JP2009277900A - Exposure device and photomask - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exposure device capable of improving the resolution of an exposure pattern in proximity exposure, thereby exposing a fine pattern. <P>SOLUTION: The exposure device exposes a pattern corresponding to a plurality of openings 11 in a predetermined shape on a body 6 to be exposed by arranging a photomask 4 having the openings 11 formed in a light shield film 10 provided on one surface of a transparent substrate 9 closely to the body 6 to be exposed and irradiating the photomask 4 with light source light L1. On the side of the body 6 to be exposed, a plurality of microlenses 12 for forming images of the openings 11 on the body 6 to be exposed are arranged corresponding to the openings 11 of the photomask 4. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an exposure apparatus that exposes a predetermined pattern with a photomask provided in close proximity to an object to be exposed, and more specifically, exposure that improves the resolution of an exposure pattern and enables exposure of a fine pattern. The present invention relates to an apparatus and a photomask.

A conventional exposure apparatus, particularly a proximity exposure apparatus, exposes a pattern formed on a photomask to the object to be exposed by bringing the photomask and the object to be exposed close to each other. A transparent glass plate provided on the lower surface, a mask suction holding means for sucking and holding the photomask in close contact with a plane, and a glass that holds the transparent glass plate so as to form a minute gap between the photomask and the object to be exposed It had a board holding means (for example, refer patent document 1).
JP-A-2005-300753

  However, in such a conventional exposure apparatus, the pattern formed on the photomask is transferred as it is onto the object to be exposed by the exposure light vertically transmitted through the photomask. Due to the presence of the half-width), there is a problem that the image of the pattern on the object to be exposed is blurred and the resolution is lowered, and a fine pattern cannot be formed by exposure.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an exposure apparatus and a photomask that address such problems and improve the resolution of an exposure pattern to enable exposure of a fine pattern.

  In order to achieve the above object, an exposure apparatus according to the present invention includes a photomask in which a plurality of openings having a predetermined shape are formed in a light-shielding film provided on one surface of a transparent substrate, and is disposed in close proximity to an object to be exposed. An exposure apparatus that irradiates a photomask with light source light to expose a pattern corresponding to the opening on the object to be exposed, the exposure object side corresponding to each opening of the photomask, A plurality of microlenses for forming an image of each aperture on the object to be exposed is provided.

  With such a configuration, a photomask in which a plurality of openings of a predetermined shape are formed in a light shielding film provided on one surface of a transparent substrate is disposed in close proximity to the object to be exposed, and the object to be exposed corresponds to each of the openings. An image of each opening is formed on the object to be exposed by a plurality of microlenses arranged on the body side, and a pattern corresponding to the opening is exposed on the object to be exposed by irradiation of light source light to the photomask.

  Each of the microlenses is formed on the surface of the transparent substrate opposite to the surface on which the opening is formed. Thereby, an image of each opening is formed on the object to be exposed by each microlens formed on the surface opposite to the surface on which the opening of the transparent substrate is formed.

  Further, each of the microlenses is formed on one surface of another transparent substrate. Thereby, an image of each opening of the transparent substrate is formed on the object to be exposed by each microlens formed on one surface of another transparent substrate.

  Then, the object to be exposed is transported at a predetermined speed parallel to one surface of the photomask by a transport means, and the light source light is intermittently irradiated onto the photomask. As a result, the light source light is intermittently applied to the photomask, and the image of each opening of the photomask is exposed by the microlenses onto the object to be exposed that is transported at a predetermined speed in parallel with one surface of the photomask by the transport means. The pattern corresponding to the opening is sequentially exposed on the object to be exposed.

  The photomask according to the present invention is provided with a plurality of openings having a predetermined shape formed in a light shielding film provided on one surface of the transparent substrate, and provided on the other surface of the transparent substrate corresponding to each of the openings. And a plurality of microlenses that form an image on an object to be exposed that is disposed in close proximity to each other.

  With such a configuration, images of a plurality of openings having a predetermined shape formed on the light-shielding film provided on one surface of the transparent substrate are transferred to the other surface of the transparent substrate by a plurality of microlenses provided corresponding to the respective openings. An image is formed on an object to be exposed that is disposed in close proximity to each other.

  According to the exposure apparatus of the first aspect, a plurality of microlenses are disposed on the exposed object side corresponding to the plurality of openings of the photomask, and an image of each opening is formed on the exposed object by the microlens. Since the image is formed, the resolution of the exposure pattern can be improved. Therefore, for example, a fine pattern with a line width of about 3 μm can be formed by proximity exposure. As a result, exposure that requires high resolution, such as the transistor portion of the TFT substrate, can be performed using an inexpensive proximity exposure apparatus with a simple optical system configuration, thereby reducing the manufacturing cost of the TFT substrate. be able to.

  According to the second aspect of the present invention, since the microlens is formed on the surface opposite to the surface on which the opening of the transparent substrate is formed, the alignment between the opening and the microlens is unnecessary. Therefore, handling of the photomask becomes easy.

  Further, according to the invention of claim 3, since the photomask having a plurality of openings and the microlens are formed separately, when the photomask has a defect or when a defect occurs later However, it is only necessary to replace the photomask, and the cost increase of the photomask can be suppressed.

  According to the fourth aspect of the present invention, exposure can be performed while continuously conveying a plurality of objects to be exposed, and the number of exposure processes per unit time can be improved. In this case, since the photomask to be used may have at least the width in the conveyance direction of the object to be exposed smaller than the width of the exposure area of the object to be exposed in the same direction, the shape of the photomask can be reduced. The manufacturing cost of the photomask can be reduced.

  According to the photomask of claim 5, a plurality of openings are formed in the light shielding film provided on one surface of the transparent substrate, and a plurality of microlenses are provided on the other surface corresponding to the openings, respectively. Since the image of the aperture can be formed on the object to be exposed that is disposed close to and opposed by the lens, the resolution of the exposure pattern can be improved. Therefore, for example, a fine pattern with a line width of about 3 μm can be formed by proximity exposure. As a result, exposure that requires high resolution, such as the transistor portion of the TFT substrate, can be performed using an inexpensive proximity exposure apparatus with a simple optical system configuration, thereby reducing the manufacturing cost of the TFT substrate. be able to.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a front view showing a schematic configuration of an embodiment of an exposure apparatus according to the present invention. This exposure apparatus exposes a predetermined pattern with a photomask provided in close proximity to an object to be exposed, and includes a stage 1, a light source 2, a mask stage 3, a photomask 4, and a collimation lens 5. Prepare.

  The stage 1 is formed with a flat upper surface to serve as a mounting surface 1a, and the object to be exposed 6 is positioned on the mounting surface 1a by suction, for example. The mounting surface 1a is moved by a moving mechanism (not shown). Is movable in the X, Y, and Z axis directions and is rotatable about a central axis perpendicular to the mounting surface 1a. The Y-axis direction is the depth direction in FIG.

  A light source 2 is provided above the stage 1. This light source 2 irradiates a photosensitive resin applied to the surface of the object to be exposed 6 by irradiating the object to be exposed 6 with ultraviolet light source light L1, and emits ultraviolet light (for example, wavelength: 355 nm). Ultra high pressure mercury lamp, ultraviolet light emitting laser light source and the like. Further, for example, a condensing lens 14 is provided in front of the light source light L1 in the radiation direction, and the light source light L1 is once condensed. The condensing point P is provided with a shutter 7 that opens and closes an optical path from the light source 2 toward the object to be exposed 6 by moving in the directions of arrows A and B.

  A mask stage 3 is provided between the stage 1 and the light source 2 so as to face the stage 1. The mask stage 3 holds a photomask 4 (described later) in close proximity to and in parallel with the surface of the exposure object 6 placed on the stage 1, and has a central portion corresponding to the pattern formation region of the photomask 4. An opening window 8 is formed on the photomask 4, and the positioning of the photomask 4 is restricted to hold the vicinity of the periphery.

  A photomask 4 is detachably held on the mask stage 3. As shown in FIG. 2, the photomask 4 has a plurality of openings (patterns) 11 having a predetermined shape in a light shielding film 10 such as chromium (Cr) provided on one surface 9a of a transparent substrate 9 such as quartz glass. The surface 9b opposite to the surface 9a on which the openings 11 of the transparent substrate 9 are formed is formed in a matrix at intervals, and the magnification is, for example, 0.25 times corresponding to each of the openings 11. A plurality of microlenses 12 having a distance of 0.683 mm with respect to ultraviolet rays having a wavelength of 355 nm are formed, and an image of each opening 11 is formed on the object to be exposed 6. In this case, as shown in FIG. 1, the photomask 4 is held on the mask stage 3 with the side on which the microlenses 12 are formed as the exposed object 6 side.

  A collimation lens 5 is provided between the mask stage 3 and the light source 2. The collimation lens 5 is for making the light source light L1 emitted from the light source 2 into parallel light, and its front focal point coincides with the condensing point P of the condensing lens 14.

Next, the operation of the exposure apparatus configured as described above will be described.
First, the light source 2 is turned on to turn on the light source 2. At this time, the shutter 7 is closed. When the light emission of the light source 2 is stabilized after a predetermined time has passed, the photomask 4 is positioned and placed on the mask stage 3 with the microlens 12 side facing the stage 1 and held by suction.

  Next, the object to be exposed 6 whose surface is coated with a photosensitive resin is positioned and placed on the placement surface 1a on the stage 1, and is sucked and held. Thereafter, an imaging unit (not shown) captures an alignment mark previously formed on the photomask 4 and an alignment mark previously formed on the object 6 to be exposed within the same field of view, and controls not shown so that both marks coincide. Controlled by the means, the stage 11 is moved in the X and Y axis directions and rotated by a predetermined angle as necessary to align the photomask 4 and the object 6 to be exposed. When the alignment between the photomask 4 and the object to be exposed 6 is completed, the stage 1 is moved by a predetermined amount to the Z axis so that a predetermined gap is formed between the surface of the object to be exposed 6 and the lower surface of the photomask 4. Ascend in the direction. As a result, the opening 11 formed on the upper surface of the photomask 4 is imaged on the surface of the object to be exposed 6 by the opposed microlens 12.

  Subsequently, the exposure switch is turned on, the shutter 7 is moved in the direction of arrow A and opened for a predetermined time to perform exposure. As a result, the light source light L1 emitted from the light source 2 irradiates the photomask 4 as shown in FIG. 3, passes through the opening 11 formed in the photomask 4 as the exposure light L2, and is covered by the microlens 12. It is condensed on the exposed body 6. Therefore, the image of the opening 11 is reduced and projected on the exposed object 6 by the microlens 12, and a pattern having a shape corresponding to the opening 11 is exposed and formed on the photosensitive resin applied to the surface.

  In the above embodiment, the case where the photomask 4 in which the opening 11 and the microlens 12 are formed on the same transparent substrate 9 has been described. However, the present invention is not limited to this, and as shown in FIG. The microlens 12 may be formed on a transparent substrate 13 different from the photomask 4 in which the opening 11 is formed. In this case, the photomask 4 has its surface 9a on which the opening 11 is formed in close contact with the surface 13b on the opposite side to the surface 13a on which the microlens 12 of the other transparent substrate 13 is formed, as indicated by an arrow in FIG. It is good to use. Alternatively, if the microlens 12 can form an image of the opening 11 of the photomask 4 on the surface of the object to be exposed 6, the surface 9b opposite to the surface 9a on which the opening 11 of the photomask 4 is formed is different from the above. You may make it closely_contact | adhere to the surface 13b on the opposite side to the surface 13a in which the micro lens 12 of the transparent substrate 13 was formed.

  Further, in the above description, the case where the exposure object 6 held at a predetermined position is exposed has been described. However, the present invention is not limited to this, and the exposure object 6 is transferred to the photomask 4 by the conveying means. The light source light L1 is intermittently irradiated to the photomask 4 at a predetermined time interval while being transported at a predetermined speed in parallel with one surface, and corresponds to the opening 11 of the photomask 4 at a predetermined position of the object 6 The formed pattern may be formed by exposure. In this case, the intermittent irradiation of the light source light L1 may be performed using a flash lamp or may be performed by opening and closing the shutter 7. In addition, an image pickup unit that picks up an image of the exposure position of the exposure object 6 on the front side in the transport direction of the photomask 4 is captured, and a reference position formed in advance on the exposure object 6 is picked up by the image pickup unit. The photomask 4 and the object to be exposed 6 may be aligned based on the above, and the reference position or another reference position is imaged, and the irradiation timing of the light source light L1 is controlled based on the captured image. Also good.

It is a front view which shows schematic structure of embodiment of the exposure apparatus by this invention. It is a figure which shows one structural example of the photomask by this invention, (a) is a top view, (b) is a front view, (c) is a bottom view. It is explanatory drawing which shows the image formation by the micro lens of the opening of the said photomask. It is explanatory drawing which shows the usage example at the time of forming the said opening and a micro lens separately.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 ... Light source 4 ... Photomask 6 ... Exposed body 9 ... Transparent substrate 10 ... Light shielding film 11 ... Opening 12 ... Micro lens 13 ... Another transparent substrate L1 ... Light source light

Claims (5)

A photomask in which a plurality of openings having a predetermined shape is formed in a light shielding film provided on one surface of a transparent substrate is disposed in close proximity to an object to be exposed, and the photomask is irradiated with light source light to thereby expose the object to be exposed. An exposure apparatus for exposing a pattern corresponding to the opening on the top,
An exposure apparatus comprising a plurality of microlenses for forming an image of each opening on the object to be exposed on the object side corresponding to each opening of the photomask.   2. The exposure apparatus according to claim 1, wherein each of the microlenses is formed on a surface of the transparent substrate opposite to a surface on which the opening is formed.   2. The exposure apparatus according to claim 1, wherein each of the micro lenses is formed on one surface of another transparent substrate. The object to be exposed is transported at a predetermined speed in parallel with one surface of the photomask by a transport means,
The light source light is intermittently applied to the photomask.
The exposure apparatus according to any one of claims 1 to 3, wherein A plurality of openings of a predetermined shape formed in a light shielding film provided on one surface of the transparent substrate;
A plurality of microlenses provided on the other surface of the transparent substrate corresponding to the openings, respectively, and forming an image of the opening on an object to be exposed that is disposed in close proximity to each other;
A photomask characterized by comprising:

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