JP2005352069A - Aligner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the exchange time for substrates and to improve the throughput. <P>SOLUTION: The aligner is equipped with: a substrate stage 2 which is mounted on a moving table 3x movable in the axial direction and holds a substrate W as a material to be exposed; a mask stage 5 which holds a mask M having a pattern for exposure and allows the mask to oppose the substrate W when the moving table 3x stops at a predetermined position; and an irradiating means 6 which irradiates the mask M with exposure light so as to transfer the pattern of the mask M onto the substrate W by exposure. In the aligner, the moving stroke of the moving table 3x in the axial direction is controlled to be longer than the dimension of the substrate W in the axial direction and to be long enough to completely eject the substrate W from the mask M. The aligner is equipped with a substrate exchanging apparatus 10 which carries in and out the substrate W with respect to the substrate stage 2 at the position where the substrate W is located completely away out of the mask M. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an exposure apparatus that is used in a manufacturing process of a large flat panel display such as a liquid crystal display or a plasma display, and is suitable for exposing and transferring a mask pattern onto a substrate.

For example, in a manufacturing process of a liquid crystal display or the like, there is a process of exposing and transferring a pattern such as a color filter or electrode circuit onto a substrate such as glass.
Proximity exposure as an example of an exposure method is to hold a substrate as an exposure material on a substrate stage of a proximity exposure apparatus and bring the substrate close to a mask held on a mask holding frame of a mask stage so that a gap between the two is obtained. The pattern drawn on the mask is exposed and transferred onto the substrate by irradiating the exposure light toward the mask with an irradiation device from the side away from the substrate of the mask. It is what I did. There are other methods such as projection exposure.

By the way, in proximity exposure, there is a method in which the mask is made the same size as the substrate and is exposed in a lump. However, in such a method, when the mask pattern is exposed and transferred onto a large substrate, the mask becomes large and the mask is exposed. This causes problems in terms of the influence on the pattern accuracy due to the bending of the pattern and the cost.
Under these circumstances, conventionally, when a mask pattern is exposed and transferred onto a large substrate, a mask smaller than the substrate is used, and a moving table on which a substrate stage is mounted is stepped, for example, in the X-axis direction with respect to the mask. The pattern exposure light is irradiated in a state where the mask is moved close to the substrate on the substrate table for each step, and thereby a plurality of patterns drawn on the mask are exposed and transferred onto the substrate. A proximity exposure method may be used. In addition, there is a method of exposing a large substrate by combining a scanning method.

After the exposure is completed, the exposed substrate is unloaded from the substrate stage by the substrate exchange apparatus, and the next exposure is performed after a new substrate is loaded onto the substrate stage. As a substrate exchange device used for loading and unloading a substrate, for example, a device having a direct-acting arm telescopic shaft or a device having a telescopic shaft by an articulated arm is disclosed (for example, see Patent Document 1).
JP 2003-136442 A

In the conventional exposure apparatus described above, the axial movement stroke of the substrate stage is smaller than the axial size of the substrate and is as short as possible in relation to the footprint. There is a problem that the amount of expansion / contraction of the expansion / contraction shaft of the exchange device becomes long, and it takes time to carry in and out the substrate, thereby reducing the throughput of the entire device.
In particular, in a substrate exchanging apparatus having a telescopic shaft by an articulated arm, the section in which high speed can be obtained in the direction of the telescopic shaft is limited, so that the arm telescopic operation is slow and it takes time to carry in and out the substrate. End up.
In other systems, the substrate exchange apparatus has a limit in increasing the substrate transfer speed due to its structure.
The present invention has been made in order to eliminate such inconveniences, and an object of the present invention is to provide an exposure apparatus capable of reducing the substrate replacement time and improving the throughput.

In order to achieve the above object, the invention according to claim 1 is mounted on a moving table that is movable in the axial direction, and holds a substrate as a material to be exposed, and drives the moving table in the axial direction. A driving means for controlling, a control means for controlling the driving means, a mask stage for holding a mask having a pattern to be exposed so as to face the substrate, and an exposure device for exposing and transferring the pattern of the mask to the substrate. In an exposure apparatus comprising irradiation means for irradiating the mask with light toward the mask,
The moving stroke of the moving table in the axial direction is longer than the dimension of the substrate in the axial direction, and the substrate is completely removed from the mask, and the substrate is placed on the substrate stage at a position where the substrate is completely removed from the mask. On the other hand, a substrate exchange device for carrying in and out the substrate is provided.

According to a second aspect of the present invention, in the first aspect, the first sensor that detects the position of the moving table in the axial direction and the position of the moving table in the axial direction are detected with lower resolution than the first sensor. And a second sensor, wherein the control means selects signals from the first sensor and the second sensor and controls the driving means based on the selection signal.
The invention according to claim 3 is characterized in that in claim 2, at least one of the first sensor and the second sensor is a linear scale.

  According to the present invention, the moving stroke in the axial direction of the moving table is longer than the axial dimension of the substrate, and the substrate is completely removed from the mask, and the substrate is replaced at a position where the substrate is completely removed from the mask. By unloading the substrate after exposure from the substrate stage by the apparatus and loading a new substrate onto the substrate stage, the substrate moving distance during the loading and unloading operations by the substrate exchange device is shortened, and the movement speed is reduced accordingly. It can be replaced by a fast moving table movement operation, whereby the time required for loading and unloading the substrate is shortened, and the throughput of the entire apparatus can be improved.

Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a plan view for explaining a proximity exposure apparatus as an example of an embodiment of the present invention, FIG. 2 is a view seen from the direction of arrow A in FIG. 1, and FIG. 3 is an enlarged sectional view of a linear motor section. .
As shown in FIGS. 1 and 2, the proximity exposure apparatus as an example of the embodiment of the present invention includes an X-axis movement table 3x provided on the base 7 so as to be movable in the X-axis direction, and an X-axis movement table. A Y-axis moving table 3y provided on the 3x so as to be movable in the Y-axis direction, and a substrate stage 2 mounted on the Y-axis moving table 3y and having a work chuck 1 on its upper surface for holding a substrate W as an exposed material; A mask stage 5 that holds a mask M smaller than the substrate W through the mask holding frame 4 in a state of facing the substrate W, and exposure light for exposing and transferring the pattern of the mask M to the substrate W. And a substrate exchanging device 10 that carries the substrate W in and out of the substrate stage 2 and is disposed at the end of the base 7 in the X-axis direction.

The mask stage 5 is provided with a fine movement mechanism capable of finely adjusting the position and posture of the mask M, and the positional deviation amount between the mask M and the substrate W or the positional deviation amount between the mask M and the substrate stage 2 is obtained. For example, an imaging device such as a CCD camera is used. Then, based on the imaging result by the imaging device, the mask M is positioned by the fine movement mechanism (so-called alignment).
A slider 24 of a linear guide device is attached to the back surface of the X-axis moving table 3x, and the slider 24 has rolling elements (not shown) on guide rails 8 installed in parallel on the base 7 along the X-axis direction. It is straddled through. Thereby, the X-axis moving table 3x is supported by the guide rail 8 so as to be movable along the X-axis direction.

In this embodiment, the linear motor 14 is employed as a driving means for driving the X-axis movement table 3x in the X-axis direction (including step movement).
As shown in FIG. 3, the linear motor 14 has a surface polarity alternately N-pole, S-pole, etc. on both side walls of the groove 15 formed along the X-axis direction in the substantially central portion of the base 7. A plurality of permanent magnets 16 mounted side by side along the X-axis direction so as to change, and an armature 17 attached to both side surfaces of the ridges 18 provided along the X-axis direction on the back surface of the X-axis moving table 3x. The control device 20 appropriately controls the current flowing to the armature 17 to give the X-axis moving table 3x thrust in the X-axis direction and perform positioning in the X-axis direction.

The linear motor 14 is not limited to the above-described configuration. For example, an armature may be provided in the groove 15, and a permanent magnet may be provided in the ridge 18. You may provide in the lower surface of the protruding item | line 18. FIG. In the latter case, the grooves 15 or the ridges 18 may be omitted.
In addition to the linear motor 14, as a driving means for the X-axis moving table 3x, for example, a combination of a ball screw device and a motor that rotationally drives the screw shaft of the ball screw device, a timing belt and a driving motor Combinations, cylinder devices, and the like can be used.

  Further, on both sides of the base 7 in the Y-axis direction, detected bodies constituting two linear scales 30 and 40 for detecting the position of the X-axis moving table 3x in the X-axis direction are provided along the X-axis direction. It has been. Although not shown in the drawings, the sensor bodies that constitute the linear scales 30 and 40 and read the position information of the X-axis movement table 3x are provided on the lower surface of the X-axis movement table 3x, respectively, facing the corresponding detected object. It has been.

  One linear scale (first sensor) 30 of the two linear scales 30 and 40 is shorter than the other linear scale (second sensor) 40, and is a highly accurate X-axis mainly in the exposure region. The other linear scale 40 is disposed in an area where positioning of the moving table 3x is required, and detects the position of the X-axis moving table 3x in the X-axis direction with a lower resolution than the linear scale 30. Are arranged over substantially the entire length in the X-axis direction.

  The signals of the linear scales 30 and 40 are output to the control device 20. The control device 20 selects a signal from the linear scale 30 in the high-precision positioning region of the X-axis movement table 3x and selects the X-axis movement table 3x. The linear motor 14 is controlled so that the position of the X-axis moving table 3x is increased by selecting the signal from the linear scale 40 having a lower resolution than the linear scale 30 in other areas. 14 is controlled. In FIG. 1, reference numeral 21 denotes a power line of the linear motor, 22 denotes a signal line of the linear scale 30, and 23 denotes a signal line of the linear scale 40.

  Thus, the linear scale (first sensor) 30 that detects the position of the X-axis movement table 3x in the axial direction and the linear scale that detects the position of the X-axis movement table 3x in the axial direction with a lower resolution than the linear scale 30. A scale (second sensor) 40, and the control device (control means) 20 selects a signal from the linear scale 30 and the linear scale 40, and drives the X-axis moving table 3x based on the selection signal. By controlling this, the signal from the linear scale 30 is selected in the high-precision positioning area of the X-axis movement table 3x to reduce the speed of the X-axis movement table 3x, and the resolution is higher than that of the linear scale 30 in the other areas. Since the signal from the low linear scale 40 can be selected to increase the speed of the X-axis moving table 3x, It can be faster the speed of the moving table 3x.

  The slider 24 of the linear guide device is attached to the back surface of the Y-axis moving table 3y, and the slider 24 rolls on the guide rail 8 installed in parallel along the Y-axis direction on the X-axis moving table 3x. (Not shown). Thereby, the Y-axis movement table 3y is supported by the guide rail 8 on the X-axis movement table 3x so as to be movable along the Y-axis direction.

  Further, between the Y-axis moving table 3y and the substrate stage 2, the clearance between the mask M and the substrate W is measured up to a preset position by performing a simple vertical movement of the substrate stage 2. Vertical coarse movement device (not shown) that moves up and down without performing it, and vertical fine movement device (not shown) that finely adjusts the gap between the opposing surfaces of the mask M and the substrate W to a predetermined amount by finely moving the substrate stage 2 up and down. Is installed.

  The Y-axis moving table 3y includes Y-axis drive control means dedicated to step feed (for example, a combination of a ball screw device, a motor that rotationally drives the screw shaft of the ball screw device, and a control device that controls the motor, a linear motor, The linear motor can be moved stepwise in the Y-axis direction by a combination of control devices for controlling the linear motor, and the X-axis and Y-axis of the substrate W on the substrate stage 2 by this and the driving means in the X-axis direction. It enables two-axis step exposure of the axis. For the positioning control of the Y-axis moving table 3y in the Y-axis direction, the same resolution as that of the linear scale 30 is used, and the detection target is provided along the Y-axis direction on the X-axis moving table 3x. A sensor main body is provided on the lower surface of the Y-axis moving table 3y (not shown).

Here, in this embodiment, the movement stroke in the X-axis direction of the X-axis movement table 3x is longer than the dimension in the X-axis direction of the substrate W, and the substrate W is completely removed from the mask M. The substrate W is carried into and out of the substrate stage 2 by the substrate exchange device 10 at a position completely removed from the mask M.
The substrate exchange apparatus 10 is installed at the end of the base 7 in the X-axis direction, and includes two hand portions 50L and 50R that are spaced apart from each other in the Y-axis direction. The hand portions 50L and 50R have gripping portions that hold the substrate W by suction on the upper surface. On the other hand, the substrate stage 2 is configured such that the pins 1a protrude from the chuck surface of the work chuck 1 when the substrate W is loaded and unloaded. The tip portions of the hand portions 50L and 50R can be inserted between the plurality of pins 1a of the substrate stage 2 (see FIG. 2).

Vacuum suction holes are provided in the substrate placement surfaces of the hand portions 50L and 50R and the tips of the pins 1a, respectively, so that the substrate W can be sucked and held. Each is connected to an air pressure control mechanism including a suction pump (not shown), and suction / release control is possible when the substrate W is delivered.
Further, the hand portions 50L and 50R are independently driven up and down in the Z-axis direction, and are driven to rotate around the Z-axis. Further, a linear guide device or the like (for example, a combination of a motor and a ball screw, or the like) (Including a driving device such as a linear motor).

Next, the operation of the proximity exposure apparatus of the present embodiment will be described with reference to FIG.
Here, the hand unit 50L is used for carrying out and the hand unit 50R is used for carrying in. Further, when the substrate is carried in and out, the X-axis movement table 3x is positioned at the substrate replacement position indicated by the two-dot chain line in FIG.
FIG. 1 shows a state in which the unloading hand unit 50L of the substrate exchange apparatus 10 is on standby. Each of the hand units 50L and 50R has the tip portion facing the X-axis direction, and the left hand unit 50L is the X of the base 7. A new substrate W that is disposed above the center of the end portion in the axial direction and is pre-aligned by a pre-alignment device (not shown) to the right hand unit 50R is delivered and held from the pre-alignment device. At this time, with respect to the Z-axis direction, the hand portion 50L is in the lowered position and the hand portion 50R is in the raised position.

  When the step exposure of the substrate W at the exposure position is completed, the suction of the substrate W by the work chuck 1 is released, and instead, the pin 1a is protruded in a state where the substrate W is attracted by the tip of the pin 1a. In this state, the X-axis movement table 3x moves to the end of the base 7 on the substrate exchange apparatus 10 side in the X-axis direction (substrate exchange position indicated by a two-dot chain line in FIG. The substrate W after exposure is placed between the pins 1a of the chuck 1 and above the hand portion 50L.

At this time, the control device 20 selects the signal from the linear scale 40 having a resolution lower than that of the linear scale 30 and controls the linear motor 14 so as to increase the speed of the X-axis movement table 3x. Moves to the loading / unloading position of the substrate W at high speed.
Here, the moving distance of the substrate stage 2 that can be moved at high speed is increased, and the movement of the hand portions 50L and 50R in the X-axis direction is unnecessary.

  Next, the hand unit 50L is lifted in the Z-axis direction to deliver the exposed substrate W held by the pin 1a to the hand unit 50L, and the hand units 50L and 50R are integrally moved to the left in the Y-axis direction. The hand unit 50R holding the new substrate W is moved above the work chuck 1 of the substrate stage 2, and in this state, the hand unit 50R is lowered in the Z-axis direction. The substrate W is transferred to the pins 1a.

When a new substrate W is held on the plurality of pins 1a, the X-axis moving table 3x moves along the X-axis direction to the exposure position below the mask M, and the first exposure area of the substrate W is arranged opposite to the mask M. Then, the substrate W is attracted and held by the work chuck 1 and new step exposure is performed. In this case as well, the control device 20 controls the linear motor 14 so as to increase the speed of the X-axis moving table 3x by selecting a signal from the linear scale 40 having a resolution lower than that of the linear scale 30. The moving table 3x moves to the exposure position at high speed.
On the other hand, the substrate exchange apparatus 10 uses the rotation of the hand units 50L and 50R, the movement in the Y-axis direction, and the movement in the Z-axis direction as appropriate to carry out the exposed substrate W and deliver a new substrate W to the hand unit 50R. I do.

Step exposure is performed in the following procedure.
First, the substrate stage 2 is raised to approach the mask M, the amount of positional deviation of the mask M with respect to the substrate W or the substrate stage 2 is obtained by the imaging device, fine positioning (alignment) of the mask M is performed, and the micro positioning is completed. And exposure. When the exposure in the first exposure area is completed, the substrate stage 2 is lowered, and the X-axis movement table 3x or the Y-axis movement table 3y is driven to the next exposure area by the driving means, whereby the substrate stage 2 is stepped. Do. Thereafter, alignment of the mask M, exposure, and step feed of the substrate stage 2 to the next exposure area are repeated.

When the X-axis moving table 3x is moved in the X-axis direction by step feed, the control device 20 selects and uses the high-resolution linear scale 30 as the linear scale for positioning control. As a result, the substrate stage 2 can be positioned with high accuracy, the amount of misalignment correction of the mask M can be kept small, and the time required for alignment of the mask M can be shortened.
When the exposure of all the regions is completed, the exposed substrate W is carried out and a new substrate W is carried in as described above. As the resolution of the linear scale 40 to be used, when the X-axis moving table 3x is moved at a high speed and moved to the first exposure area, the reference mark on the substrate W or the substrate stage 2 becomes an image pickup device on the mask stage 5. As long as it is within the visual field range.

  For example, by using a linear scale 40 having a resolution of several μ to several tens of microns, a feed rate of about 1 m / s can be easily obtained, and the subsequent alignment process can be prevented. On the other hand, the linear scale 30 is, for example, one having a resolution of 0.1 micron and performs step feed with high accuracy. These conditions may be appropriately determined according to the performance of the control device or the like.

  As described above, in this embodiment, the movement stroke in the X-axis direction of the X-axis movement table 3x is longer than the dimension in the X-axis direction of the substrate W, and the substrate W is completely removed from the mask M. Since the substrate exchange apparatus 10 unloads the exposed substrate W from the substrate stage 2 and unloads the new substrate W into the substrate stage 2 at a position completely removed from the mask M. The expansion / contraction operation of the slow expansion / contraction axis of the substrate exchange apparatus can be replaced with the movement operation of the X-axis movement table 3x having a high movement speed, thereby reducing the time required for loading and unloading the substrate W, and the entire apparatus Throughput can be improved.

  In addition, a linear scale 30 for detecting the position of the X-axis movement table 3x in the X-axis direction and a linear scale 40 for detecting the position of the X-axis movement table 3x in the X-axis direction with a lower resolution than the linear scale 30 are provided. The control device 20 selects signals from the linear scale 30 and the linear scale 40 and controls the linear motor 14 based on the selection signal, so that the linear scale 30 is used in the high-precision positioning region of the X-axis moving table 3x. To select the signal from the linear scale 40 having a resolution lower than that of the linear scale 30 in other areas and select the signal from the X-axis moving table 3x. Since the speed is increased, the speed of the X-axis moving table 3x to the board replacement position can be further increased. Thus, loading of the substrate W, it is possible to further shorten the time it takes to carry-out.

In addition, this invention is not limited to the said embodiment, In the range which does not deviate from the summary of this invention, it can change suitably.
For example, in the above embodiment, the case where the linear scale is adopted for both the first sensor and the second sensor for detecting the position in the X-axis direction of the X-axis moving table 3x is taken as an example, but the present invention is not limited to this. When a combination of a ball screw device and a rotary motor is used as the driving means for the X-axis moving table 3x, one of the first sensor and the second sensor is a resolver that detects the rotational speed of the rotary motor. Alternatively, the position of the X-axis movement table 3x may be detected from the detection signal as a rotary encoder or the like.

In the present invention, since the substrate transfer distance by the substrate exchange apparatus can be minimized, even if the substrate exchange apparatus is an articulated arm type, the rate of decrease in throughput is small. Therefore, an articulated arm type may be used as the substrate exchange device.
Further, in the above-described embodiment, the two-axis (X-axis, Y-axis) step exposure is taken as an example, but the present invention can also be applied to a uniaxial (X-axis) step exposure.
Further, in the above embodiment, the proximity exposure type exposure apparatus is taken as an example, but the present invention is not limited to this, and the present invention may be applied to other types of exposure apparatuses such as projection exposure.

It is a top view for demonstrating the proximity exposure apparatus which is an example of embodiment of this invention. It is the figure seen from the arrow A direction of FIG. It is an expanded sectional view of a linear motor part.

Explanation of symbols

W Substrate M Mask 2 Substrate stage 3x X-axis moving table 4 Mask holding frame 5 Mask stage 6 Irradiation device (irradiation means)
10 Substrate changer 14 Linear motor (drive means)
20 Control device (control means)
30 Linear scale (first sensor)
40 Linear scale (second sensor)

Claims (3)

A substrate stage mounted on a moving table movable in the axial direction and holding a substrate as an exposure material, a driving means for driving the moving table in the axial direction, a control means for controlling the driving means, and exposure An exposure provided with a mask stage for holding a mask having a pattern to be opposed to the substrate, and an irradiating means for irradiating light for exposure toward the mask in order to expose and transfer the pattern of the mask onto the substrate In the device
The moving stroke of the moving table in the axial direction is longer than the dimension of the substrate in the axial direction, and the substrate is completely removed from the mask, and the substrate is placed on the substrate stage at a position where the substrate is completely removed from the mask. An exposure apparatus comprising a substrate exchange device for carrying in and carrying out the substrate.   A first sensor for detecting the position of the moving table in the axial direction; and a second sensor for detecting the position of the moving table in the axial direction with a lower resolution than the first sensor; 2. The exposure apparatus according to claim 1, wherein signals from the first sensor and the second sensor are selected, and the driving unit is controlled based on the selection signal.   3. The exposure apparatus according to claim 2, wherein at least one of the first sensor and the second sensor is a linear scale.

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