Impact Of Ion Irradiation On Bipolar Junction Transistors: Mechanisms Of Degradation And Implications For Radiation-Resilient Electronic Systems

Abstract

This paper presents a comprehensive investigation into the radiation-induced effects on bipolar power transistors, focusing on indigenously manufactured n-p-n BJTs of type 2N 3866, 2N 3055, and 2N 6688 by BEL, Bangalore, India. The research underscores the imperative of assessing radiation response before integrating domestically produced devices into circuits intended for operation in radiation-intensive environments, especially considering the escalating demand for indigenous components in space and radiation-rich applications. The selected transistors, recognized for their roles in amplification and switching, are subjected to irradiation with various ion species, including 50 MeV lithium, 60 MeV boron, 108 MeV oxygen, 110 MeV silicon, and 120 MeV nickel ions, conducted at the Inter University Accelerator Centre (IUAC), New Delhi. Notably, experiments involving oxygen and silicon ions are conducted at 77K to simulate low-temperature irradiation conditions, facilitated by the MS beam line. In-situ measurements, performed to monitor ion fluence effects, utilize a fabricated target ladder capable of accommodating multiple samples simultaneously. An experimental setup within the GPSC beam line enables the generation of low ion fluence through direct beam scattering from a gold foil. The research evaluates forward current gain, Gummel characteristics, capacitance, and conductance variations induced by ion irradiation. Furthermore, deep level transient spectroscopy (DLTS) characterization of lithium-ion irradiated transistors elucidates the generation of deep level defects. Computational simulations using SRIM and TRIM software facilitate Total Ionizing Dose (TID) and Non-Ionizing Energy Loss (NIEL) calculations, establishing correlations with observed electrical phenomena. In summary, this study contributes significant insights into radiation-induced effects on bipolar power transistors, crucial for advancing reliability and performance in radiation-rich environments.