Scanning Probe Microscope Techniques for the Engineering of Nanoelectronic Devices

Using CNT network sensors as our working example, we review AFM-based techniques which are used to study and engineer nanoelectronic devices. We have used dc-EFM and ac-EFM to identify the locations and resistances of individual CNTs that are electrically connected in parallel. Next, 5GM and tm-SGM were used to reveal the semiconducting response of each CNT. With the information available in these scans a single CNT with desirable properties was singled out for further experimentation. The unwanted CNTs were electrically cut with a biased AFM probe to leave a device containing a single CNT. An atomic-sized transistor with chemical functionality was engineered in the remaining CNT using a voltage pulse from the AFM probe. This nanotransistor was then demonstrated to be a single molecule sensor sensitive to EDC in an aqueous environment. This multi-step measurement and manipulation process illustrates the power of AFM-based techniques to map out and control the properties of na noelectron ic devices.