Described herein are IC devices include vias deposited in a regular array, e.g., a hexagonal array, and processes for depositing vias in a regular array. The process includes depositing a guiding pattern over a metal grating, depositing a diblock copolymer over the guiding pattern, and causing the diblock copolymer to self-assemble such one polymer forms an array of cylinders over metal portions of the metal grating. The polymer layer can be converted into a hard mask layer, with one hard mask material forming the cylinders, and a different hard mask material surrounding the cylinders. A cylinder can be selectively etched, and a via material deposited in the cylindrical hole to form a via.