First results on NUV-SiPMs at FBK

In this paper we show selected results on the first release of Near Ultra Violet SiPM technology (NUV-SiPM) produced at FBK. In particular, we focus our attention on the photo-detection efficiency (PDE) performance. The PDE in the near-UV part of the light spectrum is mainly limited by the quantum efficiency term since the photo-generation takes place in a very shallow region of the silicon. Thus, besides using a p+-on-n junction configuration to have an avalanche triggered by the electrons, we need to implement a very shallow p+ layer. In this context, we will show that our NUV-SiPM technology features a quantum efficiency higher than 80% in the measured range between 360 and 420 nm. This allows to reach a PDE of about 30% at 9 V over-voltage on a SPAD featuring 50 × 50 μ m 2 cell size and 45% fill factor. We will also show other important features of the device such as noise, breakdown voltage temperature dependence and single-cell response uniformity to prove its functionality.