PHOTOMASK BLANK, PHOTOMASK, AND METHOD FOR MANUFACTURING PHOTOMASK BLANK

摘要

The present invention provides a photomask blank used for producing a photomask to which an ArF excimer laser light is applied, wherein: a light-shielding film is provided on a light transmissive substrate; the light-shielding film has a laminated structure in which a back-surface antireflection layer, a light-shielding layer and a front-surface antireflection layer are laminated in this order from the side close to the light transmissive substrate; the thickness of the entire light-shielding film is 60 nm or less; the back-surface antireflection layer is made of a film containing a metal and has a first etching rate; the front-surface antireflection layer is made of a film containing a metal and has a third etching rate; the light-shielding layer is made of a film containing the same metal as that contained in the back-surface antireflection layer or the front-surface antireflection layer and has a second etching rate that is lower than the first etching rate and the third etching rate; and the thickness of the light-shielding layer is 30% or less of the thickness of the entire light-shielding film.