Extreme ultraviolet and x-ray resist: Comparison study

Extreme ultraviolet lithography (EUVL) is a next generation lithography technology aimed at critical dimension of 70 nm and below. It is important to characterize the imaging properties of the resist in this wavelength range. In this article we present results of EUVL and x-ray lithography studies of the dissolution properties of modern resists (SAL605, UV6, and PMMA) in terms of development properties and surface roughness. The exposure response curves and surface roughness were measured for each resist for EUV and x-ray exposures. We find that the absorbed dose can be used as a common parameter to compare exposure response curves from EUV and x ray on the same scale. We also find that the surface roughness is a specific property of each resist system. The relative importance of shot noise effects on roughness is discussed.