JP3258194B2 - Exposure apparatus and exposure method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus used for manufacturing a semiconductor device, an LCD panel, etc., and to expose a pattern formed on an original plate to a substrate mounted on a stage via a projection lens. It relates to an exposure method.

[0002]

2. Description of the Related Art The configuration of an XY stage and a fine movement stage of a conventional semiconductor exposure apparatus is shown in FIG. The apparatus shown in FIG. 1 includes a mount 1, a surface plate 2 and a lens barrel surface plate 3 supported by the mount 1, a projection lens 4 having a structure integrated with the lens barrel surface plate 3, and A stage base 5 arranged and having a reference surface on an upper surface, a Y stage 6 arranged on the stage base 5 and movable in the Y direction, and an X stage arranged on the Y stage 6 and movable in the X direction 7 and
A fine movement stage 8 arranged on the X stage 7, an X stage position measurement mirror 9 and a Y stage position measurement mirror (not shown) arranged on the fine movement stage 8,
Laser interferometer for X stage 1 fixed to lens barrel base 3
A laser interferometer for the 0 and Y stages (not shown);
Three fine movement stage position detectors (not shown) that are fixed to the fine movement stage 8 and detect the Z direction position and the tilt amount of the fine movement stage 8 with reference to the upper surface of the X stage 7
A Y stage driving actuator (not shown) having a structure integrated with the stage base 5, and a Y stage 6
And an X-stage driving actuator 11 having an integral structure, and three fine-movement stage driving actuators (not shown) arranged on the X-stage 7. The wafer 12 is placed on the upper surface of the fine movement stage 8. The mount 1 is used to reduce the vibration caused by the vibration applied to the surface plate 2 when the XY stages 6 and 7 move, and to reduce the influence of floor vibration.

In the apparatus shown in FIG. 4 , X-stage position information is fed back by an X-stage laser interferometer 10, a current command for an X-stage driving actuator 11 is generated by a controller (not shown), and a motor driver is used to control the X-stage driving. Actuator 11 is driven to X
The stage 7 is positioned at a target position.

Further, the Y stage position information is fed back by a Y stage laser interferometer (not shown),
The controller generates a current command for a Y stage driving actuator (not shown), and drives a Y stage driving actuator (not shown) by a motor driver to drive the Y stage.
The stage 6 is positioned at a target position.

Further, the position information of the fine movement stage in the Z direction is fed back by three fine movement stage position detectors (not shown), and a current command for a fine movement stage driving actuator (not shown) is generated by the controller, and the driver gives a current command. The three fine movement stage driving actuators (not shown) are driven to position the fine movement stage 8 at the target position. In this case, for example, a piezo element is used as three actuators (not shown) for driving the fine movement stage, and the Z direction drive and the tilt drive of the fine movement stage 8 are performed by the three piezo elements. Then, as a fine movement stage position detector (not shown), a capacitance type non-contact minute displacement meter is arranged near each of the piezo elements, and the Z direction drive amount and the tilt drive amount of the fine movement stage 8 are measured to perform fine movement. The positioning of the stage 8 was controlled.

[0006]

However, in the above conventional example, the platen 2 receives a reaction force when the XY stages 6 and 7 are step-driven, and if the rigidity of the lens barrel platen 3 is low, the mirror The projection lens 4, which has a structure integral with the cylinder base 3, does not follow the vibration of the base 2, and it is one of the factors that influence the exposure performance of the apparatus. The reproducibility of the distance will be poor. Therefore, there is a disadvantage that the rigidity of the lens barrel base must be increased. Further, there is a defect that the planar processing accuracy of the reference surface of the stage base 5 and a change over time adversely affect the exposure performance.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems in the conventional example, and an exposure apparatus in which the rigidity of a lens barrel base, the accuracy of flat processing of a reference surface of a stage base, and changes over time does not directly affect exposure performance. And an exposure method .

[0008]

According to the present invention, there is provided an exposure apparatus for exposing a pattern formed on an original plate to a substrate mounted on a stage via a projection lens. A laser interferometer having a structure integrated with the stage, and a distance between the lower surface of the lens barrel base holding the projection lens and the upper surface of the stage is determined by laser.
Position detection of the user beam located on the lower surface of the barrel base
And a position detector for measuring the light reflected by the mirror . In this exposure apparatus, it is preferable to further provide control means for feeding back the output of the position detector and performing servo control on a target position in the Z direction of the stage. Thereby, the distance between the lower surface of the lens barrel base and the upper surface of the stage is always measured by the position detector,
The position information is fed back to servo the target position in the Z direction of the stage. That is, the position detection
Mirror on the lower surface of the barrel base near the projection lens
Laser beam emitted from the laser interferometer
A laser beam to the position detecting mirror and the laser interferometer.
The distance between the position detection mirrors is always measured, and the position
Feedback the information to move the stage to the target position in the Z direction.
Servo the unit.

In one embodiment of the present invention, there is provided an anti-vibration mount for supporting both a stage on which the substrate is mounted and a lens barrel base for holding the projection lens.
Thus, the distance between the lower surface of the lens barrel base and the upper surface of the stage is always measured by the position detector, and the position information is fed back to servo the stage to a target position in the Z direction. In a second aspect of the present invention, a separate anti-vibration mount is provided for supporting a stage on which the substrate is mounted and a lens barrel base holding the projection lens. Thus, the distance between the lower surface of the lens barrel base and the upper surface of the stage is always measured by the position detector, and the position information is fed back to servo the stage to a target position in the Z direction.

Further, the present invention relates to an exposure method for exposing a pattern formed on an original plate to a substrate mounted on a stage via a projection lens. An exposure method comprising: reflecting a laser beam of a laser interferometer from the stage by a position detecting mirror disposed on a lower surface, and measuring a distance between a lower surface of the lens barrel base and an upper surface of the stage. It is. In this exposure method, it is preferable that the position of the measured lower surface of the barrel base and the upper surface of the stage be fed back to control the stage.

[0011]

According to the present invention, there is provided an exposure apparatus for exposing a pattern formed on an original plate to a substrate mounted on a stage via a projection lens, wherein the stage and the structure are integrated. By providing a position detector that measures the distance between the lower surface of the lens barrel base holding the projection lens and the upper surface of the stage, the distance between the lower surface of the lens barrel base and the upper surface of the stage is always determined by the position detector. By measuring and feeding back the position information, the stage can be servo-controlled to a target position in the Z direction. As a result, the distance between the upper surface of the stage or the wafer surface and the lower surface of the projection lens is always constant, and is not directly affected by the rigidity of the lens barrel base, the planar processing accuracy of the reference surface of the stage base, or a change over time. As a result, it is not necessary to increase the rigidity of the lens barrel base, and the material cost of the base can be reduced and the weight of the apparatus can be reduced.
Further, it is not necessary to increase the planar processing accuracy of the reference surface of the stage base, and the stage base processing cost can be reduced.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. First Embodiment FIG. 1 shows a configuration of an exposure apparatus according to one embodiment of the present invention.
In the figure, members denoted by reference numerals 1 to 12 are
4 is common to the conventional example shown in FIG. Reference numeral 13 denotes a Z-direction position measuring laser interferometer having a structure integrated with the fine movement stage 8, and 14 reflects the laser beam emitted from the Z-direction position measuring laser interferometer 13 to reflect the Z-direction position. A Z-direction position measurement mirror for returning to the laser interferometer 13 and measuring the Z-direction position of the fine movement stage 8.

In the configuration shown in FIG. 1, the Z-direction position measuring mirror 14 has a size such that it can reflect the laser beam emitted from the Z-direction position measuring laser interferometer 13 over the entire movable range of the XY stage. The arrangement is decided. That is, assuming that the movable distance of the X stage 7 is A and the movable distance of the Y stage 6 is B, the Z direction position measuring mirror 14 is a plane mirror having a minimum size of A in the X direction and B in the Y direction. Is required.

In the apparatus shown in FIG. 1, three fine movement stage position detectors in the conventional apparatus shown in FIG. 4 are eliminated, and an X-direction pitching measurement laser interferometer (not shown) is provided near the X-stage laser interferometer 10. ) Is arranged, the laser beam emitted from the interferometer is applied to the mirror 9 for measuring the X-stage position, and the difference from the measurement value of the laser interferometer 10 for X-stage is calculated to measure the pitching amount in the X direction. Also Y
A laser interferometer for Y-direction pitching measurement (not shown) is arranged near a laser interferometer for stage (not shown), and a laser beam emitted from this interferometer is used for a mirror for Y-stage position measurement (not shown). , The difference from the measurement value of the Y stage laser interferometer is calculated, and the pitching amount in the Y direction is measured. A laser interferometer (not shown) for measuring the amount of rotation is arranged near the laser interferometer for the Y stage, and the laser beam emitted from this interferometer is applied to a mirror for measuring the Y stage position, and the laser interferometer for the Y stage is used. The difference from the measured value is calculated to measure the amount of rotation. Further, the Z
The translational amount in the Z direction is measured by the direction position measuring laser interferometer 13 to enable six-axis control of the stage system.

FIG. 2 shows a control block diagram of the stage system. The Z-direction position measuring laser interferometer 13 having a structure integrated with the fine movement stage 8 always measures the distance to the Z-direction position measuring mirror 14 arranged on the lower surface of the lens barrel base 3, and controls the stage system. Feedback to the device 21 and output a current command to the fine movement stage driver 22,
The fine movement stage driver 22 drives the fine movement stage actuator 23 to servo the fine movement stage to a target position. Further, a laser interferometer group 24 for measuring X and Y linear, X and Y pitches and θ arranged on the lower surface of the barrel base 3 (the laser interferometer 10 for the X stage, Y
The laser interferometer for the stage, the laser interferometer for the X-direction pitching measurement, the laser interferometer for the Y-direction pitching measurement, and the laser interferometer for the rotation amount measurement) always measures 5 axes and feeds back to the stage controller 21. The XY linear component outputs a current command to the XY stage motor driver 25, and the XY stage motor driver 25 drives the XY stage drive motor 26 to servo the XY stage to the target position. XY
The pitch component and the θ component output a current command to the fine movement stage driver 22, and the fine movement stage driver 22 drives the fine movement stage actuator 23 to servo the fine movement stage to the target position.

Thus, the distance between the lower surface of the lens barrel base 3 and the fine moving stage 8 is always measured by the Z direction position measuring laser interferometer 13, and the position information is fed back to move the fine moving stage 8 to the Z direction target position. The distance between the fine movement stage or wafer surface and the lower surface of the projection lens always coincides with the target distance, and the rigidity of the lens barrel base and the precision of flat processing of the reference surface of the stage base and changes over time. Will not be directly affected by That is, the reproducibility of the distance between the projection lens 4 and the upper surface of the wafer 12 can be maintained without being directly affected by the rigidity of the lens barrel base.
In addition, the effects of planar processing accuracy of the reference surface of the stage base 5 and changes with time can be corrected by the Z-direction servo of the fine movement stage.

( Second Embodiment) FIG. 3 is a drawing for explaining a second embodiment of the present invention. In the figure, reference numeral 1a denotes a first mount for supporting a lens barrel base, and 1b denotes a first mount for reducing vibration of the stage base 5 generated by movement of the XY stage and reducing the influence of floor vibration. Reference numeral 1c denotes a positioning platen for positioning the relative positions of the first mount 1a and the second mount 1b and installing these mounts. In the figure, 3 to 14 are the same as those of the first embodiment.

In the above configuration, the difference from the first embodiment is that the surface plate 2 is eliminated, and the support of the lens barrel surface plate 3 for holding the projection lens and the support of the stage surface plate 5 are performed by separate mounts. That is. The effect of this is the same as in the first embodiment.

[0019]

As described above, according to the present invention,
An exposure apparatus for exposing a pattern formed on an original plate to a substrate placed on a stage via a projection lens, wherein the stage and the structure are integrated, and a lens barrel base holding the projection lens By providing a position detector that measures the distance between the lower surface of the stage and the upper surface of the stage, the distance between the lower surface of the lens barrel base and the upper surface of the stage is always measured by the position detector, and the position information is fed back. The stage can be servo-controlled to a target position in the Z direction, the distance between the upper surface of the stage or the wafer surface and the lower surface of the projection lens is always constant, and the rigidity of the lens barrel base and the plane of the reference surface of the stage base are maintained. It is not directly affected by processing accuracy or aging. As a result, it is not necessary to increase the rigidity of the lens barrel base, and the material cost of the base can be reduced and the weight of the apparatus can be reduced. Further, it is not necessary to increase the planar processing accuracy of the reference surface of the stage base, and the stage base processing cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a first embodiment of the present invention.

FIG. 2 is a control block diagram of a stage system for explaining the first embodiment.

FIG. 3 is a diagram for explaining a second embodiment of the present invention.

FIG. 4 is a diagram for explaining a conventional example.

[Explanation of symbols]

1: Mount, 1a: First mount, 1b: Second mount, 1c: Positioning surface plate, 2: Surface plate, 3: Barrel surface plate, 4: Projection lens, 5: Stage surface plate, 6: Y Stage, 7: X stage, 8: fine movement stage, 9: mirror for X stage position measurement, 10: laser interferometer for X stage, 11: actuator for X stage drive, 12: wafer, 13: laser for Z direction position measurement Interferometer, 14:
Z-direction position measurement mirror, 21: controller, 22: fine movement stage driver, 23: fine movement stage actuator (θ, Z, tilt), 24: XY linear, XY pitch,
θ measurement laser interferometer, 25: motor driver for XY stage, 26: drive motor for XY stage.

Claims (6)

(57) [Claims] 1. A exposure apparatus for exposing a substrate placed on the stage via the projection lens pattern formed on the original plate, the stage and the structure together
Has a laser interferometer are, the distance between the lower surface and the stage upper surface of barrel platform that holds the projection lens, the laser
Beam for position detection arranged on the lower surface of the barrel base
An exposure apparatus, comprising: a position detector for measuring a light reflected by a mirror . 2. The exposure apparatus according to claim 1, further comprising control means for feeding back the output of said position detector to servo the Z-direction target position of said stage. 3. The exposure apparatus according to claim 2, further comprising an anti-vibration mount for supporting both the stage and the barrel base. 4. The exposure apparatus according to claim 2, further comprising separate anti-vibration mounts respectively supporting the stage and the lens barrel base. 5. An exposure method for exposing a pattern formed on an original plate to a substrate mounted on a stage via a projection lens, wherein the pattern is disposed on a lower surface of a lens barrel base holding the projection lens. An exposure method for reflecting a laser beam of a laser interferometer from the stage by the position detecting mirror and measuring a distance between a lower surface of the barrel base and an upper surface of the stage. 6. The control of the stage by feeding back measured position information on the distance between the lower surface of the lens barrel base and the upper surface of the stage.
6. The exposure method according to 5 .