Speaker
Description
AC-coupled Low Gain Avalanche Diodes (AC-LGADs) are a silicon detector technology capable of simultaneous micrometer-scale position resolution and picosecond-level timing, making them attractive for 4D particle tracking in high-energy physics. The spatial performance of AC-LGADs is strongly influenced by lateral charge spreading within the n-type resistive surface layer, yet systematic studies of how resistive layer depth affects detector behavior remain limited.
We present a comparative characterization study of AC-LGAD sensors fabricated at Brookhaven National Laboratory (BNL) with a deep and a deeper n-resistive layer variant. Current-voltage (IV) and capacitance-voltage (CV) measurements establish the electrical operating characteristics of the functional sensors. Signal response measurements using Transient Current Technique (TCT) with a 1024 nm IR laser and a multichannel readout board designed at Fermilab characterize charge collection and pulse-shape properties.
This work is ongoing; additional sensors, including standard-process LGADs for baseline comparison, are being prepared for wirebonding and characterization. Results to be presented include the electrical characterization of the working sensors, a comparison of signal response across design variants, and an interpretation of findings as design guidance for future AC-LGAD fabrication targeting 4D tracking applications
