Nanoscopic strain detection

A non-invasive method for detecting nanoscale strains in semiconductors has been demonstrated by a Spanish-German research collaboration; a development that could lead to more reliable electronic devices.

Scientists at the nanoscience research centre CIC nanoGUNE in San Sebastian, Spain and the Max Planck Institutes of Biochemistry and Plasma Physics in Munich, Germany, were able to map nanoscale material properties with Scanning Near-field Optical Microscopy (s-SNOM).

The technique uses extreme light concentration at the sharp tip of an Atomic Force Microscope to resolve nanoscale images at visible, infrared and terahertz frequencies.

The research team was able to demonstrate for the first time that this microscopy technique is capable of mapping local strain and cracks of nanoscale dimensions. This was demonstrated by pressing a sharp diamond tip into the surface of a silicon carbide crystal. With the near-field microscope, the researchers were able to visualise the nanoscopic strain field around the depression and the generation of nanocracks.