Design, fabrication and characterization of 8x9 n-type silicon pad array for sampling calorimetry

Abstract This paper reports the development and testing of n-type silicon pad array detectors intended for the Forward Calorimeter (FoCal) detector, which is an upgrade of the ALICE detector at CERN, scheduled for data taking in Run 4 (2029–2034). The FoCal detector will consist of a hadronic and an electromagnetic calorimeter. The electromagnetic part is made up of alternating tungsten absorber and silicon detector layers, read out using the High Granularity Calorimeter Readout Chip (HGCROC). This paper covers the various processes involved in the design, fabrication and testing of the detector. The current vs voltage (IV) measurements showed that 90% of the pads in the detector had leakage current below 10 nA, and capacitance vs voltage (CV) measurements determined the full depletion voltage, consistent with the design simulations. The detector's performance was tested with an LED light source and a 90 Sr β - electron source. Furthermore, radiation harness studies were performed on 1 × 1 cm 2 pads with a neutron fluence of 5 × 10 13 1 MeV n eq /cm 2 .