JPH0648745A - Production of glass filter for xef laser - Google Patents

Abstract

PURPOSE:To provide a quartz-based filter for XeF laser having excellent durability. CONSTITUTION:Fine particles of GeO2-SiO2 glass obtained by flame hydrolysis method or thermal oxidation reaction are formed in a laminar state on a quartz substrate, the fine particle layer of GeO2-SiO2 glass is made into transparent glass in an atmosphere of He, H2 or both and processed to give GeO2-SiO2 plate glass having several mm thickness. Since the GeO2-SiO2 plate glass has a light absorption peak at 340-360nm wavelength, the plate glass acts as a filter to XeF laser.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silica-based glass filter suitable for eye protection against excimer lasers, especially XeF lasers.

[0002]

2. Description of the Related Art In recent years, the use of excimer lasers has increased, and eyeglasses for protecting eyes have been required. Specifically, visible light is well transmitted, but light having a wavelength of a laser is not transmitted, and a laser having high durability is required. Conventionally, there is a filter made of polycarbonate as a filter for blocking this kind of laser light.

[0003]

However, the polycarbonate glass not only deteriorates the transmittance of visible light when hitting a laser, but also has a problem of poor durability.

[0004]

The present invention has been made from the above point of view, and the invention according to claim 1 is characterized in that GeO ₂ -obtained by flame hydrolysis and / or thermal oxidation reaction. The SiO ₂ glass fine particle layer is formed with He.
It is to make transparent glass in the atmosphere. Further, the invention according to claim 2 is characterized in that the GeO ₂ —SiO ₂ glass fine particle layer obtained by flame hydrolysis and / or thermal oxidation reaction is transparentized in an H ₂ atmosphere. Furthermore, the invention according to claim 3 characterized in that a GeO ₂ —SiO ₂ glass fine particle layer obtained by flame hydrolysis and / or thermal oxidation reaction is added with He and H ₂
The purpose is to make transparent glass in a mixed gas atmosphere.

[0005]

H ₂ and He deprive oxygen of GeO ₂ —SiO ₂ glass particles when they are made into transparent glass, and GeO ₂ —S.
It causes oxygen defects in the iO ₂ glass. As a result, the obtained GeO ₂ —SiO ₂ glass was 340 to 360 nm.
Has a peak of light absorption in the XeF laser (wavelength 351
(nm) to exert a filter effect. Quartz glass is basically durable against laser.

[0006]

【Example】

Example 1 A GeO ₂ —SiO ₂ glass fine particle layer was formed on a quartz substrate. As the method, a concentric multi-tube burner was used, with SiCl ₄ and GeCl _{4 at the} centers of 1 mol / min and 0.1 mol / min, respectively, and Ar as a seal gas for the second layer was 0.2 mol / min. Add H ₂ to the 3rd layer
L / min, O ₂ was flowed in the fourth layer at 5 L / min, and GeO ₂ -Si was formed by flame hydrolysis and thermal oxidation reaction.
O ₂ glass particles were produced and deposited in layers on a quartz substrate. Next, this GeO ₂ —SiO ₂ glass fine particle layer was made into a transparent glass in a 100% He atmosphere. Then, the substrate was dissolved and removed using hydrofluoric acid. The remaining G
The eO ₂ —SiO ₂ glass was processed into a quartz glass filter having a thickness of 5 mm. The transmittance of this filter at a wavelength of 351 nm was measured and found to be 0.5%. Further, this filter was irradiated with XeF laser light at 1 J / cm ² · pulse for 1 × 10 ⁴ pulses, but was not destroyed and had sufficient durability. Incidentally, the transmittance of the above-mentioned GeO ₂ —SiO ₂ glass fine particle layer was 30% when it was made into a transparent glass in an oxidizing atmosphere of O ₂ of 0.5% and He of 99.5%. Further, the conventional polycarbonate filter was destroyed by 1 × 10 ⁴ pulses of the same laser beam.

(Example 2) A filter was obtained in the same manner as in Example 1 except that the vitrification of the GeO ₂ -SiO ₂ glass fine particle layer was performed in a 100% H ₂ atmosphere. When the transmittance of this filter at a wavelength of 351 nm was measured, it was 0.5.
%, And the durability was almost the same as in Example 1.

Example 3 A filter was obtained in the same manner as in Example 1 except that the vitrification of the GeO ₂ —SiO ₂ glass fine particle layer was performed in an atmosphere of 50% H ₂ and 50% He.
When the transmittance of this filter at a wavelength of 351 nm was measured, it was 0.5%, and its durability was almost the same as that of Example 1.

[0009]

The filter according to the present invention is a GeO _2-
GeO obtained by transparentizing vitreous SiO ₂ glass fine particle layer in He or H ₂ or mixed gas atmosphere of both
Since it is made of _2- SiO ₂ glass, it has a wavelength of 34
Since it has a light absorption peak at 0 to 360 nm, it is suitable as a filter for XeF laser and has excellent durability.

Front page continuation (72) Inventor Koji Tamanuma 1440 Rokuzaki, Sakura City, Chiba Prefecture, Sakura Factory, Fujikura Electric Cable Co., Ltd. (72) Kazuo Sanada, 1440, Rosaki, Sakura City, Chiba Prefecture

Claims (3)

[Claims] 1. A XeF characterized in that a GeO ₂ —SiO ₂ glass fine particle layer obtained by flame hydrolysis and / or thermal oxidation reaction is transparentized in a He atmosphere.
Manufacturing method of glass filter for laser. 2. A XeF characterized in that a GeO ₂ --SiO ₂ glass fine particle layer obtained by flame hydrolysis and / or thermal oxidation reaction is transparentized in an H ₂ atmosphere.
Manufacturing method of glass filter for laser. 3. A glass filter for XeF laser, characterized in that a GeO ₂ --SiO ₂ glass fine particle layer obtained by flame hydrolysis and / or thermal oxidation reaction is made into a transparent glass in a mixed gas atmosphere of He and H ₂ . Production method.