Patent ID: 8501372

Claim:
A mask blank for use in the manufacture of a binary mask adapted to be applied with ArF excimer laser exposure light, the mask blank comprising, on a transparent substrate, a light-shielding film for forming a transfer pattern, wherein the light-shielding film has a laminated structure of a lower layer and an upper layer and has an optical density of 2.8 or more for the exposure light and a thickness of 45 nm or less, the lower layer is made of a material in which the total content of a transition metal and silicon is 90 at % or more, and has a thickness of 30 nm or more, the upper layer has a thickness of 3 nm or more and 6 nm or less, and a phase difference between the exposure light transmitted through the light-shielding film and the exposure light transmitted in air for a distance equal to the thickness of the light-shielding film is 30 degrees or less.