  In order to build a new concept of photomultiplier based on silicon
technology, design and characterization of 5x5 arrays of a new generation of
single photon avalanche diodes (SPAD) manufactured by ST-Microelectronics have
been performed. Single photons sensitivity, dark noise and timing resolution of
the SPAD- STM devices in several experimental conditions have been evaluated.
Moreover, the effects arising from the multiple integration of many elements
and the study of their common read-out have been deeply investigated.
