Blank mask and photomask using the same

A photomask comprising:

• a transparent substrate and a multilayer light shielding pattern film disposed on the transparent substrate,
• wherein the multilayer light shielding pattern film comprises chromium (Cr) and at least one of oxygen (O) and nitrogen (N),
• wherein the multilayer light shielding pattern film comprises a first light shielding film and a second light shielding film disposed on the first light shielding film,
• wherein the first light shielding film comprises chromium (Cr) in an amount of 25 atomic percent (at %) to 50 at %,
• wherein the second light shielding film comprises chromium (Cr) in an amount of 55 at % to 70 at %,
• wherein the multilayer light shielding film has an optical density of 1.8 or more with respect to a light with the wavelength of 193 nm,
• wherein the second light shielding film comprises an upper light shielding layer and an adhesion enhancing layer disposed between the upper light shielding layer and the first light shielding film, and wherein the adhesion enhancing layer has a thickness of 12 Å to 30 Å,
• wherein the adhesion enhancing layer is a distinct layer having a first interface with the first light shielding film and a second interface with the upper light shielding layer, and wherein a composition of the adhesion enhancing layer is substantially uniform across the thickness of the adhesion enhancing layer and different from the compositions of the first light shielding film and the upper light shielding layer,
• wherein an absolute value of a difference between the amount of chromium in the adhesion enhancing layer and the amount of chromium in the upper light shielding layer is 10 at % or less,
• wherein the multilayer light shielding pattern film comprises a total nine parts formed by trisection in a width direction and a length direction of an upper surface of the transparent substrate,
• wherein each part of the multilayer light shielding pattern film comprises a measuring range disposed on a side thereof,
• wherein the measuring range corresponds to a range between a point distant from an upper boundary of the first light shielding film to a lower boundary of the first light shielding film and a point distant from a lower boundary of the second light shielding film to an upper boundary of the second light shielding film, and
• wherein the multilayer light shielding pattern film has pdR (difference value of roughness for a photomask) values of Equation 2 measured from the total nine parts of the multilayer light shielding pattern film, and an average value of the pdR values is 3 nm or less:
• pdR=pRac−pRb [Equation 2]
• wherein pRac is a surface roughness [unit:
• nm] measured from the measuring range of the multilayer light shielding pattern film after soaking the multilayer light shielding pattern film for 800 second in SC-1 solution and rinsing with ozone water,
• wherein pRbc is a surface roughness [unit:
• nm] measured from the measuring range of the part of the multilayer light shielding pattern film before soaking in SC-1 solution,
• wherein the SC-1 solution comprises NH4OH (14.3 wt %), H2O2 (14.3 wt %), and H2O (71.4 wt %), and
• wherein the ozone water comprises ozone at 20 ppm in ultrapure water.

A method of manufacturing a semiconductor element, the method comprising:

• preparing a light source, a photomask, and a semiconductor wafer with a resist film applied;
• exposing the semiconductor wafer by selectively transmitting light from the light source to the semiconductor wafer through the photomask;
• and
• developing a pattern on the semiconductor wafer,
• wherein the photomask comprises a transparent substrate and a multilayer light shielding pattern film disposed on the transparent substrate,
• wherein the multilayer light shielding pattern film comprises chromium (Cr) and at least one of oxygen (O) and nitrogen (N),
• wherein the multilayer light shielding pattern film comprises a first light shielding film and a second light shielding film disposed on the first light shielding film,
• wherein the first light shielding film comprises chromium (Cr) in an amount of 25 atomic percent (at %) to 50 at %,
• wherein the second light shielding film comprises chromium (Cr) in an amount of 55 at % to 70 at %,
• wherein the multilayer light shielding film has an optical density of 1.8 or more with respect to light of wavelength 193 nm,
• wherein the second light shielding film comprises an upper light shielding layer and an adhesion enhancing layer disposed between the upper light shielding layer and the first light shielding film, and wherein the adhesion enhancing layer has a thickness of 12 Å to 30 Å,
• wherein the adhesion enhancing layer is a distinct layer having a first interface with the first light shielding film and a second interface with the upper light shielding layer, and wherein a composition of the adhesion enhancing layer is substantially uniform across the thickness of the adhesion enhancing layer and different from the compositions of the first light shielding film and the upper light shielding layer,
• wherein an absolute value of a difference between the amount of chromium in the adhesion enhancing layer and the amount of chromium in the upper light shielding layer is 10 at % or less,
• wherein the multilayer light shielding pattern film comprises a total of nine parts formed by trisection in a width direction and a length direction of an upper surface of the transparent substrate, and
• wherein each part of the multilayer light shielding pattern film comprises a measuring range disposed on a side thereof,
• wherein the measuring range corresponds to a range between a point distant from an upper boundary of the first light shielding film to a lower boundary of the first light shielding film and a point distant from a lower boundary of the second light shielding film to an upper boundary of the second light shielding film, and
• wherein the multilayer light shielding pattern film has pdR (difference in roughness for a photomask) values of Equation 2 measured from the total nine parts of the multilayer light shielding pattern film, and an average value of the pdR values is 3 nm or less:
• pdR=pRac−pRbc [Equation 2]
• wherein pRac is a surface roughness [unit:
• nm] measured from the measuring range of the part of the multilayer light shielding pattern film after soaking the multilayer light shielding pattern film for 800 second in SC-1 solution and rinsing with ozone water,
• wherein pRbc is a surface roughness [unit:
• nm] measured from the measuring range of the part of the multilayer light shielding pattern film before soaking in SC-1 solution,
• wherein the SC-1 solution comprises NH4OH (14.3 wt %), H2O2 (14.3 wt %), and H2O (71.4 wt %), and
• wherein the ozone water comprises ozone at 20 ppm in ultrapure water.