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Silicon carbide is widely used in radiation environments due to its excellent properties. However, when exposed to the strong radiation environment constantly, plenty of defects are generated, thus causing the material performance downgrades or failures. In this paper, the two-temperature model (2T-MD) is used to explore the defect recovery process by applying the electronic energy loss (Se) on the pre-damaged system. The effects of defect concentration and the applied electronic energy loss on the defect recovery process are investigated, respectively. The results demonstrate that almost no defect recovery takes place until the defect density in the damage region or the local defect density is large enough, and the probability of defect recovery increases with the defect concentration. Additionally, the results indicate that the defect recovery induced by swift heavy ions is mainly connected with the homogeneous recombination of the carbon defects, while the probability of heterogeneous recombination is mainly dependent on the silicon defects.

The impact of Ge profile on the TID susceptibility of SiGe HBTs from two manufacturers is investigated based on TCAD simulation. The results indicate that the modulation of potential distribution across the base region by Ge grading has significant impacts on the base current degradation. The Box Ge profile can cause a strong retarding potential near the EB junction, thereby leading to high recombination rates at the trap-enriched EB-spacer/SiGe interface. While Ge profiles with high accelerating field near the EB junction can prevent the injected carriers from diffusing to the EB-spacer/SiGe interface and suppress the increase of excess base current. Besides, this impact of Ge profile is closely related to the base thickness and integrated Ge content.

AD8561 (Analog Device Inc.) MACRO-SPICE model is used to investigate the coupled effects of multiple photocurrents generated by gamma pulse radiation in its Input and Output modules. Firstly, the test circuit is built to find sensitive devices according to previous studies. Besides, Gummel-Poon bipolar junction transistor (BJT) model including photocurrent generators implemented by the exponential current sources is adopted to replace the initial device model. Finally, the effects caused by each photocurrent and multiple photocurrents under different input states are simulated and analyzed. The simulation results indicate that there are competitive relationships among the multiple photocurrents generated in the input-stage bipolar transistors, even in a single bipolar transistor, and the relationship changes with the input state. The transient upset induced by photocurrents generated in the Input and Output modules have superimposed effects on the output ports, but the transient upset duration depends mainly on the Input module.

This paper presents an investigation into the impact of neutron-induced displacement damage on the single event transient (SET) charge collection in silicon–germanium heterojunction bipolar transistors (SiGe HBT) based on pulsed laser micro-beam experiment and technology computer aided design (TCAD) simulation. Experimental results show that the transient charge collection of the collector terminal decreases after neutron irradiation with a fluence of 5 × 1013 n/cm2 . In addition, the decrease of charge collection is more significant outside the collector–substrate (C–S) junction than inside. Combining with the TCAD simulation results, it is confirmed that the minority carrier lifetime which is shortened by neutron-induced defects plays an important role in the decrease of charge collection, and the disparity between the decreases of charge collection outside and inside the C–S junction is related to the dominating collection mechanism and transient duration.

This paper presents an investigation into the impact of substrate contact structure on the heavy ion-induced current transient in silicon‑germanium heterojunction bipolar transistor (SiGe HBT) based on Technology Computer Aided Design (TCAD) simulation. The results show that the size of the heavily doped ring wall used for substrate contact extraction has a significant impact on the collector current transient features. In addition, the impact of the ring size is position-dependent. For the strike positions inside or near the collector-substrate (C S) junction, the variation of transient features is attributed to the shape and volume of the funnel potential. While for the strike positions far from the C S junction, the variation is dominated by the diffusion process of the ion-induced electrons.

The 28 nm system-on-chip (SoC) was irradiated by 12 MeV electron at the China Institute of Atomic Energy (CIAE) for the first time. Soft errors in the on-chip memory (OCM), D-Cache, Register and BR...

The single event effects (SEE) in ferroelectric random access memories (FRAM) are investigated and the error modes are analyzed using heavy ions. Under the irradiation of heavy ions with high linear energy transfer (LET) values, data upsets are dominated by "0" to "1" upsets of which the cross section is larger than that of "1" to "0" upsets by an order of magnitude and most upsets are detected in addresses with the all "1" error pattern (FFFFH). In addition, most of the upsets occur in events that involve several consecutively accessed addresses. With the increase of ion LET, the percentage of the data upsets in events involving more than 10 consecutively accessed addresses increases monotonically.

Layout and profile adjustments are presented based on TCAD simulation to improve the inverse-mode performances of silicon-germanium heterojunction bipolar transistor (SiGe HBT). Then the single event transient (SET) and total ionizing dose (TID) sensitivity of the optimized devices are investigated. The results indicate that profile optimizations result in better enhancement of the inverse-mode performances but also greater changes of the radiation responses. Most of all, the optimized Ge profile in base may lead to opposite impacts on SET and TID responses due to the change of local electric field in base caused by Ge grading.

Space-related electronics contain different types of oxide isolations which are the crucial factor resulting in device degradation and failure. Previous studies show that the local oxidation of silicon (LOCOS) isolation Silicon‑germanium heterojunction bipolar transistor (SiGe HBT) experience more significantly low dose rate sensitivity than that of shallow trench (STI) isolation SiGe HBTs and behave a “true” dose rate effect. In our work, the electron-hole pairs (EHPs) generation, holes trapped and protons transport inside oxide are simulated in LOCOS and STI isolation SiGe HBTs to explanation the different response t enhanced low dose rate sensitivity (ELDRS). The simulation results show that LOCOS oxide has a larger generation of EHPs than that of STI oxide leading to more surviving holes and protons release within oxide.

This paper presents an investigation into the impact of proton-induced alteration of carrier lifetime on the single-event transient (SET) caused by heavy ions in silicon–germanium heterojunction bipolar transistor (SiGe HBT). The ion-induced current transients and integrated charge collections under different proton fluences are obtained based on technology computer-aided design (TCAD) simulation. The results indicate that the impact of carrier lifetime alteration is determined by the dominating charge collection mechanism at the ion incident position and only the long-time diffusion process is affected. With a proton fluence of 5×1013 cm−2, almost no change is found in the transient feature, and the charge collection of events happened in the region enclosed by deep trench isolation (DTI), where prompt funneling collection is the dominating mechanism. Meanwhile, for the events happening outside DTI where diffusion dominates the collection process, the peak value and the duration of the ion-induced current transient both decrease with increasing proton fluence, leading to a great decrease in charge collection.

In this paper we investigate two techniques for single event effect (SEE) mitigation by using back junction and p+ buffer layer in non-deep trench isolation (DTI) domestic silicon–germanium heterojunction bipolar transistors (SiGe HBTs) based on technology computer aided design (TCAD) simulation. The effectiveness of the two mitigation techniques and the influence of various structure parameters are investigated. Simulation results indicate that the two techniques are more effective in reducing collector charge collection induced by heavy ions striking at positions outside the collector–substrate (C–S) junction where charge collection is dominated by diffusion. By properly adjusting the parameters, charge collection of events outside the C–S junction can be reduced by more than an order of magnitude, while charge collection of events in the device center is halved without affecting the direct current (DC) and alternating current (AC) characteristics of the SiGe HBTs.