Speaker
Description
While the acceptor removal mechanism in standard n-in-p Low-Gain Avalanche Diodes (LGADs) is well understood and recognised as a key factor limiting their operational lifespan, the emergence of next-generation LGADs, such as resistive (RSDs) and compensated LGADs, calls for a deeper investigation into the donor removal mechanism, particularly at high initial donor concentrations (ND > 1016 atoms/cm³).
In this contribution, we present pre- and post-irradiation results from a novel LGAD batch with an n-type doped gain implant on an n substrate (NLGADs), developed by Fondazione Bruno Kessler (FBK, Italy). These results offer new insights into donor removal, facilitating optimisation of RSD and compensated LGAD designs. Furthermore, this work introduces a novel characterisation method of dopant removal, based on sheet resistance measurements using van der Pauw structures, rather than traditional capacitance-based approaches.
Therefore, we will present comparative measurements and simulations for test structures and sensors from AC-LGAD (or RSD), DC-RSD, compensated LGAD, and NLGAD batches, highlighting the correlation between resistance- and capacitance-based removal assessments and their potential as characterisation tools for donor and acceptor removal. Preliminary data indicate a stronger donor removal coefficient compared to the acceptor removal coefficient. The upcoming results will be detailed in the final paper.
