Optimization of capacitive coupled Low Gain Avalanche Diode (AC-LGAD) sensors for precise time and spatial resolution

TL;DR

This paper presents optimized fabrication parameters for AC-LGAD sensors to achieve high spatial and temporal resolution, high detection efficiency, low cross talk, and radiation tolerance for particle physics and light detection applications.

Contribution

It introduces specific fabrication optimizations for AC-LGAD sensors to enhance their spatial, temporal, and radiation performance, including new insights into doping and insulator capacitance effects.

Findings

Achieved ~10 μm spatial resolution and 30 ps time resolution.

Detection efficiency exceeds 99% at a 10^{-4} fake rate.

Demonstrated radiation tolerance and potential for visible and IR light detection.

Abstract

Capacitive-coupled Low-Gain Avalanche Diode (AC-LGAD) sensors are being developed for high-energy particle physics experiments as a detector which provides fast time information with fine spatial resolution. This paper describes optimizations of AC-LGAD sensor fabrication parameters, such as doping concentrations of the gain and electrode layers as well as the AC insulator capacitance, to realize $\mathcal{O}$(10)~\um{} spacial resolution, small charge cross talk to the neighboring electrodes, detection efficiency higher than 99\% at a 10$^{-4}$ fake rate and time resolution of about 30~ps. The radiation tolerance of the sensor is presented. In addition, further application to a device capable of visible and infra-red light detection is discussed.