JP3126645B2 - Scanning exposure apparatus, device manufacturing method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a scanning exposure apparatus used for manufacturing semiconductor elements, liquid crystal panels, etc., a device manufacturing method using the same, and a device manufactured by the manufacturing method.

[0002]

2. Description of the Related Art Conventionally, as a method of exposing a semiconductor element, a liquid crystal panel, or the like, a mask and a substrate (or wafer) are exposed through a projection optical system.
There is a method in which an image on the entire surface of a mask is transferred onto a substrate by carrying out scanning exposure while moving integrally on a carriage. However, a recent trend has been to reduce the cost of the liquid crystal panel by increasing the size of the substrate and increasing the number of liquid crystal panels that can be obtained from one substrate. As a problem that occurs at that time, there is a problem that the weight of the carriage that integrally holds the mask and the substrate increases due to the increase in the size of the substrate. As a result, it is difficult to control the carriage at high speed, and the throughput is greatly reduced. As a countermeasure, there is a method in which an individual scanning stage, a driving system, and a laser interferometer are provided for each of the mask and the substrate, and the image of the mask is transferred onto the substrate by synchronous driving (Japanese Patent Publication No. 5-15054).
In the case of this method, the carriage for connecting the conventional mask and the substrate is not required, and the scanning weight is greatly reduced. As a result, the synchronization between the mask and the substrate can be controlled at high speed, and the throughput is greatly improved. However, there are also new problems. That is, the position A of the main body structure where the interference part of the laser interferometer for measuring the position of the mask being scanned is mounted and the main body structure where the interference part of the laser interferometer for measuring the position of the substrate being scanned is mounted In the position B, a relative position change occurs between the positions A and B of the main body structure due to a weight movement accompanying the movement of the moving body or a reaction force at the time of acceleration of the moving body. As a result, a synchronization position error occurs between the mask and the substrate, and the overlay accuracy deteriorates.

This will be specifically described with reference to FIG.
FIG. 2 shows a configuration of an exposure apparatus according to a conventional example. In the drawing, 1 is a mask on which a printing pattern is formed, 2 is a mask stage on which the mask 1 is mounted and can be moved in the X, Y and θ directions, and 3 is a large number of masks on the surface thereof for manufacturing a liquid crystal display panel. A glass substrate on which pixels and switching transistors for controlling on / off of these pixels are formed by ordinary photolithography means; 4 a substrate stage which can hold the substrate 3 and move in the X, Y and θ directions It is.

An illumination optical system 5 illuminates the mask 1 located at the exposure position with light of a specific wavelength. The illumination optical system 5 exposes a photosensitive layer on the substrate 3 through a pattern on the mask 1 so as to expose the mask 1 on the mask 1. This is for enabling the pattern to be transferred to the substrate 3. Reference numeral 6 denotes a concave mirror, which constitutes a well-known mirror projection system in combination with the convex mirror 7 and the bending mirror 8, and projects a pattern image of the mask 1 aligned at a predetermined position on the substrate 3 by the mask stage 2 at the same magnification. Is what you do.

Reference numeral 9 denotes a base platen on which the substrate stage 4 is mounted, and reference numeral 10 denotes a mask stage platen on which the mask stage 2 is mounted. The mask stage base 10 is connected to the base base 9 by a connection plate 11. 12
And 14 are motors for moving the mask stage 2 and the substrate stage 4 in the X direction, respectively. 13
And 15 are length measuring devices for monitoring the positions of the stages 2 and 4, ie, the mask 1 and the substrate 3, respectively, and are, for example, laser interferometers.

Reference numeral 16 denotes motors 12 and 1 based on stage position information of the laser interferometers 13 and 15 during scanning exposure.
By controlling the driving amount of stage 4, stages 2 and 4
Are synchronized with each other. The control circuit 16 drives, for example, the motor 12 at a constant voltage to make the mask stage 2 run at a constant speed, and the laser interferometers 13 and 1
The drive amount corresponding to the positions of the stages 2 and 4 measured at 5 is supplied to the motor 14 to move the substrate stage 4.
In this case, the moving speed of each stage does not necessarily have to be the same, and an appropriate speed ratio may be provided.

A problem that occurs in the case of this control method is that the weight accompanying the movement of the moving body between the members to which the length measuring devices 13 and 15 for monitoring the moving positions of the mask stage 2 and the substrate stage 4 are attached. The relative position changes due to the reaction force at the time of movement or acceleration of the moving body. In this case, the relative position change cannot be corrected by the above-described control method, and a synchronous position error occurs between the mask 1 and the substrate 3 by the relative position change amount, so that the mask pattern cannot be transferred to a predetermined position on the substrate. As a result, a characteristic failure of the switching transistor for controlling the pixel occurs.

SUMMARY OF THE INVENTION An object of the present invention is to provide a scanning exposure apparatus capable of performing high-accuracy exposure transfer and capable of coping with high integration of semiconductor elements and high definition of a liquid crystal display panel in view of the problems of the prior art. Is to provide.

[0009]

To achieve this object, a scanning exposure apparatus according to the present invention comprises a first moving means for moving an original, a first measuring means for measuring the position of the original, and a substrate. , A second measuring means for measuring the position of the substrate, an illumination optical system for illuminating the pattern on the original, and a first measuring means based on the measured values of the first measuring means and the second measuring means. A control unit for controlling the driving of the moving unit and the second moving unit; and a pattern on the original by scanning and exposing while moving the original and the substrate relative to the illumination optical system in a state of being aligned. Scanning exposure apparatus for transferring the first position on a substrate, the third position measuring unit for measuring a relative position between the first measuring unit and the second measuring unit, and the control unit sets the first position in consideration of the relative position. Means of transport or second
The method is characterized in that an error in the alignment state caused by a change in the relative position is corrected by driving the moving means.

The third measuring means is a laser interferometer fixed near the first or second measuring means, and measures the position of the second or first measuring means which is not located near the first or second measuring means. It is characterized by the following.

Further, the present invention is characterized in that it is of a step-and-scan type in which scanning exposure is repeated every time the substrate is stepped.

In addition, the apparatus has a projection optical system, and scan exposure is performed through the projection optical system.

Further, the projection optical system is characterized in that it is a mirror projection optical system.

The projection optical system is a lens projection optical system.

Further, the projection optical system is a reduction projection optical system.

Further, according to the device manufacturing method of the present invention, while the position of the original plate and the position of the substrate are respectively measured by the first and second measuring means, the original plate and the substrate are positionally matched based on the measurement results. In a device manufacturing method in which a pattern on an original is transferred onto a substrate by performing scanning exposure while relatively moving the illumination optical system in a state, a third measurement unit sets a relative position between the first and second measurement units. The method is characterized in that, while measuring the position, the movement is performed in an aligned state based on the measurement result.

The third measuring means is a laser interferometer fixed near the first or second measuring means, and measures the position of the second or first measuring means which is not located near the first or second measuring means. It is characterized by the following.

Further, the present invention is characterized in that step-and-scan type exposure is performed in which scanning exposure is repeated every time the substrate is stepped.

Further, it has a projection optical system, and the scanning exposure is performed through this projection optical system.

Also, the projection optical system is characterized in that it is a mirror projection optical system.

Further, the projection optical system is characterized in that it is a lens projection optical system.

The projection optical system is a reduction projection optical system.

The device of the present invention measures the position of the original plate and the position of the substrate by the first and second measuring means, respectively, and moves the original plate and the substrate synchronously based on the measurement results. A device manufacturing method for scanning and exposing a pattern of an original onto a substrate, comprising:
And measuring the relative position between the first and second measuring means by the measuring means, and performing a synchronous movement based on the measurement result.

Thus, the relative position change between the first measuring means and the second measuring means, that is, the synchronization error due to the deformation of the main body structure on which these measuring means are installed is corrected.

[0025]

FIG. 1 is a view showing the arrangement of an exposure apparatus according to one embodiment of the present invention. In this device, the following elements 17 to 20 are added to those in FIG. That is, reference numeral 17 denotes a length measuring device, for example, a laser interferometer, which is mounted near the measuring device 15 for measuring the position of the substrate stage 4 and which is mounted on the base plate 9.
9 is fixed. The length measuring device 17 is a measurement for measuring a change in the position of the mask stage base 10 to which the measuring device 13 for measuring the position of the mask stage 2 is fixed via a bending mirror 18 fixed to a gantry 19. It is a vessel.
The control circuit 20 controls the amount of drive to the motors 12 and 14 based on the stage position information of the laser interferometers 13 and 15 and the relative position change information of the main body structure of the laser interferometer 17 during scanning exposure. The stages 2 and 4 are moved in synchronization with each other. More specifically, for example, the mask stage 2 is driven at a constant speed by driving the motor 12 at a constant voltage, and the laser interferometer is adjusted to a driving amount corresponding to the positions of the stages 2 and 4 measured by the laser interferometers 13 and 15. 1
The substrate stage 4 may be moved by supplying the motor 14 with a drive amount obtained by adding a drive amount corresponding to the position change amount measured in step 7. Although a mirror projection optical system is used as the projection optical system in the above description, a lens projection optical system can be used instead. Further, the length measuring device for measuring the amount of deformation of the main body structure is not necessarily limited to the laser interferometer, but may be a minute displacement measuring device such as a capacitance sensor.

[0026]

As described above, the present invention has the third measuring means for measuring the relative position between the first measuring means and the second measuring means, and performs the first movement in consideration of the relative position. A main body having a measuring device mounted thereon for measuring the respective positions of the original (mask) and the substrate (wafer) because the synchronization error caused by the relative position change is corrected by driving the means or the second moving means. The structure can correct a synchronous position error caused by a relative position change at the time of scanning exposure, and the pattern of the mask can be transferred onto the substrate with high placement accuracy. As a result, it is possible to sufficiently cope with higher integration of semiconductor elements and higher definition of liquid crystal display panels, which will be further advanced in the future.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an exposure apparatus according to one embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing an exposure apparatus according to a conventional example.

[Explanation of symbols]

1: mask, 2: mask stage, 3: substrate, 4: substrate stage, 5: illumination system, 6: concave mirror, 7: convex mirror, 8:
Folding mirror, 9: base platen, 10: mask stage platen, 11: connecting plate, 12, 14: motor, 13, 15,
17: length measuring device, 16, 20: control circuit, 18: bending mirror, 19: mount.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 21/027

Claims (15)

(57) [Claims] 1. A first moving means for moving an original, a first measuring means for measuring a position of the original, a second moving means for moving a substrate, and a second measuring means for measuring a position of the substrate. An illumination optical system for illuminating the pattern on the original,
And control means for controlling the driving of the first moving means and the second moving means based on the measurement values of the first measuring means and the second measuring means, wherein the original and the substrate are aligned in position. A scanning exposure apparatus for transferring a pattern on the original onto the substrate by performing scan exposure while relatively moving with respect to the illumination optical system, wherein the first measurement unit and the second measurement unit A third measuring unit that measures a relative position, wherein the control unit drives the first moving unit or the second moving unit in consideration of the relative position, and the control unit causes the change in the relative position. A scanning exposure apparatus for correcting an error in a matching state. 2. The third measuring means is a laser interferometer fixed near the first or second measuring means, and measures the position of the second or first measuring means not located near the first or second measuring means. The device manufacturing apparatus according to claim 1, wherein the device manufacturing apparatus is a device. 3. The scanning exposure apparatus according to claim 1, wherein the scanning exposure apparatus is of a step-and-scan method in which the scanning exposure is repeated every time the substrate is stepped. 4. A scanning exposure apparatus according to claim 1, further comprising a projection optical system, wherein said scanning exposure is performed via said projection optical system. 5. A scanning exposure apparatus according to claim 4, wherein said projection optical system is a mirror projection optical system. 6. The scanning exposure apparatus according to claim 4, wherein said projection optical system is a lens projection optical system. 7. The scanning exposure apparatus according to claim 4, wherein said projection optical system is a reduction projection optical system. 8. The illumination optical system in a state where the position of the original and the position of the substrate are measured by the first and second measuring means, respectively, and the position of the original and the substrate are aligned based on the measurement results. A device for transferring the pattern on the original onto the substrate by scanning and exposing the substrate while moving relatively to each other, wherein a relative position between the first and second measuring units is measured by a third measuring unit. And performing movement in the aligned state based on the measurement result. 9. The third measuring means is a laser interferometer fixed near the first or second measuring means, and measures the position of the second or first measuring means which is not located near the first or second measuring means. The device manufacturing method according to claim 8, wherein 10. The device manufacturing method according to claim 8, wherein the step-and-scan exposure is performed by repeating the scan exposure each time the substrate is stepped. 11. The device manufacturing method according to claim 8, further comprising a projection optical system, wherein the scanning exposure is performed via the projection optical system. 12. The device manufacturing method according to claim 11, wherein the projection optical system is a mirror projection optical system. 13. The device manufacturing method according to claim 11, wherein said projection optical system is a lens projection optical system. 14. The device manufacturing method according to claim 11, wherein said projection optical system is a reduction projection optical system. 15. A pattern of the original is measured while the position of the original and the position of the substrate are measured by first and second measuring means, respectively, and the original and the substrate are synchronously moved based on the measurement results. A device manufacturing method for performing scanning exposure on the substrate, wherein a third measuring unit measures a relative position between the first and second measuring units, and performs the synchronized movement based on the measurement result. A device manufactured by a device manufacturing method.