Integration of a templated directed self-assembly-based hole shrink in a short loop via chain

The use of directed self-assembly (DSA) of cylinder forming block copolymers (BCP) for contact hole shrink applications has gained increased attention due to the dimensions that can be achieved with this materials. Recent work has focused on engineering the dimensions and surface energy of the templates to obtain straight profiles of the cylinders assembled in them. However, the impact of process optimization on defect formation is measured using scanning electron microscopy before and after transferring the BCP features to a hardmask, which provides limited information about the presence of defects or three-dimensional morphologies in the polymer structures. To identify the presence of single defects in arrays of various densities and sizes, we use Kelvin and chain structures available in the IMEC 28-nm node via chain electrical test vehicle, Everest, in combination with templated DSA. We tuned the surface energy and dimensions of the templates with the use of random copolymers and through the exposure conditions, respectively. Finally, the contact holes obtained with templated DSA of BCP were subsequently transferred into a relevant stack to apply advanced metallization processes and, ultimately, validated electrically.