JPH08213311A - Exposure device - Google Patents

Abstract

PURPOSE: To provide an exposure device for pattern on a substrate of a large solid-state electronic device. CONSTITUTION: An exposure device aligns a glass mask M with a specific pattern drawn therein on a mask position alignment means 3 as well as a substrate 3 coated with a photoresist on a substrate position alignment means 6. Next, when a light source 1 lighted for a specific time or a shutter arranged between the light source 1 and substrate B is opened for a specific time leaving the light source 1 in the lighted state, the pattern of the glass mask M is enlargement-projected as a pattern light L4 in parallel with the photoresist on the substrate B in larger multiplying factor larger then one to enlargement- transfer the pattern to the photoresist. Next, a stable pattern is left on the substrate through a development step after this exposure step so that a thin film may be etched away on this substrate B similar to the manufacture of an ordinary integrated circuit using this pattern as an etching mask.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus for forming a pattern on a substrate of a solid-state electronic device when manufacturing the solid-state electronic device represented by an integrated circuit, for example.

[0002]

2. Description of the Related Art Photolithography technology is frequently used in the manufacturing process of solid-state electronic devices represented by integrated circuits, and exposure of a pattern by an exposure apparatus is indispensable.

In this exposure apparatus, a mask in which a predetermined pattern is drawn and a substrate of a solid-state electronic device to which the pattern of the mask is transferred are overlapped in a contact state and exposed, and a mask and a substrate are provided. There are a proximity method in which exposure is performed in an overlapping manner with a distance of about 50 μm, and a projection exposure method in which a mask and a substrate are sufficiently separated and placed in a projection optical system for exposure.

The contact method and the proximity method include devices corresponding to various substrate sizes.
Since the mask and the substrate are overlapped, it is easy for the photoresist applied to the surface of the substrate to adhere to the mask or the mask to be scratched, and the pattern transferred to the substrate has many defects.
As a solution to this defect, a projection exposure type exposure apparatus has appeared, and it is becoming the mainstream in the field of integrated circuits.
In this projection exposure apparatus, since the mask and the substrate are arranged at a sufficient distance, the defects caused by photolithography are significantly reduced.

Further, currently used projection exposure apparatuses include one for projecting a mask pattern on a substrate at the same size and another for projecting a pattern reduced to 1/5 or 1/10. The system includes a reflective type using a mirror and a refractive type using a lens.

On the other hand, looking at the current performance of the mask, in the case of a glass mask, a 7-inch square substrate, that is, an effective pattern area of 6 inches is required to satisfy a high-precision specification with an error of 1 μm or less for a 10 μm pattern. The maximum size is about square, and if the size is larger than this, it is difficult to obtain a high-precision mask due to problems such as maintaining flatness of the substrate, accumulated pitch error amount, or glass mask manufacturing apparatus.

Therefore, when performing projection exposure using a high-precision mask, only a pattern with a maximum of about 6 inches square can be obtained, but at the same time, with a mask up to a size of 7 inches square, an ultrahigh precision 1 μm pattern is obtained. And the error is 0.1μ
It is also possible to obtain the thing of about m.

Recently, a thin film transistor (Thin Film Transistor) is known as an active matrix liquid crystal display device.
A high-precision and high-performance display device using a substrate in which film transistors are arranged in a matrix has been actively developed. An introduction is given on page 41).

The display device is required to have a certain size and resolution in view of human eyes. For example, the display device has a diagonal of 10 inches or 14 inches and a pixel number of 40.
The 0 × 640 type is one of the goals of the display device development, and the active matrix type liquid crystal display element is a promising one that can realize a large-sized display device. It is necessary to perform the above-mentioned lithography, a high-precision mask having a pattern of about 10 μm and a high-performance exposure apparatus are usually required, and furthermore, it is necessary to perform exposure by a projection exposure method to obtain a defect-free pattern. .

[0010]

However, the combination of a high-precision mask having a 10 μm pattern with an error of about 1 μm and a conventional projection exposure apparatus for equal-magnification exposure or reduction exposure has an active matrix type. The liquid crystal display device has a problem that only a 6 inch square device can be obtained.

The present invention has been made in view of the above problems, and an object thereof is to provide an exposure apparatus for exposing a pattern on a substrate of a large-sized solid-state electronic device.

[0012]

According to the present invention, a light source for irradiating light, a mask positioning means for positioning a mask on which a pattern is drawn while irradiating the light from the light source, and a photoresist are applied. Substrate positioning means for positioning the substrate of the solid-state electronic device in a state where light from the light source is irradiated through the mask, and light from the light source is irradiated to the substrate through the mask, and the pattern of the mask And an optical system for exposing the photoresist by enlarging and projecting it on the photoresist of the substrate at a magnification exceeding 1 ×, and the light of the light source is drawn on the mask positioned by the mask positioning means by the optical system. The mask pattern is magnified at a magnification exceeding 1x on the photoresist applied to the substrate positioned by the substrate positioning means through the pattern. Projected onto the photoresist of the substrate Te,
A relatively small mask is used to expose the photoresist on a relatively large substrate with the enlarged mask pattern with high precision.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of an exposure apparatus of the present invention will be described below with reference to the drawings.

FIG. 1 shows a first embodiment.
Reference numeral 1 denotes a light source, which emits light L0 emitted from the light source 1 into parallel light L1.
It has a lens system as an optical system and a mask positioning means 3 for positioning the glass mask M vertically to the parallel light L1. The glass mask M is a relatively small one having a fine pattern (shown as AB in the drawing) on its surface. Further, the parallel pattern light L2 transmitted through the glass mask M positioned by the mask positioning means 3 is once condensed and then expanded as a radial pattern light L3. A lens system 4 as an optical system, and an expanded radial pattern light. It has a lens system 5 as an optical system for converting L3 into parallel pattern light L4, and a substrate positioning means 6 for vertically positioning the substrate B of the solid-state electronic device to the enlarged parallel pattern light L4. B is a relatively large type having a photoresist coated on the surface. The housing and the like are omitted for the sake of simplicity.

In the case of the embodiment shown in FIG. 1, the glass mask M having a predetermined pattern is positioned on the mask positioning means 3 and the substrate B coated with the photoresist is positioned on the substrate positioning means 6. In this state, the light source 1 is turned on for a predetermined time, or when a shutter (not shown) provided between the light source 1 and the substrate B is opened for a predetermined time while the light source 1 is turned on, the pattern of the glass mask M is 1 or more. The pattern light L4 parallel to the photoresist on the substrate B is projected once at a large magnification, and the pattern is enlarged and transferred to the photoresist.

After the exposure process, the substrate B is
After the development step and the fixing step, a stable pattern is left, and using this pattern as an etching mask, a thin film or the like is etched on the substrate B in the same manner as in the usual manufacturing of integrated circuits.

At the time of this enlargement transfer, as described above, when the substrate B is for an active matrix type liquid crystal display element, a highly accurate pattern of about 10 μm is required, but for the glass mask M it is about 1 μm. Since an ultra-high precision pattern can be obtained, the magnification of the lens system 4 can be set up to about 10 times.

Since the glass mask M and the substrate B can be sufficiently separated from each other, they are not in contact with each other,
Therefore, if the environment is dust-free and the photoresist on the substrate B has no dust or the like, the pattern enlarged and transferred to the photoresist is a defect-free pattern.

Further, when the substrate B is for a multiplex type liquid crystal display element, only one layer of wiring is required, so that exposure is only required once. However, when the substrate B is for an active matrix type liquid crystal display element, a thin film transistor is used. A plurality of glass masks M are used to form the glass mask M, and each glass mask M is sequentially positioned on the mask positioning means 3 to perform exposure several times. Then, at this time, it is necessary to match the pattern of the next glass mask M with the predetermined pattern formed on the substrate B in advance. In such a case, it is necessary to correspond to each glass mask M and the substrate B. The marks M1 and B1 for alignment are provided in advance, and the marks M1 and B1 may be aligned by moving the substrate positioning means 6, for example.

As a positioning mechanism for adjusting the pattern of the next glass mask M to the predetermined pattern formed on the substrate B in advance, an aligner (usually added to this type of exposure apparatus is used. An aligning mechanism called an Aligner) is used. The alignment method is a manual method in which an operator looks at each mark M1 and B1 with a microscope and moves the substrate positioning means 6, a laser beam scan. A method of recognizing the position of the substrate B by means of the automatic alignment, a method of recognizing the position of the substrate B by the interference of the laser beam and performing the automatic alignment, or a CCD method in place of human eyes in the manual method. There is a method of automatically aligning using.

Further, when the substrate positioning means 6 is provided with a step & repeat function so that the substrate B can be moved vertically to the optical axis, the same glass mask M is used and the photoresist of the substrate B is used. It is also possible to expose the same pattern at a plurality of positions, or to draw a plurality of patterns on the glass mask M and simultaneously expose each of these patterns to the photoresist on the substrate B.

FIG. 2 shows a second embodiment, which is a modification of the first embodiment shown in FIG. 1. In order to make the exposure apparatus compact, a lens system 2 as an optical system is provided. Between the glass masks M of the mask positioning means 3,
The optical axis is bent at a right angle by a plane mirror 11 as an optical system.

Further, FIG. 3 shows a third embodiment, in which a lens system 21 as an optical system is a radiated light L from a light source 1.
0 is condensed and is evenly applied to the glass mask M positioned by the mask positioning means 3 to form a lens system as an optical system.
Reference numeral 22 forms an image of the pattern light L5 transmitted through the mask M on the photoresist of the substrate B positioned by the substrate positioning means 6 at a magnification greater than 1, and is projected onto the substrate B in the case of the third embodiment. Pattern is not parallel light,
When the flatness of the substrate B is good, it can be applied without any problem.

In the third embodiment, the first
The number of lens systems can be reduced by one as compared with the embodiment of FIG.
The diameter of can be reduced.

Further, FIG. 4 shows a fourth embodiment, in which a plane mirror 31 as an optical system has an optical axis of the parallel pattern light L2 transmitted through the glass mask M positioned by the mask positioning means 3. The plane mirror 32 as an optical system is bent at a right angle, and the parallel pattern light L2 bent by the plane mirror 31 is obliquely applied to the photoresist of the substrate B positioned by the substrate positioning means 6 and projected at a magnification greater than 1. . In the case of the fourth embodiment, the glass mask M is formed by the refraction type optical system such as the lens systems 4 and 22 as in the first embodiment, the second embodiment and the third embodiment. Instead of enlarging the pattern of, the pattern of the glass mask M is enlarged by a reflection type optical system such as the plane mirror 32.

As an optical system having a magnifying function for enlarging a pattern, not only a refracting lens or a reflecting plane mirror but also a reflecting curved mirror such as a concave mirror or a convex mirror or a refracting prism is used. However, in any case, the distortion and aberration of the optical system must be extremely small in order to form a highly accurate pattern of about 10 μm.

Although the glass mask is used in the above description, a film mask or a metal mask may be used depending on the purpose.

By enlarging and projecting the pattern of the entire mask at one time and forming it on the photoresist of the substrate, a highly accurate large-sized display device can be formed in a short time.

[0029]

According to the present invention, a relatively small mask is used and a mask pattern is enlarged and formed on a substrate of a relatively large solid-state electronic device at a magnification exceeding 1: 1.
Since this enlarged pattern is projected and exposed on the photoresist of the substrate, it is possible to form a highly precise pattern on a large substrate by using an ultra-high precision mask. It becomes possible to upsize a high-precision display device as described above, and a large amount of such display devices can be made inexpensive.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing a second embodiment of the same.

FIG. 3 is a configuration diagram showing a third embodiment of the above.

FIG. 4 is a configuration diagram showing a fourth embodiment of the above.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 light source 2, 4, 5, 21, 22 lens system as an optical system 3 mask positioning means 6 substrate positioning means 11, 31, 32 plane mirror as an optical system M mask B substrate

Claims (6)

[Claims] 1. A light source for irradiating light, a mask positioning means for positioning the mask on which a pattern is drawn while irradiating the mask with the light from the light source, and a substrate of a solid-state electronic device coated with a photoresist. Substrate positioning means for positioning while irradiating light from the light source through a mask, irradiating the substrate with light from the light source through the mask, and patterning the mask on the photoresist of the substrate, etc. An exposure apparatus comprising: an optical system that exposes a photoresist by magnifying and projecting it at a magnification exceeding 2 times. 2. The exposure apparatus according to claim 1, wherein the optical system projects the enlarged mask pattern as parallel light onto the photoresist of the substrate. 3. The exposure apparatus according to claim 1, wherein the optical system is mainly composed of a refractive optical system. 4. The exposure apparatus according to claim 1, wherein the optical system is mainly composed of a reflective optical system. 5. A plurality of masks are sequentially positioned on the mask positioning means, and the mask positioning means and the substrate positioning means are relatively moved so that the patterns of the respective masks are aligned with each other in a predetermined relationship. 5. The exposure apparatus according to claim 1, wherein the photoresist on the substrate is sequentially exposed in this state. 6. The substrate positioning means is moved so that the same pattern is exposed at a plurality of locations on the photoresist of the same substrate by the same mask.
Any one of the exposure apparatuses.