Preparation of Nanogap Electrodes of Silicon by Chemical Etching

Abstract

We have prepared nanogap electrodes of silicon by chemical etching. The substrate used was silicon(001)-on-insulator (SOI). A metal film used as an etching mask was fabricated on SOI by a conventionally lithographic process. The direction of the mask patterns with respect to the crystal axes of silicon is a key factor for anisotropic chemical etching. The substrate was, then, immersed in a KOH aqueous solution to etch the (001) plane selectively, which resulted in the formation of the electrodes with the shape of square pyramid.

Keywords:

• anisotropic etching
• nanogap electrodes
• silicon-on-insulator (SOI)

Acknowledgments

The authors would like to thank SUMCO CORPORATION for providing the SOI wafer.