Thanks to the steady improvement in the detectors' performance, single-photon techniques are nowadays employed in a large number of applications ranging from single molecule dynamics to astronomy. In particular, silicon Single Photon Avalanche Diodes (SPAD) play a crucial role in this field thanks to their remarkable performance in terms of Photon Detection Efficiency (PDE), temporal response and Dark Count Rate (DCR). While CMOS technology allows the fabrication of large arrays of SPAD with built-in electronics, it is only resorting to custom fabrication processes that is possible to attain detectors with high-end performance required by most demanding applications. However, the fabrication of arrays for timing applications, even with a small number of pixels, is quite challenging with custom processes owing to electrical coupling between pixels. In this paper we will discuss technological solutions for the …