Characterization of Radiation Tolerance of Bipolar Transistor with Al2O3 Dielectric at Different Dose Rates

The radiation response of specially designed bipolar Darlington transistors with $Al_{2}O_{3}$-based dielectric after $^{60}$Co gamma-ray irradiation at various dose rates have been examined in this paper as a function of total dose. The base current sensitive to irradiation increases linearly with dose, dependent of the bias conditions and thickness of dielectric. According to the experimental results, it is shown that $Al_{2}O_{3}$ as a promising dielectric material may be achievable to resist the ionizing dose radiation for a bipolar transistor. Additionally, an enhanced effect occurring when the dose rate decreases is discussed with respect to interface traps buildup near the interfacial $SiO_{2}/Si$ structure. This suggests that reducing the thickness of the interfacial $SiO_{2}$ layer near the interface or increasing electron traps may be benefit to improve the enhanced low dose rate sensitivity (ELDRS) tolerance.