Single event effects evaluation on convolution neural network in Xilinx 28 nm system on chip

Convolutional neural networks(CNNs) exhibit excellent performance in the areas of image recognition and object detection, which can enhance the intelligence level of spacecraft. However, in aerospace, energetic particles, such as heavy ions, protons, and alpha particles, can induce single event effects(SEEs) that lead CNNs to malfunction and can significantly impact the reliability of a CNN system. In this paper, the MNIST CNN system was constructed based on a 28 nm systemon-chip(SoC), and then an alpha particle irradiation experiment and fault injection were applied to evaluate the SEE of the CNN system. Various types of soft errors in the CNN system have been detected, and the SEE cross sections have been calculated. Furthermore, the mechanisms behind some soft errors have been explained. This research will provide technical support for the design of radiation-resistant artificial intelligence chips.

Sensitivity investigation of 100-MeV proton irradiation to SiGe HBT single event effect

The single event effect(SEE) sensitivity of silicon–germanium heterojunction bipolar transistor(Si Ge HBT) irradiated by 100-Me V proton is investigated. The simulation results indicate that the most sensitive position of the Si Ge HBT device is the emitter center, where the protons pass through the larger collector-substrate(CS) junction. Furthermore, in this work the experimental studies are also carried out by using 100-Me V proton. In order to consider the influence of temperature on SEE, both simulation and experiment are conducted at a temperature of 93 K. At a cryogenic temperature, the carrier mobility increases, which leads to higher transient current peaks, but the duration of the current decreases significantly.Notably, at the same proton flux, there is only one single event transient(SET) that occurs at 93 K. Thus, the radiation hard ability of the device increases at cryogenic temperatures. The simulation results are found to be qualitatively consistent with the experimental results of 100-Me V protons. To further evaluate the tolerance of the device, the influence of proton on Si Ge HBT after gamma-ray(^(60)Coγ) irradiation is investigated. As a result, as the cumulative dose increases, the introduction of traps results in a significant reduction in both the peak value and duration of the transient currents.

Effect of temperature on heavy ion-induced single event transient on 16-nm FinFET inverter chains

The variations of single event transient(SET)pulse width of high-LET heavy ion irradiation in 16-nm-thick bulk silicon fin field-effect transistor(Fin FET)inverter chains with different driven strengths are measured at different temperatures.Three-dimensional(3D)technology computer-aided design simulations are carried out to study the SET pulse width and saturation current varying with temperature.Experimental and simulation results indicate that the increase in temperature will enhance the parasitic bipolar effect of bulk Fin FET technology,resulting in the increase of SET pulse width.On the other hand,the increase of inverter driven strength will change the layout topology,which has a complex influence on the SET temperature effects of Fin FET inverter chains.The experimental and simulation results show that the device with the strongest driven strength has the least dependence on temperature.

Sensitivity study of the SiGe heterojunction bipolar transistor single event effect based on pulsed laser and technology computer-aided design simulation

The single event effect of a silicon–germanium heterojunction bipolar transistor(SiGe HBT) was thoroughly investigated. By considering the worst bias condition, the sensitive area of the proposed device was scanned with a pulsed laser.With variation of the collector bias and pulsed laser incident energy, the single event transient of the SiGe HBT was studied.Moreover, the single event transient produced by laser irradiation at a wavelength of 532 nm was more pronounced than at a wavelength of 1064 nm. Finally, the impact of the equivalent linear energy transfer of the 1064 nm pulsed laser on the single event transient was qualitatively examined by performing technology computer-aided design simulations, and a good consistency between the experimental data and the simulated outcomes was attained.

Synergistic effect of total ionizing dose on single-event gate rupture in SiC power MOSFETs

The synergistic effect of total ionizing dose(TID) and single event gate rupture(SEGR) in SiC power metal–oxide–semiconductor field effect transistors(MOSFETs) is investigated via simulation. The device is found to be more sensitive to SEGR with TID increasing, especially at higher temperature. The microscopic mechanism is revealed to be the increased trapped charges induced by TID and subsequent enhancement of electric field intensity inside the oxide layer.

Single-event-transient effect in nanotube tunnel field-effect transistor with bias-induced electron–hole bilayer

The single event transient(SET)effect in nanotube tunneling field-effect transistor with bias-induced electron–hole bilayer(EHBNT-TFET)is investigated by 3-D TCAD simulation for the first time.The effects of linear energy transfer(LET),characteristic radius,strike angle,electrode bias and hit location on SET response are evaluated in detail.The simulation results show that the peak value of transient drain current is up to 0.08 m A for heavy ion irradiation with characteristic radius of 50 nm and LET of 10 Me V·cm^(2)/mg,which is much higher than the on-state current of EHBNTTFET.The SET response of EHBNT-TFET presents an obvious dependence on LET,strike angle,drain bias and hit location.As LET increases from 2 Me V·cm^(2)/mg to 10 Me V·cm^(2)/mg,the peak drain current increases monotonically from 0.015 mA to 0.08 mA.The strike angle has an greater impact on peak drain current especially for the smaller characteristic radius.The peak drain current and collected charge increase by 0.014 mA and 0.06 fC,respectively,as the drain bias increases from 0.1 V to 0.9 V.Whether from the horizontal or the vertical direction,the most sensitive hit location is related to wt.The underlying physical mechanism is explored and discussed.

Single Event Transients of Operational Amplifier and Optocoupler

The single event transient effects of the operational amplifier LM124J and the optocoupler HCPL 5231 are investigated by a pulsed laser test facility. The relation of transient pulse shape to pulsed laser equivalent LET is tested,the sensitive areas of the SET effects are identified in voltage follower application mode of LM124J, and the mechanism is initially analyzed. The transient amplitude and duration of HCPL5231 at various equivalent LET are examined,and the SET cross-section is measured. The results of our test and heavy ion experimental data coincide closely,indicating that a pulsed laser test facility is a valid tool for single event effect evaluation.

Study of leakage current degradation based on stacking faults expansion in irradiated SiC junction barrier Schottky diodes

A comprehensive investigation was conducted to explore the degradation mechanism of leakage current in SiC junction barrier Schottky(JBS)diodes under heavy ion irradiation.We propose and verify that the generation of stacking faults(SFs)induced by the recombination of massive electron-hole pairs during irradiation is the cause of reverse leakage current degradation based on experiments results.The irradiation experiment was carried out based on Ta ions with high linear energy transfer(LET)of 90.5 MeV/(mg/cm^(2)).It is observed that the leakage current of the diode undergoes the permanent increase during irradiation when biased at 20%of the rated reverse voltage.Micro-PL spectroscopy and PL micro-imaging were utilized to detect the presence of SFs in the irradiated SiC JBS diodes.We combined the degraded performance of irradiated samples with SFs introduced by heavy ion irradiation.Finally,three-dimensional(3D)TCAD simulation was employed to evaluate the excessive electron-hole pairs(EHPs)concentration excited by heavy ion irradiation.It was observed that the excessive hole concentration under irradiation exceeded significantly the threshold hole concentration necessary for the expansion of SFs in the substrate.The proposed mechanism suggests that the process and material characteristics of the silicon carbide should be considered in order to reinforcing against the single event effect of SiC power devices.

Estimation of pulsed laser-induced single event transient in a partially depleted silicon-on-insulator 0.18-μm MOSFET

In this paper, we investigate the single event transient （SET） occurring in partially depleted silicon-on-insulator （PDSOI） metal-oxide-semiconductor （MOS） devices irradiated by pulsed laser beams. Transient signal characteristics of a 0.18-p.m single MOS device, such as SET pulse width, pulse maximum, and collected charge, are measured and an- alyzed at wafer level. We analyze in detail the influences of supply voltage and pulse energy on the SET characteristics of the device under test （DUT）. The dependences of SET characteristics on drain-induced barrier lowering （DIBL） and the parasitic bipolar junction transistor （PBJT） are also discussed. These results provide a guide for radiation-hardened deep sub-micrometer PDSOI technology for space electronics applications.

Recovery of single event upset in advanced complementary metal-oxide semiconductor static random access memory cells

Using computer-aided design three-dimensional （3D） simulation technology, the recovery mechanism of single event upset and the effects of spacing and hit angle on the recovery are studied. It is found that the multi-node charge collection plays a key role in recovery and shielding the charge sharing by adding guard rings. It cannot exhibit the recovery effect. It is also indicated that the upset linear energy transfer （LET） threshold is kept constant while the recovery LET threshold increases as the spacing increases. Additionally, the effect of incident angle on recovery is analysed and it is shown that a larger angle can bring about a stronger charge sharing effect, thus strengthening the recovery ability.

Synergistic effect of total ionizing dose on single event effect induced by pulsed laser microbeam on SiGe heterojunction bipolar transistor

The synergistic effect of total ionizing dose（TID） on single event effect（SEE） in SiGe heterojunction bipolar transistor（HBT） is investigated in a series of experiments. The SiGe HBTs after being exposed to 60 Co g irradiation are struck by pulsed laser to simulate SEE. The SEE transient currents and collected charges of the un-irradiated device are compared with those of the devices which are irradiated at high and low dose rate with various biases. The results show that the SEE damage to un-irradiated device is more serious than that to irradiated SiGe HBT at a low applied voltage of laser test. In addition, the g irradiations at forward and all-grounded bias have an obvious influence on SEE in the SiGe HBT, but the synergistic effect after cutting off the g irradiation is not significant. The influence of positive oxide-trap charges induced by TID on the distortion of electric field in SEE is the major factor of the synergistic effect. Moreover, the recombination of interface traps also plays a role in charge collection.

Identifying the driving factors of sediment delivery ratio on individual flood events in a long-term monitoring headwater basin

The Sediment Delivery Ratio(SDR) has multi-fold environmental implications both in evaluating the soil and water losses and the effectiveness of conservation measures in watersheds. Various factors, including hydrological regime and watershed properties, may influence the SDR at interannual timescales. However, the effect of certain important dynamic factors, such as rainfall peak distribution, runoff erosion power and sediment bulk density, on the sediment delivery ratio of single flood events(SDRe) has received little attention. The Qiaogou headwater basin is in the hilly-gully region of the Chinese Loess Plateau, and it encompasses a 0.45 km^2 catchment. Three large-scale field runoff plots at different geomorphological positions were chosen to obtain the observation data, and the 20-year period between 1986 and 2005 is presented. The results showed that the SDRe of the Qiaogou headwaters varied from 0.49 to 2.77. Among the numerous influential factors, rainfall and runoff were the driving factors causing slope erosion and sediment transport. The rainfall erosivity had a significant positive relationship with the sediment transport modulus(R^2=0.85, P<0.01) but had no significant relationship with SDRe. The rainfall peak coefficient was significantly positively correlated with the SDRe(R^2=0.64, P<0.05), indicating the influence of rainfall energy distribution on the SDRe. The runoff erosion power index was not only significantly related to the sediment transport modulus(R^2=0.84, P<0.01) but also significantly related to the SDRe(R^2=0.57, P<0.01). In addition, the relative bulk density was significantly related to the SDRe, indicating that hyper-concentrated flow characteristics contributed to more transported sediment in the catchment. Thus, the rainfall peak coefficient, runoff erosion power and sediment relative bulk density could be used as dynamic indexes to predict the SDRe in the hilly areas of the Chinese Loess Plateau.

Temperature dependence of the P-hit single event transient pulse width in a three-transistor inverter chain

A comparison of the temperature dependence of the P-hit single event transient （SET） in a two-transistor （2T） inverter with that in a three-transistor （3T） inverter is carried out based on a three-dimensional numerical simulation. Due to the significantly distinct mechanisms of the single event change collection in the 2T and the 3T inverters, the temperature plays different roles in the SET production and propagation. The SET pulse will be significantly broadened in the 2T inverter chain while will be compressed in the 3T inverter chain as temperature increases. The investigation provides a new insight into the SET mitigation under the extreme environment, where both the high temperature and the single event effects should be considered. The 3T inverter layout structure （or similar layout structures） will be a better solution for spaceborne integrated circuit design for extreme environments.

Comparative research on “high currents” induced by single event latch-up and transient-induced latch-up

By using the pulsed laser single event effect facility and electro-static discharge （ESD） test system, the characteristics of the ＂high current＂, relation with external stimulus and relevance to impacted modes of single event latch-up （SEL） and transient-induced latch-up （TLU） are studied, respectively, for a 12-bit complementary metal--oxide semiconductor （CMOS） analog-to-digital converter. Furthermore, the sameness and difference in physical mechanism between ＂high current＂ induced by SEL and that by TLU are disclosed in this paper. The results show that the minority carrier diffusion in the PNPN structure of the CMOS device which initiates the active parasitic NPN and PNP transistors is the common reason for the ＂high current＂ induced by SEL and for that by TLU, However, for SEL, the minority carder diffusion is induced by the ionizing radiation, and an underdamped sinusoidal voltage on the supply node （the ground node） is the cause of the minority carrier diffusion for TLU.

Three-dimensional simulation of fabrication process-dependent effects on single event effects of SiGe heterojunction bipolar transistor

The fabrication process dependent effects on single event effects （SEEs） are investigated in a commercial silicon- germanium heterojunction bipolar transistor （SiGe HBT） using three-dimensional （3D） TCAD simulations. The influences of device structure and doping concentration on SEEs are discussed via analysis of current transient and charge collection induced by ions strike. The results show that the SEEs representation of current transient is different from representation of the charge collection for the same process parameters. To be specific, the area of C/S junction is the key parameter that affects charge collection of SEE. Both current transient and charge collection are dependent on the doping of collector and substrate. The base doping slightly influences transient currents of base, emitter, and collector terminals. However, the SEEs of SiGe HBT are hardly affected by the doping of epitaxial base and the content of Ge.

The supply voltage scaled dependency of the recovery of single event upset in advanced complementary metal-oxide-semiconductor static random-access memory cells

Using computer-aided design three-dimensional simulation technology,the supply voltage scaled dependency of the recovery of single event upset and charge collection in static random-access memory cells are investigated.It reveals that the recovery linear energy transfer threshold decreases with the supply voltage reducing,which is quite attractive for dynamic voltage scaling and subthreshold circuit radiation-hardened design.Additionally,the effect of supply voltage on charge collection is also investigated.It is concluded that the supply voltage mainly affects the bipolar gain of the parasitical bipolar junction transistor（BJT） and the existence of the source plays an important role in supply voltage variation.

The modulation effect of substrate doping on multi-node charge collection and single-event transient propagation in 90-nm bulk complementary metal-oxide semiconductor technology

Variation of substrate background doping will affect the charge collection of active and passive MOSFETs in complementary metal-oxide semiconductor （CMOS） technologies, which are significant for charge sharing, thus affecting the propagated single event transient pulsewidths in circuits. The trends of charge collected by the drain of a positive channel metal-oxide semiconductor （PMOS） and an N metal-oxide semiconductor （NMOS） are opposite as the substrate doping increases. The PMOS source will inject carriers after strike and the amount of charge injected will irlcrease as the substrate doping increases, whereas the source of the NMOS will mainly collect carriers and the source of the NMOS can also inject electrons when the substrate doping is light enough. Additionally, it indicates that substrate doping mainly affects the bipolar amplification component of a single-event transient current, and has little effect on the drift and diffusion. The change in substrate doping has a much greater effect on PMOS than on NMOS.

Single-event response of the SiGe HBT in TCAD simulations and laser microbeam experiment

In this paper the single-event responses of the silicon germanium heterojunction bipolar transistors(SiGe HBTs) are investigated by TCAD simulations and laser microbeam experiment. A three-dimensional(3D) simulation model is established, the single event effect(SEE) simulation is further carried out on the basis of Si Ge HBT devices, and then, together with the laser microbeam test, the charge collection behaviors are analyzed, including the single event transient(SET) induced transient terminal currents, and the sensitive area of SEE charge collection. The simulations and experimental results are discussed in detail and it is demonstrated that the nature of the current transient is controlled by the behaviors of the collector–substrate(C/S) junction and charge collection by sensitive electrodes, thereby giving out the sensitive area and electrode of SiGe HBT in SEE.

Parasitic bipolar amplification in a single event transient and its temperature dependence

Using three-dimensional technology computer-aided design （TCAD） simulation, parasitic bipolar amplification in a single event transient （SET） current of a single transistor and its temperature dependence are studied. We quantify the contributions of different current components in a SET current pulse, and it is found that the proportion of parasitic bipolar amplification in total collected charge is about 30% in both ]30-nm and 90-nm technologies. The temperature dependence of parasitic bipolar amplification and the mechanism of the SET pulse are also investigated and quantified. The results show that the proportion of charge induced by parasitic bipolar increases with rising temperature, which illustrates that the parasitic bipolar amplification plays an important role in the charge collection of a single transistor.

Temperature and drain bias dependence of single event transient in 25-nm FinFET technology

In this paper, we investigate the temperature and drain bias dependency of single event transient （SET） in 25-nm fin field-effect-transistor （FinFET） technology in a temperature range of 0-135 ℃ and supply voltage range of 0.4 V- 1.6 V. Technology computer-aided design （TCAD） three-dimensional simulation results show that the drain current pulse duration increases from 0.6 ns to 3.4 ns when the temperature increases from 0 to 135 ℃. The charge collected increases from 45.5 ℃ to 436.9 fC and the voltage pulse width decreases from 0.54 ns to 0.18 ns when supply voltage increases from 0.4 V to 1.6 V. Furthermore, simulation results and the mechanism of temperature and bias dependency are discussed.