Patent ID: 8137867

Claim:
A photomask blank having a light-shielding film comprising at least two layers on a transparent substrate, wherein the light-shielding film comprises: a light-shielding layer made of a material mainly containing tantalum nitride and further containing xenon, wherein the light-shielding layer is formed by sputtering using a sputtering target made of tantalum or a material mainly containing tantalum and using a mixed gas of a xenon gas and a nitrogen-based gas as a sputtering gas; and a front-surface antireflection layer formed on the light-shielding layer, the front-surface antireflection layer being made of a material mainly containing tantalum oxide and further containing argon, wherein the front-surface antireflection layer is formed by sputtering using a sputtering target made of tantalum or a material mainly containing tantalum and using a mixed gas of an argon gas and an oxygen-based gas as a sputtering gas, wherein the light-shielding layer has a compressive stress while the front-surface antireflection layer has a tensile stress, and the compressive stress and the tensile stress are cancelled by each other to reduce an internal stress of the light-shielding film as a whole.