Experimental Study of Sub DSA resolution Assist Features (SDRAF)

摘要

Cylindrical directed self-assembly (DSA) nanostructures is a promising candidate for patterning the contacts and vias in integrated circuits. To match the contact patterns in an IC layout, physical guiding templates have been adopted to generate aperiodic DSA patterns, and templates of different sizes could lead to various DSA patterns. It is found in the experiment that the density of guiding templates has a strong influence on the DSA patterns. At a low template density, templates tend to become overfilled and result in DSA defects. In this paper, we experimentally demonstrate an effective solution to counteract the influence of template pattern density on the quality of DSA using sub-DSA-resolution Assist Features (SDRAFs). We show that SDRAFs can reduce the DSA defects significantly.