Speaker
Description
To meet the stringent requirements of the High Luminosity LHC (HL-LHC) upgrade, the ATLAS inner tracker (ITk) requires silicon sensors with exceptional radiation hardness and maximized geometrical efficiency. Active edge technology is essential to minimize inactive peripheral areas; however, accurately predicting their behavior under extreme radiation remains a challenge. This work presents a novel 3D TCAD simulation framework developed with Silvaco™ to perform a comprehensive comparative analysis of various active edge n-on-p planar pixel sensor structures. Unlike conventional 2D modeling, these advanced 3D simulations provide a precise evaluation of the localized electric field distributions and charge transport mechanisms at the sensor boundaries. The methodology incorporates a refined three-level trap model for p-type FZ silicon, calibrated with experimental doping profiles from Secondary Ion Mass Spectrometry (SIMS). The radiation-induced degradation is investigated for fluences exceeding $2 \times 10^{16} \text{ n}_{eq}/\text{cm}^2$, pushing the study into the high-radiation regime expected for future tracker layers. Key results focus on the impact of different edge geometries on breakdown voltage stability, leakage current evolution, and Charge Collection Efficiency (CCE). The 3D analysis reveals critical insights into charge loss mechanisms and field enhancements that are often underestimated in 2D models. By comparing multiple design iterations, this study identifies the most robust active edge configurations for high-fluence environments, providing crucial guidelines for the optimization of next-generation planar pixel sensors in high-energy physics experiments.