Summary report of generic R&D projects and evaluation of the approach eXflu-innova project

State-of-the-art silicon sensors can operate efficiently up to fluences of 1E16/cm². Future frontier accelerators envision the use of tracking detectors in environments with fluences exceeding 1E17/cm². If not overcome, this gap will limit the use of silicon sensors in future hadron-collider experiments. The Thin Silicon Sensors for Extreme Fluences – eXFlu-innova blue-sky project goal is to extend the silicon detector range of operation by more than one order of magnitude, up to fluences of ~1E17/cm².

The Low-Gain Avalanche Diode (LGAD) technology is used to overcome the present limitations in the radiation tolerance of silicon detectors. This is achieved by designing a gain implant able to withstand a factor of 50 higher fluences than what is presently available. In a standard LGAD, the active doping density of the gain implant (p-doped) decreases with irradiation due to the process of acceptor removal. In the eXFlu-innova design, referred to as compensated LGAD, the effective doping of the gain implant is obtained by combining a p-doped and a n-doped implant. The resulting compensation yields an effective doping profile equivalent to that of standard LGADs, while offering enhanced radiation hardness.

To reach the goal, the project focuses on three deliverables:

[D1]    Simulation and design of the p–n compensated gain implant, to determine the optimal production parameters to fabricate compensated LGAD.

[D2]    Production of p–n compensated LGAD sensors, as a proof-of-concept of the technology, and n-doped sensors (NLGADs), to investigate donor removal in a simpler environment, crucial to properly design future productions of compensated LGADs.

[D3]    Identifications of the best parameters to manufacture compensated LGADs.

The main results and achievements of the eXFlu-innova project are reported here.