Title:
The glass substrate for mask blanks
Document Type and Number:
Japanese Patent JP6256422
Kind Code:
B2
Abstract:
A glass substrate for a mask blank has a rectangular planar shape. In four square regions each positioned at each corner of a first region (quality assurance region) and having one side of 8 mm, an angle between a least square plane in each the square region and that in the first region is 3.0 μad or less, and a PV value relative to the least square plane is 30 nm or less. In four strip regions each positioned in an area between one side of the first region and 8 mm inside the side and excluding the square regions, an angle between a least square plane in each the strip region and that in the first region is 1.5 μad or less, and a PV value relative to the least square plane is 15 nm or less.
Inventors:
Yusuke Hirabayashi
Application Number:
JP2015135912A
Publication Date:
January 10, 2018
Filing Date:
July 07, 2015
Export Citation:
Assignee:
Asahi Glass Co., Ltd.
International Classes:
G03F1/60; C03B20/00; C03C15/00; C03C19/00; G03F1/22
Domestic Patent References:
| JP2012009833A | ||||
| JP2011141536A | ||||
| JP2014099461A | ||||
| JP2010085867A | ||||
| JP2014038333A | ||||
| JP2010078769A | ||||
| JP2005043838A |
Attorney, Agent or Firm:
Nozomi Watanabe
Haruko Sanwa
Takemoto Yoichi
Haruko Sanwa
Takemoto Yoichi
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