PHOTO MASK WITH IMPROVED CONTRAST AND METHOD OF FABRICATING THE SAME

摘要

A photo mask which enhances contrast and a method of fabricating the same are provided. The photo mask includes a transparent substrate and a light shielding layer pattern formed on the transparent substrate. The light shielding layer pattern includes apertures through which the transparent substrate is exposed. Depressions aligned with these apertures extend into the transparent substrate. Light exposed at an angle through the transparent layer would then pass into the depressions and reflect or diffuse from the sidewalls of the depressions and out through the apertures. The etching depth of the depressions is preferably equal to or less than a depth at which threshold intensity of the exposure light is saturated as the etching depth is increased. In another embodiment, the etching depth of the depressions is less than the wavelength of the exposure light.