the positioning object 10 and the position reference 11 does not change. Therefore, since there is no change in the distance between the positioning target 10 and the position reference 11, the position of the position reference 11 measured by the position measuring means 12 can be regarded as the position of the positioning target 10, and there is no error in the position measurement. In addition, when the temperature change of the driving unit 1a or 1b is reduced, a change in the ambient temperature, particularly, the temperature of the optical path 13 to be measured can be prevented, and the measured value of the position measuring unit 12 can be prevented from fluctuating. Disappears.

As described above, when the driving device is driven for positioning the positioning object, the temperature of the driving device is measured and the flow rate of the refrigerant is adjusted so that the temperature does not change. Temperature changes in the vicinity or the atmosphere can be suppressed, and thermal deformation of the structure and fluctuations of air can be suppressed, so that positioning accuracy can be improved as compared with the related art.

FIG. 4 is a configuration diagram showing an example of the arrangement of the temperature sensors extracted from the dashed line in FIG. In FIG. 4, 5 is a temperature sensor arranged on the driving means 1b, 5a, 5b and 5c are temperature sensors arranged on the driving means 1a, and 5d is arranged in an atmosphere near the driving means 1a or 1b to set the atmospheric temperature. The temperature sensor 5e to be measured is a temperature sensor arranged on the refrigerant 3b on the return side. The temperature sensor is arranged at any one of the driving means 1a, 1b, the atmosphere, the refrigerant 3b, or the like among these arrangement positions, or is arranged at two or more of these points. The cooling control means 4 controls the flow rate of the refrigerant based on the temperature above the point. The temperature sensor 5d is effective for suppressing a change in the temperature of the air, and the temperature sensor 5e can estimate the increase or decrease in the amount of heat generated by the amount of increase in the temperature of the refrigerant. It is possible to suppress a temperature change of the driving means 1a, 1b and its vicinity or the atmosphere.

[Embodiment 4] FIG. 5 shows a fourth embodiment of the present invention, and is a configuration diagram (partially sectional view) showing another embodiment using a linear motor as a driving means. In the figure, 21a, 21b, 21c, 21d are permanent magnets, 22
Is a yoke to which the permanent magnets 21a to 21d are fixed, 23 is a coil through which current flows, and 24 is a
It is a coil support which is a flow path of a and 3b. The position measuring means, the controller, the driver and the like are not shown. Since the coil 23 is in the magnetic field generated by the permanent magnet 21, when a current flows through the coil 23, a Lorentz force is generated in the left-right direction in the drawing, and the yoke 22 and the coil support 24 are driven relatively to each other in the left-right direction. You. When this linear motor is driven, a current flows through the coil 23 and the coil 23 generates heat. The temperature sensor 5 is disposed at or near the coil 23, the temperature of which is measured by the temperature measuring means 2, and in accordance with a cooling amount command from the cooling control means 4, the cooling device 6.
Flows a predetermined amount of the refrigerant 3a. Since this refrigerant directly cools the coil 23 and the coil support 24, which are heat sources, and recovers heat, it has the effect of suppressing temperature changes in the structure of the drive device and the atmosphere. The same effect can be obtained by arranging the temperature sensor 5 on the coil support 24, the yoke 22, the refrigerant 3b, and the like.

[Embodiment 5] FIG. 6 is a block diagram showing a fifth embodiment of the present invention in which a multi-pole linear motor is used as a driving means, in which a coil portion of a linear motor is extracted. 23a, 23b, 23c are coils, 5A, 5B, 5
C is a temperature sensor disposed on each of the coils 23a, 23b and 23c. In the case of a multi-pole linear motor, since there are a plurality of coils, the temperature sensor can be arranged at an appropriate point as in the case of the single pole in FIG. 5, but as shown in FIG. And the flow rates of the refrigerants 3a and 3b can be determined based on the plurality of temperatures measured by the temperature measuring means 2. Since the current flowing through each coil is different and the temperature is also different, the flow rate of the refrigerant can be controlled by weighting each temperature or selecting the maximum value of each temperature. In the case of a multi-pole linear motor, the same effect as in the above embodiment can be obtained.

[0024]

As described above, according to the present invention, the linear motor exothermic performed Me-position-decided, a cooling device for circulating a refrigerant
A, a cooling means for recovering the heat, the linear motors
Since it provided a temperature measuring means for measuring the temperature of the refrigerant passing through the refrigerant or linear motor of the near neighbor, and a cooling control means for controlling the cooling amount of the cooling means in accordance with the temperature, linear motor, around This has the effect of reducing the temperature change of the structure, atmosphere, etc., reducing the length measurement error caused by the thermal deformation and temperature change of the structure, and further improving the positioning accuracy on the order of nanometers by the driving device.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a driving device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a second embodiment of the present invention showing an example in which the cooling control unit of FIG. 1 gives a command to a cooling device that drives the cooling unit.

FIG. 3 shows a third embodiment of the present invention when a refrigerant is used as a cooling means.
1 is a configuration diagram illustrating an embodiment of a driving device according to an example of FIG.

FIG. 4 is a configuration diagram showing an example of arrangement of temperature sensors by extracting the inside of a dashed line in FIG. 3;

FIG. 5 is a configuration diagram of a drive device according to a third embodiment of the present invention when the drive means is a linear motor.

FIG. 6 is a block diagram showing a fourth embodiment of the present invention in which the driving means of the present invention is a multi-pole linear motor, in which only the coil portion is extracted.

FIG. 7 is a configuration diagram of a conventional driving device.

[Explanation of symbols]

1: driving means, 1a: fixed-side driving means, 1b: movable-side driving means, 2: temperature measuring means, 3: cooling means, 3a:
Supply side refrigerant, 3b: return side refrigerant, 4: cooling control means, 5, 5a, 5b, 5c, 5d, 5e: temperature sensors,
6: cooling device, 6a: temperature controller, 6b: regulator, 6c: flow meter, 6d: flow command means, 10: positioning target, 1
1: Position reference, 12: Position measurement means, 13: Length to be measured, 14: Controller, 15: Driver, 21a, 2
1b, 21c, 21d: permanent magnet, 22: yoke, 2
3: coil, 24: coil support, 23a, 23b, 2
3c: coil, 5A, 5B, 5C: temperature sensor.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI H01L 21/68 H01L 21/68 K 21/30 515G

Claims (7)

(57) [Claims] 1. A position A driving device for use in-decided Me apparatus, a linear motor to perform Me-position-decided, and cooling means having a cooling device for circulating a refrigerant, recovering the heat generated from the linear motor Temperature measurement for measuring the temperature of the refrigerant near the linear motor
And a cooling control means for controlling a cooling amount of the cooling means in accordance with the temperature obtained by the temperature measuring means. 2. A driving device used for a positioning device.
A linear motor that performs positioning, and a cooling device that circulates refrigerant.
Cooling means for recovering heat generated from the cooling medium, and a temperature for measuring a temperature of the refrigerant passing through the linear motor.
Measuring means and the cooling means according to the temperature obtained by the temperature sensor.
Cooling control means for controlling the cooling amount of the stage.
Driving device. 3. The driving device according to claim 1, wherein
There are, before Symbol cooling control means driving device is characterized in that controls the flow rate of the refrigerant. 4. A driving apparatus according to claim 1 Symbol mounting, characterized in that said temperature measuring means is for measuring the linear motor coil, a permanent magnet or a temperature of at least one location in the vicinity thereof, Drive. 5. The driving device according to claim 1 , wherein the linear motor is a multi-pole linear motor having a plurality of coils. 6. The driving device according to claim 5, wherein a temperature measuring means is arranged for each coil. 7. The driving device according to claim 1, wherein a position of a positioning target is measured by a laser interferometer.