Proton beam writing nanoprobe facility design and first test results

A second generation proton beam writing line has been installed at the Centre for Ion Beam Applications at the National University of Singapore. This system features a high demagnification lens system based on compact OM52 lenses with reduced working distance. The system can operate in a variety of high demagnification configurations, including the spaced Oxford triplet and the double-crossover Russian quadruplet. It features an electrostatic scanning system and a new collimator slit aperture design. Here we present the first results with this system operating in a spaced Oxford triplet configuration with a beam focus in one direction down to 20 nm. One of the limitations of the current system is the inferior quality of the high-voltage supply driving the electrostatic scanning system. The second focus of this paper is the performance of the new collimator slit aperture design for MeV nanoprobe forming systems. Cylindrically strained electroplated Ni surfaces with a bending radius of 50 mm are used as slit edges. An incident molecular beam of 2 MeV H2+ ions was used for the slit scattering measurements. Any scattering by the slits resulting in dissociation of the incident molecular beam into 1 MeV protons facilitated the measurements of scattered and non-scattered components by the passivated implanted planar silicon (PIPS) detector. The studies showed the expected correlation between the aperture size and scattering. The quality of the beam was satisfactory even for small aperture dimensions with a very small percentage of the beam showing energy loss.