Cluster ion beams enable depth profiling analysis of polymers with minimal loss of chemical information due to ion beam damage. This is crucial in analysis of modern multi-layer structures, such as in OLED and OPV devices, but also shows a marked improvement in analysis of well-established materials.
Ions are generated in the ion source by a 2-stage process. Firstly, argon clusters are formed by the adiabatic expansion of argon gas through a nozzle, starting at high pressure and passing into a region which is pumped to low vacuum. Then, passing through skimmer apertures into the next vacuum stage, the clusters enter an ionization chamber and they are ionized by electron bombardment. The cluster ions are accelerated into an ion column which contains a Wien filter, a gate valve (for isolating the source from an instrument during maintenance), a bend to remove neutrals, scan plates and a final focussing lens. The Wien filter can select single cluster sizes for the small clusters; for the larger clusters the beam consists of a mass distribution around the nominal cluster size.
The GCIB 10S system comprises:
- Ion source, with cluster generation and ionization chambers
- Ion optical column, including a mass filter
- Two turbo pumps, two backing pumps, gauge, pipework, and controllers
- Power supply units and interface software to drive the ion source and column
The GCIB 10S can be installed on a wide range of instruments, the main requirement being a NW63CF flange aiming at the sample. A selection of supports are available to relieve strain on the instrument flange where necessary. Installation packages already developed include ones for:
- Kratos Axis Ultra
- Phi ESCA 5400
- Omicron ESCA Multiprobe
- VG ESCA LAB 220i
- Zeiss ULTRA SEM