Photomask used in manufacture of semiconductor device, photomask blank, and method of applying light exposure to semiconductor wafer by using said photomask

摘要

The photomask of the present invention comprises a transparent substrate, a pattern, and a calcium fluoride film. The transparent substrate has a first main surface and a second main surface opposite to the first main surface and is transparent to the exposed light. The pattern is formed on the first main surface of the transparent substrate and has at least one of a opaque film, a translucent film, and a phase control film. The opaque film does not transmit the exposed light. The translucent film partly transmits the exposed light. Further, the phase control film serves to control the phase of the exposed light. The calcium fluoride film is formed on the second main surface of the transparent substrate and performs the function of an antireflection coating for suppressing the re-reflection of light on the back surface of the transparent substrate.