Broadband dielectric microwave microscopy on micron length scales

Abstract

We demonstrate that a near-field microwave microscope based on a transmission line resonator allows imaging in a substantially wide range of frequencies, so that the microscope properties approach those of a spatially-resolved impedance analyzer. In the case of an electric probe, the broadband imaging can be used in a direct fashion to separate contributions from capacitive and resistive properties of a sample at length scales on the order of one micron. Using a microwave near-field microscope based on a transmission line resonator we imaged the local dielectric properties of a Focused Ion Beam (FIB) milled structure on a high-dielectric-constant Ba 0.6 Sr 0.4 TiO 3 (BSTO) thin film in the frequency range from 1.3 GHz to 17.4 GHz. The electrostatic approximation breaks down already at frequencies above ~10 GHz for the probe geometry used, and a full-wave analysis is necessary to obtain qualitative information from the images.

Nondestructive imaging of atomically thin nanostructures buried in silicon

“…Unlike destructive imaging techniques such as focused ion beam milling combined with scanning electron microscopy ( 22 ), transmission electron microscopy (TEM) ( 23 ), and secondary ion mass spectrometry (SIMS) ( 24 ), SMM experiments can be performed with virtually no sample modification, in an ambient environment, using a standard atomic force microscope (AFM) ( 25 ) or STM ( 26 ) combined with a vector network analyzer (VNA) ( 27 ) or custom-made electronics ( 28 ). Typically, resonators ( 29 ) or matching circuits ( 28 ), as well as simpler direct connections ( 30 , 31 ), are used to sense the minute electrical changes that come from the SMM probe. Recently, it has been shown that SMM is capable of visualizing buried conducting structures ( 20 , 21 , 32 ) and differently doped bulk regions buried below an insulating layer ( 33 ).…”

High Capacitance and Cycle‐Life Performance of a Binder‐Free Supercapacitor Nanocomposite Electrode by Direct Growth of Manganese Oxide Nanostructures on Carbon Nanotubes

“…Quite the reverse, the presence of a high pressure of the gas in the deposition chamber will decrease the kinetic energy of the plasma species, which provokes a variation of the surface mobility of the deposited species leading to a porous film ( Figure 1c and Figure 1d). Further details regarding the influence of the atmosphere chamber on the physical processes of laser-material interaction can be found elsewhere [33][34][35][36][37]. The XRD spectra (not shown) of CNT/MnO x films did not reveal specific peak of crystalline MnO x indicating the amorphous structure of the as-deposited MnO x films.…”

Quasistatics and electrodynamics of near-field microwave microscope

“…In Ref. 29, the NF measurements were analyzed versus QS calculations for a high-dielectric-constant film in a wide frequency range. It was found out that the QS approximation breaks down at frequencies above 10 GHz, so the authors suggested ED analysis to be the right tool for an adequate description of their experimental data.…”