Blank mask and photomask using the same

Abstract

The blank mask according to one embodiment of the present disclosure comprises a transparent substrate and a multilayer light shielding film disposed on the transparent substrate. The multilayer light shielding film comprises a transition metal and at least any one between oxygen and nitrogen. The multilayer light shielding film comprises a first light shielding film and a second light shielding film disposed on the first light shielding film. The multilayer light shielding film comprises total nine parts that are formed by trisection in a width direction and a length direction of an upper surface of the multilayer light shielding film. Each part of the multilayer light shielding film comprises a measuring range disposed in a side thereof. The measuring range is corresponded 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, in respective sides of the parts of the multilayer light shielding film. The multilayer light shielding film has dR (difference value of roughness) values of Equation 1 below respectively measured from the total nine parts of the multilayer light shielding film, and an average value of dR values of the Equation 1 is 3 nm or less.  [Equation 1] The Rac is a surface roughness [unit: nm] measured from the measuring range of the part of the multilayer light shielding film, after the part of the multilayer light shielding film are soaked for 800 seconds in SC-1 (Standard Clean-1) solution and rinsed by ozone water. The Rbc is a surface roughness [unit: nm] measured from the measuring range of the part of the multilayer light shielding film before the part of the multilayer light shielding film are soaked in the SC-1 solution. The SC-1 solution is a solution comprising NHOH of 14.3 wt %, HOof 14.3 wt %, and HO of 71.4 wt %. The ozone water is a solution comprising ozone in an amount of 20 ppm (by weight) with ultrapure water as a solvent. In such a case, during an enhanced cleaning, the multilayer light shielding film can have excellent durability against a cleaning solution in all the areas thereof.