JP5319378B2 - Drive apparatus, exposure apparatus, and device manufacturing method - Google Patents

Description

  The present invention relates to a driving apparatus, an exposure apparatus including the driving apparatus, and a device manufacturing method for manufacturing a device using the driving apparatus.

  An exposure apparatus is used in a lithography process for manufacturing a device such as a display device or an integrated circuit device. The exposure apparatus projects a pattern of an original (also called a mask or a reticle) onto a substrate (for example, a glass substrate or a semiconductor substrate) and exposes the substrate.

  The exposure apparatus is provided with a driving device (stage device) for positioning the substrate. FIG. 4 is a diagram illustrating an example of a driving device. The X guide 7 is driven in the Y direction by a linear motor 9, and the position of the X guide 7 in the X direction is restrained by a guide (YAW guide) 3 and a slider (YAW slider) 6. Further, the X guide 7 is supported by the surface plate 13 at one end side via the YL slider 4 and at the other end side via the YR slider 5. The X movable portion 8 is guided by the X guide 7 so as to move along the X direction. The X movable portion 8 is supported by the surface plate 13 via the X slider 14. The substrate stage S that holds the substrate is supported by the X movable portion 8.

  In the driving device that drives the substrate, pitching and yawing may occur due to the accuracy of the guide surface. Patent Document 1 discloses a technique for maintaining the posture of a movable body by controlling the pressure of gas supplied to an air slider.

JP 58-25637 A

  In the driving apparatus as shown in FIG. 4, the X movable portion 8 that supports the substrate stage S and the X guide 7 are both supported by the surface plate 13, so that the X guide even if the X movable portion 8 moves in the X direction. The load applied to 7 does not fluctuate. Accordingly, conventionally, posture fluctuations such as pitching and yawing due to the movement of the substrate stage have not been considered.

  However, in the current situation in which the substrate becomes larger, in the configuration as shown in FIG. 4, it is necessary to manufacture the large surface plate 13 with high surface accuracy. Therefore, at present, the driving device illustrated in FIG. 1 is used. Tend to. In the driving apparatus as illustrated in FIG. 1, a YL slider 4 is provided at a lower portion on one end side of an X guide 7 moving in the Y direction, and a YR slider 5 is provided at a lower portion on the other end side. The YL slider 4 and the YR slider 5 are guided in a floating state by the guides 2 and 2 '. The X guide 7 is driven in the Y direction by a linear motor 9. The X movable portion 8 that supports the substrate stage S moves in the X direction while being supported and guided by the X guide 7. The position of the X guide 7 in the X direction is restrained by the slider 6 connected to the X guide 7 and the guide 3. The guides 2, 2 ′ and the guide 3 are supported by a vibration isolation table (surface plate) 1.

  In the configuration shown in FIG. 1, when the X movable portion 8 supporting the substrate stage S moves in the X direction, the load applied to the YL slider 4 and the YR slider 5 varies. As a result, the flying height of the YL slider 4 and the YR slider 5 (in other words, the flying height of the X movable portion 8 at the portion where the YL slider 4 and the YR slider 5 are disposed) can vary. Such a variation in the flying height causes a variation in the posture of the substrate stage S in the rolling direction (around the Y axis).

  In recent years, the stroke in the X direction of the stage S has increased, while the size of the vibration isolation table 1 is limited by the limit of manufacturing and the limit of the transportable width. Therefore, the distance between the YL slider 4 and the YR slider 5 is also limited. Therefore, the influence of the load fluctuation due to the movement of the stage S (X movable portion 8) in the X direction becomes larger, and the posture accuracy in the rolling direction can be further lowered.

  In order to solve the above problems, a method of controlling the pressure of the gas supplied to the gas bearing for levitating the slider according to the method described in Patent Document 1 can be considered. However, in such a method, there is a limit in responsiveness and accuracy, and the posture of the movable part (or the driving object) cannot be controlled with high accuracy.

  The present invention has been made in view of the above background, and an object of the present invention is to control the attitude of a movable part with high accuracy, for example.

  One aspect of the present invention relates to a drive device, which includes a first movable portion that moves in a first direction and a gas that floats and supports the first movable portion on one end side and the other end side thereof. Two levitation mechanisms each including a bearing, a second movable part that moves in a second direction orthogonal to the first direction while being supported and guided by the first movable part, and a control unit that controls the two levitation mechanisms And the two levitation mechanisms each include an electromagnet that changes the levitation amount of the first movable part by a magnetic force, and the control unit excites the electromagnets of the two levitation mechanisms. Control is performed according to the position of the two movable parts in the second direction.

  According to the present invention, for example, the posture of the movable part can be controlled with high accuracy.

It is a perspective view which shows schematic structure of the drive device of suitable embodiment of this invention. It is a front view which shows schematic structure of the drive device of suitable embodiment of this invention. It is a figure which shows the preload value which a preload mechanism should generate | occur | produce in order to maintain the gap (flying amount) of a YL slider and a YR slider, and a guide constant. It is a figure which shows an example of a drive device. It is a figure which shows schematic structure of the control system with which a drive device is provided in order to maintain the gap (flying amount) of a YL slider and a YR slider, and a guide constant. It is a figure which shows schematic structure of the exposure apparatus of suitable embodiment of this invention.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

  1 and 2 are a perspective view and a front view showing a schematic configuration of a drive device according to a preferred embodiment of the present invention. The driving device 100 is configured to drive and position the substrate stage S, which is a driving object, in the X direction (second direction) and the Y direction (first direction). The drive device 100 may further incorporate a mechanism for driving and positioning the substrate stage S in the Z direction. The driving device 100 may further incorporate a mechanism for driving and positioning the substrate stage S about axes in the X, Y, and Z directions. Note that the X, Y, and Z directions are orthogonal to each other and follow the XYZ coordinate system. The substrate stage S is provided with a mirror 10 for measuring its position with an interferometer.

  A YL slider 4 is provided at a lower portion on one end side of an X guide (Y movable portion or first movable portion) 7 that moves in the Y direction, and a YR slider 5 is provided at a lower portion on the other end side. The YL slider 4 and the YR slider 5 are guided while being supported in a floating state via gas bearings by floating mechanisms (guide mechanisms) G and G ′, respectively. Therefore, the X guide 7 is guided while being supported in a floating state via the gas bearings by the two floating mechanisms G and G ′ on one end side and the other end side thereof.

  The levitation mechanism (guide mechanism) G includes a guide 2 fixed on a vibration isolation table (surface plate) 1, a gas injection unit 11 constituting a gas bearing, and a preload for attracting the YL slider 4 to the guide 2 side. The magnetic body 12 and the electromagnet 56 which comprise a mechanism are included. The levitation mechanism (guide mechanism) G ′ guides the guide 2 ′ fixed on the vibration isolation table (surface plate) 1, the gas injection part 11 ′ constituting the gas bearing, the YR slider 5 and the YR slider 5. It includes a magnetic body 12 ′ and an electromagnet 56 ′ constituting a preload mechanism for attracting to the 2 ′ side. The guides 2 and 2 'may be integrated with the vibration isolation table (surface plate) 1, or the surface of the vibration isolation table (surface plate) 1 may be used as the guides 2 and 2'.

  The gas injection unit 11 for levitating the X guide 7 (or the YL slider 4 and the YR slider 5) can typically be incorporated in the YL slider 4 and the YR slider 5.

  In a preferred embodiment, the magnetic bodies 12 and 12 ′ are provided on the YL slider 4 and the YR slider 5, and the electromagnets 56 and 56 ′ are provided on the guides 2 and 2 ′. Such an arrangement includes a current line (not shown) for supplying current to the electromagnets 56 and 56 ', and a cooling line (not shown) connected to the cooling channel C for recovering the heat generated by the electromagnets 56 and 56'. ) Is preferable from the viewpoint of avoiding dragging by the movement of the X guide 7.

  The X guide 7 is driven in the Y direction by a linear motor 9. The X movable portion 8 that supports the substrate stage S moves in the X direction while being supported and guided by an X guide (Y movable portion or first movable portion) 7. The position of the X guide 7 in the X direction is restrained by the slider 6 connected to the X guide 7 and the guide 3 fixed on the vibration isolation table (surface plate) 1.

  All the loads of the X movable part (second movable part) 8 and the substrate stage S supported thereby are supported by the X guide (Y movable part or first movable part) 7. The load applied to the YL slider 4 (in other words, the guide mechanism G) and the YR slider 5 (in other words, the guide mechanism G ′) varies according to the position of the X movable portion 8 in the X direction.

Here, the force applied to the YL slider 4 is F _L , the force applied to the YR slider 5 is F _R , the distance of the YL slider 4 from the origin (X = 0) in the movement range of the X movable unit 8 is L _L , and the X movable unit the distance YR slider 5 and _{L R} 8 origin (X = 0). Further, the weight of the X guide (Y movable portion) 7 is M _y , the distance from the origin (X = 0) of the X movable portion 8 to the center of gravity of the X guide 7 is L _My , and the weight of the X movable portion 8 is M _X , The distance from the reference position of the X movable part 8 to the center of gravity of the X movable part 8 is _{defined as LMx} . In addition, the amount of movement in the X direction (the distance from the origin (X = 0) to the reference position of the X movable unit 8) is x.

Force according to the force applied to the YL slider 4 _F L, the YR slider 5 _{F R} can be calculated according to the following equation. In addition, g is a gravitational acceleration.

F _L = [M _y · g · (L _L + L _My ) + M _X · g · {L _L + (x−L _Mx )}] / (L _L + L _R )
_{F L = [M y · g} · (L R -L My) + M X · g · {L R - (x-L Mx)}] / (L L + L R)
The distance between the YL slider 4 and the YR slider 5 and the guides 2 and 2 (that is, the flying height) depends on the characteristics of the gas bearing constituted by the gas injection unit 11, the magnetic bodies 12 and 12 ', and the electromagnets 56 and 56'. Depending on the characteristics of the preload mechanism to be constructed.

  In this embodiment, the gap (that is, the flying height) between the YL slider 4 and the YR slider 5 and the guides 2 and 2 is controlled by controlling the preload mechanism, and more specifically, the magnetic force generated by the electromagnets 56 and 56 ′ (that is, The excitation current of the electromagnets 56 and 56 ′ is controlled. That is, in this embodiment, the gap (that is, the flying height) between the YL slider 4 and the YR slider 5 and the guides 2 and 2 is changed by controlling the excitation current of the electromagnets 56 and 56 '. On the other hand, the pressure of the gas supplied to the gas bearing is kept constant. Therefore, according to this embodiment, compared with the method of controlling the flying height by the pressure of the gas supplied to the gas bearing, the responsiveness and accuracy of controlling the flying height (rolling) are dramatically improved.

  In one embodiment, a plurality of electromagnets 56 may be arranged along the Y direction on the YL slider 4 and the YR slider 5. The electromagnet 56 excited among the plurality of electromagnets 56 can be changed according to the position in the Y direction of the X guide 7 (YL slider 4, YR slider 5). In another embodiment, one electromagnet 56 may be arranged to cover the movement range in the Y direction of the YL slider 4, and one electromagnet 56 may be arranged to cover the movement range in the Y direction of the YR slider 5. .

  FIG. 3 is a diagram exemplarily showing preload values that should be generated by the preload mechanism (magnetic body 12, electromagnet 56) in order to maintain a constant gap (flying amount) between the YL slider 4, the YR slider 5, and the guide 2. It is. The horizontal axis in FIG. 3 is the position (x) in the X direction of the X movable portion 8, and the vertical axis is the preload value for the YL slider 4 and the YR slider 5. For example, when the X movable portion 8 moves in the positive direction (direction in which x increases), the load applied to the YR slider 5 increases. Therefore, when the X movable portion 8 moves in the positive direction (direction in which x increases), the preload value for the YR slider 5 is decreased accordingly. Since the pressure of the gas supplied to the gas bearing is kept constant, a decrease in the preload value means an increase in the force that causes the YR slider 5 to float.

  The preload values illustrated in FIG. 3 are determined at a plurality of positions in the X direction so that no rolling occurs while measuring the rolling of the substrate stage S with a measuring instrument such as a collimator during adjustment of the driving device 100. It can be obtained by approximating the result with a curve.

  By controlling the excitation of the electromagnets 56, 56 'of the preload mechanism on the YL slider 4 side and YR slider 5 side so as to generate the preload value illustrated in FIG. 3, the YL slider 4, YR slider 5 and the guides 2, 2 are controlled. The gap (the flying height) can be kept constant. Thereby, rolling (rotation around the axis in the Y direction or inclination) associated with the movement of the X movable portion 8 in the X direction can be reduced.

  FIG. 5 is a diagram showing a schematic configuration of a control system provided in the driving device 100 in order to maintain a constant gap (flying amount) between the YL slider 4 and the YR slider 5 and the guide 2. The control unit CNT calculates a command value for causing the electromagnets 56 and 56 ′ to generate a preload value as illustrated in FIG. 3 according to the position (x) in the X direction of the substrate stage S (X movable unit 8). , YL guide side driver DL and YR guide side driver DL ′. The YL guide side driver DL and the YR guide side driver DL 'excite the electromagnets 56 and 56' according to the command value.

  In a configuration in which a plurality of electromagnets 56 and a plurality of electromagnets 56 ′ are arranged along the Y direction, Y of the substrate stage S (X movable portion 8) is determined in order to determine which electromagnet 56, 56 ′ is excited. The position (y) in the direction is input to the control unit CNT and used.

  FIG. 6 is a view showing the schematic arrangement of an exposure apparatus according to a preferred embodiment of the present invention. An exposure apparatus EX according to a preferred embodiment of the present invention is configured to project a pattern of an original R onto a substrate (for example, a glass substrate or a semiconductor substrate) P to expose the substrate P. The exposure apparatus EX includes an original stage RS that holds the original R, a substrate stage S that holds the substrate P, a projection optical system PO that projects the pattern of the original R onto the substrate P, and the driving device 100 described above. The driving device 100 is configured to support the substrate stage S by the X movable part (second movable part) 8.

  A device manufacturing method according to a preferred embodiment of the present invention is suitable for manufacturing semiconductor devices and liquid crystal devices, for example, and a pattern of an original is formed on the photosensitive agent on the substrate coated with the photosensitive agent using the above exposure apparatus. A step of transferring and a step of developing the photosensitive agent can be included. Furthermore, the device is manufactured through other known processes (etching, resist stripping, dicing, bonding, packaging, etc.).

Claims (5)

A first movable part that moves in a first direction;
Two levitation mechanisms each including a gas bearing that levitates and supports the first movable part at one end side and the other end side thereof;
A second movable part that moves in a second direction orthogonal to the first direction while being supported and guided by the first movable part;
A control unit for controlling the two levitation mechanisms;
Each of the two levitation mechanisms includes an electromagnet that changes the levitation amount of the first movable part by a magnetic force,
The control unit controls excitation of the electromagnets of the two levitation mechanisms according to a position of the second movable unit in the second direction;
A drive device characterized by that. The control unit controls excitation of the electromagnets of the two levitation mechanisms so as to reduce an inclination of the first movable unit accompanying movement of the second movable unit;
The drive device according to claim 1. The two levitation mechanisms each include a guide, and the electromagnet is disposed on the guide,
The first movable part includes a magnetic body.
The drive device according to claim 1, wherein the drive device is provided. An exposure apparatus for exposing a substrate,
A substrate stage for holding the substrate;
A drive device according to any one of claims 1 to 3,
The substrate stage is supported by the second movable part in the driving device,
An exposure apparatus characterized by that. A step of exposing the substrate using the exposure apparatus according to claim 4;
Developing the substrate exposed in the step;
A device manufacturing method comprising:

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