Advanced Back-Illuminated Silicon Photomultipliers With Surrounding P+ Trench

Abstract

This study conducted the TCAD simulation of an advanced back-illuminated silicon photomultipliers (BI-SiPM) device. This BI-SiPM structure with pixels was surrounded by a p+ trench, which conducted the p+ implant region available on the surface toward the back side. The removal of the metal layer from the incident SiPM surface reduced the blocking of incident light and improved the fill factor of single pixels. Therefore, the photon detection efficiency of BI-SiPM was improved to approximately 70% when the bias voltage was 5 V. The TCAD device simulations were performed to study this BI-SiPM structure, and the quenching process based on Mixedmode emulator was investigated to introduce the BI-SiPM pixel structure into a SPICE circuit. The results indicated that the proposed design could improve the uniform distribution of the electric field and avalanche triggering probability on a photon illuminating surface and increase <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">FF</i> , without affecting the crosstalk between pixels. Moreover, the design consideration of manufacturing process flow for BI-SiPM was proposed.