SiPM from ST-Microelectronics Nepomuk Otte & Hector Romo Santa Cruz Institute for Particle Physics University of California, Santa Cruz

Main Characteristics (Module H) 3 samples packaged in TO-39 cans The devices belong to the lot Y745439, Wafer 3 The SiPM has the following characteristics:  1 mm 2 total area (excluding metal pads)  n-on-p device  289 (17 x 17) pixels ( 60 µm pitch)  40 µm single pixel active area side (45% geometrical fill factor)  Single pixel quenching resistor value about 1.3 MΩ  Optical insulation to avoid optical cross-talk effects between adjacent pixels Info from ST Microelectronics Thanks to Massimo Mazzillo for samples

Anode Cathode Array Area: 1 x1 mm2 (excluding metal pads) Chip size: 4.37 x 4.37 mm2 Layout Mod H

Measurements with Noise: Gain derived from average single cell amplitude assumption of triangular pulse shape Procedure: single cell signals: 4 ns full width symmetric Temperature: 0°C Gain effective capacitance of single cell: C eff =ΔQ/ΔU ~ 15fF ΔUΔU ΔQΔQ breakdown voltage: extrapolation to zero gain U break =29.3 V Operational range: 30V-40V >30% above breakdown

Gain/Breakdown/Capacitance vs. 35V parameters from linear fit of gain vs. bias measurements change of gain 0.5% per 1°C ! 0.1% per 1°C breakdown voltage eff. cell capacitance uncertainty ~ 5%

Dark Rates discriminator set to < single cell signal Sensor area: 1mm² Dark rate: 0°C: rate doubles every 2 Volts or rate doubles if gain increases by 2·10 5

Dark Rates vs. Temperature factor 2 change per 12°C factor 2 change per 5°C Gain ~ 500,000

Measurements with Noise: Optical Crosstalk direct and indirect (delayed by max 20 ns) optical crosstalk 1 phe 2phe + extra dark counts naively expect change equal to relative change of gain but optical crosstalk increases faster  probably due to increased breakdown probability  nice task to simulate with SiSi

Optical Crosstalk vs. Temperature 3% optical crosstalk rise above 20°C can be explained by additional darkcounts e.g.: 2 25°C & 20ns gate 4% probability for additional dark count groves ! 0.8 µm wide, 8 µm long IEEE PTL, VOL. 18, NO. 15, 2006

Photon Detection Efficiency Yeah, if only I would know the PDE. packaging complicates mounting into our setup but we will fix this next Otherwise: good gain vs. temperature dependence (0.5% / °C) large bias range (30V-40V) good dark rate behaviour fast signals 3x3 mm² devices in the pipeline probably green sensitive (n-on-p) IEEE TED, VOL. 55, NO. 10, 2008