Speaker
Description
Thin Low Gain Avalanche Detectors (LGADs) are among the most promising sensors for precision timing applications in the High-Luminosity Large Hadron Collider (HL-LHC) era. Owing to their intrinsic charge-multiplication capability, thin LGADs can achieve timing resolutions of ~15 ps even under high pile-up and intense-radiation conditions. However, measurements have shown that the gain of the LGADs progressively degrades with increasing irradiation fluence, mainly due to acceptor removal in the gain layer. Therefore, robust device modelling and optimization are essential to ensure reliable operation of LGADs in future harsh hadron collider environments.
Recent results from our group have demonstrated that the two-trap neutron radiation “DELHI” model can be successfully extended to thick (300 μm) LGADs within the Silvaco TCAD framework by separately tuning the impact ionization parameters for different irradiation fluences, together with gain layer degradation modelling and two-level bulk neutron damage model. In the present work, we extend and refine this approach for thin LGADs by implementing the DELHI radiation damage model along with gain layer degradation modelling, while employing a more effective radiation-fluence based impact-ionisation framework rather than independently tuning the ionisation parameters for each irradiation condition. This provides a more consistent and predictive modelling strategy for irradiated LGAD operation.
Using measurements from the thin LGADs, this study aims to reproduce the electrical characteristics of non-irradiated and irradiated devices, including capacitance–voltage (C–V), current–voltage (I–V), and gain–voltage behaviour. The overall objective is to establish a reliable Silvaco-based simulation framework for thin LGAD optimization, which can be used to guide and improve future device designs.