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Development of a scanning atom probe for nanoscale characterisation of thin-film materials, devices and coatings

Objective



Objectives and content
New industrial materials increasingly depend for their
properties on microstructure and phase chemistry at the
nanometre scale. High-resolution microscopy and
microanalysis is crucial for understanding the properties
of nanoengineered materials and optimising their
applications for new and improved products. In
multilayered film (MLF) materials for example, which are
used in hard-disk read heads, the magnetic properties are
known to be dependent on the nano-scale chemistry of the
interface. Microanalysis on this scale is needed to
correlate the materials processing with the observed
properties. The objective of this project is to build a
new instrument, called the scanning atom probe, which
will be capable of producing 3-dimensional images with
atomic-scale resolution showing the chemical variations
within thin-film materials and coatings. Previously the
technique of atom probe analysis has had only limited
application in thin-film materials due to the problems of
producing specimens in the correct form for analysis. In
the scanning atom probe, specimens can be made within
thin films on flat substrates. This new instrument will
provide an important tool in the development of
nanostructured materials, underpinning the growth of
nanotechnology in Europe for the 21st century.
During the project, a scanning atom probe will be built
which will allow the distribution of >80% of the atoms
within a volume 20nm x 20nm x 20nm to be visualised, in
3-dimensions and with sub-nanometre resolution. An
innovative counter-electrode design will be used in this
instrument to give a mass resolution of m/Dm>300,
allowing identification of single atoms, even in
materials with elements close together in the mass
spectrum. Specimens for the new instrument will be in
the form of microtips fabricated in the surface of a thin
film specimen by a combination of masking and ion-beam
milling. The apex of these microtips which lie close to
the original surface of the specimen, represent the
sample volume for the technique. Important part of the
project will be the development of the specimen
preparation techniques so that the instrument can be
applied to as wide a range of materials as possible.
Once commissioned, the new instrument will be applied to
a number of materials science problems, with two early
applications being of interest to the end-user members of
the partnership. One of these applications is the
characterisation of multilayer films being produced for
hard-disk read head applications for high-density data
storage (5-10 Gb/in2 and beyond). The second application
is the measurement of surface composition on dedicated
scanning probe microscopy (SPM) tips which are being
fabricated for the measurement of dopant and carrier
profiles in electronic devices. The characterisation of
the chemical and electronic properties of the probe
surface resulting from this work will permit a more
thorough understanding of the tip-surface interactions
and the resultant SPM data, which is produced.
The consortium combines expertise in design and
manufacture of scientific instrumentation with end-user
applications. Members of the consortium are Oxford
University (world leaders in development and applications
of atom probe techniques), Omicron GmbH (the leading
European manufacturer of scanning probe microscopy
instrumentation), IMEC (one of Europe's major
microelectronics research organisations) and Kindbrisk
(suppliers of atom probe instrumentation). Seagate (one
of the largest suppliers of magnetic media and read head
technology in the world) are a subcontractor on the
project.

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

THE CHANCELLOR, MASTERS AND SCHOLARS OF THE UNIVERSITY OF OXFORD
Address
Parks Road
OX1 3PH Oxford
United Kingdom

Participants (3)

INTERUNIVERSITAIR MIKRO-ELEKTRONICA CENTRUM VZW
Belgium
Address
75,Kapeldreef 75
3001 Heverlee
KINDBRISK Limited
United Kingdom
Address
8,Tilgarsley Road
OX8 1HE Eynsham
Omicron Vakuumphysik GmbH
Germany
Address
78,Idsteinerstrasse
65232 Taunusstein