Low Temperature SNOM

Scanning Near-field Optical Microscopy (SNOM) is performed by focusing a light source to an Atomic Force Microscopy (AFM) tip. A dipole forms between the tip and the sample 10’s nm below it creating a strong, localised field which causes light to be elastically scattered. This scattered light contains information on the material properties of the area of the sample directly below the tip, giving this technique a resolution set by the tip radius (typically 5-30 nm).
The aim of this project is to use the SNOM technique to locate single impurities in silicon with resolution on the order of nanometres. Performing this technique at low temperatures (<10K) allows for the excitation of specific states within the impurities. This is necessary for locating the impurity and will allow for the identification of its species.
The cryo-NeaSNOM, built by Neaspec, is due to be delivered to the Advanced Technology Institute at the University of Surrey in June 2018.

An illustration of SNOM system from Neaspec