JPH06148403A - Member for optical apparatus - Google Patents

Abstract

(57) [Summary] [Object] To provide a member for optical equipment with a black coating, which has sufficient heat resistance to high-output light. [Structure] A TiCN film is formed on the surface of a member for optical equipment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a member for optical equipment provided with a film for preventing reflection and scattering of light, and more particularly to improvement of the film.

[0002]

2. Description of the Related Art In an optical device, light is reflected and scattered on the surface of a part constituting the optical path, and the scattered light is further reflected by a supporting member, a masking member, a member for covering the optical path,
If it scatters and returns to the optical path, it becomes a backlight, and an image other than the target image (this is called a ghost image) may occur, or the target image may become unclear.
It is common to apply a black coating on the surfaces of these support member, masking member, cover member, etc. to prevent reflection and scattering of light.

As such a coating, a matte organic polymer coating has been used conventionally. However, this film is not suitable for a high temperature environment, but there is also a problem that the polymer bond is broken and deteriorated depending on the wavelength used.

In recent years, various inorganic coatings have been tried in place of organic polymer coatings. Such coatings are, for example, amorphous carbon with a black color, black alumite,
Black Cr plating or the like.

[0005]

[Problems to be Solved by the Invention]

However, all of the above-mentioned inorganic coatings, when used for high-power laser light, still have the drawback that they are oxidized by heat generation due to absorption of light, causing discoloration and deterioration.

An object of the present invention is to provide a member for optical equipment with a black coating, which has sufficient heat resistance to high output light.

[0008]

In order to achieve the above object, the member for optical equipment of the present invention is characterized in that a TiCN film is provided on the surface thereof.

[0009]

[Function] TiN is known as a substance exhibiting a golden color, but TiCN in which a part of nitrogen of TiN is replaced by carbon exhibits a purple color, and the purple color of TiCN becomes darker as the carbon amount increases, and the black color becomes black. It was chosen because it will be presented.

This black film is considered to be a relatively stable film because no color change was observed even after a heating test up to 500 ° C. in the atmosphere. Further, no oxide phase was observed by X-ray diffraction measurement of the coating film after the heating test at 500 ° C. This heat resistance is extremely preferable for optical instruments using laser light.

The black TiCN film may be formed by a known method such as an ion plating method, a CVD method or a sputtering method, but ions capable of forming a film having a strong adhesive force. The plating method is particularly desirable.

The TiCN film is produced by the ion plating method, for example, using a vacuum arc discharge type ion plating apparatus, targeting Ti metal, and using methane, ethylene and acetylene as a reaction gas or a mixed gas thereof. A mixed gas of nitrogen and nitrogen gas as a raw material, and these mixed gases are mixed at a flow rate ratio (CH ₄ or C ₂
H ₄ or C ₂ H ₂ or mixed gas thereof) / N ₂ =
At 0.2 to 0.7, the reaction gas was introduced into the reaction tank, and the reaction gas pressure was 1 ×.
10 ⁻³ to 1 × 10 ⁻¹ Torr, and 0 to ⁻
A method of applying a bias voltage of 20 V to form a film of 0.05 to 10 μm can be applied.

[0013]

EXAMPLE A TiCN coating was formed on the surface of a masking blade made of SKS31-P used in an optical system of an excimer laser by a vacuum arc discharge method. The film is formed by using Ti as an evaporation source, nitrogen gas and ethylene as reaction gases, and a flow rate ratio of N ₂ : C ₂ H ₂ = 5: 1.
The total flow rate was adjusted so that the pressure was 30 × 10 ⁻³ Torr. The arc target power of 70 A was applied to the Ti target of the evaporation source, and the bias voltage applied to the masking blade of the substrate was OV. Under these conditions, TiCN coating was performed for 1 hour to obtain a black coating having a thickness of 3 μm. In the composition analysis of this coating, atomic ratio Ti = 50%, C = 12
% And N = 38%. The reflectance of the O-order scattered light with the excimer laser light (wavelength 248 nm) of the TiCN-coated masking blade was measured and found to be 5%.

This masking blade was incorporated into a resist pattern printing apparatus using excimer laser light,
Used for 24 hours. The ultraviolet energy density applied to the masking blade at this time is 15 mJ / cm ² .

When the reflectance after use was measured again, it was 5%, which was the same as before use, indicating that there was almost no deterioration due to heat.

Comparative Example: The same masking blade as in the example was plated with black Cr and the reflectance of the scattered light of the Oth order at 248 nm was measured and found to be 0.1%.

The masking blade was incorporated into a resist pattern printing apparatus using the excimer laser light used in the examples and used for 24 hours. The surface coating of the masking blade after use was discolored and some peeling occurred.

[0018]

EFFECT OF THE INVENTION By using the TiCN film-equipped member for optical equipment according to the present invention, even in an optical system using a high-power laser such as an excimer laser, deterioration of the coating does not proceed, and the effect of preventing light scattering for a long time Is obtained.

Claims (1)

[Claims] 1. A member for optical equipment, the surface of which is provided with a TiCN film.