JP5294490B2 - Photo mask - Google Patents

Description

  The present invention relates to a photomask for reducing and projecting a mask pattern image onto a to-be-exposed object to be exposed by a microlens, and more particularly to a photomask for improving the use efficiency of light irradiated to an object to be exposed. Is.

  A conventional photomask of this type is provided with a plurality of openings having a predetermined shape formed in a light-shielding film provided on one surface of a transparent substrate, and provided on the other surface of the transparent substrate corresponding to the openings. And a plurality of microlenses that form an image on an object to be exposed in close proximity to each other, thereby improving the resolution of the exposure pattern in the proximity exposure and enabling exposure of fine patterns. (For example, refer to Patent Document 1).

JP 2009-277900 A

  However, in such a conventional photomask, an opening (mask pattern) provided on one surface of the transparent substrate and a microlens (projection lens) provided on the other surface of the transparent substrate are equal to the thickness of the substrate. Therefore, some of the light passing through the opening of the photomask may not be taken into the corresponding microlens. This is because the light (light collimation half angle) exists in the light source light irradiated to the photomask, and the light passing through the opening spreads at an angle corresponding to the collimation half angle and enters the microlens. Therefore, as the distance between the opening and the microlens increases, the amount of light taken into the microlens decreases, and the amount of light applied to the object to be exposed decreases, which may reduce the light utilization efficiency.

  In particular, in the case of a photomask used for exposure of a large-area TFT display substrate, for example, the thickness of the transparent substrate is as thick as several mm to several tens of mm, and the above problem becomes more prominent.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a photomask that addresses such problems and attempts to improve the utilization efficiency of light irradiated to an object to be exposed.

In order to achieve the above object, a photomask according to the present invention includes a mask substrate on which a plurality of mask patterns having a predetermined shape are formed on one surface of a transparent substrate, and an object to be exposed that is oppositely disposed on one surface of another transparent substrate. A plurality of projection lenses for reducing and projecting the images of the plurality of mask patterns, and a plurality of field lenses for condensing incident light on the projection lens on the other surface so that the optical axes of the projection lenses coincide with the optical axes. And a projection lens having a diameter smaller than that of the field lens, and the mask pattern and the field lens are closely opposed to each other with a predetermined gap. The mask substrate and the microlens array are joined together.

With such a configuration, the light that has passed through the mask pattern is less than the diameter of the field lens by the field lens of the microlens array that is disposed in close proximity to the mask pattern of the mask substrate with a predetermined gap. The light is condensed on a small projection lens, and the image of the mask pattern is reduced and projected onto the object to be exposed facing the projection lens.

  Further, a light shielding film is formed on at least an outer region of the plurality of projection lenses of the microlens array. Thereby, the light irradiated outside the projection lens is blocked by the light shielding film formed in the outer region of at least the plurality of projection lenses of the microlens array.

  Furthermore, an alignment mark is provided on the surface of the microlens array on which the plurality of projection lenses are formed for alignment with the object to be exposed with reference to the projection lenses. Thus, the alignment with the object to be exposed is performed by the alignment mark provided with the projection lens as a reference on the surface on which the plurality of projection lenses of the microlens array are formed.

  Further, the object to be exposed is transported at a constant speed in one direction during exposure, and the alignment mark is separated by a predetermined distance on the front side in the transport direction of the object to be exposed in the region where the plurality of projection lenses are formed. Is provided. Accordingly, the position of the object to be exposed and the position being conveyed at a constant speed in one direction during exposure by the alignment mark provided at a predetermined distance away from the object in the conveying direction of the area in which the plurality of projection lenses are formed. Align.

  Further, the alignment mark is a pair of fine line patterns parallel to the conveyance direction of the object to be exposed and a single line provided between the pair of fine line patterns and intersecting the conveyance direction of the object to be exposed at a predetermined angle. It consists of a fine line pattern. Thus, an alignment comprising a pair of fine line patterns parallel to the conveyance direction of the object to be exposed and a single thin line pattern provided between the pair of fine line patterns and intersecting the conveyance direction of the object to be exposed at a predetermined angle. The mark aligns with an object to be exposed that is conveyed at a constant speed in one direction.

  The surface of the projection lens is provided with a stop having a circular opening whose diameter is smaller than the diameter of the field lens. Thus, the diameter of the light beam emitted from the projection lens is limited by a diaphragm provided on the surface of the projection lens and having a circular opening whose diameter is smaller than the diameter of the field lens.

According to the first aspect of the present invention, substantially the entire amount of light that has passed through the mask pattern can be condensed on the projection lens by the field lens that is disposed in close proximity to the mask pattern. Therefore, it is possible to improve the utilization efficiency of the light irradiated to the object to be exposed through the projection lens. Thereby, the power of the light source can be lowered and the burden on the light source can be reduced. Further, the resolution of the projection lens can be improved by eliminating the influence of the spherical aberration of the projection lens.

  Moreover, according to the invention which concerns on Claim 2, the unnecessary leakage light which passes a photomask can be interrupted | blocked, and the resolution of an exposure pattern can be improved more.

  Furthermore, according to the invention of claim 3, the alignment mark of the photomask can be brought close to the surface of the object to be exposed that is disposed in close proximity to the photomask, and the alignment formed in advance on the object to be exposed And the alignment mark of the photomask can be observed simultaneously. Therefore, alignment between the photomask and the object to be exposed can be easily performed. Even when the center of the mask pattern and the optical axis of the projection lens are misaligned, the projection image of the mask pattern is formed on the optical axis of the projection lens, so the alignment mark formed on the basis of the projection lens By using the alignment, the mask pattern image can be accurately positioned and exposed at a predetermined position of the object to be exposed.

  According to the fourth aspect of the present invention, exposure can be performed while correcting misalignment between the photomask and the object to be exposed moving in one direction, and the tact time of the exposure process can be shortened. .

  Furthermore, according to the fifth aspect of the present invention, it is possible to detect the positional deviation between the photomask and the object to be exposed and to control the exposure timing for the moving object to be exposed with a single alignment mark. Can do. Therefore, it is possible to expose the mask pattern image with high accuracy by positioning the object to be exposed.

  According to the sixth aspect of the invention, the influence of spherical aberration of the projection lens can be eliminated, and the resolution of the projection lens can be further improved. Therefore, the resolution of the exposure pattern can be further improved.

It is a figure which shows embodiment of the photomask by this invention, (a) is a top view, (b) is the XX sectional view taken on the line of (a). It is explanatory drawing which shows one form of the alignment mark for aligning the mask substrate and micro lens array of the said photomask, (a) shows a mask side alignment mark, (b) shows a lens side alignment mark. Show. It is sectional drawing which shows the structure of the said micro lens array, and is explanatory drawing which shows image formation of the mask pattern by paraxial ray tracing. It is a top view which shows the N type alignment mark of the said photomask. It is a schematic diagram which shows the exposure apparatus which uses the said photomask. It is a block diagram which shows the structure of the control means of the said exposure apparatus. It is explanatory drawing shown about position shift correction with a photomask and the imaging center of an imaging means by the said N type alignment mark. It is explanatory drawing shown about the position shift correction of the said photomask and to-be-exposed body. It is a top view which shows the other structural example of the photomask of this invention.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 1A and 1B are diagrams showing an embodiment of a photomask 1 according to the present invention, in which FIG. 1A is a plan view and FIG. 1B is a cross-sectional view taken along line XX of FIG. The photomask 1 projects a mask pattern image on a to-be-exposed object to be reduced by a microlens, and includes a mask substrate 2 and a microlens array 3.

  The mask substrate 2 is formed by forming a plurality of mask patterns having a predetermined shape on one surface of a transparent substrate. As shown in FIG. 1B, chromium (Cr) or the like formed on the lower surface 4a of the transparent substrate 4 is used. A plurality of mask patterns 5 having a predetermined shape are formed on the opaque film 6 in a matrix, for example. Then, the four corners outside the mask pattern formation region 7 sandwiched between two broken lines in FIG. 2A are used for alignment with a microlens array 3 described later, for example, in FIG. A cross-shaped mask side alignment mark 8 formed of an opaque film as shown is formed. In FIG. 1A, the mask pattern 5 is simply shown as a square because the drawing becomes complicated.

  A microlens array 3 is provided facing the mask substrate 2. The microlens array 3 projects an image of the mask pattern 5 of the mask substrate 2 on an object to be exposed, which is disposed in close proximity to each other. As shown in FIG. A plurality of projection lenses 10 for reducing and projecting the plurality of mask patterns 5 on the object to be exposed, which are opposed to each other, are formed on the lower surface 9a of the substrate 9 in a matrix, for example, corresponding to the mask pattern 5 of the mask substrate 2. As shown in the figure, a field lens 11 for condensing incident light on the projection lens 10 is formed on the upper surface 9b in a state where the optical axis of the projection lens 10 is matched with the optical axis as shown in FIG. . A light shielding film 12 made of an opaque film such as chromium (Cr) is formed on the outer area of the field lens 11 and the projection lens 10. In this case, a diaphragm having a circular opening whose diameter is smaller than the diameter of the field lens 11 may be provided on the surface of the projection lens 10. Thereby, the influence of the spherical aberration of the projection lens 10 can be eliminated and the resolution of the projection lens can be improved. In the present embodiment, as shown in FIG. 3, the diameter of the projection lens 10 is made smaller than the diameter of the field lens 11 so that substantially the same effect as that obtained when a stop is provided can be obtained. ing.

  A mask substrate corresponding to the mask-side alignment mark 8 of the mask substrate 2 is provided at the four corners outside the lens forming region 13 sandwiched between the two broken lines shown in FIG. For example, a lens-side alignment mark 14 in which a cross-shaped opening is formed in an opaque film as shown in FIG. Further, the light shielding film 12 on the lower surface 9 a side of the transparent substrate 9 is formed with a rectangular opening 15 corresponding to the lens side alignment mark 14, and transmits illumination light irradiated from the lower surface 9 a side of the transparent substrate 9. The lens side alignment mark 14 can be illuminated.

  An alignment mark (hereinafter referred to as “N-type alignment mark 16”) is provided on the surface (lower surface 9a) on which the plurality of projection lenses 10 of the microlens array 3 are formed. This N-type alignment mark 16 is used to align the mask pattern 5 of the mask substrate 2 with the exposure target position of the object to be exposed that is conveyed in one direction shown by the arrow A in FIG. In FIG. 1, the exposure object transport direction (hereinafter referred to as “substrate transport direction”) indicated by arrow A among the plurality of projection lenses 10 in the lens forming region 13 sandwiched between two broken lines in FIG. It is provided a predetermined distance away from the projection lens 10 positioned on the front side in the substrate transport direction (arrow A direction). The opaque film 6 of the mask substrate 2 and the light shielding film 12 on the upper surface 9b of the microlens array 3 in the region corresponding to the N-type alignment mark 16 are removed so that the N-type alignment mark 16 can be observed from above the mask substrate 2. ing. As described above, the N-type alignment mark 16 is formed on the same surface as the projection lens 10 forming surface of the microlens array 3, so that the surface of the object to be conveyed conveyed in close proximity to the photomask 1 is aligned with the N-type alignment. The marks 16 are close to each other, and the reference pattern formed in advance on the object to be exposed and the N-type alignment mark 16 can be observed at the same time, and the alignment between the photomask 1 and the object to be exposed becomes easy. Even when the center of the mask pattern 5 and the optical axis of the projection lens 10 are deviated, the projection image of the mask pattern 5 is formed on the optical axis of the projection lens 10, so that it is formed with reference to the projection lens 10. The mask pattern 5 can be accurately exposed at a predetermined position of the object to be exposed by the alignment using the N-type alignment mark 16.

  Here, the N-type alignment mark 16 specifically includes a pair of fine line patterns 17a and 17b parallel to the substrate transport direction (arrow A direction) and the pair of fine line patterns 17a and 17b, as shown in FIG. 1 is a substantially N-shaped mark composed of a single thin line pattern 17c that is provided in between and intersects the substrate transport direction (arrow A direction) at a predetermined angle θ (for example, θ = 45 °). As shown in a), the N-type alignment mark is arranged so that the center line parallel to the substrate transport direction (arrow A direction) of the thin line pattern 17c coincides with the center of any one of the plurality of projection lenses 10. 16 is formed. The N-type alignment mark 16 has a distance D between the central axis orthogonal to the substrate transport direction (arrow A direction) and the projection lens 10 located on the front side of the microlens array 3 in the substrate transport direction. It is set in advance.

Such a microlens array 3 can be formed as follows.
First, the lens forming region 13 is etched in a state where the outside of the lens forming region 13 is masked by the upper surface 9b of the transparent substrate 9, and is dug down to a depth of about 50 μm to 300 μm, for example. Further, a plurality of convex field lenses 11 having a predetermined curvature are formed in the lens forming region 13 using a known technique. Next, after a light shielding film 12 such as chromium (Cr) is formed on the entire upper surface 9b of the transparent substrate 9, a portion corresponding to the field lens 11 and a light shielding film 12 in a region corresponding to the N-type alignment mark 16 are formed. Etch away. At the same time, the lens-side alignment mark 14 may be formed by etching. Subsequently, a plurality of convex projection lenses 10 are formed in the lens forming region 13 on the lower surface 9 a of the transparent substrate 9 by using a known technique corresponding to the field lens 11. Then, after a light shielding film 12 such as chromium (Cr) is formed on the entire lower surface 9a of the transparent substrate 9, the portion corresponding to the projection lens 10 and the portion corresponding to the lens side alignment mark 14 are removed by etching. At that time, the N-type alignment mark 16 may be formed simultaneously.

  Note that a plurality of N-type alignment marks 16 may be provided in a direction substantially orthogonal to the substrate transport direction, instead of only one in the photomask 1. In this case, a plurality of imaging means 24 (see FIG. 5) described later may be provided corresponding to each N-type alignment mark 16. Thereby, alignment of the photomask 1 and the object to be exposed can be performed using any one of the plurality of N-type alignment marks 16. The photomask 1 provided with such a plurality of N-type alignment marks 16 is particularly suitable for exposure of an object to be exposed having a large area.

Next, the production of the photomask 1 of the present invention will be described.
First, an adhesive is applied to a portion outside the lens formation region 13 of the field lens 11 on the upper surface 9 b of the microlens array 3. Next, the mask substrate 2 and the microlens array 3 are arranged to face each other with the lower surface 4a on which the mask pattern 5 of the mask substrate 2 is formed and the upper surface 9b to which the adhesive of the microlens array 3 is applied facing each other. Subsequently, while simultaneously observing the mask-side alignment mark 8 and the lens-side alignment mark 14 with a microscope, the mask substrate 2 and the microlens array 3 are relatively translated so that the two alignment marks match. Further, alignment is performed by rotating around the center of the surface of each of the substrates 4 and 9. And the said adhesive agent is hardened in the state which pressurized the mask board | substrate 2 and the microlens array 3 from the side of the surface of each board | substrate 4 and 9, and both are joined. Thereby, the photomask 1 of the present invention as shown in FIG. 1 is completed. At this time, the mask pattern 5 and the field lens 11 are close to a distance of about 50 μm to 300 μm.

  FIG. 5 is a front view showing an exposure apparatus using the photomask 1 of the present invention. This exposure apparatus exposes the object to be exposed 19 while conveying it at a constant speed in one direction indicated by an arrow A, and includes a conveying means 20, a light source 21, a coupling optical system 22, a mask stage 23, and imaging. Means 24 and control means 25 are provided.

  The conveying means 20 places the exposed body 19 on the upper surface 20a and conveys it at a constant speed in the direction indicated by the arrow A. The air is ejected and sucked from the upper surface 20a, and the air is ejected and sucked. And the object to be exposed 19 is conveyed in a state of being floated by a predetermined amount. Further, the transport unit 20 is provided with a speed sensor that detects the moving speed of the object to be exposed 19 and a position sensor (not shown) that detects the position of the object to be exposed 19.

  A light source 21 is provided above the conveying means 20. The light source 21 emits ultraviolet rays as light source light and is a laser light source. In the present embodiment, the light source 21 emits light intermittently under the control of the control means 25 described later.

  A coupling optical system 22 is provided in front of the light source 21 in the light emission direction. The coupling optical system 22 converts the light source light emitted from the light source 21 into parallel light and irradiates the mask pattern formation region 7 of the photomask 1 described later, and includes optical components such as a photo integrator and a condenser lens. It consists of Further, a mask for shaping the cross-sectional shape of the light source light in accordance with the outer shape of the mask pattern formation region 7 of the photomask 1 is also provided.

  A mask stage 23 is provided so as to face the upper surface 20 a of the transport means 20. The mask stage 23 positions and holds the photomask 1 of the present invention, and an opening 26 is formed at the center corresponding to the mask pattern formation region 7 and the N-type alignment mark 16 formation region of the photomask 1. The peripheral edge of the photomask 1 is formed and held. And it is controlled by the control means 25 mentioned later, and is provided with the moving mechanism so that it may move in the direction orthogonal to a board | substrate conveyance direction (arrow A direction) within the surface parallel to the upper surface 20a of the conveyance means 20. Yes.

  An imaging unit 24 is provided so as to be able to image the N-type alignment mark 16 of the photomask 1 held on the mask stage 23 above the conveying unit 20. The imaging unit 24 simultaneously images the N-type alignment mark 16 of the photomask 1 and a reference mark (for example, a pixel on the display substrate) formed in advance on the surface of the object to be exposed 19. This is a line camera in which a plurality of light receiving elements are arranged in a straight line in a direction substantially orthogonal to the substrate transport direction (arrow A direction) in a plane parallel to the upper surface 20a.

  A control unit 25 is provided in electrical connection with the transport unit 20, the light source 21, the mask stage 23, and the imaging unit 24. This control means 25 moves the mask stage 23 and controls the light emission timing of the light source 21 so as to correct the misalignment between the photomask 1 and the exposed object 19 based on the image taken by the imaging means 24. As shown in FIG. 6, the image processing unit 27, the memory 28, the calculation unit 29, the transport unit drive controller 30, the mask stage drive controller 31, the light source drive controller 32, and the control unit 33 are provided. ing.

Here, the image processing unit 27 processes a captured image of the surface of the object to be exposed 19 captured by the image capturing unit 24, and a reference formed in advance on the object to be exposed 19 by a luminance change that changes beyond a predetermined threshold. An edge portion substantially parallel to the substrate carrying direction of the pattern and an edge portion intersecting with the substrate carrying direction are detected. Further, the memory 28 detects the leading edge of the reference pattern formed in advance on the object 19 in the substrate conveyance direction, and the first exposure target position on the object 19 is the substrate conveyance of the photomask 1. A target value TG ₁ for the distance to which the object to be exposed 19 is moved before reaching the projection position of the image of the mask pattern 5 located on the front side in the direction, a target value TG _{2 for} the alignment between the photomask 1 and the object to be exposed 19, In addition to storing the arrangement pitch P of the mask pattern 5 of the photomask 1 in the substrate transport direction, the calculation result in the calculation unit 29 described later is temporarily stored. Further, the calculation unit 29 calculates the movement distance of the object to be exposed 19 based on the output of the position sensor of the transport unit 20, and positions of the photomask 1 and the object to be exposed 19 based on the output of the image processing unit 27. The amount of deviation is calculated. The transport unit drive controller 30 controls the transport unit 20 so that the object 19 is transported at a constant speed. The mask stage drive controller 31 controls the movement of the mask stage 23 so as to correct the amount of positional deviation between the photomask 1 and the object 19 to be exposed based on the output of the calculation unit 29. Further, the light source drive controller 32 controls the turning on and off of the light source 21. And the control part 33 integrates and controls the whole so that each said element may drive appropriately.

Next, the operation of the exposure apparatus configured as described above will be described.
First, the amount of positional deviation between the photomask 1 and the imaging center of the imaging means 24 is measured in advance. This can be done as follows. That is, first, the N-type alignment mark 16 of the photomask 1 held on the mask stage 23 is imaged by the imaging means 24, and the image data is subjected to image processing in the image processing unit 27, as shown in FIG. Next, the positions of the edges of the three dark portions corresponding to the thin line patterns 17a to 17c of the N-type alignment mark 16 are detected from the luminance change in the direction substantially orthogonal to the substrate transport direction (arrow A direction). The center position of each dark part is calculated. Next, the calculation unit 29 calculates distances G ₁ and G ₂ between two adjacent dark parts. Further, based on the difference between the distances G ₁ and G ₂ , the amount of deviation between the imaging center of the imaging means 24 and the center line in the direction orthogonal to the substrate transport direction (arrow A direction) of the N-type alignment mark 16 of the photomask 1. G is calculated. In this case, when the inclination angle θ with respect to the substrate transport direction (arrow A direction) of the thin line pattern 17c is θ = 45 °, the deviation G is G = (G ₁ −G ₂ ) / 2. Then, the deviation amount G is added to the target value TG ₁ of the movement distance of the object to be exposed 16 stored in the memory 28 is the target value TG ₁ is corrected, the corrected target value (TG 1 + _G) Is stored in the memory 28.

  Next, after the object 19 is positioned and placed on the upper surface 20a of the conveying means 20, the driving of the conveying means 20 is controlled by the conveying means drive controller 30 to move the exposed object 19 in the direction of arrow A at a constant speed. Start conveyance.

  When the object to be exposed 19 is conveyed and the leading edge of the substrate conveying direction (arrow A direction) reaches the image pickup position of the image pickup means 24, the surface of the object to be exposed 19 is picked up by the image pickup means 24. At this time, the captured image of the imaging means 24 is subjected to image processing in the image processing unit 27, and intersects the substrate transport direction of the reference pattern formed in advance on the exposure object 19 from the luminance change from dark to bright in the substrate transport direction. The edge to be detected is detected. Based on the output of the position sensor of the conveying means 20, the position of the object to be exposed 19 at the edge detection time of the reference pattern is detected.

Subsequently, the calculation unit 29 starts calculating the movement distance of the object 19 to be exposed. The calculation result is compared with the corrected target value (TG ₁ + G) of the movement distance of the object 19 stored in the memory 28. When the two match, the first exposure target position on the exposure object 19 is positioned at the projection position of the image of the mask pattern 5 located on the front side of the photomask 1 in the substrate transport direction.

On the other hand, as shown in FIG. 8A, the imaging unit 24 images the N-type alignment mark 16 of the photomask 1 and the reference pattern 34 of the object 19 to be exposed. The captured image is subjected to image processing by the image processing unit 27, and a luminance change in a direction substantially orthogonal to the substrate transport direction (arrow A direction) is detected as shown in FIG. 34, the positions of the edges substantially parallel to the substrate transport direction (arrow A direction) of the dark portion corresponding to the three thin line patterns 17a to 17c of the N-type alignment mark 16 are detected. Then, the calculation unit 29 calculates the center position of each dark part based on these position data. Further, in the calculation unit 29, the distance G ₃ between the center position of the dark part corresponding to, for example, the left thin line pattern 17 a of the N-type alignment mark 16 and the center position of the dark part corresponding to between the two adjacent reference patterns 34. Is compared with the alignment target value TG ₂ stored in the memory 28. Then, while controlling the mask stage drive controller 31 to move the mask stage 23 so that the target value TG ₂ of the distance G ₃ and alignment matches in a direction substantially perpendicular to the substrate conveying direction (arrow A direction). This alignment operation is always performed during the movement of the object to be exposed 19 until the exposure of the object to be exposed 19 is completed.

After the leading edge of the reference pattern 34 of the exposure object 19 in the substrate transport direction (arrow A direction) is detected by the imaging unit 24, the exposure object 19 is equal to the corrected target value (TG ₁ + G). When moved by the distance, the light source drive controller 32 is activated with the lighting command output from the calculation unit 29 as a trigger, and the light source 21 is lit for a predetermined time. As a result, the image of the mask pattern 5 on the front side of the photomask 1 in the substrate transport direction is reduced and projected onto the first exposure target position of the object 19 to form a similar exposure pattern to the mask pattern 5.

  Thereafter, the calculation unit 29 calculates the movement distance of the object to be exposed 19 based on the output of the position sensor of the conveying means 20, and the object to be exposed 19 moves in the substrate conveying direction of the mask pattern 5 stored in the memory 28. A lighting command is output to the light source drive controller 32 every time it moves by a distance equal to the arrangement pitch P of the light source. As a result, each time the object to be exposed 19 moves by a distance equal to the arrangement pitch P of the mask pattern 5 in the substrate transport direction, the light source 21 is turned on for a predetermined time to perform exposure, and the image of the mask pattern 5 is captured. The exposure target position on the exposure body 19 is sequentially exposed. In the photomask 1 of the present embodiment, a plurality of mask patterns 5 (in FIG. 1, three mask patterns 5 are shown) in which the same positions on the object to be exposed 19 are arranged in the substrate transport direction (arrow A direction). ) Is subjected to multiple exposure. Therefore, the power of the light source 21 can be reduced, and the burden on the light source 21 can be reduced.

  In the above embodiment, the photomask 1 in which the mask pattern 5 is formed in a matrix at a predetermined pitch has been described. However, the present invention is not limited to this, and the mask pattern 5 is arranged in a direction orthogonal to the substrate transport direction. A plurality of mask pattern rows arranged in a row at a predetermined pitch are formed, and the mask pattern 5 of the subsequent mask pattern row is complemented with the mask pattern 5 between the adjacent mask pattern rows located on the head side in the substrate transport direction. Further, the photomask 1 may be arranged such that each subsequent mask pattern row is shifted by a predetermined dimension in a direction substantially perpendicular to the substrate transport direction. Thereby, an exposure pattern can be formed densely. In this case, the plurality of mask pattern rows may be set as one set, and a plurality of sets may be arranged in the substrate transport direction.

  In the above-described embodiment, the case where the photomask 1 is a single mask substrate 2 and a single microlens array 3 is described. However, the present invention is not limited to this, and FIG. As shown, a plurality of microlens arrays 3 may be arranged side by side in the major axis direction of the mask substrate 2 with respect to a single mask substrate 2. Thereby, the manufacturing cost of the microlens array 3 can be reduced, and the manufacturing cost of the photomask 1 can also be reduced.

  Furthermore, in the above-described embodiment, the case where the field lens 11 is formed by digging the upper surface 9b of the transparent substrate 9 of the microlens array 3 by a predetermined depth has been described. A lens 11 is formed, and another substrate is bonded to the end surface of the transparent substrate 9 on which the projection lens 10 is formed on the lower surface 9a to form a predetermined gap between the mask pattern 5 of the mask substrate 2 and the field lens 11. May be. Alternatively, a spacer having a predetermined thickness is disposed outside the lens formation region 13 on the upper surface 9b of the transparent substrate 9, and the mask substrate 2 and the microlens array 3 are joined via the spacer, and the mask pattern 5 and the field are formed. A predetermined gap may be formed between the lens 11 and the lens 11.

  In the embodiment described above, the case where the photomask 1 exposes the object 19 being conveyed in one direction has been described. However, the present invention is not limited to this, and the photomask 1 is stationary. You may expose with respect to the to-be-exposed body 19. FIG.

DESCRIPTION OF SYMBOLS 1 ... Photomask 2 ... Mask substrate 3 ... Micro lens array 4 ... Transparent substrate for mask substrates 5 ... Mask pattern 9 ... Transparent substrate for micro lenses 10 ... Projection lens 11 ... Field lens 12 ... Light shielding film 16 ... N type alignment Marks 17a to 17c ... fine line pattern 19 ... object to be exposed

Claims (6)

A mask substrate in which a plurality of mask patterns having a predetermined shape are formed on one surface of the transparent substrate;
A plurality of projection lenses for reducing and projecting the images of the plurality of mask patterns are formed on one surface of another transparent substrate oppositely to be exposed, and a plurality of lenses for condensing incident light to the projection lens on the other surface A microlens array formed by matching the optical axis of the projection lens with the optical axis of the projection lens,
A diameter of the projection lens is formed smaller than a diameter of the field lens, and the mask substrate and the microlens array are placed in a state where the mask pattern and the field lens are closely opposed to each other with a predetermined gap. A photomask characterized by bonding.   The photomask according to claim 1, wherein a light shielding film is formed at least in an outer region of the plurality of projection lenses of the microlens array.   The alignment mark for aligning with the said to-be-exposed body is provided in the surface in which the said several projection lens of the said microlens array was formed in reference to this projection lens. Photo mask. The exposed object is conveyed at a constant speed in one direction during exposure,
4. The photomask according to claim 3, wherein the alignment mark is provided at a predetermined distance away from the front side in the transport direction of the object to be exposed in an area where the plurality of projection lenses are formed.   The alignment mark includes a pair of fine line patterns parallel to the conveyance direction of the object to be exposed and a single thin line pattern provided between the pair of fine line patterns and intersecting the conveyance direction of the object to be exposed at a predetermined angle. The photomask according to claim 4, comprising:   6. The photomask according to claim 1, wherein a diaphragm having a circular opening having a diameter smaller than that of the field lens is provided on the surface of the projection lens.

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