New processes associated with electron-beam lithography for ultra-small resonators

Abstract

High density ultrahigh resolution patterning with desired shape and size is a crucial requirement in nanotechnology and its applications. Electron beam lithography (EBL) is the most widely used lithography tool for these applications. However, achieving cost-effective patterning with sub-10-nm critical dimension has been challenging due to the inherent tradeoff between resolution and throughput. In this paper, we present cost-effective new processes associated with EBL technique, which include optimized resist selection and processing as well as sonicated cold development process. Using this process, we demonstrate sub-10-nm diameter metal dots at a pitch of ~34 nm and sub-15 nm wide metal lines. Based on the same processes, we demonstrate the fabrication of u-shaped split ring resonator array of different metals with smallest fabricated resonator with ~60 nm size and v-shape SRRs with the smallest gap spacing of ~30 nm. By adjusting the SRR gap spacing through its arm length and opening angle, we have successfully demonstrated magnetic and electric resonances across the visible and ultraviolet range.