Project 12 (Tofwerk)

Title: Laser-assisted GD sputtering for spectrochemical imaging

Researcher: Giovanni Lotito (ESR)

Coordinator: TOFWERK AG, Thun Switzerland; Other partners: AQura, JFC

Responsible scientist: Katrin Fuhrer

State of the Art:

Currently the Tofwerk GD-TOF does not have the possibility for imaging, only for depth profiling.  This allows for recoding of 3 dimensional data when operating in pulsed Glow Discharge mode (depth, pulse, m/q).  Many SIMS (secondary ion mass spectrometer) allow for imaging, e.g. the recording of chemical images.  This allows for the analysis of small structures as well as inhomogeneous samples. LAMS (laser ablation mass spectrometer) with post ionisation by glow discharge has been published.  A laser is used to desorb material from a surface and a GD plasma is used for post ionisation of the desorbed material.

Project:

In this thesis work a laser will be used to either locally assist GD sputtering or for pure laser ablation.  By rastering the laser across the sample surface, image information will be recorded.  Mathematical methods will be used for recreating the chemical image.  This will result in 4D data (spatial-x, spatial-y, spatial-depth, m/q) or even 5D data when using pulsed GD. To our knowledge there is no commercial instrument with of this type on the market and to our knowledge there is also no research instrument.

About the ESR: Giovanni Lotito performed his diploma and master studies at the university of Rome "La Sapienza" where he graduated getting the master of science in Physics. He performed his master thesis working on the realisation of nano-electrodes for molecular electronics at an Italian research centre ENEA- Casaccia near Rome. One of the techniques he used to fabricate the nano-electrodes was the pulsed laser ablation. He decided to join the GLADNET project because this is a great opportunity to grow and learn in an international environment.