Description

A defect in the multilayer of a EUV mask or mask blank that disrupts the pitch of coating and causes a phase shift of light when the light is reflected by the multilayer. Phase defects contribute to non-uniformity in the scale of pattern prints in lithography. By contrast, a defect that hinders the reflection of light on the multilayer of EUV mask (a defect that affects the intensity of light) is called an "amplitude defect."