Open AccessInterferometer Scanning Microwave Microscopy: Performance Evaluation
Author(s) -
Silviu-Sorin Tuca,
Manuel Kasper,
Ferry Kienberger,
Georg Gramse
Publication year - 2017
Publication title -
ieee transactions on nanotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 82
eISSN - 1941-0085
pISSN - 1536-125X
DOI - 10.1109/tnano.2017.2725383
Subject(s) - components, circuits, devices and systems , computing and processing
A systematic and quantitative comparison of electrical detection systems in scanning microwave microscopy is reported. Scanning microwave microscopy (SMM) is capable of investigating nanoscale electrical properties with high accuracy over a broad frequency range of 1-20 GHz. However, due to the passive matching network only discrete frequencies can be used every 1 GHz with varying signal-to-noise ratio (SNR). Here we study in detail the impedance matching mechanism using an interferometric network where a two-port measurement is implemented with a reduction of the trace noise due to signal subtraction. The interferometer setup shows superior performance resulting in a 2-8 fold increased SNR with respect to the standard shunt solution, in addition to stable broadband performance over the full frequency range. We perform a comparison of the electrical sensitivity obtained using a direct connection from the network analyser to probe, the typically implemented shunt-resonator impedance matching network, and the proposed interferometer setup. The interferometer SMM allows us also for calibrated impedance measurements, which we demonstrate on Tobacco mosaic viruses with 18-nm diameter, with a capacitance resolution of 0.67 attoFarads at 10 ms acquisition time per pixel.