Gradated photomask and its fabrication process

Abstract

The invention provides a gradated photomask for reducing photolithography steps and its fabrication process, which make use of a generally available photomask blank, prevents the reflectance of a light shield film from growing high, makes alignment easy during the formation of a semitransparent film, and enables the semi-transparent film on a light shield pattern with good step coverage. A photomask () comprises a mixture of a light shield area including a light shield film () having a desired pattern on a transparent substrate wherein a film forming the pattern is substantially opaque to photolithographic light, a semitransparent film () that transmits the photolithographic light at a desired transmittance, and the light shield film () and the semitransparent film () are stacked on the transparent substrate () in that order; a semi-transparent area wherein there is only the semitransparent film (); and a transmissive area there is neither the light shield film () nor the semitransparent film (), and is characterized in that the semitransparent film () has an antireflection function with respect to the photolithographic light.