TWI548947B - Exposure apparatus and photomask - Google Patents

Description

Exposure device and mask

The present invention relates to an exposure apparatus and a photomask, relating to an exposure apparatus for performing exposure of a specific pattern by using a mask close to and facing an object to be exposed, and more specifically, improving the resolution of the exposure pattern and performing Exposure of fine patterns.

In a conventional exposure apparatus, particularly a proximity exposure apparatus, the reticle is brought close to the object to be exposed, so that the pattern formed on the reticle is exposed on the object to be exposed, and the lower surface has a mask that can be closely attached. a transparent glass substrate that is in close contact with the flat surface, a reticle absorbing and holding mechanism for absorbing and holding the reticle to the close contact plane, and a glass substrate for holding the transparent glass substrate to form a small gap between the reticle and the object to be exposed The mechanism (for example, refer to Japanese Laid-Open Patent Publication No. 2005-300753).

However, the conventional exposure apparatus uses the exposure light vertically transmitted through the reticle to directly transfer the pattern formed on the reticle to the object to be exposed, but since the light source has a viewing angle (parallel half angle), it is The image of the pattern on the exposure body is blurred so that the resolution is lowered, and there is a problem that the fine pattern cannot be exposed.

Accordingly, the present invention has been made to solve the above problems, and an object thereof is to provide an exposure apparatus and a photomask which can improve the resolution of an exposure pattern and can expose a fine pattern.

In order to achieve the above object, in the exposure apparatus of the present invention, a mask having a plurality of openings having a specific shape formed on a light-shielding film provided on one surface of a transparent substrate is disposed close to and opposed to the object to be exposed, and the light source is irradiated thereon. Forming, on the reticle, a pattern corresponding to the opening on the object to be exposed; wherein each of the openings corresponding to the reticle is disposed on the side of the object to be exposed, and an image of the openings is imaged at the A plurality of microlenses on the exposed body.

With such a configuration, the masks having a plurality of openings having a specific shape formed on the light-shielding film provided on one surface of the transparent substrate are approached and opposed to the object to be exposed, and are respectively exposed to be exposed corresponding to the respective openings. A plurality of microlenses on the body side image an image of each opening on the object to be exposed, and illuminate the light source on the reticle to expose a pattern corresponding to the opening on the object to be exposed. Therefore, the resolution of the exposure pattern can be improved. For example, even a fine pattern having a line width of about 3 μm can be formed by proximity exposure. Thereby, even if the transistor portion of the TFT substrate is exposed to a pattern having a high resolution, it is possible to use a proximity exposure apparatus having a simple optical system and a low cost, and the manufacturing cost of the TFT substrate can be reduced.

Further, each of the microlenses is formed on a surface opposite to a surface on which the opening of the transparent substrate is formed. The microlenses formed on the surface opposite to the surface on which the opening of the transparent substrate is formed are used to form an image of each opening on the object to be exposed. At this time, since the microlens is formed on the surface opposite to the surface on which the opening of the transparent substrate is formed, it is not necessary to align the opening with the microlens. Therefore, the processing of the mask becomes easier.

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 imaged on the object to be exposed by using the respective microlenses formed on one side of the other transparent substrate. In this case, the photomask and the microlens system in which the plurality of openings are formed are formed as separate bodies. Therefore, when the photomask has a defect or a defect occurs later, the photomask can be replaced, so that the cost of the mask can be suppressed. .

Then, the exposed system is transported in parallel to a side of the reticle at a specific speed by a transport mechanism, and the light source ray is intermittently irradiated onto the reticle. Thereby, the light source light is intermittently irradiated onto the reticle, and each microlens is used to image the image of each opening of the reticle to be exposed to the side of the reticle at a specific speed in parallel by the transport mechanism. The body is sequentially exposed on the object to be exposed in a pattern corresponding to the opening. Therefore, it is possible to expose a plurality of exposed objects while continuously transporting sequentially, and to increase the number of exposure processes per unit time. Further, since the width of the mask used at this time is at least smaller than the width of the exposure region of the object to be exposed in the same direction, the mask shape can be reduced and the manufacturing cost of the mask can be reduced.

Further, the photomask of the present invention has a plurality of openings formed in a light shielding film provided on one surface of the transparent substrate and having a specific shape; and the other surface of the transparent substrate corresponding to the openings, respectively, so that the mask The image of the opening is imaged at a plurality of microlenses on the exposed body that are disposed adjacent and opposite each other.

With such a configuration, a plurality of microlenses provided on the other surface of the transparent substrate corresponding to the respective openings are used to form a plurality of openings having a specific shape formed on the light shielding film provided on one surface of the transparent substrate. For example, imaging is performed on the exposed body that is placed close to and opposite. Therefore, the resolution of the exposure pattern can be improved. For example, even a fine pattern having a line width of about 3 μm can be formed by proximity exposure. Thereby, even if the transistor portion of the TFT substrate is exposed to a high-resolution pattern, it is possible to use a proximity-type exposure apparatus having a simple and inexpensive optical system, and it is possible to reduce the manufacturing cost of the TFT substrate.

Hereinafter, embodiments of the present invention will be described 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 of the present invention. The exposure apparatus has a mounting table 1, a light source 2, a mask table 3, a mask 4, and a collimator lens 5 by exposing a specific pattern to a mask that is close to and facing the object to be exposed.

The mounting table 1 has a flat mounting surface 1a formed thereon, and is used for positioning (for example, absorbing and holding) the exposed object 6 on the mounting surface 1a, which can be paralleled by a moving mechanism (omitted from the drawing) The surface of the mounting surface 1a moves in the X-axis and Y-axis directions, and is also movable in the Z-axis direction and is rotatable about a central axis perpendicular to the mounting surface 1a. Further, in Fig. 1, the Y-axis direction is a direction in which the penetrating paper surface faces deep.

A light source 2 is disposed above the mounting table 1. The light source 2 is a source light L1 that irradiates the exposed object 6 with ultraviolet light to expose the photosensitive resin coated on the surface of the object to be exposed 6, and is a xenon lamp or an ultrahigh pressure mercury lamp for emitting ultraviolet rays (for example, a wavelength of 355 nm). , ultraviolet light-emitting laser light source, etc. Further, for example, a condensing mirror 14 is disposed in front of the radiation direction of the light source ray L1, and the condensing mirror 1 temporarily condenses the source ray L1. Then, a shutter 7 that moves in the directions of arrows A and B and opens and closes the light path from the light source 2 toward the object to be exposed 6 is provided at the condensing point P.

A mask table 3 facing the mounting table 1 is provided between the mounting table 1 and the light source 2. The mask table 3 is configured such that the mask 4 described later is brought into close proximity and held in opposition to the surface of the object to be exposed 6 placed on the mounting table 1 so as to correspond to the pattern forming region of the mask 4 at the center portion. An opening window 8 is formed and positioned to restrict the reticle 4 to maintain a portion near its circumference.

The mask 4 is detachably held by the mask table 3. As shown in FIG. 2, the photomask 4 is formed on a light-shielding film 10 such as chromium (Cr) provided on one surface 9a of a transparent substrate 9 such as quartz glass, and a plurality of openings of a specific shape are formed in an array at a predetermined interval ( The pattern 11 has a magnification of 0.25 times corresponding to each of the openings 11 on the surface 9b opposite to the surface 9a on which the opening 11 of the transparent substrate 9 is formed, and a focal length of 0.683 with respect to ultraviolet rays having a wavelength of 355 nm. A plurality of microlenses 12 of mm are formed so that an image of each opening 11 is imaged on the object 6 to be exposed. At this time, as shown in FIG. 1, the mask 4 is held by the mask stage 3 with the side on which the microlens 12 is formed as the side of the object to be exposed 6.

A collimator lens 5 is disposed between the mask stage 3 and the light source 2. The collimator lens 5 is configured to make the light source ray L1 emitted from the light source 2 into parallel light, and to make the front focus coincide with the condensed point P of the condensing mirror 14.

Next, the operation of the exposure apparatus constructed as described above will be described.

First, the switch of the light source 2 is turned on to illuminate the light source 2. At this time, the shutter 7 is in a closed state. After the light emission of the light source 2 is stabilized for a predetermined period of time, the photomask 4 is positioned and held by the photomask 2 in a state in which the microlens 12 side faces the mounting table 1, and is placed on the mask stage 3.

Next, the object to be exposed 6 on which the photosensitive resin is applied is positioned, sucked and held, and placed on the mounting surface 1a on the mounting table 1. Thereafter, the positioning marks previously formed in the mask 4 and the positioning marks previously formed in the exposure target 6 are imaged in the same field of view by the imaging means (omitted from the drawing), and the control means (omitted from the drawing) is used to control the loading. The table 1 is moved in the X-axis and Y-axis directions so that the positions of the two marks coincide, and the position of the mask 4 and the object to be exposed 6 can be positioned by rotating a specific angle as needed. Then, after the positioning of the mask 4 and the object 6 to be exposed is completed, the stage 1 is raised by a specific amount in the Z-axis direction so that a specific gap is formed between the surface of the object 6 to be exposed and the lower surface of the mask 4. The microlens 12 opposed to the opening 11 formed on the mask 4 is used to image the surface of the object 6 to be exposed.

Next, the exposure switch is turned on to move the shutter 7 in the direction of the arrow A and only for a certain time to perform exposure. Thereby, as shown in FIG. 3, the light source light L1 emitted from the light source 2 is irradiated onto the reticle 4 and becomes the exposure light L2 through the opening 11 formed in the reticle 4, and is condensed by the microlens 12 Exposure body 6. Then, the image of the opening 11 is projected onto the object to be exposed 6 by the microlens 12, and a pattern corresponding to the shape of the opening 11 is formed on the photosensitive resin applied to the surface.

Further, the above embodiment has been described with respect to the case where the mask 4 having the opening 11 and the microlens 12 formed on the same transparent substrate 9 is used. However, the present invention is not limited thereto, and as shown in FIG. A microlens 12 is formed on the different transparent substrate 13 of the mask 4 of 11. In this case, the surface 9a of the mask 4 on which the opening 11 is formed is in close contact with the surface opposite to the surface 13a of the other transparent substrate 13 on which the microlens 12 is formed as indicated by the arrow in the figure. 13b to use. Alternatively, as long as the opening 11 of the mask 4 can be formed on the surface of the object to be exposed 6 by the microlens 12, the surface 9b opposite to the surface 9a of the mask 4 in which the opening 11 is formed may be adhered to the other side. The surface 13a of the transparent substrate 13 on which the microlenses 12 are formed is the surface 13b on the opposite side.

Moreover, the above description has been described with respect to the case where the object to be exposed 6 held at a specific position is exposed. However, the present invention is not limited thereto, and the object to be exposed 6 may be transported in parallel at a specific speed by the transport mechanism. To one surface of the photomask 4, the light source light L1 is intermittently irradiated to the photomask 4 at specific time intervals to expose a pattern corresponding to the opening 11 of the photomask 4 to a specific position of the object 6 to be exposed. At this time, the intermittent irradiation of the light source light L1 may be performed using a flash lamp or by opening and closing the shutter 7. Further, an image pickup mechanism for photographing the front side of the object to be exposed of the exposure body 6 determined by the exposure position of the mask 4 can be provided, and the reference position formed on the object to be exposed 6 can be imaged in advance by the image pickup unit to be based on the imaged image. The photomask 4 and the object to be exposed 6 are positioned, or a reference position different from the above-described reference position is captured, and the irradiation time point of the light source light L1 is controlled based on the captured image.

1. . . Mounting table

1a. . . Mounting surface

2. . . light source

3. . . Mask table

4. . . Mask

5. . . Collimating lens

6. . . Exposed body

7. . . Shutter

8. . . Open window

9‧‧‧Transparent substrate

9a, 9b‧‧‧

10‧‧‧Shade film

11‧‧‧ openings

12‧‧‧Microlens

13‧‧‧Transparent substrate

13a, 13b‧‧‧

14‧‧‧Condenser

A, B‧‧ arrows

L1‧‧‧Light source

L2‧‧‧Exposure light

P‧‧‧ spotlight

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a front elevational view showing the schematic configuration of an embodiment of an exposure apparatus of the present invention.

Fig. 2 is a view showing a configuration example of the reticle of the present invention, Fig. 2(a) is a plan view, Fig. 2(b) is a front view, and Fig. 2(c) is a bottom view.

Fig. 3 is an explanatory view showing imaging of the above-described mask opening using a microlens.

Fig. 4 is an explanatory view showing an example of use when the opening and the microlens are formed as individual cases.

1. . . Mounting table

1a. . . Mounting surface

2. . . light source

3. . . Mask table

4. . . Mask

5. . . Collimating lens

6. . . Exposed body

7. . . Shutter

8. . . Open window

9. . . Transparent substrate

10. . . Sunscreen

11. . . Opening

12. . . Microlens

14. . . Condenser

A, B. . . arrow

L1. . . Light source

P. . . Spotlight

Claims (4)

An exposure apparatus in which a mask having a plurality of openings having a specific shape formed on a light-shielding film provided on one surface of a transparent substrate is approached and opposed to an object to be exposed which is conveyed at a specific speed, and is determined by the mask The front side of the object to be exposed at the exposure position is photographed at a reference position set in advance by the object to be exposed, and the light source ray is intermittently irradiated with respect to the irradiation time of the reticle based on the image of the reference position. Light source light, such that a pattern corresponding to the opening is exposed on the object to be exposed; the mask is respectively provided with a plurality of microlenses on the side of the object to be exposed corresponding to the openings, and the mask is exposed A predetermined gap is provided between the bodies to reduce the image of the openings on the object to be exposed by the plurality of microlenses. The exposure apparatus of claim 1, wherein each of the microlenses is formed on a surface opposite to a surface on which the opening of the transparent substrate is formed. The exposure apparatus of claim 1, wherein the microlenses are formed on one side of another transparent substrate. A photomask having a plurality of openings formed in a light shielding film disposed on one surface of a transparent substrate and having a specific shape; and a plurality of microlenses respectively disposed on the other side of the transparent substrate corresponding to the openings The reticle is attached to a user of the exposure apparatus, and the exposure apparatus is The reticle is brought close to and facing the object to be exposed at a specific speed, and the front side of the object to be exposed in the exposure position of the pattern formed by exposure to the opening is placed on the front side of the object to be exposed Taking a pre-formed reference position for shooting, controlling the illumination time point of the light source light based on the captured image of the reference position to intermittently illuminate the light source light, so that the pattern is exposed on the exposed object; the reticle is exposed to the exposure The bodies are disposed with a predetermined gap to reduce the image of the opening by the plurality of microlenses on the exposed and oppositely disposed objects.