Proton Beam Writing

Instrumentation

Accelerators

The MeV proton source, and the layout of the prototype writer at CIBA.

At the present time, there are no commercial proton beam writers available: The first working prototype has been constructed in the Centre for Ion Beam Applications (CIBA), Physics Dept, National University of Singapore.

The layout of the prototype proton beam writer at CIBA is shown in figure 1. An ion accelerator produces a beam of MeV protons, which are then passed through an object aperture. A lens system focuses the beam down to small spot sizes, and using a scanning system the beam is scanned over the sample in a predetermined shape as controlled by the proton beam writing software. The exposed sample is then developed using a suitable chemical developer to realise 3D structures.

The accelerator used in the proton beam writing prototype in CIBA is the HVEE 3.5 MV ‘Singletron’ accelerator, which also feeds the CIBA proton microscope, and the CIBA high resolution advanced materials characterization facility.

Schematic of a proton beam writer: accelerator, object aperture, lens system, scanning system and sample.
Figure 1. Schematic diagram of a proton beam writer.