AVS 53rd International Symposium
    Electronic Materials and Processing Thursday Sessions
       Session EM1-ThA

Paper EM1-ThA4
Silicon-on-Insulator Based Nanogap Electrode Device for DNA Conductivity Measurements

Thursday, November 16, 2006, 3:00 pm, Room 2001

Session: Contacts to Organic and Molecular Devices
Presenter: S. Strobel, Walter Schottky Institute, TU Munich, Germany
Authors: S. Strobel, Walter Schottky Institute, TU Munich, Germany
A.G. Hansen, Walter Schottky Institute, TU Munich, Germany
K. Arinaga, Fujitsu Laboratories Ltd., Japan
M. Tornow, Walter Schottky Institute, TU Munich, Germany
Correspondent: Click to Email
The objective to investigate DNA in hybrid bio-molecular electronic devices originates from the fundamental interest in DNA charge transfer mechanism, its potential role in future self-assembled nano-electronic networks, and from its prospective role in novel bio-sensing applications. Here, an electrical scheme allowing for the contacting of short DNA (few 10 nm) in an array-like chip format, and supporting in-situ measurements, i.e., with the DNA in aqueous buffer solution, at the same time, would be highly advantageous.   We have developed a novel nanogap electrode concept based on standard Silicon microtechnology. Starting material is a Silicon-on-Insulator (SOI) substrate with a thin buried oxide layer (thickness 10-40 nm). Using standard optical lithography and reactive ion etching a large array of individual, pillar-like device structures is prepared with the buried oxide layer exposed at their edges. After selectively recess-etching this layer and evaporating a metal thin film from an angle, nanogap electrodes of predetermined spacing are formed.   We successfully verified the functionality of our devices by electrically trapping gold nanoparticles onto the gap, both, on bare metal electrodes, and on those previously functionalized with monolayers of oligonucleotides. In the latter case a pronounced non-linear I-V characteristic develops at T=4.2 K which can be related to Coulomb blockade effects. Concepts for measuring DNA conductivity under aqueous conditions will be discussed.