Photomask blank, photomask, and methods of manufacturing the same

A method of manufacturing a photomask blank, comprising:

• forming, on a surface of a transparent substrate, a light-shielding layer made of a material mainly containing tantalum nitride, 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
• forming, on the light-shielding layer, a front-surface antireflection layer made of a material mainly containing tantalum oxide, by sputtering using the sputtering target made of tantalum or the 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 a light-shielding film as a whole, the light shielding film comprising the light-shielding layer and the front-surface antireflection layer.

A method of manufacturing a photomask blank, comprising:

• forming, on a surface of a transparent substrate, a light-shielding layer made of a material mainly containing tantalum nitride, by sputtering using a sputtering target made of a sintered body of tantalum and boron, and using a mixed gas of a xenon gas and a nitrogen-based gas as a sputtering gas;
• and
• forming, on the light-shielding layer, a front-surface antireflection layer made of a material mainly containing tantalum oxide, by sputtering using the sputtering target made of the sintered body of tantalum and boron, 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 a light-shielding film as a whole, the light shielding film comprising the light-shielding layer and the front-surface antireflection layer.

A photomask blank having a layered film comprising at least two layers on a transparent substrate,

• wherein the layered film comprises:
• a first layer made of a material mainly containing tantalum nitride and further containing xenon, wherein the first 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 second layer formed on the first layer, the second layer being made of a material mainly containing tantalum oxide and further containing argon, wherein the second 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 first layer has a compressive stress while the second 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 layered film as a whole.

A method of manufacturing a photomask blank, comprising:

• forming, on a surface of a transparent substrate, a first layer made of a material mainly containing tantalum nitride, 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
• forming, on the first layer, a second layer made of a material mainly containing tantalum oxide, by sputtering using the sputtering target made of tantalum or the material mainly containing tantalum and using a mixed gas of an argon gas and an oxygen-based gas as a sputtering gas,
• wherein the first layer has a compressive stress while the second layer has a tensile stress, and
• the compressive stress and the tensile stress are cancelled by each other to reduce an internal stress of a layered film as a whole, the layered film comprising the first layer and the second layer.

A method of manufacturing a photomask blank, comprising:

• forming, on a surface of a transparent substrate, a first layer made of a material mainly containing tantalum nitride, by sputtering using a sputtering target made of a sintered body of tantalum and boron, and using a mixed gas of a xenon gas and a nitrogen-based gas as a sputtering gas;
• and
• forming, on the first layer, a second layer made of a material mainly containing tantalum oxide, by sputtering using the sputtering target made of the sintered body of tantalum and boron, and using a mixed gas of an argon gas and an oxygen-based gas as a sputtering gas,
• wherein the first layer has a compressive stress while the second layer has a tensile stress, and
• the compressive stress and the tensile stress are cancelled by each other to reduce an internal stress of a layered film as a whole, the layered film comprising the first layer and the second layer.