Multi level RTS in proton irradiated CMOS image sensors manufactured in deep submicron technology

A new automated method able to detect multi level random telegraph signals in pixel arrays and to extract their main characteristics is presented. The proposed method is applied to several proton irradiated pixel arrays manufactured using a 0.18 μm CMOS process dedicated to imaging. Despite the large proton energy range and the large fluence range used, similar exponential RTS amplitude distributions are observed. A universal mean amplitude is extracted from these distributions and the number of RTS defects appears to scale well with total NIEL. These conclusions allow the prediction of RTS amplitude distributions. The effect of electric field on RTS amplitude is also studied and no significant relation between electric field and RTS amplitude is observed.