Contact hole shrink and multiplication by directed self-assembly of block copolymers: from material to integration. Issue 1750 (16th March 2015) - Tiron, Raluca
ABSTRACT: Density multiplication of patterned templates by directed self-assembly (DSA) of block copolymers (BCP) stands out as a promising alternative to overcome the limitation of conventional lithography. Using the 300mm pilot line available in LETI and Arkema's materials, the main objective is to integrate DSA directly into the conventional CMOS lithography process in order to achieve high resolution and pattern density multiplication at a low cost. Thus we investigate the potential of DSA to address contact and via level patterning by performing either CD shrink or contact multiplication. Our approach is based on the graphoepitaxy of PS-b-PMMA block copolymers. Lithographic performances of block copolymers are evaluated both for contact shrink and contact doubling. Furthermore, advanced characterization technics are used to monitor in-film self-assembly process. These results show that DSA has a high potential to be integrated directly into the conventional CMOS lithography process in order to achieve high resolution contact holes.