Method for fabricating a photomask

FIGS. 2A-2F are cross-sectional views of a photomask, schematically illustrating a fabrication process of the photomask, according to a preferred embodiment of the invention. In FIG. 2A, a transparent substrate 60 including, for example, quartz or silicon glass is provided. The choice of material depends on the wavelength of a light source. An anti-reflection layer 62 is formed over the transparent substrate 60. The anti-reflection layer 62 includes, for example, CrO.sub.2 and is used to prevent a light reflection during a subsequent metallization process. A transparent layer 64 is formed over the anti-reflection layer 62. The transparent layer 64 includes, for example, silicon oxide and is formed by, for example, chemical vapor deposition (CVD).

In FIG. 2B, the transparent layer 64 is patterned to form a transparent bar layer 66. A portion of the anti-reflection layer 62 is exposed. An opaque layer 68 is formed over the transparent substrate 60 so that the anti-reflection layer 62 and