There are physical reasons why the continued effort towards miniaturisation in the electronic industry is meeting severe difficulties.
 Computer-rendered schematic illustration of on eof the gold nano-capacitors made at UTS. A gold nano-particle is attached to a conductive gold substrate by a nest of organic molecules. |
These include limitations of the lithographic process, as well as the onset of electron tunnelling through the ultra-thin dielectrics now being used. Therefore, the exploration of alternative or modified designs of electronic devices is currently of great interest. At UTS we have harnessed our interests in gold nanoparticles, organic self-assembly and scanning tunnelling microscopy to model and finally produce two different prototypes of working 'nano-capacitors'.
 Configuration of the Mk I nano-capacitors produced at UTS, showing how they can be charged, one at a time, by the tip of a scanning tunnelling microscope |
The properties of these tiny devices depend closely on the dielectric properties of the self-assembled monolayers (SAMS) used in their construction. Some molecules such as alkyl thiols and DNA fragments have shown good insulating properties, whereas others such as p-xylyenedithiol (XYL) are reasonably conductive. We aim to show that the desired capacitance and current leakage envelope can be achieved by judicious combination of gold nano-shape and SAM.
 Potential Energy Surface of Au20 on MgO |
The project started with the Masters project of Mr Ramesh Ekayanake (supervised by Prof. M. Cortie) and has now grown to become the topic of a jointly-funded CSIRO-UTS post-doc. The post-doc incumbent is Dr Jingquan Liu, formerly of UNSW. Great strides have already been made, with some good publications resulting.
 Leakage currents predicted in such capacitors for dielectric SAMs of the molecules p-xylyenedithiol (XYL) and do-decanedithiol (c12). |
