JPH01181420A - Proximity exposure apparatus - Google Patents

Abstract

PURPOSE:To prevent deterioration of resolution, by performing proximity exposure of a substrate and a photo mask held vertically by respective holders. CONSTITUTION:A proximity exposure apparatus of the invention comprises a substrate holder 2 for holding a substrate 1 vertically, a mask holder 7 for holding vertically a photo mask 6 close to and parallel with the substrate 1 and an exposure optical system 10 for projecting parallel light rays vertically to the surface of the substrate 1 for exposing the mask pattern on the substrate 1. This exposure apparatus is adapted to perform exposure with the photo mask 6 and the substrate 1 disposed vertically. Accordingly, deflection of the photo mask 6 due to its own weight can be eliminated and the width of the gap defined between the substrate 1 and the photo mask 6 can be held at a predetermined value. Thus, deterioration of resolution can be prevented effectively even in a large-sized substrate.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to an exposure apparatus used for exposing a pattern on a photomask onto a substrate whose surface is coated with a photoresist, and particularly relates to an exposure apparatus used for exposing a pattern on a photomask onto a substrate whose surface is coated with a photoresist. The present invention relates to a proximity exposure apparatus that performs exposure while holding the substrate parallel to the substrate with a small gap between them.

(Prior Art) As an exposure apparatus of this type, for example, the one shown in FIG. 2 is conventionally known (Optical Engineering Hand Hook, p. 682, published by Asakura Shoten, February 1986).

The substrate 101 and the photomask 106 are held on a flat board with a minute gap between them, and the pattern on the photomask is exposed onto the photoresist coated on the surface of the substrate 101 using parallel irradiation light from the exposure optical system 110. It is configured.

(Problems to be Solved by the Invention) In recent years, there has been a tendency for substrates to become larger due to industry demands, and accordingly, larger-sized photomasks have also come to be used. For example, some substrates for liquid crystal display devices have a size of 300 mm x 300 mm or more.

However, when exposing the substrate 101 and the photomask 106 while being held horizontally as in the conventional example, the substrate 101 is held flat along the top surface of the substrate holder 102 as shown in FIG. However, the photomask 106 formed of a glass plate bends in an imaginary line shape due to its own weight.
The gap between the substrate 101 and the photomask 106 is small at the center and wide at the periphery, and as a result, the resolution during pattern printing is reduced at the periphery. Under conditions where the substrate 101 and the photomask 106 are not in contact with each other, the larger the amount of deflection of the photomask 106, the larger the gap between the substrate 101 and the photomask 106 must be set, and the resolution at the periphery becomes even worse. This will result in a decline.

(Means for Solving the Problems) The present invention has been made to solve the above problems and is constructed as follows.

In other words, there is a substrate holder that holds the substrate upright, a mask holder that holds the photomask close to and parallel to the substrate, and a mask holder that irradiates parallel light perpendicularly to the surface of the substrate.
The apparatus is characterized in that it is equipped with an exposure optical system that exposes a pattern, and is configured to perform exposure with a photomask and a substrate placed upright.

(Function) In the present invention, since proximity exposure is performed with the substrate and photomask held upright by their respective holders, the photomask does not bend due to its own weight as in the conventional example. Thereby, there is no need to set a gap in consideration of the deflection of the photomask, and the problem of reduced resolution is resolved.

(Example) FIG. 1 is a schematic diagram of a proximity exposure apparatus according to the present invention.

This exposure apparatus is used, for example, in the manufacturing process of substrates for liquid crystal display devices, and includes a substrate holder 2 that holds a substrate 1 upright, and a mask 6 that holds a photomask 6 upright in parallel with the substrate 1. It comprises a holder 7 and an exposure optical system 10 that irradiates parallel printing light perpendicular to the surface of the substrate 1 to expose a mask pattern onto the substrate 1.

A negative pressure chamber 3 communicating with a forced exhaust means 5 is formed inside the substrate holder 2, and a large number of suction holes 4 are formed in a flat substrate holding surface S to communicate with the negative pressure chamber 3. By suctioning the substrate 1 under negative pressure through the suction hole 4, the substrate 1 is held flat along the substrate holding surface S1.

The mask holder 7 has a mask holding surface S2 that holds the peripheral edge of the photomask 6, and a suction groove 8 that communicates with the forced exhaust means 9 is formed in the mask holding surface S2. By suctioning negative pressure at step 8, the mask is placed flat along the mask holding surface S2 and close to the substrate 1,
It is configured so that the photomask 6 can be held upright.

As in the conventional example, the exposure optical system 10 includes a xenon lamp LS for ultraviolet irradiation, a concave mirror EM that collects light from the xenon lamp LS, and a 7-ray eye lens O8 arranged near the second focal point of the concave mirror EM. , a collimator lens CL disposed between the fly fly lens O8 and the photomask 6
and a set of optical path reversing mirrors M1 and M2, and forms an image of the exit pupil of the 7-ray eye lens O8, which is a secondary light source, on the photomask 6, which is the irradiated surface, to minimize the exposure as much as possible. The illuminance distribution on the irradiated surface 6 is made uniform, and the mask pattern is printed using parallel light perpendicular to the irradiated surface 6.

Note that although the above embodiment has been described as a proximity exposure apparatus used in the manufacturing process of a substrate for a liquid crystal display device, the present invention is not limited to this. It goes without saying that this method can be widely implemented in a variety of proximity exposure apparatuses.

(Effects of the Invention) As is clear from the above explanation, according to the present invention, the gap between the substrate and the photomask can be maintained at a predetermined value without bending due to the photomask's own weight, and it is possible to This can also prevent a decrease in resolution.

[Brief Description of the Drawings] Fig. 1 is a schematic diagram of a proximity exposure apparatus according to the present invention, Fig. 2 is a schematic diagram of a conventional proximity exposure apparatus, and Fig. 3 is a schematic diagram showing the problem of photomask deflection. It is an explanatory diagram shown in an exaggerated manner. 1... Board, 2... Board holder, 6...
Photomask, 7...mask holder, 101i
Optical optical system.

Claims (1)

[Claims] 1. A substrate holder that holds the substrate upright; a mask holder that holds the photomask upright in parallel with the substrate;
It is characterized by being equipped with an exposure optical system that exposes the mask pattern by irradiating parallel light perpendicularly to the surface of the substrate, and configured to perform exposure while the photomask and substrate are placed upright. Proximity exposure equipment