Nanogap electrode formation by sacrificial layer technique

This paper presents a controlled lateral etching-based technique for realizing nanogap structures. These structures have applications in different bio-medical/ biochemical sensors. The sensitivity of such sensors depends on the gap size. The method method uses single mask lithography, followed by etching for the first electrode material and lift-off for the second electrode material. Controlled under-etching of the first metal layer defines the gap between two electrodes. Aluminum (0.7 μm) as metal one and titanium (0.2 μm) as metal two was used for fabricating nano-gap electrodes. Gap of 90 nm was achieved using the present technique.