Fabrication of partly encapsulated vertical nanoelectrodes for an intracellular microelectrode array

In this work, a concept and proof of principle regarding a fabrication technique for vertical nanoelectrodes is presented. CMOS-compatible processes for the fabrication of three-dimensional tubes which are partly encapsulated by an insulation layer are conceived. An extended sacrificial layer technique using deep reactive ion etching (DRIE) and atomic layer deposition (ALD) of encapsulation and electrode material was developed. Additional spacing techniques for tapering of electrode diameter and tip post-lithographically are investigated. Finally, free-standing nanoelectrodes and test structures were produced. The resulting tunable nanoelectrode array can lead to a novel device for a bidirectional interface between integrated circuits and living cells.