Physical Analysis
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Head of the group:
Ao. Univ. Prof. Dr. techn. Herbert HUTTER

Tel. +43 (0) 1 58801 15120
Fax: +43 (0) 1 58801-15199

e-mail: herbert.hutter@tuwien.ac.at

 

Time-of-Flight secondary ion mass spectrometry (ToF-SIMS)

Time-of-Flight secondary ion mass spectrometry (ToF-SIMS) is known to be a very versatile, extremely sensitive mass spectrometric technique that provides detailed information on the elemental as well as on the molecular composition of all kinds of solid surfaces with extremely high sensitivity.

The bombardment of a surface with energetic primary ions leads to the emission of atoms, clusters, intact molecules and fragments from the uppermost monolayer of a surface, and the ionised fraction of the emitted particles can be mass analysed.

ToF mass spectrometry is a pulsed primary ion beam technique and based on the fact that secondary ions with the same energy but different masses travel with different velocities. Measuring the flight time for each ion over a fixed distance allows the determination of its mass.                                    

The time-of-flight technique offers parallel detection of all secondary ion species with ultra-high transmission and high mass resolution. This technique can be used for virtually all kinds of conductive and non-conductive materials. In the ion microprobe mode, a highly focused ion beam is scanned over an area of interest and complete spectra are recorded for every pixel. In this way, images can be acquired for all atoms including hydrogen and molecules in parallel with high sensitivity. For a well-controlled removal of surface layers a second ion beam with low energy sputter ions like oxygen, cesium (200 eV - 2000 eV) or cluster ions is simultaneously used in order to measure depth profiles of all species with high depth resolution in the nanometer range (dual beam mode).

Nitrogen distribution in bone sample

By the combination of imaging and sputtering, the distribution of all species in a 3-dimensional object can be analysed. For each voxel (volume pixel, 3-dimensional pixel in a 3D dataset) a complete mass spectrum with elemental and molecular in- formation is stored. This concept enables very powerful retrospective analysis capabilities. Spectra and profiles can be re- constructed from any user-defined region of interest, images and 3D distributions for every mass of interest.

This makes the technique very powerful for the 3D analysis of complex structures with “unknown” or partially “unknown” composition.

Applications

  • Ceramics
  • Coatings
  • Corrosion
  • Metals
  • Organic Surfaces
  • Semiconductors
  • Surface & Interface Analysis
  • 3D Reconstruction

Current Projects

Ceramics: 18O-Tracer diffusion in electro ceramics (ZrO2, PZT, SrTiO3, etc.) for Solid Oxide Fuel Cells (SOFC) in cooporation with the Solid State Electrochemistry and Electroceramics Laboratory group. Thermodynamic and field driven diffusion of oxygen in oxides by isotope labeling experiments.

Molecular and Elemental Imaging of Bio Samples: Tissue Samples, Single Cells MEI-Bio

Corrosion in Semiconductor Devices: Investigated with Cyclic Voltametry, Impedance Spectroscopy, REM, TEM in cooperation with Infineon Technologies Austria AG and KAI Kompetenzzentrum Automobil- und Industrie-Elektronik GmbH. supervised by Prof. Linhardt.

Investigation of mobile ion diffusion in semiconductor devices: Bias-temperature stress tests, Impedance Spectroscopy, Advanced Materialdesign in cooperation with Infineon Technologies Austria AG and KAI Kompetenzzentrum Automobil- und Industrie-Elektronik GmbH.