"Multi-Technique Problem Solving in an Industrial
Environment"
Shell, Thornton Laboratories, Chester-
Wednesday 6th of January 1999
Parallel Workshop Sessions
"Surface Analysis outside UHV?"
Leader:- Dr. J. F. Watts
Raporteur:- Michael Hill-King, Veeco Instruments Ltd
Surface analysis is essentially interested in four key areas:-
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Topographic
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Elemental
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Chemical
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Structural
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A diverse range of techniques exists for characterising the surface
with respect to these four areas. The number of available techniques exceeds 80. Most of
these techniques require the use of UHV. The workgroup unanimously agreed that the only
area which can be fully investigated outside UHV is topographic. The other three areas
present both challenges and obstacles for analysis outside UHV. The use of UHV presents
several disadvantages.
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UHV can damage some samples, e.g. electrochemical or
biological samples.
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QC requirements in production environments demand immediate
measurements, without removing samples to a laboratory.
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Particular environmental processes require in situ
measurement e.g. electrode surface in electrolyte.
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UHV takes time and involves cost.
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However, several techniques do not require UHV. They can be performed
at low vacuum, under atmospheric conditions or in aqueous solution. These techniques
include:-
The key questions are: "What does one really want to
measure/analyse/characterise?" and "What is the surface?" The answer to the
second question could be from monolayers to tens of nanometers. The practicalities of the
various available technologies have to be considered. Current developments are tending
towards low vacuum rather than no vacuum. Important considerations include size of
sample/instrument and safety, as not all available techniques may be hazard-free outside
UHV enclosures. Analysis outside UHV leaves open the possibility of introducing
contamination, and lowers the detection limit of the instrumentation.
In conclusion it was felt that the use of surface analysis techniques
outside UHV presented a two-fold balance.
There are opportunities for surface analysis outside of UHV. SPMs and
other instruments provide a wealth of topographical and other information. The challenge
lies in integrating multi-function instruments to operate outside UHV to cover elemental,
structural and chemical analysis.
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