Radiation damage study of a p-type silicon sensor under extreme particle fluence

Abstract

We investigate the radiation tolerance of p-type silicon pad sensors, indigenously developed for use in high-fluence environments relevant to heavy-ion collider experiments, cosmic-ray observatories, and deep-space missions. Single-pad test structures were irradiated with neutrons over a range of fluence, and post-irradiation performance was characterized. The evolution of leakage current and the calorimetric response of the devices were systematically analyzed as functions of accumulated neutron fluence. In addition, we introduce a simple exponential-annealing model that predicts the time dependence of leakage current after irradiation. The measurements and model together quantify performance degradation and recovery trends, providing guidance for the design and operation of silicon-based calorimetry in harsh radiation environments.

Figures (9)

• Figure 1: The schematic of the final mask used for the fabrication of the large area pad sensor array. The test structures used for irradiation study are highlighted in red dashed borders.
• Figure 2: (Left)Schematic of the neutron irradiation facility at IPR. Actual placement of a test sensor during the irradiation test is shown in the inset figure.
• Figure 3: The leakage current as a function of reverse bias voltage corresponding to each test sensor. The planned irradiation dose for each is mentioned in legend.
• Figure 4: I-V characteristics after irradiation for different sensors. The number of days elapsed since irradiation are mentioned in the legend. For the sensor with higher irradiation dose, their current levels before irradiation are shown as insets with bias voltage measured in Volts(V) and leakage current measured in micro amperes($\mu A$).
• Figure 5: Leakage current (at 300 V) as a function of time after irradiation for the test sensors.