PHOTOMASK BLANK, PHOTOMASK, AND METHOD FOR MANUFACTURING PHOTOMASK BLANK

摘要

Provided is a photomask blank used for fabricating a photomask to which an ArF excimer laser beam is applied. The photomask blank is characterized by comprising a light shielding film on a light transmissive substrate, wherein the light shielding film has a stacked structure in which a rear surface antireflection layer, a light shielding layer, and a front surface antireflection layer are stacked in sequence from the side close to the light transmissive substrate, the thickness of the entire light shielding film is 70 nm or less, the rear surface antireflection layer consists of a film containing metal and has a first etching rate, the front surface antireflection layer consists of a film containing metal and has a third etching rate, the light shielding layer consists of a film containing the same metal as the metal contained in the rear surface antireflection layer or the front surface antireflection layer and has a second etching rate slower than the first etching rate and the third etching rage, and the thickness of the light shielding layer is 45% or less of the thickness of the entire light shielding film.