ELECTRICAL CHARACTERIZATION OF SiPM AS A FUNCTION OF TEST FREQUENCY AND TEMPERATURE

Silicon Photomultipliers (SiPM) represent a promising alternative to classical photomultipliers for the detection of photons in high energy physics and medical physics, for instance. In the present work, electrical characterizations of test devices - manufactured by STMicroelectronics - are presented. SiPMs with an area of 3.5 × 3.5mm² and a cell pitch of 54 μm were manufactured as arrays of 64 × 64 cells and exhibiting a fill factor of 31%. The capacitance of SiPMs was measured as a function of reverse bias voltage at frequencies ranging from about 20 Hz up to 1 MHz and temperatures from 310K down to 100 K. Leakage currents were measured at temperatures from 410 K down to 100 K. Thus, the threshold voltage - i.e., the voltage above a SiPM begins to operate in Geiger mode - could be determined as a function of temperature. Finally, an electrical model capable of reproducing the frequency dependence of the device admittance is presented.