Compensated LGAD — an innovative design of thin silicon sensors for very high fluences

This contribution presents a new development of radiation-resistant silicon sensors based on Low Gain Avalanche Diode (LGAD) technology, combined with 30 μm-thick substrate, intrinsically less affected by radiation. The key feature of LGAD technology is its internal gain, which generates large and fast signals, suitable to track temporally charged particles with excellent time precision (∼30 ps). An innovative design of the multiplication layer has been developed and fabricated, exploiting the compensation of acceptor and donor dopants, to recreate the effective acceptor gain implant of standard LGAD technology. The proof of concept of compensated LGADs was produced by Fondazione Bruno Kessler, at the end of 2022. In this contribution, more relevant characterization measurements on first irradiated prototypes of compensated LGADs, in the presence of external stimulus by particle beam for signal generation, will be presented and discussed. The compensated LGAD technology has the ultimate goal to operate in radiation environments where the irradiation fluence will exceed 10^17 n_eq/cm^2, maintaining the time-tracking capability of standard LGAD sensors.