Picosecond Avalanche Detector — working principle and gain measurement with a proof-of-concept prototype

Abstract The Picosecond Avalanche Detector is a multi-junction silicon pixel detector based on (NP) drift gain structure, devised to enable charged-particle tracking with high spatial resolution and picosecond time-stamp capability. It uses continuous junction deep inside the sensor volume amplify primary charge produced by ionizing radiation in thin absorption layer. signal then induced secondary charges moving thicker region. A proof-of-concept monolithic prototype, consisting of matrix hexagonal pixels 100 ?m pitch, has been using 130 nm SiGe BiCMOS process IHP microelectronics. Measurements probe station 55 Fe X-ray source show that prototype functional displays avalanche up maximum electron 23. study characteristics, corroborated TCAD simulations, indicates space-charge effects due large conversion X-rays from ^55Fe limits effective gain.