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

Journal Article

Steinhauer, D.E, C.P Vlahacos, F.C Wellstood, S.M Anlage, C Canedy, Ramamoorthy Ramesh, A Stanishevsky, J Melngailis

10.1063/1.1150687

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 μm. The microscope is sensitive to the linear permittivity, as well as to nonlinear dielectric terms, which can be measured as a function of an applied electric field. We introduce a versatile finite element model for the system, which allows quantitative results to be obtained. We demonstrate use of the microscope at 7.2 GHz with a 370 nm thick Ba0.6Sr0.4TiO3 thin film on a LaAlO3 substrate. This technique is nondestructive and has broadband (0.1-50 GHz) capability. The sensitivity of the microscope to changes in permittivity is Δ∈r=2 at ∈r=500, while the nonlinear dielectric tunability sensitivity is Δ∈113=10-3 (kV/cm)-1. © 2000 American Institute of Physics.

Review of Scientific Instruments

71

2000

00346748

cited By 70

Ramesh Lab