Abstract
We demonstrated a sidewall spacer nanofabrication technique for nanogap electrodes fabrication. Nanogap between gold and polycrystalline silicon (ploy-Si) electrodes is defined without using any advanced lithographic techniques. The feature size of nanogap electrodes fabricated using this technique is mainly determined by the thickness of sidewall spacer. The proposed technique showed that reproducible nanogap distances from 10 to 100 nm on the 6 in. wafer were easily obtained. Binding of 15 nm gold nanoparticles across the 10 nm electrodes leading to a drastic change of the electrical conductance has also been demonstrated. Under a bias of 3 V, the conductive current increases from 2 pA to 300 nA after binding of 15 nm gold nanoparticles across the 10-nm electrodes. We believed that this technique can be contributed to the development of high-density nanogap electrodes for applications in biomolecules or nanoparticles detection.