JP4422843B2 - Scan exposure equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an exposure apparatus that can efficiently perform exposure of an electronic circuit pattern formed on a glass plate or a silicon wafer in a short time.
[0002]
[Prior art]
In order to manufacture a device such as a liquid crystal panel, a fine electronic circuit is formed on a glass plate by an exposure apparatus. In recent years, with the increase in size of liquid crystal panels, an exposure apparatus used for manufacturing these devices has attracted attention as an apparatus that performs scanning exposure by synchronizing a mask stage and a plate stage.
[0003]
As for a conventional scanning exposure apparatus, as described in Japanese Patent Application Laid-Open No. 9-69481, a master that controls a driving system with low responsiveness as a master and a driving system on the mask stage side with high responsiveness as a slave. Some have taken the slave synchronous control method.
[0004]
In the master-slave synchronous control system, as shown in FIG. 6, the master drive system has a master speed command value generator 50 that generates a speed command value, and a speed comparator of speed control means that operates to follow the speed command. 51, the speed compensator 52, and the like, and the speed information v1 to be controlled and the position information y1 obtained by the integrator 54 are output.
[0005]
The slave drive system inputs the speed information v1 of the master control system as a speed command value, and the speed comparator 61 and the speed compensator 62 of the speed control system that operate to follow the speed command value, and the master It has a position control system that detects the slave relative position with the position comparator 60 and operates the slave side position information y2 obtained from the integrator 64 so as to follow the master side position information y1. The drive system was synchronously scanned to perform exposure processing. In FIG. 6, reference numerals 57 and 67 denote position compensators.
[0006]
[Problems to be solved by the invention]
However, in the above-mentioned conventional example, in the master / slave control system, when the relative position in the scanning direction between the master and the slave is about to move to a position that is significantly different from that during the synchronous scan after the synchronous scan exposure, the stage is temporarily stopped and the master・ Slave synchronization was required, and the two-axis stage had to be driven separately and moved to the target position. For this reason, the tact time of the apparatus has been reduced.
The present invention eliminates the cause of a decrease in tact time in the conventional exposure apparatus, maintains high synchronization accuracy, and moves to the next stage position without stopping the stage after the synchronous scan exposure is completed. An object of the present invention is to provide an exposure apparatus that can contribute to an improvement in throughput of the apparatus and the entire production line.
[0007]
[Means for Solving the Problems]
To achieve the above object, the present onset bright, has two control system for driving and controlling each individually operable two controlled object, and master less responsive drive system, highly responsive driving An exposure apparatus constituting a master / slave control system with a system as a slave, the master drive system having a speed control system that operates to follow the speed command value generated by the master system speed command value generator and outputs a position information and speed information of the object to be controlled, the slave drive system, of the velocity information outputted from the driving system of the speed command value or the master which is generated by the slave system speed command value generator , a speed control system which operates to follow either selected by the first switching hands stage, the driving system of the position command or the master obtained from the slave system speed instruction value generator Of the force is a value obtained by adding the offset to the position information is, the master by a second switch and a position control system which operates to follow either selected by the hand stage, the first and second switching means by the information output from the drive system is selected, the drive system of the slave and the drive system of the master are controlled synchronously, to switch the toggle means in a pre-specified position during the synchronous driving I it, the synchronization of the two drive system is disconnected in and said Rukoto are individually driven to.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
In the exposure apparatus according to the embodiment of the present invention, the speed command value generator, which has been conventionally only one on the master side at the time of synchronous scanning, is prepared for both the master and the slave. The slave side follows control of the side speed command value generator, and the slave side performs control to follow the master. When the exposure period ends, the slave side is immediately switched to follow the slave side speed command value generator. This switching is performed by comparing the master position information with the synchronous switching position calculated in advance from the exposure range. In addition, when switching, in order not to increase the speed deviation and position deviation of the slave system, the value obtained by adding the relative position offset between the master and slave to the master system speed command value generator is also obtained in the slave system even during the synchronization period. The speed command value generator is also generated at the same time. Thus, smooth signal switching is performed, and master-slave synchronization can be disconnected without stopping the stage, and switching to individual control of each drive system is possible.
[0009]
With the above configuration, after the synchronous scan exposure, when moving to the exposure preparation position or home position of the next shot (shot), the stage is not temporarily stopped. It is possible to perform a continuous exposure operation without causing a decrease in time.
[0010]
【Example】
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a basic block diagram showing a scan exposure apparatus according to an embodiment of the present invention. In FIG. 1, 1 is a photomask, and a circuit pattern of a liquid crystal panel is formed on the photomask 1. A mask stage 2 on which the photomask 1 is mounted has a structure that can be driven in the Y direction along a yaw guide (not shown). The scanning direction position of the mask stage 2 is measured by the laser interferometer 3 a, and the measurement result is transferred to the stage control circuit 30 via the communication bus 31. In this exposure apparatus, the stage control circuit 30 calculates an output current command value to the mask stage linear motor 4a, and drives the mask stage linear motor 4a via the D / A converter 32a and the power amplifier 33a. .
The mirror optical system 20 is composed of a concave mirror and a convex mirror, and forms an image on its image plane in an arc shape at an equal magnification.
[0011]
Reference numeral 12 denotes a glass plate having a resist coated on the surface, and a plurality of exposed areas (shots) formed in the previous exposure process are arranged. Reference numeral 11 denotes a plate stage on which the glass plate 12 is mounted. The plate stage 11 receives a glass plate 12 and sucks and fixes it to the upper surface, an XY stage that horizontally moves in the X-axis direction and the Y-axis direction, and a mirror optical system 20 that moves in the axial direction that is the optical axis direction. , A rotation stage that can rotate around an axis parallel to the Z axis, and the like, and has a 6-axis configuration for matching the circuit pattern formed on the mask 1 on the glass plate 12.
[0012]
The scanning direction position of the plate stage 11 is measured by the laser interferometer 3 b, and the measurement result is transferred to the stage control circuit 30 via the communication bus 31. The stage control circuit 30 calculates an output current command value to the plate stage linear motor 4b, and drives and controls the plate stage linear motor 4b via the D / A converter 32b and the power amplifier 33b. In FIG. 1, reference numeral 34 denotes a clock.
[0013]
FIG. 2 shows a control configuration originally realized in the control circuit. Here, the plate stage 11 side with low responsiveness is set as a master, and the mask stage 2 side is set as a slave. FIG. 2 showing the synchronous control configuration shows a control configuration aiming at two-axis synchronization with the position information of each axis as y1 and y2 and the speed information as v1 and v2. Hereinafter, description will be made according to the signal flow. First, this control system has two control modes, and the control mode is switched by a signal selector 107 surrounded by a broken line.
[0014]
The speed command value is generated by the generator 108a and input to the master system. At the time of synchronous driving, this command value is input only to the master system and does not directly act on the slave system. The comparator 104a compares the speed command value with the speed v1, and the deviation signal is input to the speed compensator 102a. The output of the speed compensator 102a becomes an operation amount input to the master side linear motor 4b via the master D / A converter 32b and the power amplifier 33b. The dynamic characteristic 101a of the master system is represented by a transfer function Q1, and a speed control system minor loop is configured together with the speed compensator transfer function Cv. Reference numeral 103a denotes an integrator, which shows the relationship between the velocity v1 and the corresponding position y1. The master system has been described so far, but the same applies to the slave system, and the reference numerals are also associated.
[0015]
That is, the speed command value is generated by the generator 108b and input to the slave system. At the time of synchronous driving, this command value is input only to the slave system and does not directly act on the master system. The speed command value is compared with the speed v2 by the comparator 104b, and the deviation signal is input to the speed compensator 102b. The output of the speed compensator 102b becomes an operation amount input to the slave side linear motor 4a through the slave D / A converter 32a and the power amplifier 33a. The dynamic characteristic 101b of the slave system is represented by a transfer function Q1, and a speed control system minor loop is configured together with the speed compensator transfer function Cv. Reference numeral 103b denotes an integrator, which shows the relationship between the velocity v2 and the corresponding position y2.
[0016]
Hereinafter, switching of synchronization control in accordance with an actual exposure sequence will be described.
FIG. 3 is a flowchart showing an exposure sequence in the scanning exposure apparatus. This flowchart shows a second exposure step (2nd Layer) sequence in which exposure is performed in accordance with the pattern formed in the previous exposure step. In this second exposure step, in order to improve the tact time, the alignment measurement is performed in the order from the first shot (1stshot) to the nth shot. After the alignment measurement of all shots is completed, the nth shot to the first shot are performed. The exposure is performed in this order. That is, it is determined in step 22 whether or not it is the final shot (n-th shot). If it is not the final shot, step-like driving is performed in step 23. In step 24, alignment measurement is performed, and steps 22 to 24 are repeated until the final nth shot. After the final shot is made, the process proceeds to step 25, where it is determined whether or not it is the first shot (1stshot) which is the final shot in exposure. If it is not the first shot, exposure and step (step) are performed (step 26). ), Repeated until the first shot is reached. When the first shot is reached, exposure and home position movement are performed (step 27).
[0017]
FIG. 4 shows the relationship between the shot layout on the glass plate 12 and the exposure direction, taking a glass plate with four shots as an example. Here, the direction of the arrow indicates the relative movement direction of the mirror optical system slit surface on the glass plate 12. In the figure, if the distance in the Y direction between the centers of the shots is 2L, the plate relative position to the mask 1 in shot 4 (shot 4) and shot 3 (shot 3) is + L, shot 1 (shot 1), and shot 2 The plate relative position with respect to the mask 1 in (shot 2) is −L.
[0018]
FIG. 5 is a diagram showing an optimum drive pattern for each axis of the master and slave when moving to the second shot exposure preparation position after the third shot exposure. Sections A to B are the third shot (3rdshot) exposure section, and the master and slave 2 axes are driven synchronously, sections B to C are disconnected, and driving is performed aiming at different target positions in this section. It will be.
[0019]
Now, the point of master / slave synchronization control switching is the relationship between the master and slave systems, which is the setting of the signal selector 107 in FIG. 2 and its switching timing.
[0020]
Sections A to B shown in FIG. 5 are synchronous sections. In FIG. 2, information transmitted between both axes is two points of speed v1 and position y1, and the signal selector 107 for switching is set in the direction a. Keep it. In this state, the speed signal v1 is transmitted as a command value to the speed control minor loop of the slave system. A value obtained by adding + L as the master-slave relative position offset 110 to the position signal y1 is compared with the slave system position y2, and a deviation, that is, a synchronization error is input to the slave system position compensator 104b to perform synchronization control. .
[0021]
Sections B to C in FIG. 5 are master and slave asynchronous sections. In C, each stage is driven so that the relative position of the slave to the master is −L. Point C is the master / slave stage position relationship at the exposure preparation position of the second shot (2ndshot).
[0022]
When the signal selector 107 shown in FIG. 2 is set in the b direction at the moment when the point B is passed, the master / slave synchronization is disconnected and the two axes are driven to the individual target positions.
[0023]
The signal switching timing can be generated by comparing the scanning direction and master side position information y1 with the synchronization switching position 109.
Further, when switching signals, smooth signal switching is required because there is a risk of an increase in the speed deviation and position deviation of the slave system depending on the switching timing, resulting in an error in the control system. Therefore, the slave system speed command value generator 108b is initialized together with the master system speed command value generator 108a at the start of driving from the point A shown in FIG. A value to which an offset of + L is added is also generated simultaneously in the slave system speed command value generator 108b. Of course, the output of the slave system speed command value generator must not be input to the slave control system in the synchronization period.
[0024]
The above is an example of processing when moving to the next shot after scan exposure, but the same applies when moving to the home position after the end of the final shot scan exposure. Can be moved to the exposure preparation position for the next shot without stopping, and the apparatus tact time can be improved.
[0025]
[Example of device production method]
Next, an embodiment of a device production method using the above-described exposure apparatus or exposure method will be described.
FIG. 7 is a diagram showing a flow of manufacturing a microdevice (a semiconductor chip such as an IC or LSI, a liquid crystal panel, a CCD, a thin film magnetic head, a micromachine, etc.). In step 1 (circuit design), a device pattern is designed. In step 2 (mask production), a mask on which the designed pattern is formed is produced. On the other hand, in step 3 (wafer manufacture), a wafer is manufactured using a material such as silicon or glass. Step 4 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer by lithography using the prepared mask and wafer. The next step 5 (assembly) is referred to as a post-process, and is a process for forming a semiconductor chip using the wafer produced in step 4, such as an assembly process (dicing, bonding), a packaging process (chip encapsulation), and the like. including. In step 6 (inspection), the semiconductor device manufactured in step 5 undergoes inspections such as an operation confirmation test and a durability test. Through these steps, the semiconductor device is completed and shipped (step 7).
[0026]
FIG. 8 shows a detailed flow of the wafer process. In step 11 (oxidation), the wafer surface is oxidized. In step 12 (CVD), an insulating film is formed on the wafer surface. In step 13 (electrode formation), an electrode is formed on the wafer by vapor deposition. In step 14 (ion implantation), ions are implanted into the wafer. In step 15 (resist process), a photosensitive agent is applied to the wafer. In step 16 (exposure), the circuit pattern of the mask is printed on the wafer by exposure using the exposure apparatus described above. In step 17 (development), the exposed wafer is developed. In step 18 (etching), portions other than the developed resist image are removed. In step 19 (resist stripping), unnecessary resist after etching is removed. By repeatedly performing these steps, multiple circuit patterns are formed on the wafer.
[0027]
By using the production method of this embodiment, a highly integrated device that has been difficult to manufacture can be manufactured at low cost.
[0028]
【The invention's effect】
As described above, according to the present invention, it is possible to move to the next stage position without stopping once after completion of synchronous scan exposure while maintaining high synchronization accuracy, which contributes to improvement of throughput of the apparatus and the entire production line. I can do it.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a synchronous scan exposure apparatus according to a first embodiment of the present invention.
FIG. 2 is a block diagram showing a control configuration originally realized in the control circuit according to the embodiment of the present invention.
FIG. 3 is a flowchart showing an exposure sequence according to an embodiment of the present invention.
FIG. 4 is a view showing a shot layout and an exposure direction on a glass plate according to an embodiment of the present invention.
5 is an optimum drive pattern for each axis of the master and slave when moving to the second shot exposure preparation position after the third shot exposure in FIG. 4. FIG.
FIG. 6 is a block diagram showing a control configuration of a conventional example.
FIG. 7 is a diagram showing a flow of manufacturing a microdevice.
8 is a diagram showing a detailed flow of the wafer process in FIG. 7. FIG.
[Explanation of symbols]
1: Photomask, 2: Mask stage, 3: Laser interferometer, 4: Linear motor, 11: Plate stage, 12: Glass plate, 20: Mirror optical system, 30: Stage control circuit, 31: Communication bus, 32: DAC (D / A converter), 101: axis characteristic, 102: speed compensator, 103: integrator, 104: speed comparator, 105: position compensator, 106: position comparator, 107: signal selector ( Switching means), 108: speed command value generator, 109: synchronization switching position, 110: master-slave relative position offset, v1, v2: speed information, y1, y2: position information.

Claims (4)

Configures a master / slave control system that has two control systems that drive and control two controllable objects that can be operated individually, with the low-responsive drive system as the master and the high-responsive drive system as the slave. An exposure apparatus,
The master drive system has a speed control system that operates to follow the speed command value generated by the master system speed command value generator, and outputs speed information and position information of the controlled object.
Slave drive system, of the velocity information outputted from the speed command value or the drive system of the master that is generated in the slave system speed command value generator, to follow either selected by the first switching hands stage to a speed control system which operates, among the values obtained by adding the offset to the position information output from a driving system of the position command or the master obtained from the slave system speed instruction value generator, selected by the second switching hands stage is provided with a position control system which operates to follow either,
Wherein by information output from a driving system of the master is selected by the first and second switching means, the drive system of the the drive system of the master-slave is controlled synchronously,
The I by the switching the toggle means in a pre-designated position in synchronization during driving, the synchronization of the two drive systems is disconnected is controlled individually scan exposure apparatus according to claim Rukoto. Said second switching means, scanning exposure according to claim 1, characterized in that intends line switching by comparing the position information output from a driving system of the master, a preset synchronous switching position apparatus. In the synchronization period, the scan according to claim 1, characterized in that allowed to occur simultaneously the value which the offset is added to the master system speed instruction value generator in the slave system speed instruction value generator Exposure device.   A device manufacturing method, wherein a device is manufactured using the exposure apparatus according to claim 1.

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