Authors: G.Y. Jung, W. Wu, Z. Li, S.Y. Wang, W.M. Tong and R.S. Williams
Affilation: Hewlett Packard Laboratories, United States
Pages: 251 - 254
Keywords: nanoimprint, UV, crossbar, drop method, surface linker
Nanoimprinting lithography was initiated as an alternative way to achieve nanoscale structures with high throughput and low cost. We have developed a UV-nanoimprint process to fabricate 34 by 34 crossbar circuits with a half-pitch of 50 nm (equivalent to a bit density of 10 Gbit/cm2) with single layer structure, which required fewer processing steps than any bilayer process, but yielded high quality results. The focus on this presentation will be on two innovative ideas to overcome challenges in the nanoimprint at shrinking dimensions: (1) Trapped air during the initial mold-substrate contact. (2) Resist adhesion to the nanoscale patterns on the mold after mold-substrate separation. We applied “drop method” to form a uniform resist film between the substrate and the mold without any air trapped by engineering the surface energy of the substrate. Resist adhesion to the gaps is a challenge that becomes more severe as the feature size shrinks. By utilizing a monolayer of surface linker, the adhesion of the resist to the substrate surface was much improved. 66 by 66 crossbar structure with a half-pitch of 30 nm was produced.