JP2002006117A - Method for producing optical slit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce an optical slit having a constant slit width with high reproducibility without adjusting the slit width. SOLUTION: An optically opaque silicon film 2 is deposited on an optically transparent base substrate 1 using a sputter deposition apparatus or the like, and then a portion of the silicon film 2 serving as a passage of light is removed with the specified slit width using a photolithography technique and an etching technique so as to produce the slit 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an optical slit constituting an optical system used in a spectrophotometer or the like.

[0002]

2. Description of the Related Art In a spectrophotometer, light from a light source is separated using a diffraction grating or the like, the spectrum of light transmitted through a sample to be measured is measured, and the wavelength of the light absorbed by the sample or transmitted. The sample components are analyzed by examining the wavelength of the light. In the optical system of this spectrophotometer, an optical slit is provided between the light source and the diffraction grating in order to remove scattered light from the light generated from the light source. After the light from the light source is separated by the diffraction grating, an optical slit is provided between the diffraction grating and the sample to be measured in order to extract light of a predetermined wavelength. The optical slit has a slit width of about 10 to 20 μm. For example, when extracting a predetermined wavelength, the narrower the slit width, the better the resolution of the wavelength that can be extracted, but the smaller the amount of light that can be extracted, the smaller the amount of light that can be extracted. The width is determined.

FIG. 3 is a perspective view showing the structure of a conventional optical slit. The optical slit is composed of two tapered metal plates 12, 1
It is manufactured by adjusting and fixing 3 to a base 11 having a hole 15 in the center. The interval between the metal plates 12, 13 must be fixed at a predetermined width according to the analysis conditions.
Furthermore, in order to obtain a constant light quantity and wavelength resolution, the metal plate 1
2, 13 must be installed in parallel.

[0004]

In the above-described optical slit, the distance between the metal plates, which is the width of the slit, is adjusted with an accuracy of, for example, about 20 .mu.m. +-. 2 .mu.m. Must be done manually under microscopic observation. However,
This operation requires skill, and it is difficult to produce with good reproducibility. Further, it takes a long time to adjust the slit width, and the manufacturing cost must be expensive.

When it is necessary to extract a plurality of wavelengths simultaneously, a plurality of optical slits must be provided between the diffraction grating and the sample to be measured. In this case, the slit width of each slit is required. , And the distance between the slits must be accurately adjusted, the time required for production,
The costs are even greater.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problem, and has as its object to provide a method for producing an optical slit having a constant slit width with good reproducibility without adjusting the slit width. And

[0007]

In order to solve the above problems, in the method of manufacturing an optical slit according to the present invention, a metal film that does not transmit light is provided on an optically transparent base that transmits light from a light source. Is formed, and a photolithography technique and an etching technique are used to remove the metal film in a portion to be a slit with a predetermined width. As a base that transmits light, for example, quartz glass can be used. Here, the thickness of the glass base is desirably as small as possible in order to suppress the absorption of the measuring light by the glass, and several hundred μm to 1 mm
A certain thickness is desirable. A metal film (for example, nickel or gold) is formed on the quartz glass surface by vapor deposition, sputtering, or the like, and a slit is formed using photolithography and etching techniques. A parallel slit having a width of can be produced with good reproducibility. Further, the slit width can be changed, and a plurality of slits can be easily formed on one base. Further, by increasing the size of the substrate, a large number of optical slits can be manufactured at one time, and the manufacturing cost can be greatly reduced.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a perspective view of one embodiment of an optical slit realized by the present invention. Optically transparent quartz glass is used as the base 1, and an optically opaque Si film 2 is formed on one surface of the base 1.
The slit 3 having a width of 20 μm is formed by removing a part of the i film 2.

A process for producing the above optical slit will be described with reference to FIG. First, as shown in FIG. 2A, after washing a glass base 1 made of quartz glass, a Si film 2 (thickness 3000 Å) is formed by a thin film forming apparatus (for example, a sputtering film forming apparatus). . The thickness of the Si film 2 is not particularly limited, and may be any thickness as long as it is optically opaque and can be etched in an etching step described later.

Next, as shown in FIG. 2B, photolithography for patterning an etching protection film on the Si film 2 is performed. After applying the photoresist 5 on the Si film 2, a photomask 7 having a light transmitting portion 8 having the same width of 20 μm as the slit is arranged on the photoresist 5, and the photoresist 5 is exposed. Here, a positive type photoresist is used, and the exposure of the photoresist 5 can be performed using an aligner or a stepper generally used in semiconductor manufacturing.

Next, as shown in FIG. 2C, after removing the photomask 7, the photoresist 5 is developed. The developer for developing the photoresist 5 is not particularly limited as long as it is used for developing the photoresist to be used. Further, the material and thickness of the photoresist 5 used as the etching protection film are not particularly limited. After removing the exposed portion of the photoresist 5 using a means such as ultrasonic cleaning, the Si film 2 is etched by, for example, reactive ion etching (RIE) using SF6 gas. Finally, by removing the photoresist 5, the optical slit shown in FIG. 1 is manufactured.

In the optical slit having the above structure and the method of manufacturing the same, the slit formed by the photolithography technique and the etching technique has a width of exactly 20 μm.
Thus, an optical slit having a predetermined light amount and wavelength resolution can be obtained.

The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments, and various changes may be made within the scope of the present invention described in the appended claims. be able to. For example, by changing the shape of the photomask 7, without changing other operation methods,
The width of the slit 3 can be easily changed. Further, when a plurality of slits are formed in the base 1, it is possible to cope only by changing the shape of the photomask 7. The material of the base 1 can be selected according to the wavelength of the measuring light to be used. For example, Pyrex (registered trademark) glass may be used for visible light, and when light in the ultraviolet region is used, for example, HOY having a good transmittance up to the ultraviolet region may be used.
It is necessary to use an ultraviolet transmitting glass substrate such as UV-22 of A Co., Ltd., # 9741 of Corning, or the quartz glass of the above-mentioned embodiment which transmits the ultraviolet almost completely. Further, in the above embodiment, an example in which one slit is manufactured is shown, but a plurality of slits are manufactured in one base using a large base and a large photomask, and thereafter, a plurality of slits are cut. It is also possible to simultaneously create optical slits.

[0014]

According to the method for producing an optical slit of the present invention, the slit is produced using the photolithography technique and the etching technique, so that the slit width and the parallelism of the slit can be controlled with high precision. Also,
When a plurality of slits are formed on one base, the intervals between the slits can be controlled with high accuracy. Further, since the step of adjusting the slit width is unnecessary, the manufacturing time and the manufacturing cost can be significantly reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view of an optical slit according to an embodiment of the present invention.

FIG. 2 is a view showing a manufacturing process of the optical slit of FIG. 1; (A) Formation of a metal film (Si film). (B) Photoresist coating and patterning using a photomask. (C) Photoresist development and Si film etching.

FIG. 3 is a configuration perspective view of a conventional optical slit.

[Explanation of symbols]

 1, 11 --- Base 2 --- Si film 3 --- Slit 5 --- Photoresist 7 --- Photo mask 8 --- Light transmitting part 12, 13 --- Metal plate 15 --- Hole

 ──────────────────────────────────────────────────続 き Continued from the front page (72) Inventor Ichiro Makino 1-term, Kuwabaracho, Nishinokyo, Nakagyo-ku, Kyoto F-term in Shimadzu Corporation 2H042 AA12 AA23

Claims (1)

[Claims] 1. An optical system comprising: forming an optically opaque metal film on an optically transparent base; and forming a slit by removing a part of the metal film with a predetermined width. How to make a slit.