JPH07260424A - Alignment method for proximity aligner - Google Patents

Abstract

PURPOSE:To realize highly accurate alignment between a mask and a photosensitive substrate while setting a large interval between them by determining the relative positions first and second alignment marks with respect to a luminous flux individually. CONSTITUTION:An automatic halving 25 is rotated to scan the vicinity of an alignment mark 27 on a mask 4 by means of a long beam. When the laser light LA2 aligns with the alignment mark 27, a detector 30 detects a diffracted light having highest intensity and the relative position between the laser light LA2 and the mask 4 is determined. A beam length switching shutter 26 is then shifted to form a short beam which is projected onto the vicinity of an alignment mark 28 on a photosensitive substrate 6 thus aligning the laser light LA2 with the alignment mark 28. When the relative position of the alignment marks 27, 28 is determined sequentially with respect to the laser light LA2, the mask 4 is aligned accurately with the photosensitive substrate 6 through the laser light LA2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alignment method for a proximity exposure apparatus, which can be applied, for example, when manufacturing a large-area liquid crystal display device.

[0002]

2. Description of the Related Art A proximity exposure apparatus exposes a mask on which an exposure pattern is formed and a photosensitive substrate on which the exposure pattern is exposed with a minute gap. As an alignment method between a mask and a photosensitive substrate that are opposed to each other with a minute gear gap therebetween, there is a method of performing image processing on reflected light of alignment marks formed on the mask and the photosensitive substrate, respectively. FIG. 6 is a diagram showing a schematic view of an alignment device of a proximity exposure device for manufacturing a liquid crystal display device (hereinafter referred to as alignment device 1), which emits a light beam LA1 from an alignment optical system 2 and a mask holder 3 Irradiate the mask 4 fixed on top. The light beam LA1 that has passed through the mask 4 illuminates the photosensitive substrate 6 of the liquid crystal display device mounted on the stage 5.

On the side of the mask 4 facing the photosensitive substrate 6, an alignment mark 7 having a linear pattern is formed. On the photosensitive substrate 6, alignment marks 8 having two parallel linear patterns are formed. When the mask 4 and the photosensitive substrate 6 are aligned, as shown in FIG. 7A, first, the alignment mark 7 is roughly aligned with the alignment mark 8 approximately in the middle of the alignment mark 8. .

The reflected light of the light beam LA1 generated by the alignment marks 7 and 8 is condensed by the objective lens 9 of the optical system 2 and is passed through a half prism 10 to a CCD (Charge Coupl).
ed Device) to the image receiving device 11. The video signal of the image receiving device 11 is given to a control device (not shown). The control device detects the position where the signal in the direction orthogonal to the alignment marks 7 and 8 has the maximum value based on this video signal.

That is, as shown in FIG. 7B, the positions where the signal waveform 12 of this signal has a maximum value coincide with the positions of the alignment marks 7 and 8, respectively. As a result, the control device detects the maximum value and detects the positions of the alignment marks 7 and 8. Subsequently, the control device scans the mask 4 or the photosensitive substrate 6 in the direction orthogonal to the alignment marks 7 and 8, and the distances L1 and L between the maximum values of the signal waveform 12 are increased.
Compare with 2. In this way, the control device mutually positions the mask 4 and the photosensitive substrate 6 at a position where the distances L1 and L2 between the maximum values of the signal waveform 12 are equal to each other. After this,
The entire surface of the photosensitive substrate 6 is exposed.

By the way, in the alignment apparatus 1 described above, as described above, a predetermined minute interval is provided between the alignment mark 7 on the mask 4 and the alignment mark 8 on the photosensitive substrate 6. Therefore, as described above, the method of comparing the distances L1 and L2 between the large values of the signal waveform 12 and mutually positioning the mask 4 and the photosensitive substrate 6 is the optical system 2.
Subject to depth of focus constraints.

That is, in order to improve the accuracy of alignment between the mask 4 and the photosensitive substrate 6, the image of the alignment marks 7 and 8 which are in sufficient focus is given to the image receiving device 11 so that the maximum value of the signal waveform 12 can be obtained. It is necessary to narrow the width.
Therefore, the gap between the mask 4 and the photosensitive substrate 6 needs to be set to be equal to or less than the depth of focus. For example, when an objective lens 9 having a magnification of 5 is used, the numerical aperture NA is about 0.1 and the depth of focus is about 100 [μm]. Therefore, it is necessary to set the gap between the mask 4 and the photosensitive substrate 6 to 100 [μm] or less.

[0008]

However, in the exposure apparatus 1 described above, when the photosensitive substrate 6 is upsized as in the case of manufacturing a liquid crystal display device, it is formed to have substantially the same size as the photosensitive substrate 6. The mask 4 is also enlarged. For this reason, the amount of deflection of the mask 4 and the deviation of the flatness of the photosensitive substrate 6 become large, and the gap between the mask 4 and the photosensitive substrate 6 becomes extremely uneven in the same plane.

For this reason, if the gap between the mask 4 and the photosensitive substrate 6 is set to a small gap similar to that when the photosensitive substrate 6 is small, the mask 4 and the photosensitive substrate 6 come into contact with each other during the alignment, and the mask 4 is exposed. There is a problem that the formed pattern may be damaged or dust may be attached to the mask 4 to cause a common defect.

Particularly, at the time of alignment, the mask 4 and the photosensitive substrate 6 are relatively moved in the X-axis and Y-axis directions parallel to the surfaces of the mask 4 and the photosensitive substrate 6 while keeping a small gap between them. By doing so, there is an increased possibility that the above-mentioned pattern damage and common defects will occur.

When alignment is performed using an alignment mark formed of a low-contrast material such as an ITO (Indium Titan Oxide) film, as shown in FIG. 7 (B), the control device has a maximum value and a minimum value. Since only the signal waveform 13 having a small difference from is obtained, there is a drawback that it is difficult to obtain sufficient alignment accuracy by the image processing method as described above.

The present invention has been made in consideration of the above points, and easily aligns the mask and the photosensitive substrate with high accuracy in a state in which the gap between the mask and the photosensitive substrate is set to be larger than the conventional one. An attempt is made to propose a possible alignment method for a proximity exposure apparatus.

[0013]

In order to solve the above problems, the present invention will be described with reference to FIG. 1 and FIG. 2 showing an embodiment, and an alignment of a proximity exposure apparatus according to claim 1 will be described. In the method, an alignment method of a proximity exposure apparatus in which a mask (4) and a photosensitive substrate (6) are brought close to each other to expose a pattern formed on the mask (4) onto the photosensitive substrate (6) is used. Marks (27A and 27B) at regular intervals (D1)
A step of moving a light shielding plate (32) between the mask (4) and the photosensitive substrate (6) so as to face the first alignment marks (27) provided on the mask (4) at a distance from each other;
A step of shaping the light flux (LA2) emitted from the light source (23) in association with the size of the first alignment mark (27), and a step of scanning the first alignment mark (27) with the shaped light flux (LA2). And a step of determining the relative position between the light flux (LA2) and the mask (4) based on the diffracted light obtained from the first alignment mark (27) by scanning, and blocking the light at a position not facing the constant interval (D1). The step of retracting the plate (32) and the light source (2
3) the step of shaping the luminous flux (LA2) emitted from the same to be smaller than the constant interval (D1), and the shaped luminous flux (LA
The second alignment mark (28) provided on the photosensitive substrate (6) so as to be substantially opposite to the first alignment mark (27) in 2) moves the stage (5) on which the photosensitive substrate (6) is placed. The step of scanning and the step of determining the relative position between the mask (4) and the photosensitive substrate (6) based on the diffracted light obtained from the second alignment mark (28) by the scanning. To do. The alignment method for a proximity exposure apparatus according to claim 2, wherein the mask (4) and the photosensitive substrate (6) are brought close to each other,
In a proximity exposure apparatus alignment method for exposing a pattern formed on a mask (4) onto a photosensitive substrate (6), the alignment marks (27A and 2A) of a diffraction grating are used.
7B) are separated by a constant distance (D1), and the light flux (LA2) emitted from the light source (23) is passed through the constant interval (D1) of the first alignment marks (27) formed on the mask (4). The second alignment mark (28) provided on the photosensitive substrate (6) so as to substantially face the first alignment mark (27) by the step of shaping and transmitting and the light flux (LA2) passing through the fixed interval (D1). Is moved by a movement of the stage (5) on which the photosensitive substrate (6) is mounted, and a step (S1) for scanning, and based on the diffracted light obtained from the second alignment mark (28) by the scanning, passes through a fixed interval (D1). The light-shielding plate between the mask (4) and the photosensitive substrate (6) so as to face the first alignment mark (27) and the step for determining the relative position between the luminous flux (LA2) and the photosensitive substrate (6). 32) and the step to move,
In relation to the size of the first alignment mark (27),
The step of shaping the light flux (LA2) emitted from the light source (23), and the first alignment mark (27) moved by the shaped light flux (LA2) and the mask stage (3) on which the mask (4) is placed. And a step of determining the relative position between the mask (4) and the photosensitive substrate (6) based on the diffracted light obtained from the first alignment mark (27) by the scanning. To do. In the alignment method of the proximity exposure apparatus according to the third aspect, the light source (23) is a He-Ne laser. In the alignment method of the proximity exposure apparatus according to the fourth aspect, the distance between the mask (4) and the photosensitive substrate (6) is 100 [μm] or more and 300 [μm] or less.

[0014]

In the alignment method of the proximity exposure apparatus according to the first aspect, the light beam (LA2) and the stage (5) formed in association with the sizes of the first and second alignment marks (27 and 28) are scanned. The relative position of the first and second alignment marks (27 and 28) with respect to the light beam (LA2) is separately determined with high accuracy based on the diffracted light obtained by the above, and the position of the optical axis of the light beam (LA2) is determined. By sequentially fixing the position of the stage (5),
With the gap between the mask (4) and the photosensitive substrate (6) set larger than in the conventional case, the light flux (LA2) is not affected by the contrast state of the first and second alignment marks (27 and 28). The mask (4) and the photosensitive substrate (6) can be easily aligned with high accuracy via the.
In the alignment method of the proximity exposure apparatus according to claim 2, a light flux (LA2) shaped in association with the sizes of the second and first alignment marks (28 and 27).
And the relative positions of the second and first alignment marks (28 and 27) with respect to the light flux (LA2) are separately determined with high accuracy based on the diffracted light obtained by scanning the mask stage (3), and the light flux ( By sequentially fixing the position of the optical axis of LA2) and the position of the mask stage (3), the distance between the mask (4) and the photosensitive substrate (6) is set larger than in the conventional case, The mask (4) and the photosensitive substrate (6) can be easily aligned with high accuracy via the light flux (LA2) without being affected by the contrast state of the second and first alignment marks (28 and 27). In the alignment method of the proximity exposure apparatus according to claim 3, a laser beam (L) of a He-Ne laser (23) is used.
A2) can be used to deepen the depth of focus of the optical system (22) to sufficiently increase the focusing distance of the laser light (LA2). The alignment method for a proximity exposure apparatus according to claim 4, wherein during the alignment, the mask (4) is used.
The stage (5) can be scanned with the distance between the photosensitive substrate (6) and the photosensitive substrate (6) set sufficiently larger than in the conventional case. As a result, the mask (4) and the photosensitive substrate (6) come into contact with each other, and the mask (4)
It is possible to prevent the possibility of damaging the upper pattern or attaching dust on the mask (4) to cause a common defect. Therefore, the photosensitive substrate (6) can be easily increased in size.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 in which parts corresponding to those in FIG. 6 are assigned the same reference numerals is a diagram showing an outline of an alignment device 21 of a proximity exposure apparatus for manufacturing a liquid crystal display device. An alignment optical system 22 is provided instead of the alignment optical system 2 of the conventional alignment apparatus 1.

The alignment optical system 22 uses a laser beam LA2 emitted from a helium neon (He-Ne) laser 23 to set a deep focal depth.
The laser beam LA2 is shaped into a straight line in a predetermined direction (here, the up-down direction of the paper surface) by a cylindrical lens 24, and the optical axis is aligned by an automatic harving 25 that displaces the optical axis. Irradiate.

The laser beam LA2 is shaped by the beam length switching shutter 26 to have a long or short beam length. The laser beam LA2 whose beam length is shaped enters the objective lens 9 through the half prism 10. The objective lens 9 irradiates the incident laser beam LA2 with an alignment mark 27 or 28 formed of a diffraction grating in association with a light shielding plate described later.

The diffracted light generated by the alignment mark 27 or 28 is condensed by the objective lens 9 of the alignment optical system 22, passes through the half prism 10, and passes through the space filter 2.
Irradiated to 9. Only the second- and third-order wave components of the diffracted light are passed through the spatial filter 29, and the light intensity is detected by the detector 30 having the photomultiplier tube structure. In this way, the detector 30 is provided with the diffracted light of the laser light LA2 having a deep depth of focus and being well focused, detects the light intensity without being affected by the contrast state of the alignment marks 27 and 28, and The dynamic range of change in intensity is large, and a signal whose maximum value can be easily detected is output.

The alignment mark 27 is formed on the surface of the mask 4 facing the photosensitive substrate 6. Further, as shown in FIG. 2A, the alignment mark 27 is composed of two diffraction gratings 27A and 27B formed in a line on the photosensitive substrate 6. The diffraction gratings 27A and 27B are separated by a predetermined space D1 in the central hollow portion 31. Figure 2
As shown in (B), the alignment marks 28 are diffraction gratings formed on the photosensitive substrate 6 in a line in the same direction as the alignment marks 27.

The mask 4 is provided between the mask 4 and the photosensitive substrate 6.
And a light shield plate 3 that can be inserted and removed in a direction parallel to the surface of the photosensitive substrate 6.
2 are provided.

In the above configuration, the alignment device 2
The controller 1 (not shown) aligns the mask 4 and the photosensitive substrate 6 according to the alignment processing procedure shown in FIG. That is, the control device enters from the alignment processing procedure step SP0 and then lowers the stage 5 by about 13 [mm] at the next step SP1. After that, the control device moves the light shielding plate 32 between the mask 4 and the photosensitive substrate 6 so as to face the alignment mark 27 on the mask 4, and moves to step SP2.

At step SP2, the controller moves the beam length switching shutter 26 to the side of increasing the beam length so that the beam length of the laser beam LA2 is almost equal to the alignment mark 27 as shown in FIG. 2 (A). If the long beam 33A is formed with the same length limited, the step SP3
Move on to.

At step SP3, the control device rotates the automatic harbing 25 in an arbitrary direction to move the long beam 33.
At A, when the vicinity of the alignment mark 27 on the mask 4 which is positioned and fixed with high precision is scanned, step SP4
Move on to. In step SP4, the control device determines the relative position between the laser beam LA2 and the alignment mark 27. That is, the laser beam LA2 and the alignment mark 27
If the positions of and coincide with each other, the light intensity of the diffracted light received by the detector 30 becomes maximum, and the signal output from the detector 30 becomes maximum. The controller detects this maximum value and stops the automatic harving 26 to fix the optical axis.
As a result, the control device has determined the relative position between the laser beam LA2 and the mask 4, and proceeds to step SP5.

In step SP5, the control device retracts the light shielding plate 32 from between the mask 4 and the photosensitive substrate 6 and sufficiently separates it from the position facing the hollow portion 31 of the alignment mark 27. After this, the control device moves to stage 5
To raise the mask 4 and the photosensitive substrate 6 from 100 [μm] to
When it is brought close to about 300 [μm], the process proceeds to step SP6.

In step SP6, the control unit moves the beam length switching shutter 26 to the side that shortens the beam length so that the beam length of the laser beam LA2 becomes hollow in the alignment mark 27 as shown in FIG. 2B. When the short beam 33B is formed so as to be shorter than the interval D1 of the portion 31 to the length D2, the process proceeds to step SP7.

In step SP7, the control device causes the short beam 33B to pass through the hollow portion 31 of the alignment mark 27 and project it near the alignment mark 28 on the photosensitive substrate 6. After that, the controller moves in the X-axis and Y-axis directions parallel to the surfaces of the mask 4 and the photosensitive substrate 6 while keeping the distance between the mask 4 and the photosensitive substrate 6 at about 100 [μm] to 300 [μm]. The alignment mark 28 on the photosensitive substrate 6 is scanned by moving the stage 5.

At this time, since the alignment optical system 22 uses the laser light LA2 and the depth of focus is remarkably large as compared with the conventional one, diffracted light with a sufficient focus is given to the detector 30. In this way, if the laser light LA2 and the alignment mark 28 on the photosensitive substrate 6 match, the signal output of the detector 30 becomes the maximum value. The control device detects this maximum value and stops the stage 5.

As a result, the controller determines the relative position between the laser beam LA2 and the mask 4. As a result, the control device sequentially determines the relative positions of the alignment marks 27 and 28 with respect to the laser beam LA2, and at the same time, the mask 4 and the photosensitive substrate 6 are also transmitted via the laser beam LA2.
This means that and are aligned with high accuracy. After this,
The control device moves to step SP8 and ends the alignment processing.

According to the above configuration, the laser beam LA2 of the helium neon laser 23 is used to deepen the depth of focus of the alignment optical system 22 to sufficiently increase the focusing distance of the laser beam LA2, and at the same time, the alignment mark. Relative positions of the alignment marks 27 and 28 with respect to the laser light LA2 based on the laser light LA2 linearly shaped according to the sizes of 27 and 28 and the sufficiently focused diffracted light obtained by scanning the stage 5. Is determined with high accuracy and the position of the optical axis of the laser beam LA2 and the position of the stage 5 are sequentially fixed, so that the distance between the mask 4 and the photosensitive substrate 6 is large compared to the conventional case. For example, in the state of setting about 100 [μm] to 300 [μm],
In the direction orthogonal to the alignment marks 27 and 28, the mask 4 and the photosensitive substrate 6 can be easily aligned with high accuracy via the laser beam LA2.

During alignment, the mask 4 and the photosensitive substrate 6 can be scanned by setting the gap between the mask 4 and the photosensitive substrate 6 sufficiently larger than in the conventional case.
It is possible to prevent the possibility that the pattern will come into contact with and damage the pattern on the mask 4, or that dust will be attached to the mask 4 to cause a common defect. Therefore, the size of the photosensitive substrate 6 can be easily increased. Further, by detecting the diffracted light, alignment can be performed without being affected by the contrast state of the alignment marks 27 and 28.

In the above-described embodiment, the alignment marks 27 and 28 are each formed in a straight line, and only the direction perpendicular to the alignment marks 27 and 28 is aligned. However, the present invention is not limited to this. The present invention is not limited to this, and can be applied to a case where alignment marks are formed in a shape in which two straight lines intersect in a cross shape and two orthogonal directions are simultaneously aligned. In this case, in addition to the above effects, the mask 4 and the photosensitive substrate 6 can be simultaneously aligned in the X-axis and Y-axis directions.

As shown in FIG. 4, an alignment optical system 34 of a proximity exposure apparatus for manufacturing a liquid crystal display device.
In place of the cylindrical lens 24 of the alignment optical system 22 of the alignment apparatus 21, a beam splitting / shaping unit 35 is arranged. Similarly, instead of the automatic harvesting 25, the space filter 29, and the detector 30, an automatic harvesting unit 36 and a detector unit 37 are provided, respectively.

The laser beam LA2 emitted from the helium neon laser 23 is split into two by the beam splitter 35A of the beam splitting / shaping unit 35. The one laser beam LA2 divided into two is shaped by the cylindrical lens 35B into a linear beam extending in the horizontal direction. The other laser beam LA2 is shaped into a linear beam extending in the vertical direction by the cylindrical lens 35E via the front surface mirrors 35C and 35D. The beams of the horizontal and vertical laser beams LA2 are made to coincide with each other in optical axis by the beam splitter 35F. As a result, a cross beam of the laser light LA2 is formed.

The cruciform beam is incident on the automatic harving section 36 and passes through the automatic harvings 36C and 36D. The automatic harvings 36C and 36D are respectively rotated around horizontal and vertical axes orthogonal to the optical axis by rotary actuators 36A and 36B composed of motors or the like. After this, the cross beam passes through the beam length switching shutter 26. The beam length switching shutter 26 is pushed and pulled by a linear actuator 38 such as an air cylinder to switch the aperture diameter. After that, the cross beam is projected onto the mask 4 or the photosensitive substrate 6 through the half prism 10 and the objective lens 9.

The diffracted light generated by the alignment mark formed on the mask 4 or the photosensitive substrate 6 is condensed by the objective lens 9, passes through the half prism 10, and is divided into two by the beam splitter 37A of the detector section 37. To be done. Subsequently, the diffracted light is given to the space filters 37B and 37C, respectively, and is divided into horizontal and vertical diffracted lights. Subsequently, the intensities of the diffracted lights in the horizontal and vertical directions are detected by detectors 37D and 37E having a photomultiplier tube structure, respectively.

As shown in FIG. 5 (A), the alignment mark 39 on the mask 4 has two diffraction gratings 39A and 39B formed in a line in the X-axis direction and two alignment marks 39 formed in a line in the Y-axis direction. One diffraction grating 39C and 39D. The diffraction gratings 39A and 39B and 39C and 39D are separated from each other by a predetermined space D3 and D4 in the X-axis and Y-axis directions in the central hollow portion 40, respectively. The alignment mark 39 is scanned by the cross beam 41A whose beam length is limited.

As shown in FIG. 5B, the cross-shaped beam 41 having a beam length limited to be shorter than the distances D3 and D4.
B is projected on the alignment mark 42 on the photosensitive substrate 6 through the hollow portion 40. Alignment mark 42
Is a diffraction grating 42A formed in a line in the X-axis direction, and Y
The diffraction grating 42B is formed in a line in the axial direction.

Also in the above-mentioned alignment apparatus using the alignment optical system 34, as in the embodiment, the control apparatus (not shown) of the alignment apparatus controls the cross-shaped beam 41A having a long beam length and the mask 4 on the mask 4. The relative position with respect to the alignment mark 39 is determined first (that is, the optical axis is fixed first).

After that, the controller moves the stage 5 to determine the relative position between the cross-shaped beam 41B having a short beam length and the alignment mark 42 on the photosensitive substrate 6 (that is, the stage 5 is fixed later). Be done). As a result, the controller can simultaneously align the mask 4 and the photosensitive substrate 6 in the X-axis and Y-axis directions.

Further, in the above embodiment, the laser LA
2 is moved to determine the relative position of the laser beam LA2 and the mask 4 first (that is, the optical axis is fixed first), and then the stage 5 is moved in the X-axis or Y-axis direction. Laser light L
The case where the relative position between A2 and the photosensitive substrate 6 is determined (that is, the stage 5 is fixed later) and the mask 4 and the photosensitive substrate 6 are aligned has been described, but the present invention is not limited to this, and laser light is used. Laser beam L is moved by moving the optical axis of LA2.
The relative position between A2 and the photosensitive substrate 6 is first determined (that is, the optical axis is fixed first), and then the mask holder 3 is moved in the X-axis or Y-axis direction to move the laser beam LA2 and the mask 4 together. The relative position may be determined (that is, the mask holder 3 may be fixed later), and the mask 4 and the photosensitive substrate 6 may be aligned.

Further, in the above-mentioned embodiment, the case where the laser beam LA2 of the helium neon laser 23 is used to deepen the depth of focus of the alignment optical system 22 has been described, but the present invention is not limited to this and other lasers are used. The laser beam may be used to increase the depth of focus of the optical system.

Further, in the above-described embodiment, the short beam 33B is passed through the central portion 31 of the alignment mark 27 formed in a line, and the alignment mark 28 formed in a line.
Although the case of projecting the short beam 33B has been described above, the present invention is not limited to this, and the alignment mark formed on the mask may have a shape other than a straight line if it has a hollow portion. Further, the alignment mark formed on the photosensitive substrate may have a shape other than a straight line as long as it can determine the relative position with respect to the beam projected through the hollow portion.

[0044]

As described above, in the alignment method of the proximity exposure apparatus according to the first aspect, it is obtained by scanning the light beam and the stage formed in association with the sizes of the first and second alignment marks. Based on the diffracted light,
By separately determining the relative positions of the first and second alignment marks with respect to the light flux with high accuracy and sequentially fixing the position of the optical axis of the light flux and the position of the stage, the distance between the mask and the photosensitive substrate is increased. In a state in which the mask and the photosensitive substrate are set larger than in the conventional case, the mask and the photosensitive substrate can be aligned with high accuracy and easily via the light flux without being influenced by the contrast state of the first and second alignment marks. The alignment method for a proximity exposure apparatus according to claim 2, wherein the light flux formed based on the sizes of the second and first alignment marks and the diffracted light obtained by scanning the mask stage 2 and the relative position of the first alignment mark is separately determined with high accuracy,
In addition, by sequentially fixing the position of the optical axis of the light flux and the position of the mask stage, the contrast between the second and first alignment marks can be increased in a state where the distance between the mask and the photosensitive substrate is set larger than in the past. Regardless of the state of
The mask and the photosensitive substrate can be easily aligned with high accuracy via the light flux. In the alignment method of the proximity exposure apparatus according to the third aspect, the depth of focus of the optical system can be deepened by using the laser beam of the He-Ne laser, and the focusing distance of the laser beam can be made sufficiently large. In the alignment method of the proximity exposure apparatus according to the fourth aspect, during alignment, the stage can be scanned by setting the gap between the mask and the photosensitive substrate to be sufficiently larger than the conventional one. As a result, it is possible to prevent the mask from coming into contact with the photosensitive substrate, damaging the pattern on the mask, or attaching dust on the mask to cause a common defect. Therefore, it is possible to easily cope with the size increase of the photosensitive substrate.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of an alignment device for performing alignment by an alignment method of a proximity exposure device according to the present invention.

FIG. 2 is a schematic diagram showing the alignment mark and the shape of laser light scanning the alignment mark.

FIG. 3 is a flow chart showing an alignment processing procedure between a mask and a substrate.

FIG. 4 is a perspective view for explaining an alignment optical system used in an alignment apparatus according to another embodiment.

FIG. 5 is a schematic diagram showing the alignment mark and the shape of laser light for scanning the alignment mark.

FIG. 6 is a configuration diagram for explaining a conventional alignment apparatus.

FIG. 7 is an alignment mark and a detection waveform of the alignment mark.

[Explanation of symbols]

1, 21 ... Alignment device, 2, 22, 34 ... Alignment optical system, 3 ... Mask holder, 4 ... Mask, 5 ... Stage, 6 ... Photosensitive substrate, 7, 8, 27,
28, 39, 42 ... Alignment mark, 9 ... Objective lens, 10 ... Half prism, 11 ... Image receiving device,
12, 13 ... Signal waveform, 23 ... Helium neon laser, 24, 35B, 35E ... Cylindrical lens,
25, 36C, 36D ... Automatic harving, 26 ... Beam length switching shutter, 27A, 27B, 39A to 39
D, 42A, 42B ... Diffraction grating, 29, 37B, 37
C ... Space filter, 30, 37D, 37E ... Detector, 31 ... Hollow part, 32 ... Shading plate, 33A ... Long beam, 33B ... Short beam, 35 ... Beam splitting forming part, 35A, 35F , 37A ... Beam splitter, 3
5C, 35D ... front surface mirror, 36 ... automatic harving part,
36A, 36B ... rotary actuator, 37 ... detector section, 38 ... linear actuator, 40 ... hollow section, 41A ... long cross beam, 41B ... short cross beam.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location H01L 21/027

Claims (4)

[Claims] 1. An alignment method of a proximity exposure apparatus in which a mask and a photosensitive substrate are brought close to each other and a pattern formed on the mask is exposed on the photosensitive substrate, wherein the mask is provided with alignment marks of a diffraction grating at regular intervals. And a step of moving a light shielding plate between the mask and the photosensitive substrate so as to face a plurality of first alignment marks provided in the first alignment mark, and a light beam emitted from a light source in relation to the size of the first alignment mark. A relative position between the light flux and the mask is determined based on a shaping step, a step of scanning the first alignment mark with the shaped light flux, and a diffracted light obtained from the first alignment mark by the scanning. And a step of retracting the light-shielding plate to a position that does not face the predetermined interval, A step of shaping a light beam emitted from a light source to be smaller than the predetermined interval, and a second alignment mark provided on the photosensitive substrate so as to substantially face the first alignment mark by the shaped light beam, the photosensitive substrate And a step of determining a relative position between the mask and the photosensitive substrate based on diffracted light obtained from the second alignment mark by the scanning. A method of aligning a proximity exposure apparatus having a feature. 2. An alignment method of a proximity exposure apparatus, wherein a mask and a photosensitive substrate are brought close to each other to expose a pattern formed on the mask to the photosensitive substrate, wherein the mask is provided with alignment marks of a diffraction grating at regular intervals. And a step of shaping and transmitting a light beam emitted from a light source so that the plurality of first alignment marks are passed through the fixed interval, and a light beam passing through the fixed interval substantially opposes the first alignment mark. On the basis of the step of scanning the second alignment mark provided on the photosensitive substrate by the movement of the stage on which the photosensitive substrate is placed, and the diffracted light obtained from the second alignment mark by the scanning. A step of determining a relative position between the light flux that has passed through a predetermined interval and the photosensitive substrate; An illuminating mark, a step of moving a light shielding plate between the mask and the photosensitive substrate, and a step of shaping a light beam emitted from a light source in relation to the size of the first alignment mark, A step of scanning the first alignment mark with the shaped light flux by moving a mask stage on which the mask is mounted, and the mask based on the diffracted light obtained from the first alignment mark by the scanning. And a step of determining a relative position with respect to the photosensitive substrate. 3. The alignment method for a proximity exposure apparatus according to claim 1, wherein the light source is a He—Ne laser. 4. The distance between the mask and the photosensitive substrate is 100.
The alignment method for a proximity exposure apparatus according to claim 1, 2 or 3, wherein the thickness is not less than [μm] and not more than 300 [μm].