Quantitative imaging of dielectric permittivity and tunability with a near-field scanning microwave microscope

Citation
De. Steinhauer et al., Quantitative imaging of dielectric permittivity and tunability with a near-field scanning microwave microscope, REV SCI INS, 71(7), 2000, pp. 2751-2758
Citations number
31
Categorie Soggetti
Spectroscopy /Instrumentation/Analytical Sciences","Instrumentation & Measurement
Journal title
REVIEW OF SCIENTIFIC INSTRUMENTS
ISSN journal
00346748 → ACNP
Volume
71
Issue
7
Year of publication
2000
Pages
2751 - 2758
Database
ISI
SICI code
0034-6748(200007)71:7<2751:QIODPA>2.0.ZU;2-K
Abstract
We describe the use of a near-field scanning microwave microscope to image the permittivity and tunability of bulk and thin film dielectric samples on a length scale of about 1 mu m. The microscope is sensitive to the linear permittivity, as well as to nonlinear dielectric terms, which can be measur ed as a function of an applied electric field. We introduce a versatile fin ite element model for the system, which allows quantitative results to be o btained. We demonstrate use of the microscope at 7.2 GHz with a 370 nm thic k Ba0.6Sr0.4TiO3 thin film on a LaAlO3 substrate. This technique is nondest ructive and has broadband (0.1-50 GHz) capability. The sensitivity of the m icroscope to changes in permittivity is Delta epsilon(r) = 2 at epsilon(r) = 500, while the nonlinear dielectric tunability sensitivity is Delta epsil on(113) = 10(-3) (kV/cm)(-1). (C) 2000 American Institute of Physics. [S003 4-6748(00)04307-0].