3d Modeling Of Euv Photoresist Using The Multivariate Poisson Propagation Model

As target feature sizes for EUV lithography shrink, it is becoming ever more important to understand the intricate details of pattern formation in these materials. One such frontier that is garnering more attention is the role of the "third dimension" involved in the patterning process- the dimension perpendicular to the wafer. With resist thicknesses shrinking to accommodate ever narrower linewidths, small changes in resist performance in this dimension will have a greater overall effect on pattern quality, particularly as the thickness of these resists approaches target pattern dimensions. To understand the effect that the third dimension has on resist performance, and in particular the interplay between the third dimension and resist stochastics, we have developed a 3D version of the multivariate Poisson propagation model. As a test case for the model, we explore the role of acid diffusion in the so called third dimension on a set of 10(5) vias, showing that increased z blur yields an improvement in both dose to size and pattern uniformity without sacrificing resolution.