摘要 |
A method for manufacturing a gray-tone mask that decreases the wavelength dependency with respect to an exposure wavelength under stable and simple film formation conditions. A reactive sputtering method that sputters a pure Cr target in an atmosphere of Ar and NO is used to form a Cr nitride film having a single-layer structure. Based on a plurality of different spectral transmittance curves obtained under a plurality of film formation conditions having different NO concentrations, a target concentration (intermediate value) for NO is obtained that sets the transmittance uniformity of the semi-transparent film to 1.0% or less in the range of 365 nm to 436 nm or 4.0% or less in the range of 300 nm to 500 nm. Then, a semi-transparent film is formed by using the NO target concentration. |