Fabrication of nanochannels with high aspect ratios on a silicon substrate by local focused ion beam implantation and deep reactive ion etching

Recently, demands for nanochannels have been increasing in biological and nanofluidic applications. In this paper, a fabrication process that produces a nanochannel with a width of less than 20 nm and a high aspect ratio is proposed. For the versatility of channel pattern design, focused ion beam (FIB) direct writing is applied for mask fabrication. A metal mask pattern is fabricated using localized ion implantation method and is used for a deep reactive ion etching (DRIE) process. A process condition for minimum undercut in the DRIE process is determined. The proposed method is applied to the fabrication of nanochannels with various dimension and patterns.