EMRP-IND02: Electromagnetic Characterization of Materials for Industrial Applications up to Microwave Frequencies

• Research unit: METAS
• Project number: F-5217.30005

Key words (English)

Materials, Characterization, AFM, Atomic Force Microscope, NSMM; Near Field Scanning Microwave Microscope

Short description (English)

The aim of this project is to establish a comprehensive metrology for AFM (Atomic Force Microscope)-based NSMMs (Near Field Scanning Microwave Microscope). This will be achieved by modelling of probe-tip/sample interactions and modelling the impedance matching network of the NSMM. The modelling of the tip-sample interaction condenses the material properties to a surrogate impedance. The surrogate impedance is the input to the model of the impedance matching network. The output of the impedance matching network is a translated impedance which is measured by the vector network analyzer. The data from the vector network analyzer can be translated back into material properties.  Within the work package it is planned to provide and measure reference and calibration samples and to evaluate the measurement uncertainties. These are the necessary steps to validate the measurement model. The physical measurements are executed in the Agilent laboratories in Linz, Austria. ETHZ adds essential modelling experience to the work.

This project is part of the European Metrology Research Programme (EMRP, http://www.euramet.org/index.php?id=emrp); it is partly funded by the European Union on the basis of Decision No 912/2009/EC.

Project aims (English)

The project objectives are:

• A measurement model for the NSMMs
• A comprehensive uncertainty budget
• Simplified calibration
• Increased measurement accuracy.

Abstract (English)

METAS, working with ETHZ and Agilent Technologies (Austria), has successfully developed
new algorithms, calibration artefacts and skills for measuring relative permittivity at microwave
frequencies and other electromagnetic material parameters at nanometre scales using
Near Field Scanning Microwave Microscopes (NSMMs). A special property of one of the algorithms
is that the calibration standards and the material under test do not need to be on
the same substrate and there are very few requirements on the tip shape. Another algorithm
models the measurement system as a linear network and is more general and wider applicable
than previous similar attempts. These features present major steps forward when compared
with previous approaches. Progress in this field was sufficient to allow METAS, besides
working on the Agilent NSMM, to develop an own NSMM during the course of EMINDA.
A number of scientific papers are appearing on this work.

Transfer and application (English)

METAS has shown that quantitative measurements are possible with Near Field Scanning
Microwave Microscopes (NSMM). These results will be applicable in other areas. Measurements
of electrical material properties at small dimensional scales become increasingly important
in e.g. semiconductor industry, solar cell production and, more prospective, life science.
METAS has a measurement device that can be used in R&D activities related to these
fields and support emerging technologies. In the longer run it is conceivable that METAS will
offer specific measurement services based on NSMM technology.

Publications / Results (English)

Johannes Hoffmann, Michael Wollensack, Markus Zeier, Jens Niegemann, Hans-Peter Huber, Ferry Kienberger, A Calibration Algorithm for Nearfield Scanning Microwave Microscopes, IEEE Nano 2012 Conference Digest, ISBN 978-1-4673-2198-3, pp 1-4, 2012

J. Hoffmann (METAS), G. Gramse, J.Niegemann, M. Zeier (METAS), F. Kienberger
Measuring Low Loss Dielectric Substrates with Scanning Probe Microscopes
Applied Physics Letters, Vol 105, Issue 1, pp 013102 - 013102-4, July 2014