Imaging capability of low-energy electron-beam - Proximity-projection lithography toward the 70 nm node

The technological systematics for low-energy electron-beam proximity-projection lithography (LEEPL) is discussed with particular focuses on the key ingredients such as mask, resist and alignment. We have developed a mechanically rigid 1X stencil mask supported by a grid-work of struts, high-resolution chemically-amplified resists to be used for multi layer processes, and the accurate alignment method to overlay complementarily split patterns. The LEEPL beta machine as combined with these techniques was successfully used to demonstrate its imaging capability for the 70 nm node.