Design of Low Gain Avalanche Detectors (LGAD) with 400 keV ion implantation energy for multiplication layer fabrication

Low Gain Avalanche Detectors (LGAD) are silicon sensors that can achieve a time resolution of 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) has recently developed two versions of LGAD sensors. The LGAD sensors were designed using Technology Computer-Aided Design (TCAD) simulations and optimized to obtain high breakdown voltage and a suitable gain. The n-type Junction Termination Extension (N-JTE) and p-type gain layer are two critical structures for LGAD sensors that were investigated. IHEP has tuned the fabrication process of two foundries to obtain the most promising design. The first version of the IHEP LGAD sensor, with a gain higher than six and breakdown voltage higher than 400 V, was submitted to Tianjin Zhonghuan Semiconductor Company for fabrication. The second version of the LGAD sensor benefits from the higher implantation energy available at the Institute of Microelectronics (IME) to reach a gain higher than ten and breakdown voltage higher than 420 V.