  Major advances in silicon pixel detectors, with outstanding timing
performance, have recently attracted significant attention in the community. In
this work we present and discuss the use of state-of-the-art Geiger-mode APDs,
also known as single-photon avalanche diodes (SPADs), for the detection of
minimum ionizing particles (MIPs) with best-in-class timing resolution. The
SPADs were implemented in standard CMOS technology and integrated with on-chip
quenching and recharge circuitry. Two devices in coincidence allowed to measure
the time-of-flight of 180 GeV/c momentum pions with a coincidence time
resolution of 22 ps FWHM (9.5 ps Gaussian sigma). Radiation hardness
measurements, also presented here, highlight the suitability of this family of
devices for a wide range of high energy physics (HEP) applications.
