An approach for nanometer trench and hole formation

Patterning trench-hole type of structures with CD in nanometer dimension is very challenging in optical lithography due to limited depth of focus (DOF) and exposure latitude (EL). We have proposed an integration process to convert sub-100nm line/post type of structure to trench/hole type of structure. The proposed method as well as its variations may have various potential applications, such as formation of plated perpendicular magnetic writer pole, bottom-up nanointerconnect, nano-wires and other out-of-plane nano-structures. We have shown the feasibility for formation of nanotrenches in various sub-100nm dimensions. Magnetic writer pole with 50nm critical dimensions (CD) and well-controlled sidewalls was demonstrated by using this approach. The minimum CD of the starting isolated line/post feature determines the minimum CD of the trench/hole structure.