Radiation damage study of a silicon PIN diode and signal-to-noise ratio measurement with a proton beam

We designed and fabricated silicon PIN diodes on a 5-in. high resistivity (>5 kω-cm), (100)-orientation, n-type 380 μm-thick silicon wafer and developed a diode with an active area of 1.0 × 1.0 cm². The signal-to-noise ratio (SNR) of the PIN diode with the 45-MeV proton beam of the MC-50 cyclotron at the Korea Institute of Radiological and Medical Sciences (KIRAMS) was measured to be 20.8 after being corrected for the minimum ionizing particle. The silicon diode was also exposed to the proton beam for the radiation damage study. The leakage currents of the silicon diode as a function of the reverse bias voltage were measured with a picoammeter before and after the proton beam irradiation. In this paper, we present an explanation of the radiation-induced detector deterioration and the SNR measurement for the manufactured silicon diode.