JP4106477B2 - Stage equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a stage apparatus, and more particularly, to an improvement in a mechanism for supporting and driving a fine movement table mounted on a stage.
[0002]
[Prior art]
In a conventional table apparatus used for an exposure apparatus or the like, generally, the table is supported at three points not on a straight line surrounding the center of gravity of the table, and the table is driven in the vertical direction and the tilt direction at these support points. . As a table support system, there are a system that directly supports and drives a table using a contact actuator, and a system that uses a non-contact actuator such as a VCM (voice coil motor).
[0003]
[Problems to be solved by the invention]
However, when a contact-type actuator is used, stress is generated in the table due to the frictional force generated on the contact surface between the table and the actuator. Further, when a non-contact type actuator such as a VCM is used, it is necessary to always apply thrust to support the weight of the table to the actuator, and there is a disadvantage that the table is deformed by the heat of the actuator.
[0004]
The present invention has been made in view of the above situation, and an object thereof is to provide a stage apparatus that can reduce stress and thermal deformation in a table.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, in the present invention, a first actuator (13a, 113, 15) that applies a first force that acts in the support direction of the table at the center of gravity of the table (4), and the support And a second actuator (12a, 12b, 12c, 16a, 16b, 16c) that acts on the direction and applies a second force different from the first force to the table in a non-contact manner. 13a, 113, 15) is characterized in that the first force is generated so as to be substantially equal to the weight of the table (4).
[0006]
As the second actuator, means (12a, 12b, 12c, 12c, 12c, 12c, 12c, 12c, 12c, 12c, 12c, 12c, 12c, 12c, 12c, 12c, 12c) 16a, 16b, 16c). The first actuators (26a, 26b) can be configured to apply a first force to the table (4) using a repulsive force. For example, a mechanism using a reaction force of a magnet can be used as the first actuator.
Further, a detecting means (17) for detecting the first force in the first actuator is further provided,
The first actuator can be configured to change the value of the first force according to the detected value of the first force detected by the detecting means (17). The first actuator includes a first member (26a) provided on the table, and a second member (26b) that generates the first force in cooperation with the first member in a non-contact manner. It can comprise so that the position regarding the support direction of a 2nd member can be changed. The detection means can be composed of a load cell (17).
The second actuators (12a, 12b, 12c, 16a, 16b, 16c) are preferably provided corresponding to the degrees of freedom of the table, the table has 6 degrees of freedom, and the second actuator is the first actuator. Three actuators can be provided separately from the actuator.
Furthermore, in the method for controlling a stage apparatus according to the present invention, there is provided a method for controlling a stage apparatus in which the table (4) is mounted so as to be movable at least in the support direction of the table. wherein a first force acting on the support direction first actuator (13a, 113,15) given by, and acting on the support direction, the second force different from the first force, the first By a second actuator (12a, 12b, 12c, 16a, 16b, 16c) different from the first actuator so that the force acts on the table in a non-contact position at a position different from the position acting on the table. The first force is generated so as to be substantially equal to the weight of the table.
In this case, the weight of the table can be supported by the first force, and the position of the table can be adjusted by the second force.
[0007]
[Action and effect of the invention]
Since the present invention supports the table (4) at the center of gravity (14) as described above, the weight of the table (4) is supported even when the drive mechanism of the table (4) is not contacted. Moreover, it is not necessary to give a large thrust by these non-contact type drive mechanisms (12a, 12b, 16a, 16b). Accordingly, heat generated from the actuator can be suppressed, and deformation of the table (4) due to the heat can be prevented.
[0008]
In other words, it is not necessary to employ a contact-type mechanism as the driving method of the table (4), and the inconvenience of the contact-type mechanism, that is, the table (by the frictional force generated on the contact surface between the table (4) and the actuator ( 4) It is possible to avoid the generation of stress within. In addition to the support means of the table (4), when the three points of the table are driven as the drive means, the table (4) is supported at the four points as a total, so that it becomes unstable. The problem of becoming may arise. However, the table support means (15) is provided with support force generation means (26a, 26b), and the table (4) is weaker than the other three drive means (12a, 12b, 12c, 16a, 16b, 16c). ) Is solved, the problem is solved.
Further, a support force detecting means (17) for detecting a support force for supporting the table by the support mechanism (15), and a support force changing means (18-22) for changing the support force according to the support force detected thereby. The weight of the table (4) can be reliably supported by the support mechanism (15), and the other three driving means (12a, 12b, 12c, 16a, 16b, 16c) There is no load.
Further, by providing six driving means (12a, 12b, 12c, 12d, 12e, 12f, 16a, 16b, 16c, 16d, 16e, 16f) corresponding to the degree of freedom of the table, the table (4) becomes 6 Can move with degrees of freedom.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to examples. In this embodiment, the present invention is applied to a wafer stage used in an exposure apparatus for manufacturing semiconductor devices. The stage apparatus of the present invention can be applied to various apparatuses such as a precision inspection apparatus in addition to the exposure apparatus.
[0010]
【Example】
FIG. 1 shows a stage apparatus of the present embodiment. This stage apparatus holds a wafer 1 via a wafer holder 2 and is capable of fine movement in a direction of six degrees of freedom, an X stage 5 for roughly moving the table 4 in the X direction, and a Y for roughly moving in the Y direction. A stage 6 and a base 7 that slidably supports the Y stage 6 are configured. Reflecting mirrors 3a and 3b for position measurement by an interferometer are provided on the upper side of the table 4. Since these reflection mirrors 3a and 3b serve as a reference for measuring the position of the wafer 1, if the position of the mirror 4 is displaced due to the deformation of the table 4, the alignment accuracy of the wafer 1 during the exposure operation is greatly affected.
[0011]
Two Y stage guides 11a and 11b are provided on the base 7, and the Y stage 6 moves along these guides 11a and 11b. The Y stage 6 is driven by a Y stage driving device 9. On the Y stage 6, two X stage guides 10a and 10b for guiding the X stage 5 are provided. The X stage 5 is moved on the Y stage 6 along the X stage guides 10 a and 10 b by the X stage driving device 8.
[0012]
Coils 12d, 12e, 12f of non-contact actuators such as a VCM (voice coil motor) are provided at the upper end of the X stage 5, and these coils 12d, 12e, 12f and the side of the table 4 are provided. The magnets 16d, 16e, and 16f constitute three sets of MM (Moving Mgnet) type actuators. The table 4 is driven in the XY plane by these three sets of actuators (12d and 16d, 12e and 16e, 12f and 16f). As the VCM, either an MM (Moving Mgnet) type or an MC (Moving Coil) type can be used, but it is desirable to use the MM type in consideration of the influence of heat transmitted to the table 4.
[0013]
Near the center of the top surface of the X stage 5, a substantially triangular recess is formed, and coils 12 b and 12 c of non-contact actuators are arranged at two corners. These coils 12 b and 12 c and the bottom surface of the table 4 are arranged. Two sets of actuators are configured by the magnets 16b and 16c provided in the. The table 4 is driven (leveled) in the tilt direction by these two sets of actuators (12b and 16b, 12c and 16c). A contact actuator 13a is provided at a position corresponding to the center of gravity position 14 of the table 4 in the recess of the X stage 5 so as to support the weight of the table 4 at one point.
[0014]
FIG. 2 shows details of the contact actuator 13a. In the drawing, the cams 21 and 22 move along a linear motion guide 20b provided on the X stage 5, whereby the linear motion table 18 passes through the radial bearing 19 in the Z direction along the linear motion guide 20a. Moving. A link mechanism 23 is disposed between the linear motion table and the table 4 so as to transmit the power of the linear motion table 18 to the table 4. That is, the table 4 is driven in the vertical direction (Z direction) at the center of gravity position 14 by the contact actuator 13a.
[0015]
In the first embodiment of the present invention shown in FIGS. 1 and 2, when the alignment of the wafer 1 is performed, first, the position (position shift) of the wafer 1 is measured by an alignment optical system (not shown) and based on this. Then, coarse position adjustment is performed by the X stage 5 and the Y stage 6. After that, on the X stage 5, the offset in the XY plane of the table 4 (shift in the linear direction) and the position in the rotation direction are adjusted by three sets of non-contact actuators (12d and 16d, 12e and 16e, 12f and 16f). To do. The position of the table 4 is adjusted in the vertical Z direction by the contact actuator 13a, and the tilt direction is adjusted (leveling) by two sets of non-contact actuators (12b and 16b, 12c and 16c). When the table 4 is stationary with respect to the Z direction, the weight of the table 4 is almost supported by the contact actuator 13a. Therefore, the thrust to the table 4 by the non-contact actuator (12b and 16b, 12c and 16c) is very small.
[0016]
FIG. 3 shows a contact actuator 113 according to a second embodiment of the present invention. This actuator 113 is used in place of the actuator 13a shown in FIG. In FIG. 3, components that are the same as or correspond to those of the actuator 13a in FIG. The actuator 113 of this embodiment connects the X stage 5 and the table 4 by the link mechanism 123 and drives the table 4 up and down by the piezo element 24 arranged in the middle of the link mechanism 23. As a result, the vertical position of the table 4 is adjusted at the center of gravity position 14 thereof.
[0017]
FIG. 4 shows a stage apparatus according to a third embodiment of the present invention. The stage apparatus of the present embodiment is obtained by changing the vertical driving mechanism of the table 4 of the first embodiment. In FIG. 4, the same or corresponding components as those of the stage apparatus of FIG. 1 are denoted by the same reference numerals, and description of the configuration and operation thereof is omitted. In the present embodiment, a magnet-type table weight support means 15 is arranged at a position corresponding to the center of gravity position 14 of the table 4 so that most of the weight of the table 4 is supported here. Further, coils 12a, 12b and 12c of non-contact actuators are arranged at three points on the X stage 5 surrounding the center of gravity position 14 of the table 4, and magnets 16a, 16b and 16c provided on the table 4 are inserted. It is supposed to be. The coils 12a, 12b, and 12c and the magnets 16a, 16b, and 16c constitute three sets of non-contact actuators. The table weight support means 15 has a structure in which the restraining force is weak with respect to all of the six degrees of freedom direction of the table 4, and all six sets of non-contact actuators (12 a, 16 a, 12 b) are driven in the six degrees of freedom direction. 16b, 12c and 16c, 12d and 16d, 12e and 16e, 12f and 16f).
[0018]
FIG. 5 shows details of the table weight support means 15. In FIG. 5, the same or corresponding components as those in FIG. 2 are denoted by the same reference numerals, and redundant description is omitted. In the present embodiment, the table 4 and the X stage 5 are connected by permanent magnets 26a and 26b arranged in directions that repel each other. The permanent magnet 26 a is attached to the table 4, and the other permanent magnet 26 b is attached to the linear motion table 18 via the load cell 17.
[0019]
In the present embodiment, when the position of the table 4 in the Z direction is changed by the non-contact actuator (12a, 12b, 12c, 16a, 16b, 16c), the interval between the permanent magnets 26a, 26b also changes, and the repulsive force between the magnets. Changes. The change in the repulsive force between the permanent magnets (26a, 26b) is detected by the load cell 17. Then, the linear motion table 18 is driven in the vertical direction so that the value of the repulsive force detected by the load cell 17 becomes equal to the weight of the table 4. As a result, the weight of the table 4 is supported by the table weight support means 15. Note that this embodiment differs from the first embodiment described above in that not only leveling of the table 4 but also vertical driving is performed by three sets of non-contact actuators (12a and 16a, 12b and 16b, 12c and 16c). The weight support means 15 does not directly participate in such position adjustment, and basically plays a role of supporting the table 4 at the center of gravity position without restraining force.
[0020]
The present invention has been described based on the embodiments. However, the present invention is not limited to these embodiments, and does not depart from the spirit of the technical idea of the present invention shown in the claims. Can be changed.
[Brief description of the drawings]
FIG. 1 is a front view showing a stage apparatus according to a first embodiment of the present invention.
FIG. 2 is an enlarged side view (partial cross section) showing a main part of the first embodiment.
FIG. 3 is an enlarged side view (partial cross section) showing a main part of a stage apparatus according to a second embodiment of the present invention.
FIG. 4 is a front view showing a stage apparatus according to a third embodiment of the present invention.
FIG. 5 is an enlarged side view (partial cross section) showing a main part of a third embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Wafer 4 ... Table 5 ... X stage 6 ... Y stage 12a-12f ... Coil 13a for non-contact actuator ... Contact-type actuator 14 ... Table gravity center position 15- .. Table weight support means 16a to 16f ... Magnet 23 for non-contact actuator ... Link mechanism 24 ... Piezo elements 26a, 26b ... Permanent magnet

Claims (11)

In a stage apparatus in which a table is mounted so as to be movable at least in the support direction of the table ,
A first actuator that applies a first force that acts on the table in the support direction at a position of the center of gravity of the table; and a second force that acts in the support direction and is different from the first force in a non-contact manner. A second actuator for applying to the table,
The stage device, wherein the first actuator generates the first force so as to be substantially equal to a weight of the table.   2. The stage apparatus according to claim 1, wherein the second actuator drives the table in a vertical direction and an inclination direction by applying the second force to the table at three points other than the position of the center of gravity. .   The stage apparatus according to claim 2, wherein the first actuator has a configuration using a reaction force of a magnet. A detecting means for detecting the first force in the first actuator;
4. The first actuator according to claim 1, wherein the first actuator changes a value of the first force according to a detection value of the first force detected by the detection unit. 5. The stage apparatus described in 1.   The stage apparatus according to claim 4, wherein the detection unit is a load cell. The first actuator includes a first member provided on the table, and a second member that generates the first force in cooperation with the first member in a non-contact manner. The stage apparatus according to claim 1, wherein a position of the second member in the support direction can be changed.   The said 1st actuator changes the said 1st force so that the said detected value which the said detection means detected becomes substantially equal to the weight of the said table, The any one of Claim 4 to 6 characterized by the above-mentioned. The stage apparatus described in 1. It said second actuator is a stage device according to any one of claims 1 to 7, characterized in that provided corresponding to the degrees of freedom of the table.   9. The stage apparatus according to claim 8, wherein the table has six degrees of freedom, and three second actuators are provided separately from the first actuator. A control method for a stage apparatus in which a table is mounted so as to be movable at least in the support direction of the table ,
A first force acting on the table in the support direction is applied to the table by the first actuator at the center of gravity of the table,
The second force acting in the support direction and different from the first force acts on the table in a non-contact manner at a position different from the position where the first force acts on the table. Given by a second actuator different from the one actuator,
A method for controlling a stage apparatus, wherein the first force is generated so as to be substantially equal to a weight of the table. Wherein the first force to support the weight of the table, a control method of a stage apparatus according to claim 1 0, characterized in that to carry out the position adjustment of said table by said second force.

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