Design and fabrication of Low Gain Avalanche Detectors (LGAD): a TCAD simulation study

Abstract

Low Gain Avalanche Detectors (LGAD) are silicon sensors with a time resolution better than 20 ps. The ATLAS and CMS experiments are designing LGAD detectors to address the pile-up challenge at the High Luminosity-Large Hadron Collider (HL-LHC) . The Institute of High Energy Physics (IHEP) High-Granularity Timing Detector group has recently developed its first version of LGAD sensors. The LGAD structure was designed using Technology Computer-Aided Design (TCAD) simulations and optimized to obtain a high breakdown voltage and ideal gain. The n-type Junction Termination Extension (N-JTE) zone is a critical structure to guarantee a high breakdown voltage. The gain layer is optimized for an ideal gain factor and hence good time resolution. The optimized LGAD sensor has a gain higher than six and a breakdown voltage higher than 400 V.