Shin-etsu Chemical Co., Ltd.

Other

Hisatoshi Otsuka

Shigeru Maida

Kazuo Shirota

Tetsuji Ueda

Koji Matsuo

Osamu Sekizawa

Masanobu Ezaki

Akira Fujinoki

Hiroyuki Nishimura

Motoyuki Yamada

Yukio Shibano

Kazuhiro Kumakura

Takayuki Shimakawa

Naoki Yanagisawa

On an EUV light-reflecting surface of titania-doped quartz glass, an angle (&#x3b8;) included between a straight line connecting an origin (O) at the center of the reflecting surface to a birefringence measurement point (A) and a fast axis of birefringence at the measurement point (A) has an average value of more than 45 degrees. Since fast axes of birefringence are distributed in a concentric fashion, a titania-doped quartz glass substrate having a high flatness is obtainable which is suited for use in the EUV lithography.

Titania-doped quartz glass and making method

Methods for selecting titania-doped quartz glass which experiences a reduction in OH group concentration of less than or equal to 100 ppm upon heat treatment at 900&#xb0; C. for 100 hours as suitable material for the EUV lithography member.

Titania-doped quartz glass is manufactured by mixing a silicon-providing reactant gas and a titanium-providing reactant gas, preheating the reactant gas mixture at 200-400&#xb0; C., and subjecting the mixture to oxidation or flame hydrolysis. A substrate of the glass is free of concave defects having a volume of at least 30,000 nmin an effective region of the EUV light-reflecting surface and is suited for use in the EUV lithography.

Titania doped quartz glass and making method

A member is made of titania-doped quartz glass in which striae have a curvature radius of at least 150 mm in a surface perpendicular to an EUV-reflecting surface. The member free of exposed striae and having a high flatness is useful in EUV lithography.

EUV lithography member, making method, and titania-doped quartz glass

Disclosed is a method of producing a synthetic quartz glass for excimer laser by depositing on a target silica particulates obtained by subjecting a silica raw material to vapor-phase hydrolysis or oxidative decomposition in an oxyhydrogen flame in a vacuum sintering furnace to form a porous silica base material, vitrifying the porous silica base material, and subjecting the vitrified material to hot forming, an annealing treatment and a hydrogen doping treatment, wherein the vitrification of the porous silica base material includes: (a) a step of holding a vacuum pressure at or below 20.0 Pa in a temperature range from 400&#xb0; C., inclusive, to 900&#xb0; C., exclusive; (b) a step of holding a vacuum pressure at or below 10.0 Pa in a temperature range from 900&#xb0; C., inclusive, to 1100&#xb0; C., exclusive; and (c) a step of holding a vacuum pressure at or below 3.0 Pa in a temperature range from 1100&#xb0; C. to a transparent-vitrification temperature.

Method of producing synthetic quartz glass for excimer laser

Synthetic quartz glass is prepared by subjecting a silicon-providing feedstock to flame hydrolysis in oxyhydrogen flame, depositing silica fine particles on a rotating quartz glass target while concurrently melting and vitrifying them, thereby forming a synthetic quartz glass ingot, shaping, annealing, and effecting dehydrogenation treatment at a temperature of at least 600&#xb0; C. and a pressure of up to 5 Pa for a holding time of at least 12 hours. The synthetic quartz glass has a high helium gas permeability and is suited for forming nanoimprint molds.

Nanoimprint mold-forming synthetic quartz glass and making method

A titania-doped quartz glass suited as an EUV lithographic member is prepared by feeding a silicon-providing reactant gas and a titanium-providing reactant gas through a burner along with hydrogen and oxygen, subjecting the reactant gases to oxidation or flame hydrolysis to form synthetic silica-titania fine particles, depositing the particles on a rotating target, and concurrently melting and vitrifying the deposited particles to grow an ingot of titania-doped quartz glass. The target is retracted such that the growth front of the ingot may be spaced a distance of at least 250 mm from the burner tip.

A method for manufacturing quartz glass using a main burner having a multi-tube assembly having a center tube, a first enclosure tube surrounding the center tube, a second enclosure tube surrounding the first enclosure tube, a tubular shell surrounding the multi-tube assembly, and a plurality of nozzles disposed within the tubular shell, a double-tube assembly surrounding at least a forward opening of the main burner includes feeding silica-forming compound to the center tube, a combustion-supporting gas to the first enclosure tube and the nozzles, a combustible gas to the second enclosure tube and the tubular shell, and a combustion-supporting gas to the double-tube assembly, forming oxyhydrogen flame for hydrolyzing or decomposing the silica-forming compound to form silica, depositing the silica on the target, and melting and vitrifying the deposited silica into quartz glass.

Burner and method for the manufacture of synthetic quartz glass

A titania and sulfur co-doped quartz glass member is provided. Due to co-doping of titania and sulfur, the quartz glass member undergoes zero expansion at a certain temperature and low thermal expansion over a wide temperature range, and is thus suited for use in a commercial EUV lithography tool. A manufacturing method and an optical member for EUV lithography are also provided.

Titania and sulfur co-doped quartz glass member and making method

A synthetic quartz glass ingot is prepared by vapor phase hydrolyzing or oxidatively decomposing a silica feedstock in a flame to form fine particles of silica, depositing the silica particles on a target and melting and vitrifying the particles to form a synthetic quartz glass ingot on the target while the target is moved back and forth. The method further comprises: (i) continuously feeding the silica feedstock at a predetermined rate, (ii) keeping the flame in constant contact with an overall growing face, (iii) cyclically repeating the back and forth movement of the target at a predetermined speed, and (iv) maintaining the shape of the growing ingot unchanged.

Manufacture of synthetic quartz glass ingot and synthetic quartz glass member

In a titania-doped quartz glass member having a surface where EUV light of up to 70 nm wavelength is reflected, a refractive index distribution in the surface has only one extreme point within a central 80% region of the member. The titania-doped quartz glass member has a surface with a high level of precision and thus can be formed into an EUV lithography photomask substrate which is improved in flatness and thermal expansion properties.

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Joetsu, Japan

Hisatoshi Otsuka