Timing resolution improvement of MPPC for TOF-PET imaging

Abstract

Large detection area and good timing resolution of Silicon Photomultiplier (SiPM) based scintillation detectors is required for TOF-PET imaging. Achieving good timing requires output pulse uniformity on each microcell to be good; this depends on minimizing the gain, the recovery time, the trace impedance variation, etc. A double metal trace, a metal resistor and a new structure were applied to produce uniform characteristics on a single Multi-Pixel Photon Counter (MPPC) channel. The resulting time resolution has been improved to 140 ps for approximately 10 photons irradiation and an overvoltage of 2.5 V on a 6×4 mnl single channel MPPC test pattern. Furthermore afterpulse probability has been dramatically suppressed to a typical value of 3% by applying new silicon wafers and new process conditions.