Asahi Glass Company, Limited

Ken Ebihara

Toshiyuki Uno

Yoshiaki Ikuta

Kazuyuki Hayashi

Akio Koike

Mika Yokoyama

Provision of an EUV mask whereby an influence of reflected light from a region outside a mask pattern region is suppressed, and an EUV mask blank to be employed for production of such an EUV mask. A reflective mask for EUV lithography (EUVL), comprising a substrate having a mask pattern region and an EUV light-absorbing region located outside the mask pattern region; a reflective layer provided on the mask pattern region of the substrate for reflecting EUV light and having a portion on which an absorber layer is present and a portion on which no absorber layer is present; the portion on which an absorber layer is present and the portion on which no absorber layer is present being arranged so as to constitute a mask pattern;

Reflective mask blank for EUV lithography and mask for EUV lithography

A reflective mask blank for EUV lithography is provided which has an absorber layer wherein stress and crystal structure can be easily controlled. A reflective mask blank for EUV lithography, which comprises a substrate, and at least a reflective layer for reflecting EUV light and an absorber layer for absorbing EUV light formed in this order on the substrate, wherein the absorber layer contains tantalum (Ta), nitrogen (N) and hydrogen (H); and in the absorber layer, the total content of Ta and N is from 50 to 99.9 at %, and the content of H is from 0.1 to 50 at %.

Reflective mask blank for EUV lithography

A substrate that is suitable for an EUV mask or an EUV mask blank and excellent in flatness, is provided. A substrate for an EUV mask blank, which is made of a silica glass containing from 1 to 12 mass % of TiO, wherein the surface roughness (rms) in a surface quality area of the substrate is at most 2 nm, and the maximum variation (PV) of the stress in the surface quality area of the substrate is at most 0.2 MPa.

Substrate for EUV mask blanks

A reflective mask blank for EUV lithography including a substrate having a front surface and a rear surface, a reflective layer formed over the front surface of the substrate, an absorbing layer formed over the reflective layer, and a chucking layer formed on the rear surface of the substrate and positioned to chuck the substrate to an electrostatic chuck. The substrate has a non-conducting portion which eliminates electrical conduction between the reflective layer and the chucking layer and electrical conduction between the absorbing layer and the chucking layer, and the non-conducting portion is formed by forming a portion of the substrate covered with one or more covering members and preventing formation of the reflective layer and the absorbing layer.

Reflective-type mask blank for EUV lithography

To provide a method for smoothing a surface of a glass substrate having a concave defect, such as a pit or a scratch. A method for smoothing a surface of a glass substrate having a concave defect thereon, comprising: forming a film on the surface of the glass substrate having the concave defect by a dry deposition method, the film comprising a glass material having a fluid point Tf of 150&#xb0; C. or above and of not higher than a strain point Ts (&#xb0; C.) of the glass substrate; and heating the film of the glass material at a temperature of not lower than Tf and not higher than Ts to put the film in such state that the film of the glass material can flow so as to bury the concave defect, followed by cooling the film of the glass material, thereby to smooth the surface of the glass substrate having the concave defect.

Method for smoothing a surface of a glass substrate for a reflective mask blank used in EUV lithography

There are provided a substrate with a reflective layer and an EUV mask blank, which can prevent particles from adhering to a surface of the reflective layer or an absorbing layer, or into a reflective layer or an absorbing layer during formation thereof by eliminating electrical connection between a film formed on a front surface of the substrate and a film formed on a rear surface of the substrate. A substrate with a reflective layer, which is usable to fabricate a reflective mask blank for EUV lithography, comprising a chucking layer formed on a rear surface opposite a surface with the reflective layer formed thereon, the chucking layer serving to chuck and support the substrate by an electrostatic chuck, wherein the reflective layer has no electrical connection to the chucking layer.

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Chiyoda-ku, Japan

Ken Ebihara