Preliminary results on the timing response of CMOS LGADs for the ALICE 3 experiment

The next generation of high-energy physics experiments demands dedicated R&D to meet increasingly stringent requirements. In this context, the proposed ALICE 3 experiment at the Large Hadron Collider, scheduled to start data taking in 2036 (Run 5), aims to achieve excellent particle identification capabilities, with a dedicated silicon pixel time-of-flight detector targeting a time resolution of about 20 ps. To this end, traditional LGADs with different thicknesses have been tested, demonstrating the possibility to meet the ALICE 3 requirements for thinner sensors. However, a monolithic approach would simplify production and reduce costs by integrating the sensor and readout electronics into a single substrate. In this contribution, the main results and future outlook for the development of LGAD in CMOS technology (CMOS-LGAD) are presented. The first prototypes produced within the INFN ARCADIA project, were characterized in the laboratory using a laser source to estimate the contribution of electronic jitter to the overall time resolution; this contribution is about 40 ps, but it decreases to 22 ps in a higher power consumption configuration. Initial tests with charged particle beams have demonstrated the possibility of achieving time resolutions of 75 ps and a global efficiency larger than 95%.