Efficiency and time resolution of monolithic silicon pixel detectors in SiGe BiCMOS technology

A monolithic silicon pixel detector prototype has been produced in the SiGe BiCMOS SG13G2 130 nm node technology by IHP. The ASIC contains a matrix of hexagonal pixels with pitch of approximately 100 μm. Three analog pixels were calibrated in laboratory with radioactive sources and tested in a 180 GeV/c pion beamline at the CERN SPS. A detection efficiency of (99.9$_{-0.2}$ $^{+0.1}$)% was measured together with a time resolution of (36.4 ± 0.8) ps at the highest preamplifier bias current working point of 150 μA and at a sensor bias voltage of 160 V. The ASIC was also characterized at lower bias voltage and preamplifier current.