Contribution of NIEL for Gain Degradation (β) in Si8+ Ion Irradiated Silicon Power Transistor

• Main Authors: C. M. Dinesh, Ramani, M. C. Radhakrishna, S. A. Khan, D. Kanjilal
• Format: Article
• Language: English
• Published: IFSA Publishing, S.L. 2008-12-01
• Series: Sensors & Transducers
• Subjects: BJT; Irradiation; Defects; Junction; NIEL
• Online Access: http://www.sensorsportal.com/HTML/DIGEST/december_08/Special_issue/P_SI_60.pdf

The concept of non-ionizing energy loss (NIEL) has been found useful for characterizing displacement damage defects in materials and devices. When NPN power transistors (2N6688 manufactured by BEL, India) are exposed for 110 MeV Si8+ ion irradiation in the fluence range 5 x 109 to 1 x 1013 ions cm-2 at room temperature (300 K) and at liquid nitrogen temperature (77 K) cause functional failure due to surface and bulk defects. The output collector characteristics are studied as a function of total ionizing dose (TID) and total displacement damage dose (Dd) obtained using TRIM Monte Carlo code. It is observed that the shift in the output saturation voltage is considerably less for heavy ion irradiation compared to lighter ions like lithium ion irradiation. The gain of the transistor degrades with ion irradiation. Base reverse biased leakage current (BRBLC) increases with increase in ion fluence. The observed results are almost independent of the irradiation temperature. These studies help to improve the device fabrication technology to make Radiation Hard Devices for advanced applications.