Scanning Frequency Comb Microscopy (SFCM) Shows Promise for Carrier Profiling at and Below the 7-nm Node

A new type of scanning probe microscopy is described showing promise for true sub-nanometer resolution in carrier profiling which is essential in failure analysis at and below the 7-nm technology node. The sample resistivity is determined by measuring the attenuation of low-noise attowatt microwave signals generated in a tunneling junction by optical rectification.