Development of Monolithic Multi-Element Silicon Drift Detectors

In this study, a monolithic multi-element silicon drift detector (mxdCMOS) was developed utilizing the Silicon-on-Insulator (SOI) technology, specifically designed for high count-rate measurement in synchrotron radiation X-ray spectroscopy. The fabricated chip, measuring 12.4 mm × 18.5 mm, integrates 30 Silicon Drift Detector (SDD) elements, each with an area of 1.8 mm × 1.8 mm. This study successfully demonstrated that each element operates at a count rate exceeding 1 Mcps, achieving a linear response up to 30 Mcps and a saturation throughput of 75 Mcps per chip. This performance surpasses the limits of conventional single-element SDDs, which typically saturate at the 1 Mcps level, and represents one of the highest rates among existing multi-element systems. By employing digital signal processing with a short peaking time of 130 ns, an energy resolution of 170 eV (Full Width at Half Maximum at 5.9 keV) was achieved. This unprecedented count-rate capability offers significant advantages for applications requiring high-throughput, such as fluorescence-yield Quick X-ray Absorption Fine Structure (XAFS) and high-speed elemental mapping using high-brilliance synchrotron X-ray beams. The monolithic integration of the detector array and readout electronics resolves conventional issues related to external amplifier connections, such as noise and wiring capacitance.