Study of the Dependence of Silicon Sensor Signal on Effective Thickness

The silicon PIN diode sensor is widely utilized for radiation detection. Exposure of the silicon sensor to excessive radiation may lead to damage in the sensor, consequently causing an increase in the sensor’s leakage current. This elevated leakage current results in the sensor being operated at a lower bias voltage. The signal of the PIN diode sensor directly relies on the effective thickness, commonly known as the depletion depth, which is determined by the bias voltage. Therefore, it is crucial to investigate the signal’s dependence on the bias voltage and, consequently, on the effective thickness. We present the measurement of the capacitance of a PIN diode sensor as a function of the bias voltage to determine the dependence of the effective thickness on the bias voltage. We also present the measurement of the signal dependence of the sensor on the bias voltage and the effective thickness using a β-ray source. Finally, we compare the two measurements to validate the signal dependence of the sensor on the bias voltage and, consequently, the effective thickness.