Proton-energy dependent damage to Si sensors

Silicon bulk damage is the limiting factor of detector lifetime for future HL-LHC experiments. Nowadays, the knowledge of radiation-induced bulk defects and their effects on the sensor properties are especially limited after proton irradiation. Therefore, 200 μm silicon pad-sensors (n- and p-type bulk materials: FTH, MC and dd-FZ) were irradiated with 23 MeV, 188 MeV and 23 GeV protons (with Φ_neq ≤3.10¹⁴ cm^-2). I-V, C-V-f and TSC measurements were performed at subsequent annealing steps at 353 K. In particular, the main experimental challenges will be addressed regarding the TSC filling temperature (at T=10 K) and filling forward current (I∼1 mA). The TSC spectra are analyzed with a revisited SRH statistics, modified to account for defect clusters after hadron irradiation. A proton-energy dependent introduction of defects is found, except for deep cluster-related defects. Shallow defects are present in different concentrations according to the material type. A correlation is notable between the leakage current and the concentrations of three deep defects (the V2, E5 and H(220 K) defects). Other defects affect the space charge, with positive contributions from e.g. the E(30 K) and BiOi defects, or negative contributions from deep acceptors (namely the H(116 K), H(140 K) and the H(152 K)). This information is exploited as input for a physics-based and measurement-driven radiation damage model.