Photo mask having assist pattern and method of fabricating the same

A photomask has highly reliable assist patterns, and a method of fabricating the same is provided. The photomask includes a transparent substrate, circuit pattern and assist patterns. The circuit pattern recessed into the transparent substrate relative to a surface thereof has a first thickness, and assist patterns located adjacent to, and spaced apart from, the circuit pattern are recessed into the transparent substrate relative to the surface thereof while having a second thickness less than the first thickness.