Scanning microwave microscopy (SMM) is a scanning probe technique, which combines an AFM with the measurement of local tip-sample microwave impedance, deduced from the S11 parameter, or microwave reflection coefficient. The S11 parameter is a ratio between the microwave power sent to the tip, and the one received back after being reflected at the tip-sample contact. Through the complex impedance such a measurement yields information about the local capacitance and resistance. From the local capacitance one can deduce the dielectric constant and the dopant density in semiconductors. In terms of the dopant density measurement, the SMM is very close to the scanning capacitance microscopy (SCM), however the SMM offers wider range of measurements, since it is not solely relying on the modulation of the depletion capacitance in the sample, and therefore can be used for measurements of not only semiconductors, but also dielectric materials and metals.
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Nanosurf's team of application scientists is always working on creating new interesting measurements for the benefit of the users of Nanosurf atomic force microscopes. The application notes we publish are written and edited by our global team of AFM Experts to provide you with example results in an easy to ready format and enough theoretical context to help novice users understand more complex measurement methods.