The effect of resist dissolution process on pattern formation variability: anin situanalysis using high-speed atomic force microscopy

This work focuses on the application of a high speed atomic force microscope for the in situ visualization / quantification of the pattern formation phenomenon during resist dissolution. Specifically, this paper discusses on the quantification of various factors (e.g. pattern roughness, defects, etc.) that affect pattern quality. Comparing two typical positive-tone, extreme-ultraviolet lithography resists of dissimilar lithographic performance, results show that the differences in LER between such resists already exists even during the resist dissolution. This implies the significance of the dissolution process in further improving the final LER of lines-and-spaces (L/S) patterns. Moreover, results have shown the effectiveness of applying the same analysis technique in understanding pattern defect dynamics during dissolution, not only for L/S but also for contact hole (CH) patterns. Preliminary investigations on CH pattern formation during dissolution showed position-dependent variabilities / randomness in the timing of CH formation. Such variabilities in timing imply possible pointers in defining the origin of missing CH defects, from the resist dissolution point-of-view.