Conventional inspection techniques using E-beam or DUV light can detect defects on the EUV mask surface. However, their wavelengths cannot penetrate into the EUV multilayer, which limits the ability to analyze correctly. Only actinic inspection technology, which uses EUV light of the same wavelength as the exposure wavelength, can correctly analyze the optical behavior of materials for EUV. It also applies to the EUV pellicle same: The fundamental optical properties, transmittance and reflectance, can be accurately evaluated by EUV wavelengths. Contaminant blocking, one of the main uses of EUV pellicle, also requires prior evaluation by using actinic wavelengths. Generally, it is known that contaminants blocked by EUV pellicle, which are located on the surface of EUV pellicle, do not affect the final wafer pattern.
However, impact of blocked contaminants on imaging performance must be inspected, because contaminants larger than the critical size may cause pattern loss even if they are located on the pellicle surface.
EUV IUCC provides actinic metrology and inspection services for EUV masks and pellicles using an actinic tool called a coherent scattering microscope (CSM).

• EUV mask pattern measurement using ptychography, one of coherent diffractive imaging (CDI) technology (Resolution ~ 54nm (mask side), 6” mask can be evaluated)
• Mask diffraction efficiency analysis and phase shift mask evaluation
• EUV reflectivity measurement of EUV mask and pellicle
• EUV transmittance measurement of EUV pellicle
• Through-pellicle imaging combining EUV mask and EUV pellicle
• Characterization of contaminants on EUV pellicle surface and its effect on pattern