| Popis: |
In recent semiconductor manufacturing, hardmask is unavoidable requirement to further transfer the patterning from thin photoresist to underlayer. While several types of hardmask materials have been investigated, amorphous carbon has been attractive for good etching resistance and high-aspect-ratio resolution. However, it has fatal problem with lowering overlay controllability due to its high extinction coefficient (k). Thus, the correlation of alignment and overlay performance with varying hardmask materials is required to meet a tight overlay budget of 2x nm node and beyond. In this paper, we have investigated the effects of the hardmask materials with respect to the optical properties on the performance of overlay applicable to 2x nm memory devices. |
