JPH04312914A - Ultraviolet radiating device - Google Patents

Abstract

PURPOSE:To provide an ultraviolet radiating device which allows uniform exposure utilizing ultraviolet rays from a light source effectively. CONSTITUTION:A subject 3 to be irradiated consisting of a work and a mask plate is carried to an irradiating position under a reflecting body 1 which has a short arc lamp 2 which radiates ultraviolet rays. The reflecting body 1 is formed practically paraboloidal and reflects ultraviolet rays radiated from the short arc lamp 2 at an angle R which is less then 5 deg. from the perpendicular and preferably, at an angle less than 4.5 deg.. An open angle alpha and a beam angle betaare equalized and almost all reflected beams radiate the subject 3 to be irradiated.

Description

[Detailed description of the invention]

[Object of the invention]

0002

[Industrial Application Field] The present invention is applicable to ICs, LSIs, etc.
This invention relates to ultraviolet irradiation equipment used in the exposure process when producing integrated circuits such as.

0003

2. Description of the Related Art For example, when producing an integrated circuit, photo-etching is performed to cut out an oxide film on silicon or an aluminum wiring film, and one of the steps is an exposure step of irradiating ultraviolet rays. In this exposure process, a pattern formed by a photomask is exposed by irradiating ultraviolet rays onto an object to be irradiated, on which a photomask is disposed.

[0004] Since such an exposure process involves very fine processing, in order to perform faithful exposure according to the pattern of the photomask, conventional ultraviolet irradiation equipment has to Ultraviolet rays are irradiated in almost parallel beams.

[0005]

[Problems to be Solved by the Invention] In this way, conventional ultraviolet irradiation devices irradiate the object with ultraviolet rays that are almost parallel to each other, so only a portion of the light from the light source is involved in exposure. There is. Therefore, much of the light from the light source is wasted, and as a result, the intensity of ultraviolet rays is low.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an ultraviolet irradiation device that performs exposure by effectively utilizing light from a light source.

[Configuration of the invention]

[0008]

[Means for Solving the Problems] An ultraviolet irradiation device according to claim 1 includes a short arc lamp that irradiates ultraviolet rays;
The apparatus is equipped with a reflector that reflects the ultraviolet rays irradiated from the short arc lamp and irradiates the object to be irradiated at an angle of 5 degrees or less with respect to the perpendicular line.

The ultraviolet irradiation device according to claim 2 is the ultraviolet irradiation device according to claim 1, wherein the reflector directs the ultraviolet rays irradiated from the short arc lamp onto the irradiated object at an aperture angle that is wide enough to include the irradiated object. It irradiates.

The ultraviolet irradiation device according to claim 3 is the ultraviolet irradiation device according to claim 1, wherein the reflector reflects the ultraviolet rays irradiated from the short arc lamp and is covered with an opening angle that coincides with the object to be irradiated. It irradiates the object.

[0011]

[Operation] The ultraviolet ray irradiation device according to claim 1 reflects the ultraviolet rays irradiated from the short arc lamp with a reflector and irradiates the object at an angle of 5 degrees or less with respect to the perpendicular line, thereby producing parallel rays. The irradiation is approximately the same as when irradiating.

In the ultraviolet irradiation device according to claim 2, in the ultraviolet irradiation device according to claim 1, the angle of divergence of the reflected light is adjusted to the width including the object to be irradiated in accordance with the length of the arc of the short arc lamp. By doing so, the ultraviolet rays irradiated onto the object to be irradiated are made uniform.

In the ultraviolet irradiation device according to claim 3, in the ultraviolet irradiation device according to claim 1, by matching the opening angle from the reflector corresponding to the arc of the short arc lamp with the object to be irradiated, the ultraviolet irradiation device can efficiently irradiate the object. Makes the ultraviolet rays irradiated onto the irradiated object uniform.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the ultraviolet irradiation apparatus of the present invention will be described in detail below with reference to FIGS. 1 to 7.

In FIG. 1, the ultraviolet irradiation device is comprised of a substantially parabolic reflector 1 with an open bottom surface, and a short arc lamp 2 contained therein and optically opposed to each other. Approximately 3 meters below this ultraviolet irradiation device, a conveyor etc. (not shown) is arranged, and the object 3 to be irradiated, which consists of a workpiece with a width of 225 mm and a mask plate, is sent by this conveyor to the irradiation position by the short arc lamp 2. There is. In this ultraviolet irradiation device, the distance between the reflector 1 and the short arc lamp 2, the distance between the reflector 1 and the irradiated object 3,
Furthermore, the inclination of the optical axis, etc. can be adjusted as appropriate.

FIG. 2 shows the shape of the short arc lamp 2. In this short arc lamp 2, an arc portion 7 is formed between the electrodes 5 and 6 in the glass bulb 4, and an arc portion 7 is formed between the electrodes 5 and 6. It is 6mm. Furthermore, the size of the arc portion 7 where the arc of the short arc lamp 2 occurs can also be adjusted by replacing the short arc lamp 2.

FIG. 3 shows the cross-sectional shape of the reflector 1. The reflector 1 is made of an aluminum plate with a thickness of about 1.5 mm. The cross-sectional shape of this reflector 1 is formed into a parabolic shape that satisfies the following Table 1, and the ultraviolet rays emitted from the short arc lamp 2 have an angle R with respect to the perpendicular of 5 degrees as shown in FIG. Below, preferably 4
．． It is designed to be reflected at an angle of 5 degrees or less. In other words, coordinates (X, Y) with the origin (O, O) at the position where the short arc lamp 2 included in the reflector 1 is placed.
The reflector 1 is formed in a shape that satisfies Table 1.

[0018]

[Table 1]

Table 2 shows each point (X, Y) on this reflector 1.
Angle θ (degrees) with respect to short arc lamp 2 at
It also represents the angle α1 on the left side in the figure and the angle α2 on the right side in the figure of the reflected light at each point (X, Y).

[0020] The reason why there are two types of angles of reflected light at each point (X, Y) is because the arc portion 7 of the short arc lamp 2 has a length of about 6 mm, so the ultraviolet rays from this arc portion 7 are This is because the light is reflected at the aperture angle α by the reflector 1 shown in FIG.

[0021]

[Table 2]

Next, the operation of the embodiment configured as described above will be explained.

In this ultraviolet irradiation device, the ultraviolet beam irradiated from the short arc lamp 2 is reflected by the reflector 1 and irradiates the object 3 on the conveyor (not shown).
Perform exposure. During exposure, the ultraviolet rays reflected at each point on the reflector 1 are irradiated at an angle of less than 5 degrees to the perpendicular to the irradiated object 3, so the ultraviolet rays are approximately parallel to each other according to the mask pattern of the irradiated object 3. It is possible to perform exposure with almost the same fidelity as with light beams. Moreover, since the object 3 is irradiated with ultraviolet light within a range of 5 degrees or less with respect to the perpendicular line, the intensity of the ultraviolet light becomes high.

In this embodiment, the beam angle β at which ultraviolet rays are irradiated from the arc portion 7 of the short arc lamp 2 to a point on the reflector 1, for example, point P in FIG. Since the angle at which point P is viewed, that is, the aperture angle α, is approximately equal, and the aperture angle α and the direction of the reflected beam are approximately the same, uneven irradiation is reduced. This is particularly effective in the case of the irradiated object 3 that needs to be uniformly irradiated with ultraviolet rays.
In addition, even if the object to be irradiated has a relatively large area, there is little irradiation unevenness.

Furthermore, according to this ultraviolet irradiation device, since the aperture angle α and the direction of the reflected beam almost match, most of the reflected light is irradiated onto the object 3, so the intensity of the ultraviolet rays can be increased. Therefore, the energy of the short arc lamp 2 can be used effectively.

According to experiments, if ultraviolet rays are irradiated at an angle of 5 degrees or less (preferably 4.5 degrees or less) with respect to the perpendicular to the irradiated object 3, the photo is almost the same as parallel rays. It was possible to perform faithful exposure according to the mask.

FIG. 5 shows a cross section of a reflector 1 used in another embodiment. The cross-sectional shape of this reflector 1 is
It is formed into a parabolic shape that satisfies Table 3. In other words, coordinates (X
, Y) satisfies Table 3.

[0028]

[Table 3]

Table 4 shows corner points (X, Y) on this reflector 1.
Angle θ (degrees) with respect to short arc lamp 2 at
It also represents the angle α1 on the left side in the figure and the angle α2 on the right side in the figure of the reflected light at each point (X, Y).

[0030]

[Table 4]

FIG. 7 shows an ultraviolet irradiation device according to still another embodiment of the present invention. In this embodiment, a reflector 1 is placed next to a short arc lamp 2, and an ultraviolet beam from the short arc lamp 2 is refracted by a reflection mirror 8 to expose an object 3 to be irradiated.

The embodiment shown in FIG. 7 is effective for a short arc lamp 2 that can only be lit vertically.

[0033]

According to the ultraviolet irradiation device according to claim 1, the ultraviolet rays are irradiated onto the irradiated object at an angle of 5 degrees or less with respect to the perpendicular, so that the ultraviolet rays are emitted efficiently and uniformly in substantially the same way as parallel rays. The object to be irradiated can be irradiated.

According to the ultraviolet irradiation device according to claim 2,
In addition to the ultraviolet irradiation device according to the first aspect, since the object to be irradiated is irradiated with an opening angle that includes the object to be irradiated, the object to be irradiated can be irradiated more uniformly.

According to the ultraviolet irradiation device according to claim 3,
In addition to the ultraviolet irradiation device according to the first aspect, since the object to be irradiated is irradiated with an opening angle that includes the object to be irradiated, the object to be irradiated can be irradiated more efficiently and uniformly.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of an ultraviolet irradiation device of the present invention.

FIG. 2 is a sectional view showing the short arc lamp same as above.

FIG. 3 is a sectional view showing the reflector shown above.

FIG. 4 is a diagram showing the relationship between the reflecting surface of the reflector and the beam angle of the reflected beam.

FIG. 5 is a sectional view showing a reflector used in another embodiment of the ultraviolet irradiation device of the present invention.

FIG. 6 is a diagram showing the relationship between the reflecting surface of the reflector and the beam angle of the reflected beam.

FIG. 7 is a schematic configuration diagram showing still another embodiment of the ultraviolet irradiation device of the present invention.

[Explanation of symbols]

1 Reflector 2 Short arc lamp 3 Object to be irradiated

Claims (3)

[Claims] Claim 1: A short arc lamp that irradiates ultraviolet rays, and a reflector that reflects the ultraviolet rays irradiated from the short arc lamp and irradiates the object to be irradiated at an angle of 5 degrees or less with respect to the perpendicular. An ultraviolet irradiation device featuring: 2. The ultraviolet irradiation device according to claim 1, wherein the reflector irradiates the object with the ultraviolet rays irradiated from the short arc lamp at an opening angle wide enough to include the object. 3. Claim 1, wherein the reflector reflects the ultraviolet rays irradiated from the short arc lamp and irradiates the object to be irradiated at an opening angle that matches the angle of the object to be irradiated.
The ultraviolet irradiation device described.