Mechanism of Degradation Rate on the Irradiated Double-Polysilicon Self-Aligned Bipolar Transistor

Abstract

The latent enhanced low dose rate sensitivity (ELDRS) effect is observed in the double-polysilicon self-aligned (DPSA) technology PNP bipolar junction transistor (BJT) irradiated with a high and low dose rate gamma ray, which is discussed from the perspective of the three-stage degradation rate of the excess base current. The great degradation rate as a result of the high dose irradiation of the first stage is dominantly ascribed to the positive oxide trap charges accumulated during a short irradiation, and then due to the competition between the recombination of electrons and capture of the hole by the traps. It declined sharply into a degradation rate saturated region of the second stage. However, for the low dose rate, the small increase in the degradation rate in the first stage is caused by the holes escaping from the initial recombination and being transported to the interface to form the interface states. Then, the competition between the steadily increasing interfacial trap charge and the continuously annealed shallow level oxide trap charge leads to the stable increase of degradation under low dose irradiation. Finally, in stage three, the increases of the degradation rates for high and low dose irradiation result from the different amounts of the hydrogen molecules generated by the hole reactive with depassiviated Si suspended bonds, which can interact with the deep level defects and release protons, causing an increase of interfacial trap charges with prolonged irradiation.

Radiation Tolerant Electronics

“…Results of the investigation confirmed the achievement of excellent radiation hardness and decent specific on-resistance for the device. Article [2] discussed the mechanism of degradation on the Irradiated Double-Polysilicon Self-Aligned Bipolar Transistor with a dose rate of 50 rad (Si)/s and 0.05 rad (Si)/s. The comparison of the high and low dose rate showed that the increase of the base current caused by low dose rate irradiation was larger than that caused by high dose rate irradiation, resulting in greater current gain degradation than that caused by the high dose rate, highlighting that the ELDRS effect may occur.…”

Photovoltaic Degradation Rate Affected by Different Weather Conditions: A Case Study Based on PV Systems in the UK and Australia

“…In this article, we have used a new model called year-on-year (YOY) developed by the national renewable energy laboratory (NREL). The open access software (RdTools) allows us to analyze the degradation rate for PV installations [2]. The degradation calculations consist of several steps discussed in the following processes:…”

“…Economically, PV modules degradation rates are equally important, because a higher degradation rate interprets directly into less output power produced by the system, thus reducing future cash flows [2]. Inaccuracies in determined degradation rates lead to amplified financial risks in the PV sector.…”