Semiconductor characterization with the scanning surface harmonic microscope

The scanning surface harmonic microscope, in which a microwave signal is applied across a tip-sample tunneling gap and higher harmonics are detected, is sensitive to the capacitance/voltage characteristics of semiconductor samples on a nanometer scale. We demonstrate its sensitivity to a wide range of dopant concentrations on Si, and its applications as a dopant profiler. Depletion regions are delineated with remarkable sensitivity, and variations in dopant concentration over a 35-nm scale are discussed. Indications of a 5 nm resolution have been obtained. © 1994 American Institute of Physics.