The Influence of Deep-Level Defects with Various Depths in SiO₂on Ionizing Damage

In this article, we analyzed the interaction mechanism between ionization and displacement defects in SiO2 using experimental and simulation techniques. In the experiment, the gate-controlled lateral p-n-p transistors (GLPNPs) were pretreated by He ions irradiation with different energies, which can create additional oxygen vacancy defects (Vo) at various depth ranges in SiO2. The pretreated GLPNPs were irradiated with γ -rays to analyze their response to ionization damage. It can be found that the introduction of additional deep Vo in SiO2 weakens the ionization damage of GLPNPs, and this weakening effect is heavily related to the depth of additional deep Vo. In addition, the TCAD simulation tool was used to investigate the mechanism by which the ionization damage is weakened with additional deep Vo depth. The simulation results show that as the additional deep Vo defect approaches the SiO2-Si interface, the additional deep Vo defect enhances the capture of the holes (or release of electrons), resulting in a decrease in hydrogenated Vo (VoH2+) concentration, which affects the release of protons and ultimately reduces N it. Based on the above mechanism, it would be helpful to accurately evaluate the electrical characteristics degradation of bipolar transistors in complex space environments.