Simulation of Ionizing/Displacement Synergistic Effects on NPN Bipolar Transistors Irradiated by Mixed Neutrons and Gamma Rays

Yuhao Shan,Zheng Peng,Yanfei Liu,Hao Zheng,Jariah Mohamad Juoi

doi:10.1155/2022/1283926

Yuhao Shan, Zheng Peng + Show 3 more

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https://doi.org/10.1155/2022/1283926

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Abstract

Transistors working in complex radiation environments such as space are simultaneously irradiated by neutrons and gamma rays. But the mechanism of the synergistic radiation effect between the two rays is still unclear. Based on TCAD, the synergistic radiation effects of ionizing/displacement damage caused by mixed neutrons and gamma rays are simulated. The results demonstrate that the synergistic effects are more serious than the simple sum of the two radiation effects due to their mutual enhancement. The change of the carrier recombination rate in the device at different positions shows that the displacement effects increase the peak value of surface recombination rate; meanwhile, the ionizing dose effects enhance the recombination process in bulk silicon. The mechanism of this phenomenon is that positive charges from the oxide layer and interface enhance the recombination of carriers in bulk, and the reduced carrier lifetime caused by defects from bulk makes carriers more likely to be trapped by the interface traps. In addition, the simulation result which shows the influence of temperature on the synergistic effects indicates that the synergistic effects are more sensitive to the lower temperature.

Highlights

Complementary metal oxide semiconductor (CMOS) devices have an absolute advantage in all kinds of microelectronic products because of low-power dissipation, bipolar junction transistors (BJT) still have a wide range of applications due to their inherent ultra-high-speed characteristics and superior capabilities of analog signal processing
When a transistor works in a radiation environment such as space environment, all kinds of radiation effects can damage the transistor and reduce its life span or even cause it to fail such as total ionization dose (TID) effects, displacement damage (DD) effects, and single event effects (SEE)
Based on simulations and experiments, Wang et al discovered the gain degradation caused by mixed neutrons and gamma rays on lateral PNP transistors is greater than the simple sum of the DD and TID [3,4,5]. ey all illustrated that TID effects could enhance DD effects

Summary

Introduction

Complementary metal oxide semiconductor (CMOS) devices have an absolute advantage in all kinds of microelectronic products because of low-power dissipation, bipolar junction transistors (BJT) still have a wide range of applications due to their inherent ultra-high-speed characteristics and superior capabilities of analog signal processing. When a transistor works in a radiation environment such as space environment, all kinds of radiation effects can damage the transistor and reduce its life span or even cause it to fail such as total ionization dose (TID) effects, displacement damage (DD) effects, and single event effects (SEE). Instead of studying each single radiation effect, recent research has begun to focus on the combined effect of multiple radiation effects, and it has been discovered that bipolar transistors exhibit certain synergistic effects when the ionizing damage and the displacement damage both exist in BJT. Li et al irradiated bipolar transistors with different fluences of 6 MeV carbon ions and 70 keV electrons, which can cause displacement damage and ionization damage, respectively. Our research found that this is the case, and the DD effects will have an impact on TID effects

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