Depth Profiling
Depth profiling uses an ion beam to etch layers of the surface to reveal subsurface information
Combining sequences of etch cycles with XPS analyses provides quantifiable layer thickness with elemental composition.
Clusters vs monoenergetic ions
Analysis may be performed using monoenergetic argon ions, or using argon clusters of varying sizes. Monoenergetic argon beams are useful for sample cleaning and sample profiling where perhaps the understanding of the the underlying chemistry is not critical, whilst clusters are able to analyse many groups of materials previously inaccessible to monoenergetic XPS depth profiling which induced large scale damage to the surface and undesirable changes in the surface chemistry of the analyte

Benefits
Applications
- rapid depth profiling of polymers and soft materials
- minimal observed damage in both organic and inorganic materials
- efficient and rapid cleaning of surface contaminant prior to analysis.
- surface preparation prior to analysis
- depth profiling through organic multilayers
- removal of thin oxide layers without damage or formation of suboxides at the surface
- depth profiling thin organic films on inorganic substrates (for example, photoresists on semiconductors).
Availability
All systems at Harwell, Cardiff, UCL and Manchester are equipped with monoatomic sputtering, with cluster sources available at Harwell and Cardiff.