Characterization of an Ion Beam for Quantum Applications Using the ARCADIAMD3 Fully-Depleted CMOS Monolithic Sensor

This work explores the potential of monolithic CMOS sensors as position-sensitive detectors with possible applications in quantum technologies. Single-photon sources are essential for quantum communication and computation and can be produced by introducing controlled defects into crystal lattices (e.g., silicon or diamond) using focused ion beams. However, achieving deterministic control over these implantation processes remains a major challenge. It is therefore particularly important to precisely characterize the ion beam in terms of intensity and spatial distribution. This becomes especially challenging when using low-energy, low-intensity beams. To tackle this challenge, we employed the ARCADIA-MD3 ASIC, developed by the INFN ARCADIA collaboration mostly for high-energy physics applications. The chip features a 512×512 pixel matrix with a 25μ m pitch on a 1.28×1.28 cm2 active area, operates at low power (10 mW⋅ cm−2), and supports scalable readout architecture. It was tested at the LiuTo ion implantation facility at the University of Turin using proton beams with energies down to 17 keV. Despite not being specifically optimized for this application, MD3 successfully enabled the visualization of the ion beam profile through the use of patterned masks of various sizes and geometries. It also allowed for real-time measurement of the particle rate incident on the sensor, demonstrating its suitability for monitoring and characterizing low-energy beams at the single-ion level. Future work will focus on enhancing spatial resolution and exploring the integration of analog charge readout to support real-time monitoring during beam preparation for deterministic defect creation processes for quantum device fabrication.