Prototype development of an AC-coupled pad matrix detector

We designed and fabricated AC-coupled single-sided silicon pad matrix sensors in a 5-inch fabrication line, and developed the signal readout electronics system. The fabricated sensor is fully depleted below 60 V and the leakage current at operating voltage is measured to be ~ 40 nA/cm². Measurements of the coupling capacitance and bias resistance of the sensor show uniformity in their values. The analog signal from the silicon sensor is processed by VATA ASIC chip as frontend electronics. The linearity of the VATA is measured to be good and the signal-to-noise ratio is about 10, which needs the Minimum-Ionizing-Particle (MIP) correction. The phantom image with a Cu foil is also obtained with the fabricated matrix sensor.