Fabrication of Nano-Imprint Templates for Dual-Damascene Applications Using a High Resolution Variable Shape E-Beam Writer

摘要

A 3D template fabrication process has been developed, which enables the generation of high resolution, high aspect pillars on top of lines. These templates will be used to print both vias and metal lines at once for the dual damascene technology. Due to the complexity of state of the art CMOS designs only a variable shape e-beam (VSB) writer combined with chemically amplified resists (CAR) can be considered for the patterning process. We focused our work especially on the generation of high aspect pillars with a diameter below 50nm and the development of suitable overlay strategies for getting a precise alignment between the two template tiers. In this context we investigated the influence of exposure strategies on the overlay result across the entire imprint area of 25mm x 25mm. Finally, we realized templates according to the MII standard with different test designs and confirmed printability of one of them on a MII tool.