|
In this thesis, a fine process for fabricating nano-air-bridge junction has been developed. Through electrostatic trapping technique integrated in this air-bridge device, we were able to trap nano-particle into the junction. All the properties were characterized by current-voltage curve, first and second derivative of I-V curves measurements.
A series of nano-air-bridge devices were fabricated by a bottom up process and the techniques involved are as follows : electron beam lithography, photolithography,
reaction ion etching, wet etching, thermal evaporation, sputtering system, and scanning probe microscopy. The key to get different gap-size of nano-air-bridge is varying the thickness of mid-layer of SiO2. The top and bottom gold electrodes are 50 nm and 30 nm thick, respective, and the SiO2 layer is controlled within 5 nm to 15 nm. The cross area of nano-air-bridge is below 80 nm × 80 nm. In addition, nano-airbridge is also fabricated on the top of a 100 nm SiN membran for being inspected using transmission electron microscopy(TEM).
Through four-terminal I-V measurement on Au-SiO2-Au, typical nonlinear I-V curves have been obtained. Furthermore, a photo-assisted exciting effect is also
observed in this metal-insulator-metal (MIM) structure. This phenomenon may have been caused by the coupling surface plasmon on the both side of metal electrode.
After removing SiO2 layer, the I-V curve indeed indicated a lower barrier height in Au-Air-Au junction. By dipping this junction in diluted CdSe solution and adopting with a electrostatic trapping (ET) technique, I-V curve measurement revealed that the nano-particle have been trapped into the gap successfully.
|