METHODS AND APPARATUSES FOR MEASURING PHASE ROUGHNESS IN AN EXTREME ULTRAVIOLET MASK

摘要

Example embodiments are directed to a method and an apparatus for measuring phase roughness in an extreme ultraviolet (EUV) mask. In example embodiments, a speckle generated by the phase roughness in the EUV mask is detected by irradiating an EUV beam on the EUV mask. The phase roughness in the EUV mask is calculated and measured using the speckle.