Surface Analysis Techniques

The composition and structure of the outermost layers of a surface have a profound effect on the properties and performance of materials and systems in an increasingly wide range of technological and nano-technological applications. Analysis of the compositional, chemical and physical properties of these first few atomic layers have proved invaluable in the characterisation and understanding of the surface properties of materials.

Instrumentation

X-RAY PHOTOELECTRON SPECTROMETER (XPS)

IONTOF 4 ToFSIMS instrument Our “state of the art” Thermo Fisher ESCALAB 250 Imaging XPS instrument has a monochromatic Al X-ray source, which allows energy resolution of 0.45 eV FWHM. This makes the identification of chemical states much more precise. The spatial resolution is 15 microns in spectroscopy mode and 3 microns in chemical imaging mode. It also has an Al/Mg dual anode X-ray source which allows analysis areas of up to 8mm diameter. The base pressure in the instrument is < 3 x 10 -10 mbar ensuring that instrumental contamination is never a problem. Elemental and chemical state depth profiling (up to a depth of 1 micron) can be achieved by ion etching using a differentially pumped Ar ion source of 100eV to 5keV with a rotational sample stage and non-destructive depth profiling (up to a depth of 10nm) by means of angle resolved XPS. Ion scattering spectroscopy can also be carried out on this instrument using He, Ne or Ar ions.

AUGER ELECTRON SPECTROMETER (AES)

AES instrumentOur AES instrument has a 1 to 25kV field emitting electron gun. The gun can be operated in scanning or stationary spot mode. Elemental and chemical imaging and spectroscopy can be achieved at spatial resolutions down to 5 nm. Base pressures are the same as in the XPS instrument and depth profiling can be done by Ar ion etching.

XPS is more useful when identifying the chemical or bonding state of elements in a surface, whilst AES is more useful in analyzing very small (sub 10nm) features.

TIME OF FLIGHT SECONDARY ION MASS SPECTROMETRY (TOFSIMS)

Our IONTOF 4 ToFSIMS instrument has a very high mass resolution, sensitivity and spatial resolution giving elemental, structural and molecular information in the ppm-ppb range.

OTHER TECHNIQUES

Mechanical and topographical characterisation of surfaces can be conducted at MSA. For example, nano hardness, nano scratch, impact and elastic modulus measurements of surfaces by using an MML Nano-test platform; topographical information using Atomic Force Microscopy (AFM) and Scanning Electron Microscopy SEM.

For further information, please contact info@midsurfanalysis.co.uk or telephone +44 (0)121 204 3530 or alternatively please complete our analysis request form and a consultant will be in contact.