Hosted by: Oleg Gang

Directed self-assembly (DSA) of block copolymers (BCPs) has become a promising patterning technique for advanced node hole shrink process due to its material-controlled CD uniformity and process simplicity. In practice, multiple patterning and self-aligned via (SAV) processes have been implemented in semiconductor manufacturing to address resolution issue. In this talk, DSA of lamella-forming BCP was evaluated as a candidate for forming SAV, which requires the DSA process to support structures from circular via to lines and spaces. The basic process flow is similar to general graphoepitaxy method. The morphologies of the DSA vias derived from lamellar BCPs were found to be less sensitive to the BCP coating thickness compared to the cylindrical BCP system of similar L0. This implies that lamellar BCP may provide a larger process window and higher tolerance for local pattern density variation. The profile and the thickness of the residual PS layer of DSA structures were studied using Monte Carlo simulation and FIB cross-section SEM. Furthermore, a series of defectivity study using the lamellar system will be discussed, including film stack, DSA, and etch process fine-tuning. Finally, the benefits and challenges of implementing DSA for via process will be discussed.