Combined use of a field-plate and narrow p-barriers for a wide-pitch ohmic-side readout of the BELLE double-sided SVD

We explored wide-pitch ohmic-side structures for the BELLE SVD, where we proposed a field-plate structure combined with narrow p-barriers in between the readout electrodes of 90, 113, 180, and 226 μm-pitch detectors. The effect of the p-barriers was studied with a numerical model to trace the carrier trajectories. The charge collection and sharing properties were examined in practice for prototype small-size detectors with an IR pulse shining from either the junction side or the ohmic side. The channel separation capabilities were also shown to be appropriate under nominal operation conditions.