Speaker
Description
Doping removal—whether acceptor or donor—is a well-known effect of radiation damage in silicon detectors, and has been extensively characterized at the low doping levels typical of conventional silicon substrates. The development of Low Gain Avalanche Diode (LGAD) technology has pushed detailed studies of acceptor removal at high initial concentrations ($> 10^{16}$ at/cm$^3$). With the emergence of advanced LGAD designs such as NLGAD, resistive LGADs, and compensated LGADs, a systematic investigation of donor removal at similar concentrations is now essential for further device optimization.
In this contribution, we present a novel methodology for quantifying doping removal by analyzing irradiation-induced variations in sheet resistance measured with van der Pauw test structures. This method is applied to both shallow and deep doping profiles—acceptor and donor types—from NLGAD, resistive, and compensated LGAD batches manufactured by Fondazione Bruno Kessler (FBK). Validation is performed through TCAD simulations calibrated with Secondary Ion Mass Spectrometry (SIMS), demonstrating a nearly two-fold faster removal of donors compared to acceptors.