35 research outputs found
Broadband dielectric microwave microscopy on m length scales
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.Comment: 19 pages (preprint format), 5 figures; to be published in Review of
Scientific Instrument
Near-Field Microwave Microscopy on nanometer length scales
The Near-Field Microwave Microscope (NSMM) can be used to measure ohmic
losses of metallic thin films. We report on the presence of a new length scale
in the probe-to- sample interaction for the NSMM. We observe that this length
scale plays an important role when the tip to sample separation is less than
about 10nm. Its origin can be modeled as a tiny protrusion at the end of the
tip. The protrusion causes deviation from a logarithmic increase of capacitance
versus decreasing height of the probe above the sample. We model this
protrusion as a cone at the end of a sphere above an infinite plane. By fitting
the frequency shift of the resonator versus height data (which is directly
related to capacitance versus height) for our experimental setup, we find the
protrusion size to be 3nm to 5nm. For one particular tip, the frequency shift
of the NSMM relative to 2 micrometers away saturates at a value of about -1150
kHz at a height of 1nm above the sample, where the nominal range of sheet
resistance values of the sample are 15 ohms to 150 ohms. Without the
protrusion, the frequency shift would have followed the logarithmic dependence
and reached a value of about -1500 kHz.Comment: 6 pages, 7 figures (included in 6 pages
Nanometer-Scale Materials Contrast Imaging with a Near-Field Microwave Microscope
We report topography-free materials contrast imaging on a nano-fabricated
Boron-doped Silicon sample measured with a Near-field Scanning Microwave
Microscope over a broad frequency range. The Boron doping was performed using
the Focus Ion Beam technique on a Silicon wafer with nominal resistivity of 61
Ohm.cm. A topography-free doped region varies in sheet resistance from
1000Ohm/Square to about 400kOhm/Square within a lateral distance of 4
micrometer. The qualitative spatial-resolution in sheet resistance imaging
contrast is no worse than 100 nm as estimated from the frequency shift signal.Comment: 5 pages, 3 figures, 1 tabl
Optics and Quantum Electronics
Contains reports on nine research projects split into two sections.National Science Foundation (Grant DAR80-08752)National Science Foundation (Grant ECS79-19475)Joint Services Electronics Program (Contract DAAG29-83-K-0003)National Science Foundation (Grant ECS80-20639)National Science Foundation (Grant ECS82-11650
Submicron Structure Fabrication and Research
Contains reports on six research projects.Joint Services Electronics Program (Contract DAAG29-78-C-0020)Joint Services Electronics Program (Contract DAAG29-80-C-0104)M.I.T. Sloan Fund for Basic ResearchU.S. Navy - Office of Naval Research (Contract N00014-79-C-0908)Lawrence Livermore Laboratory (Subcontract 206-92-09)U.S. Department of Energy (Contract DE-ACO2-80-E10179)Harkness Foundatio
Optics and Quantum Electronics
Contains reports on eleven research projects.Joint Services Electronics Program (Contract DAAG29-83-K-0003)National Science Foundation (Grant ECS83-05448)National Science Foundation (Grant ECS83-10718)National Science Foundation (Grant ECS82-11650)National Science Foundation (Grant ECS84-06290)U.S. Air Force - Office of Scientific Research (Contract AFOSR-85-0213)National Institutes of Health (Grant 1 RO1 GM35459
Focused Ion Beam Fabrication
Contains summary of research program and reports on four research projects.Charles Stark Draper Laboratory (Contract DL-H-225270)Hughes Research LaboratoriesInternational Business Machines, Inc. (Contract 456614)Nippon Telegraph and Telephone, Inc.U.S. Navy - Office of Naval Research (Contract N00014-84-K-0073)U.S. Department of Defense (Contract MDA903-85-C-0215)Hitachi Central Research Laborator
Quantum Electronics
Contains reports on eleven research projects.Air Force Rome Air Development Center (in collaboration with C.C. Leiby Jr)U.S. Air Force - Rome Air Development Center (Contract F19628-80-C-0077)National Science Foundation (Grant PHY79-09739)Joint Services Electronics Program (Contract DAAG29-80-C-0104)Air Force Geophysics Laboratory (Contract F 19628-79-C-0082)National Science Foundation (Grant DAR80-08752)National Science Foundation (Grant ECS79-19475)National Science Foundation (Grant ECS80-17705)National Science Foundation (Grant ENG79-09980
Focused Ion Beam Fabrication
Contains reports on five research projects.DARPA/Naval Electronic Systems Command (Contract MDA-903-85-C-0215)Charles Stark Draper Laboratory (Contract DL-H-261827)U.S. Navy - Office of Naval Research (Contract N00014-84-K-0073)Nippon Telephone and TelegraphHitachi Central Research Laborator
Focused Ion Beam Fabrication
Contains reports on four sections of one research project.Microsystems Technology LaboratoriesDefense Advanced Research Projects Agency/Naval Electronics Systems Command (Contract MDA 903-85-C-0215)U.S. Air Force (through Lincoln Laboratory)Defense Advanced Research Projects Agency (through Lincoln Laboratory)Charles Stark Draper Laboratory, Inc. (Contract DL-H-261827)Hitachi Central Research LaboratoryNippon Telegraph & TelephoneU.S. Army Research Office (Contract DAALO3-87-K-0126