Identifying sensitive areas in integrated circuits susceptible to single-event effects(SEE)is crucial for improving radiation hardness.This study presents an online multi-track location(OML)framework to enhance the hi...Identifying sensitive areas in integrated circuits susceptible to single-event effects(SEE)is crucial for improving radiation hardness.This study presents an online multi-track location(OML)framework to enhance the high-resolution online trajectory detection for the Hi’Beam-SEE system,which aims to localize SEE-sensitive positions on the IC at the micrometer scale and in real time.We employed a reparameterization method to accelerate the inference speed,merging the branches of the backbone of the location in the deployment scenario.Additionally,we designed an irregular convolution kernel,an attention mechanism,and a fused loss function to improve the positioning accuracy.OML demonstrates exceptional realtime processing capabilities,achieving a positioning accuracy of 1.83μm in processing data generated by the Hi’Beam-SEE system at 163 frames per second per GPU.展开更多
To improve the efficiency and accuracy of single-event effect(SEE)research at the Heavy Ion Research Facility at Lanzhou,Hi’Beam-SEE must precisely localize the position at which each heavy ion hitting the integrated...To improve the efficiency and accuracy of single-event effect(SEE)research at the Heavy Ion Research Facility at Lanzhou,Hi’Beam-SEE must precisely localize the position at which each heavy ion hitting the integrated circuit(IC)causes SEE.In this study,we propose a fast multi-track location(FML)method based on deep learning to locate the position of each particle track with high speed and accuracy.FML can process a vast amount of data supplied by Hi’Beam-SEE online,revealing sensitive areas in real time.FML is a slot-based object-centric encoder-decoder structure in which each slot can learn the location information of each track in the image.To make the method more accurate for real data,we designed an algorithm to generate a simulated dataset with a distribution similar to that of the real data,which was then used to train the model.Extensive comparison experiments demonstrated that the FML method,which has the best performance on simulated datasets,has high accuracy on real datasets as well.In particular,FML can reach 238 fps and a standard error of 1.6237μm.This study discusses the design and performance of FML.展开更多
We experimentally demonstrate that the dominant mechanism of single-event transients in silicon-germanium heterojunction bipolar transistors(SiGe HBTs)can change with decreasing temperature from+20℃to-180℃.This is a...We experimentally demonstrate that the dominant mechanism of single-event transients in silicon-germanium heterojunction bipolar transistors(SiGe HBTs)can change with decreasing temperature from+20℃to-180℃.This is accomplished by using a new well-designed cryogenic experimental system suitable for a pulsed-laser platform.Firstly,when the temperature drops from+20℃to-140℃,the increased carrier mobility drives a slight increase in transient amplitude.However,as the temperature decreases further below-140℃,the carrier freeze-out brings about an inflection point,which means the transient amplitude will decrease at cryogenic temperatures.To better understand this result,we analytically calculate the ionization rates of various dopants at different temperatures based on Altermatt's new incomplete ionization model.The parasitic resistivities with temperature on the charge-collection pathway are extracted by a two-dimensional(2D)TCAD process simulation.In addition,we investigate the impact of temperature on the novel electron-injection process from emitter to base under different bias conditions.The increase of the emitter-base junction's barrier height at low temperatures could suppress this electron-injection phenomenon.We have also optimized the built-in voltage equations of a high current compact model(HICUM)by introducing the impact of incomplete ionization.The present results and methods could provide a new reference for effective evaluation of single-event effects in bipolar transistors and circuits at cryogenic temperatures,and could provide a new evidence of the potential of SiGe technology in applications in extreme cryogenic environments.展开更多
Existing standards show a clear discrepancy in the specification of the maximum proton energy for qualified ground-based evaluation of single-event effects,which can range from 180 to 500 MeV. This work finds that the...Existing standards show a clear discrepancy in the specification of the maximum proton energy for qualified ground-based evaluation of single-event effects,which can range from 180 to 500 MeV. This work finds that the threshold linear energy transfer of a tested device is a critical parameter for determining the maximum proton energy. The inner mechanisms are further revealed. Highenergy deposition events(>10 MeV) in sensitive volumes are attributed to the interaction between protons and the tungsten vias in the metallization layers.展开更多
The propagation of single-event effects(SEEs)on a Xilinx Zynq-7000 system on chip(SoC)was inves-tigated using heavy-ion microbeam radiation.The irradia-tion results reveal several functional blocks’sensitivity locati...The propagation of single-event effects(SEEs)on a Xilinx Zynq-7000 system on chip(SoC)was inves-tigated using heavy-ion microbeam radiation.The irradia-tion results reveal several functional blocks’sensitivity locations and cross sections,for instance,the arithmetic logic unit,register,D-cache,and peripheral,while irradi-ating the on-chip memory(OCM)region.Moreover,event tree analysis was executed based on the obtained microbeam irradiation results.This study quantitatively assesses the probabilities of SEE propagation from the OCM to other blocks in the SoC.展开更多
Based on 3 D-TCAD simulations, single-event transient(SET) effects and charge collection mechanisms in fully depleted silicon-on-insulator(FDSOI) transistors are investigated. This work presents a comparison between28...Based on 3 D-TCAD simulations, single-event transient(SET) effects and charge collection mechanisms in fully depleted silicon-on-insulator(FDSOI) transistors are investigated. This work presents a comparison between28-nm technology and 0.2-lm technology to analyze the impact of strike location on SET sensitivity in FDSOI devices. Simulation results show that the most SET-sensitive region in FDSOI transistors is the drain region near the gate. An in-depth analysis shows that the bipolar amplification effect in FDSOI devices is dependent on the strike locations. In addition, when the drain contact is moved toward the drain direction, the most sensitive region drifts toward the drain and collects more charge. This provides theoretical guidance for SET hardening.展开更多
Single-event effects(SEEs)induced by mediumenergy protons in a 28 nm system-on-chip(SoC)were investigated at the China Institute of Atomic Energy.An on-chip memory block was irradiated with 90 MeV and 70 MeV protons,r...Single-event effects(SEEs)induced by mediumenergy protons in a 28 nm system-on-chip(SoC)were investigated at the China Institute of Atomic Energy.An on-chip memory block was irradiated with 90 MeV and 70 MeV protons,respectively.Single-bit upset and multicell upset events were observed,and an uppermost number of nine upset cells were discovered in the 90 MeV proton irradiation test.The results indicate that the SEE sensitivities of the 28 nm SoC to the 90 MeV and 70 MeV protons were similar.Cosmic Ray Effects on Micro-Electronics Monte Carlo simulations were analyzed,and it demonstrates that protons can induce effects in a 28 nm SoC if their energies are greater than 1.4 MeV and that the lowest corresponding linear energy transfer was 0.142 MeV cm^2 mg^-1.The similarities and discrepancies of the SEEs induced by the 90 MeV and 70 MeV protons were analyzed.展开更多
The single-event effect(SEE) is a serious threat to electronics in radiation environments. The most important issue in radiation-hardening studies is the localization of the sensitive region in electronics to the SEE....The single-event effect(SEE) is a serious threat to electronics in radiation environments. The most important issue in radiation-hardening studies is the localization of the sensitive region in electronics to the SEE. To solve this problem, a prototype based on a complementary metal oxide semiconductor(CMOS) pixel sensor, i.e., TopmetalM, was designed for SEE localization. A beam test was performed on the prototype at the radiation terminal of the Heavy Ion Research Facility in Lanzhou(HIRFL). The results indicated that the inherent deflection angle of the prototype to the beam was 1.7°, and the angular resolution was 0.6°. The prototype localized heavy ions with a position resolution of 3.4 μm.展开更多
Single-event microkinetic(SEMK) model of the catalytic cracking of methylcyclohexane admixed with 1-octene over REUSY zeolites at 693 K—753 K in the absence of coke formation is enhanced. To keep consistency with the...Single-event microkinetic(SEMK) model of the catalytic cracking of methylcyclohexane admixed with 1-octene over REUSY zeolites at 693 K—753 K in the absence of coke formation is enhanced. To keep consistency with the wellknown carbenium ion chemistry, hydride transfer forming and consuming allylic carbenium ions in the aromatization of cycloparaffins are further investigated and differentiated. The reversibility of endocyclic β-scission and cyclization reactions is refined by accounting explicitly for the reacting olefins and resulting cycloparaffins in the corresponding thermodynamics. 24 activation energies for the reactions involved in the cracking of cycloparaffins are obtained by the regression of 15 sets of experimental data upon taking the resulting 37 main cracking products, i. e., responses into account. The enhanced SEMK model can adequately describe the catalytic behavior of 37 main products with conversion and temperature.展开更多
The dynamics of the excess carriers generated by incident heavy ions are considered in both SiO2 and Si substrate. Influences of the initial radius of the charge track, surface potential decrease, external electric fi...The dynamics of the excess carriers generated by incident heavy ions are considered in both SiO2 and Si substrate. Influences of the initial radius of the charge track, surface potential decrease, external electric field, and the LET value of the incident ion on internal electric field buildup are analyzed separately. Considering the mechanisms of recombination, impact ionization, and bandgap tunneling, models are verified by using published experimental data. Moreover, the scaling effects of single-event gate rupture in thin gate oxides are studied, with the feature size of the MOS device down to 90 nm. The walue of the total electric field decreases rapidly along with the decrease of oxide thickness in the first period （1 2 nm to 3.3 nm）, and then increases a little when the gate oxide becomes thinner and thinner （3.3 nm to 1.8 nm）.展开更多
The developed SEMK model is used to provide an insight into the contribution of individual reactions in the cracking of methylcyclohexane as well as the site coverage by various carbenium ions. The preferred reaction ...The developed SEMK model is used to provide an insight into the contribution of individual reactions in the cracking of methylcyclohexane as well as the site coverage by various carbenium ions. The preferred reaction pathways for the conversion of methylcyclohexane are hydride transfer reactions followed by PCP-isomerizations, deprotonation and endocyclic β-scission, accounting for 61%, 22% and 12% of its disappearance, respectively, at 693 K and 30% conversion of methylcyclohexane. Protolysis plays a minor role in the cracking of methylcyclohexane. Once cyclic diolefins are formed, all of them can be instantaneously transformed to aromatics, which are easily interconverted via disproportionation. Judging from the carbenium ion concentrations it is evident that, at the investigated operating conditions, less than 5% of the acid sites are covered by carbenium ions, less than 2% of which corresponds to cyclic type species including allylic ones.展开更多
This paper presents an investigation into the impact of proton-induced alteration of carrier lifetime on the singleevent transient(SET) caused by heavy ions in silicon–germanium heterojunction bipolar transistor(SiGe...This paper presents an investigation into the impact of proton-induced alteration of carrier lifetime on the singleevent transient(SET) caused by heavy ions in silicon–germanium heterojunction bipolar transistor(SiGe HBT).The ioninduced 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.展开更多
As integrated circuits scale down in size, a single high-energy ion strike often affects multiple adjacent logic nodes.The so-called single-event transient（SET） pulse quenching induced by single-event charge sharing...As integrated circuits scale down in size, a single high-energy ion strike often affects multiple adjacent logic nodes.The so-called single-event transient（SET） pulse quenching induced by single-event charge sharing collection has been widely studied. In this paper, SET pulse quenching enhancement is found in dummy gate isolated adjacent logic nodes compared with that isolated by the common shallow trench isolation（STI）. The physical mechanism is studied in depth and this isolation technique is explored for SET mitigation in combinational standard cells. Three-dimensional（3D） technology computer-aided design simulation（TCAD） results show that this technique can achieve efficient SET mitigation.展开更多
This paper presents two approaches to perform the electronic device heating during radiation hardness assurance tests.Commonly used conductive heating approach is compared with contactless laser-based approach,charact...This paper presents two approaches to perform the electronic device heating during radiation hardness assurance tests.Commonly used conductive heating approach is compared with contactless laser-based approach,characteristics and limitations of these methods are described.Experimental results for temperature dependence of single-event latchup(SEL)cross-section during heavy ion irradiation along with some aspects of physics-based numerical simulation of heat transfer processes are presented.展开更多
In this study, we investigate the single-event transient（SET） characteristics of a partially depleted silicon-on-insulator（PDSOI） metal-oxide-semiconductor（MOS） device induced by a pulsed laser.We measure and an...In this study, we investigate the single-event transient（SET） characteristics of a partially depleted silicon-on-insulator（PDSOI） metal-oxide-semiconductor（MOS） device induced by a pulsed laser.We measure and analyze the drain transient current at the wafer level. The results indicate that the body-drain junction and its vicinity are more SET sensitive than the other regions in PD-SOI devices.We use ISE 3D simulation tools to analyze the SET response when different regions of the device are hit. Then, we discuss in detail the characteristics of transient currents and the electrostatic potential distribution change in devices after irradiation. Finally, we analyze the parasitic bipolar junction transistor（p-BJT） effect by performing both a laser test and simulations.展开更多
A radiation-hardened-by-design （RHBD） technique for phase-locked loops （PLLs） has been developed for single-event transient （SET） mitigation. By presenting a novel SET-resistant complementary current limiter （...A radiation-hardened-by-design （RHBD） technique for phase-locked loops （PLLs） has been developed for single-event transient （SET） mitigation. By presenting a novel SET-resistant complementary current limiter （CCL） and implementing it between the charge pump （CP） and the loop filter （LPF）, the PLL＇s single-event susceptibility is significantly decreased in the presence of SETs in CPs, whereas it has little impact on the loop parameters in the absence of SETs in CPs. Transistor-level simulation results show that the CCL circuit can significantly reduce the voltage perturbation on the input of the voltage-controlled oscillator （VCO） by up to 93.1% and reduce the recovery time of the PLL by up to 79.0%. Moreover, the CCL circuit can also accelerate the PLL recovery procedure from loss of lock due to phase or frequency shift, as well as a single-event strike.展开更多
Single-event transient pulse quenching （Quenching effect） is employed to effectively mitigate WSET （SET pulse width）. It en- hanced along with the increased charge sharing which is norm for future advanced technol...Single-event transient pulse quenching （Quenching effect） is employed to effectively mitigate WSET （SET pulse width）. It en- hanced along with the increased charge sharing which is norm for future advanced technologies. As technology scales, param- eter variation is another serious issue that significantly affects circuit＇s performance and single-event response. Monte Carlo simulations combined with TCAD （Technology Computer-Aided Design） simulations are conducted on a six-stage inverter chain to identify and quantify the impact of charge sharing and parameter variation on pulse quenching. Studies show that charge sharing induce a wider WSET spread range. The difference of WSET range between no quenching and quenching is smaller in NMOS （N-Channel Metal-Oxide-Semiconductor Field-Effect Transistor） simulation than that in PMOS＇ （P-Channel Met- N-Oxide-Semiconductor Field-Effect Transistor）, so that from parameter variation view, quenching is beneficial in PMOS SET mitigation. The individual parameter analysis indicates that gate oxide thickness （TOXE） and channel length variation （XL） mostly affect SET response of combinational circuits. They bring 14.58% and 19.73% average WSET difference probabilities for no-quenching cases, and 105.56% and 123.32% for quenching cases.展开更多
Single-event effects of nano scale integrated circuits are investigated. Evaluation methods for singleevent transients, single-event upsets, and single-event functional interrupts in nano circuits are summarized and c...Single-event effects of nano scale integrated circuits are investigated. Evaluation methods for singleevent transients, single-event upsets, and single-event functional interrupts in nano circuits are summarized and classified in detail. The difficulties in SEE testing are discussed as well as the development direction of test technology, with emphasis placed on the experimental evaluation of a nano circuit under heavy ion, proton, and laser irradiation. The conclusions in this paper are based on many years of testing at accelerator facilities and our present understanding of the mechanisms for SEEs, which have been well verified experimentally.展开更多
We present a single-event burnout（SEB） hardened planar power MOSFET with partially widened trench sources by three-dimensional（3 D） numerical simulation. The advantage of the proposed structure is that the work of...We present a single-event burnout（SEB） hardened planar power MOSFET with partially widened trench sources by three-dimensional（3 D） numerical simulation. The advantage of the proposed structure is that the work of the parasitic bipolar transistor inherited in the power MOSFET is suppressed effectively due to the elimination of the most sensitive region（P-well region below the N＋ source）. The simulation result shows that the proposed structure can enhance the SEB survivability significantly. The critical value of linear energy transfer（LET）,which indicates the maximum deposited energy on the device without SEB behavior, increases from 0.06 to0.7 p C/μm. The SEB threshold voltage increases to 120 V, which is 80% of the rated breakdown voltage. Meanwhile, the main parameter characteristics of the proposed structure remain similar with those of the conventional planar structure. Therefore, this structure offers a potential optimization path to planar power MOSFET with high SEB survivability for space and atmospheric applications.展开更多
基金supported by the National Natural Science Foundation of China(Nos.U2032209,12222512,12375193,12305210)the National Key Research and Development Program of China(No.2021YFA1601300)the CAS“Light of West China”Program,the CAS Pioneer Hundred Talent Program,the Guangdong Major Project of Basic and Applied Basic Research(No.2020B0301030008).
文摘Identifying sensitive areas in integrated circuits susceptible to single-event effects(SEE)is crucial for improving radiation hardness.This study presents an online multi-track location(OML)framework to enhance the high-resolution online trajectory detection for the Hi’Beam-SEE system,which aims to localize SEE-sensitive positions on the IC at the micrometer scale and in real time.We employed a reparameterization method to accelerate the inference speed,merging the branches of the backbone of the location in the deployment scenario.Additionally,we designed an irregular convolution kernel,an attention mechanism,and a fused loss function to improve the positioning accuracy.OML demonstrates exceptional realtime processing capabilities,achieving a positioning accuracy of 1.83μm in processing data generated by the Hi’Beam-SEE system at 163 frames per second per GPU.
基金supported by the National Natural Science Foundation of China (Nos.U2032209,11975292,12222512)the National Key Research and Development Program of China (2021YFA1601300)+2 种基金the CAS“Light of West China”Programthe CAS Pioneer Hundred Talent Programthe Guangdong Major Project of Basic and Applied Basic Research (No.2020B0301030008)。
文摘To improve the efficiency and accuracy of single-event effect(SEE)research at the Heavy Ion Research Facility at Lanzhou,Hi’Beam-SEE must precisely localize the position at which each heavy ion hitting the integrated circuit(IC)causes SEE.In this study,we propose a fast multi-track location(FML)method based on deep learning to locate the position of each particle track with high speed and accuracy.FML can process a vast amount of data supplied by Hi’Beam-SEE online,revealing sensitive areas in real time.FML is a slot-based object-centric encoder-decoder structure in which each slot can learn the location information of each track in the image.To make the method more accurate for real data,we designed an algorithm to generate a simulated dataset with a distribution similar to that of the real data,which was then used to train the model.Extensive comparison experiments demonstrated that the FML method,which has the best performance on simulated datasets,has high accuracy on real datasets as well.In particular,FML can reach 238 fps and a standard error of 1.6237μm.This study discusses the design and performance of FML.
基金the National Natural Science Foundation of China(Grant Nos.61704127 and 11775167)。
文摘We experimentally demonstrate that the dominant mechanism of single-event transients in silicon-germanium heterojunction bipolar transistors(SiGe HBTs)can change with decreasing temperature from+20℃to-180℃.This is accomplished by using a new well-designed cryogenic experimental system suitable for a pulsed-laser platform.Firstly,when the temperature drops from+20℃to-140℃,the increased carrier mobility drives a slight increase in transient amplitude.However,as the temperature decreases further below-140℃,the carrier freeze-out brings about an inflection point,which means the transient amplitude will decrease at cryogenic temperatures.To better understand this result,we analytically calculate the ionization rates of various dopants at different temperatures based on Altermatt's new incomplete ionization model.The parasitic resistivities with temperature on the charge-collection pathway are extracted by a two-dimensional(2D)TCAD process simulation.In addition,we investigate the impact of temperature on the novel electron-injection process from emitter to base under different bias conditions.The increase of the emitter-base junction's barrier height at low temperatures could suppress this electron-injection phenomenon.We have also optimized the built-in voltage equations of a high current compact model(HICUM)by introducing the impact of incomplete ionization.The present results and methods could provide a new reference for effective evaluation of single-event effects in bipolar transistors and circuits at cryogenic temperatures,and could provide a new evidence of the potential of SiGe technology in applications in extreme cryogenic environments.
基金supported by the National Natural Science Foundation of China(No.11505033)the Science and Technology Research Project of Guangdong,China(Nos.2015B090901048 and 2017B090901068)the Science and Technology Plan Project of Guangzhou,China(No.201707010186)
文摘Existing standards show a clear discrepancy in the specification of the maximum proton energy for qualified ground-based evaluation of single-event effects,which can range from 180 to 500 MeV. This work finds that the threshold linear energy transfer of a tested device is a critical parameter for determining the maximum proton energy. The inner mechanisms are further revealed. Highenergy deposition events(>10 MeV) in sensitive volumes are attributed to the interaction between protons and the tungsten vias in the metallization layers.
基金This work was supported by the National Natural Science Foundation of China(Nos.11575138,11835006,11690040,11690043,and 11705216)the Innovation Center of Radiation Application(No.KFZC2019050321)the China Scholarships Council program(No.201906280343).
文摘The propagation of single-event effects(SEEs)on a Xilinx Zynq-7000 system on chip(SoC)was inves-tigated using heavy-ion microbeam radiation.The irradia-tion results reveal several functional blocks’sensitivity locations and cross sections,for instance,the arithmetic logic unit,register,D-cache,and peripheral,while irradi-ating the on-chip memory(OCM)region.Moreover,event tree analysis was executed based on the obtained microbeam irradiation results.This study quantitatively assesses the probabilities of SEE propagation from the OCM to other blocks in the SoC.
基金supported by the National Natural Science Foundation of China(Nos.61434007 and 61376109)
文摘Based on 3 D-TCAD simulations, single-event transient(SET) effects and charge collection mechanisms in fully depleted silicon-on-insulator(FDSOI) transistors are investigated. This work presents a comparison between28-nm technology and 0.2-lm technology to analyze the impact of strike location on SET sensitivity in FDSOI devices. Simulation results show that the most SET-sensitive region in FDSOI transistors is the drain region near the gate. An in-depth analysis shows that the bipolar amplification effect in FDSOI devices is dependent on the strike locations. In addition, when the drain contact is moved toward the drain direction, the most sensitive region drifts toward the drain and collects more charge. This provides theoretical guidance for SET hardening.
基金supported by the National Natural Science Foundation of China(Grant Nos.11575138,11835006,11690040,and 11690043)
文摘Single-event effects(SEEs)induced by mediumenergy protons in a 28 nm system-on-chip(SoC)were investigated at the China Institute of Atomic Energy.An on-chip memory block was irradiated with 90 MeV and 70 MeV protons,respectively.Single-bit upset and multicell upset events were observed,and an uppermost number of nine upset cells were discovered in the 90 MeV proton irradiation test.The results indicate that the SEE sensitivities of the 28 nm SoC to the 90 MeV and 70 MeV protons were similar.Cosmic Ray Effects on Micro-Electronics Monte Carlo simulations were analyzed,and it demonstrates that protons can induce effects in a 28 nm SoC if their energies are greater than 1.4 MeV and that the lowest corresponding linear energy transfer was 0.142 MeV cm^2 mg^-1.The similarities and discrepancies of the SEEs induced by the 90 MeV and 70 MeV protons were analyzed.
基金supported by the National Natural Science Foundation of China(No.U1932143),the National Key Research and Development Program of China(No.2020YFE0202002)the National Natural Science Foundation of China(Nos.11875146,11927901,12075099,12075100,11875145,U2032209)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB34000000).
文摘The single-event effect(SEE) is a serious threat to electronics in radiation environments. The most important issue in radiation-hardening studies is the localization of the sensitive region in electronics to the SEE. To solve this problem, a prototype based on a complementary metal oxide semiconductor(CMOS) pixel sensor, i.e., TopmetalM, was designed for SEE localization. A beam test was performed on the prototype at the radiation terminal of the Heavy Ion Research Facility in Lanzhou(HIRFL). The results indicated that the inherent deflection angle of the prototype to the beam was 1.7°, and the angular resolution was 0.6°. The prototype localized heavy ions with a position resolution of 3.4 μm.
基金financial support from the China Scholarship Councilthe Long Term Structural Methusalem Funding by the Flemish Government
文摘Single-event microkinetic(SEMK) model of the catalytic cracking of methylcyclohexane admixed with 1-octene over REUSY zeolites at 693 K—753 K in the absence of coke formation is enhanced. To keep consistency with the wellknown carbenium ion chemistry, hydride transfer forming and consuming allylic carbenium ions in the aromatization of cycloparaffins are further investigated and differentiated. The reversibility of endocyclic β-scission and cyclization reactions is refined by accounting explicitly for the reacting olefins and resulting cycloparaffins in the corresponding thermodynamics. 24 activation energies for the reactions involved in the cracking of cycloparaffins are obtained by the regression of 15 sets of experimental data upon taking the resulting 37 main cracking products, i. e., responses into account. The enhanced SEMK model can adequately describe the catalytic behavior of 37 main products with conversion and temperature.
文摘The dynamics of the excess carriers generated by incident heavy ions are considered in both SiO2 and Si substrate. Influences of the initial radius of the charge track, surface potential decrease, external electric field, and the LET value of the incident ion on internal electric field buildup are analyzed separately. Considering the mechanisms of recombination, impact ionization, and bandgap tunneling, models are verified by using published experimental data. Moreover, the scaling effects of single-event gate rupture in thin gate oxides are studied, with the feature size of the MOS device down to 90 nm. The walue of the total electric field decreases rapidly along with the decrease of oxide thickness in the first period （1 2 nm to 3.3 nm）, and then increases a little when the gate oxide becomes thinner and thinner （3.3 nm to 1.8 nm）.
基金the financial support from the China Scholarship Councilthe Long Term Structural Methusalem Funding by the Flemish Government
文摘The developed SEMK model is used to provide an insight into the contribution of individual reactions in the cracking of methylcyclohexane as well as the site coverage by various carbenium ions. The preferred reaction pathways for the conversion of methylcyclohexane are hydride transfer reactions followed by PCP-isomerizations, deprotonation and endocyclic β-scission, accounting for 61%, 22% and 12% of its disappearance, respectively, at 693 K and 30% conversion of methylcyclohexane. Protolysis plays a minor role in the cracking of methylcyclohexane. Once cyclic diolefins are formed, all of them can be instantaneously transformed to aromatics, which are easily interconverted via disproportionation. Judging from the carbenium ion concentrations it is evident that, at the investigated operating conditions, less than 5% of the acid sites are covered by carbenium ions, less than 2% of which corresponds to cyclic type species including allylic ones.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11775167,61574171,11575138,and 11835006)
文摘This paper presents an investigation into the impact of proton-induced alteration of carrier lifetime on the singleevent transient(SET) caused by heavy ions in silicon–germanium heterojunction bipolar transistor(SiGe HBT).The ioninduced 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.
基金Project supported by the National Natural Science Foundation of China(Grant No.61376109)the Opening Project of National Key Laboratory of Science and Technology on Reliability Physics and Application Technology of Electrical Component,China(Grant No.ZHD201202)
文摘As integrated circuits scale down in size, a single high-energy ion strike often affects multiple adjacent logic nodes.The so-called single-event transient（SET） pulse quenching induced by single-event charge sharing collection has been widely studied. In this paper, SET pulse quenching enhancement is found in dummy gate isolated adjacent logic nodes compared with that isolated by the common shallow trench isolation（STI）. The physical mechanism is studied in depth and this isolation technique is explored for SET mitigation in combinational standard cells. Three-dimensional（3D） technology computer-aided design simulation（TCAD） results show that this technique can achieve efficient SET mitigation.
文摘This paper presents two approaches to perform the electronic device heating during radiation hardness assurance tests.Commonly used conductive heating approach is compared with contactless laser-based approach,characteristics and limitations of these methods are described.Experimental results for temperature dependence of single-event latchup(SEL)cross-section during heavy ion irradiation along with some aspects of physics-based numerical simulation of heat transfer processes are presented.
基金Project supported by Funds of Key Laboratory,China(Grant No.y7ys011001)Youth Innovation Promotion Association,Chinese Academy of Sciences(Grant No.y5yq01r002)
文摘In this study, we investigate the single-event transient（SET） characteristics of a partially depleted silicon-on-insulator（PDSOI） metal-oxide-semiconductor（MOS） device induced by a pulsed laser.We measure and analyze the drain transient current at the wafer level. The results indicate that the body-drain junction and its vicinity are more SET sensitive than the other regions in PD-SOI devices.We use ISE 3D simulation tools to analyze the SET response when different regions of the device are hit. Then, we discuss in detail the characteristics of transient currents and the electrostatic potential distribution change in devices after irradiation. Finally, we analyze the parasitic bipolar junction transistor（p-BJT） effect by performing both a laser test and simulations.
基金supported by the National Natural Science Foundation of China(Nos.60836004,60676010)the PhD Program of Ministry of Education of China(No.20079998015)the Program for Changjiang Scholars and Innovative Research Team in University of China
文摘A radiation-hardened-by-design （RHBD） technique for phase-locked loops （PLLs） has been developed for single-event transient （SET） mitigation. By presenting a novel SET-resistant complementary current limiter （CCL） and implementing it between the charge pump （CP） and the loop filter （LPF）, the PLL＇s single-event susceptibility is significantly decreased in the presence of SETs in CPs, whereas it has little impact on the loop parameters in the absence of SETs in CPs. Transistor-level simulation results show that the CCL circuit can significantly reduce the voltage perturbation on the input of the voltage-controlled oscillator （VCO） by up to 93.1% and reduce the recovery time of the PLL by up to 79.0%. Moreover, the CCL circuit can also accelerate the PLL recovery procedure from loss of lock due to phase or frequency shift, as well as a single-event strike.
基金supported by the Harbin Science and Innovation Research.(Grant No.2012RFXXG042)
文摘Single-event transient pulse quenching （Quenching effect） is employed to effectively mitigate WSET （SET pulse width）. It en- hanced along with the increased charge sharing which is norm for future advanced technologies. As technology scales, param- eter variation is another serious issue that significantly affects circuit＇s performance and single-event response. Monte Carlo simulations combined with TCAD （Technology Computer-Aided Design） simulations are conducted on a six-stage inverter chain to identify and quantify the impact of charge sharing and parameter variation on pulse quenching. Studies show that charge sharing induce a wider WSET spread range. The difference of WSET range between no quenching and quenching is smaller in NMOS （N-Channel Metal-Oxide-Semiconductor Field-Effect Transistor） simulation than that in PMOS＇ （P-Channel Met- N-Oxide-Semiconductor Field-Effect Transistor）, so that from parameter variation view, quenching is beneficial in PMOS SET mitigation. The individual parameter analysis indicates that gate oxide thickness （TOXE） and channel length variation （XL） mostly affect SET response of combinational circuits. They bring 14.58% and 19.73% average WSET difference probabilities for no-quenching cases, and 105.56% and 123.32% for quenching cases.
文摘Single-event effects of nano scale integrated circuits are investigated. Evaluation methods for singleevent transients, single-event upsets, and single-event functional interrupts in nano circuits are summarized and classified in detail. The difficulties in SEE testing are discussed as well as the development direction of test technology, with emphasis placed on the experimental evaluation of a nano circuit under heavy ion, proton, and laser irradiation. The conclusions in this paper are based on many years of testing at accelerator facilities and our present understanding of the mechanisms for SEEs, which have been well verified experimentally.
基金Project supported by the National Natural Science Foundation of China(Nos.61404161,61404068,61404169)
文摘We present a single-event burnout（SEB） hardened planar power MOSFET with partially widened trench sources by three-dimensional（3 D） numerical simulation. The advantage of the proposed structure is that the work of the parasitic bipolar transistor inherited in the power MOSFET is suppressed effectively due to the elimination of the most sensitive region（P-well region below the N＋ source）. The simulation result shows that the proposed structure can enhance the SEB survivability significantly. The critical value of linear energy transfer（LET）,which indicates the maximum deposited energy on the device without SEB behavior, increases from 0.06 to0.7 p C/μm. The SEB threshold voltage increases to 120 V, which is 80% of the rated breakdown voltage. Meanwhile, the main parameter characteristics of the proposed structure remain similar with those of the conventional planar structure. Therefore, this structure offers a potential optimization path to planar power MOSFET with high SEB survivability for space and atmospheric applications.
