Total Ionizing Dose Radiation Effects on MOS Transistors with Different Layouts

Both nMOS and pMOS transistors with two-edged and multi-finger layouts are fabricated in a standard commercial 0.6μm CMOS/bulk process to study their total ionizing dose （TID） radiation effects. The leakage current, threshold voltage shift, and transconductance of the devices are monitored before and after T-ray irradiation. Different device bias conditions are used during irradiation. The experiment results show that TID radiation effects on nMOS devices are very sensitive to their layout structures. The impact of the layout on TID effects on pMOS devices is slight and can be neglected.

Total Ionizing Dose Radiation Effects in the P-Type Polycrystalline Silicon Thin Film Transistors

The total ionizing dose radiation effects in the polycrystalline silicon thin film transistors are studied. Transfer characteristics, high-frequency capacitance-voltage curves and low-frequency noises (LFN) are measured before and after radiation. The experimental results show that threshold voltage and hole-field-effect mobility decrease, while sub-threshold swing and low-frequency noise increase with the increase of the total dose. The contributions of radiation induced interface states and oxide trapped charges to the shift of threshold voltage are also estimated. Furthermore, spatial distributions of oxide trapped charges before and after radiation are extracted based on the LFN measurements.

Synergistic effects of total ionizing dose and radiated electromagnetic interference on analog-to-digital converter

The influence of combined total ionization dose(TID)and radiated electromagnetic interference(EMI)in a commercial analog-to-digital converter(ADC)was studied.The degradation of the direct-current response,the static parameters,and the dynamic parameters caused by the TID and EMI separately and synergistically is presented.The experimental results demonstrate that the increase in TID intensifies data error and the signal-tonoise ratio(SNR)degradation caused by radiated EMI.The cumulative distribution function of EMI failure with respect to data error and SNR with different TIDs was extracted.The decreasing trend of the threshold was acquired with a small sample size of five for each TID group.The result indicates that the ADC is more sensitive in a compound radiation environment.

New Method of Total Ionizing Dose Compact Modeling in Partially Depleted Silicon-on-Insulator MOSFETs

On the basis of a detailed discussion of the development of total ionizing dose （TID） effect model, a new commercial-model-independent TID modeling approach for partially depleted silicon-on-insulator metal-oxide- semiconductor field effect transistors is developed. An exponential approximation is proposed to simplify the trap charge calculation. Irradiation experiments with 60Co gamma rays for IO and core devices are performed to validate the simulation results. An excellent agreement of measurement with the simulation results is observed.

Machine learning-based analyses for total ionizing dose effects in bipolar junction transistors

Machine learning methods have proven to be powerful in various research fields.In this paper,we show that research on radiation effects could benefit from such methods and present a machine learning-based scientific discovery approach.The total ionizing dose(TID)effects usually cause gain degradation of bipolar junction transistors(BJTs),leading to functional failures of bipolar integrated circuits.Currently,many experiments of TID effects on BJTs have been conducted at different laboratories worldwide,producing a large amount of experimental data which provides a wealth of information.However,it is difficult to utilize these data effectively.In this study,we proposed a new artificial neural network(ANN)approach to analyze the experimental data of TID effects on BJTs An ANN model was built and trained using data collected from different experiments.The results indicate that the proposed ANN model has advantages in capturing nonlinear correlations and predicting the data.The trained ANN model suggests that the TID hardness of a BJT tends to increase with base current I.A possible cause for this finding was analyzed and confirmed through irradiation experiments.

Total ionizing dose induced single transistor latchup in 130-nm PDSOI input/output NMOSFETs

Total ionizing dose induced single transistor latchup effects for 130 nm partially depleted silicon-on-insulator （PDSOI） NMOSFETs with the bodies floating were studied in this work. The latchup phenomenon strongly correlates with the bias configuration during irradiation. It is found that the high body doping concentration can make the devices less sensitive to the single transistor latchup effect, and the onset drain voltage at which latchup occurs can degrade as the total dose level rises. The mechanism of band-to-band tunneling （BBT） has been discussed. Two-dimensional simulations were conducted to evaluate the BBT effect. It is demonstrated that BBT combined with the positive trapped charge in the buried oxide （BOX） contributes a lot to the latchup effect.

Influence of characteristics' measurement sequence on total ionizing dose effect in PDSOI nMOSFET

The influence of characteristics’ measurement sequence on total ionizing dose effect in partially-depleted SOI nMOSFET is comprehensively studied. We find that measuring the front-gate curves has no influence on total ionizing dose effect.However, the back-gate curves’ measurement has a great influence on total ionizing dose effect due to high electric field in the buried oxide during measuring. In this paper, we analyze their mechanisms and we find that there are three kinds of electrons tunneling mechanisms at the bottom corner of the shallow trench isolation and in the buried oxide during the backgate curves’ measurement, which are: Fowler–Nordheim tunneling, trap-assisted tunneling, and charge-assisted tunneling.The tunneling electrons neutralize the radiation-induced positive trapped charges, which weakens the total ionizing dose effect. As the total ionizing dose level increases, the charge-assisted tunneling is enhanced by the radiation-induced positive trapped charges. Hence, the influence of the back-gate curves’ measurement is enhanced as the total ionizing dose level increases. Different irradiation biases are compared with each other. An appropriate measurement sequence and voltage bias are proposed to eliminate the influence of measurement.

Total ionizing dose effect in an input/output device for flash memory

Input/output devices for flash memory are exposed to gamma ray irradiation. Total ionizing dose has been shown great influence on characteristic degradation of transistors with different sizes. In this paper, we observed a larger increase of off-state leakage in the short channel device than in long one. However, a larger threshold voltage shift is observed for the narrow width device than for the wide one, which is well known as the radiation induced narrow channel effect. The radiation induced charge in the shallow trench isolation oxide influences the electric field of the narrow channel device. Also, the drain bias dependence of the off-state leakage after irradiation is observed, which is called the radiation enhanced drain induced barrier lowing effect. Finally, we found that substrate bias voltage can suppress the off-state leakage, while leading to more obvious hump effect.

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.

Total Ionizing Dose Radiation Effects of RF PDSOI LDMOS Transistors

The effects of total ionizing dose radiation on direct current （DC） and small-signal radio frequency （RF） performance of multi-finger RF partial deplete silicon-on-insulator lateral double diffused MOS （PDSOI LDMOS） transistors are investigated. The radiation response of the LDMOS transistors with different device structures is characterized for an equivalent gamma dose up to 1Mrad（Si） at room temperature. The front and back gate threshold voltages, off-state leak- age, transconductance, and output characteristics are measured before and after radiation, and the results show a significant degradation of DC performance. Moreover, high frequency measurements for the irradiated transistors indicate remarkable declines of S-parameters, cutoff frequency, and maximum oscillation frequency to 1Mrad（Si） exposure levels. Compared to the transistors with the BTS contact structure,the transistors with the LBBC contact do not show its excellent DC radiation hardness when the transistors operate at alternating current （AC） mode.

Total ionizing dose radiation effects on NMOS parasitic transistors in advanced bulk CMOS technology devices

In this paper, total ionizing dose effect of NMOS transistors in advanced CMOS technology are exam- ined. The radiation tests are performed at 60Co sources at the dose rate of 50 rad （Si）/s. The investigation＇s results show that the radiation-induced charge buildup in the gate oxide can be ignored, and the field oxide isolation struc- ture is the main total dose problem. The total ionizing dose （TID） radiation effects of field oxide parasitic transistors are studied in detail. An analytical model of radiation defect charge induced by TID damage in field oxide is estab- lished. The I-V characteristics of the NMOS parasitic transistors at different doses are modeled by using a surface potential method. The modeling method is verified by the experimental I V characteristics of 180 nm commer- cial NMOS device induced by TID radiation at different doses. The model results are in good agreement with the radiation experimental results, which shows the analytical model can accurately predict the radiation response characteristics of advanced bulk CMOS technology device.

Impact of substrate bias on radiation-induced edge effects in MOSFETs

This paper investigates the effects of gamma-ray irradiation on the Shallow-Trench Isolation （STI） leakage currents in 180-nm complementary metal oxide semiconductor technology. No hump effect in the subthreshold region is observed after irradiation, which is considered to be due to the thin STI corner oxide thickness. A negative substrate bias could effectively suppress the STI leakage, but it also impairs the device characteristics. The three-dimensional simulation is introduced to understand the impact of substrate bias, Moreover, we propose a simple method for extracting the best substrate bias value, which not only eliminates the STI leakage but also has the least impact on the device characteristics.

Effect of total ionizing dose radiation on the 0.25 μm RF PDSOI nMOSFETs with thin gate oxide

Thin gate oxide radio frequency （RF） PDSOI nMOSFETs that are suitable for integration with 0.1μm SO1 CMOS technology are fabricated, and the total ionizing dose radiation responses of the nMOSFETs having four different device structures are characterized and compared for an equivalent gamma dose up to 1 Mrad （Si）, using the front and back gate threshold voltages, off-state leakage, transconductance and output characteristics to assess direct current （DC） performance. Moreover, the frequency response of these devices under total ionizing dose radiation is presented, such as small-signal current gain and maximum available/stable gain. The results indicate that all the RF PDSOI nMOSFETs show significant degradation in both DC and RF characteristics after radiation, in particular to the float body nMOS. By comparison with the gate backside body contact （GBBC） structure and the body tied to source （BTS） contact structure, the low barrier body contact （LBBC） structure is more effective and excellent in the hardness of total ionizing dose radiation although there are some sacrifices in drive current, switching speed and high frequency response.

Comparison of radiation degradation induced by x-ray and 3-MeV protons in 65-nm CMOS transistors

The total ionizing dose（TID） response of 65-nm CMOS transistors is studied by 10-ke V x-ray and 3-Me V protons up to 1 Grad（SiO_2） total dose.The degradation levels induced by the two radiation sources are different to some extent.The main reason is the interface dose enhancement due to the thin gate oxide and the low energy photons.The holes＇ recombination also contributes to the difference.Compared to these two mechanisms,the influence of the dose rate is negligible.

In-Flight Total Dose Estimation Using RADEM Instrument on JUICE

Missions flying to giant planets frequently provide telemetry data after substantial time lag. Determination of crucial environmental characteristic sometimes detrimental for the mission health may be further delayed by duration of subsequent data analysis. We propose a fast method used in-flight to assess the electron total ionizing dose and dose rate onboard of the JUICE ESA mission to JUPITER. The procedure provides estimated values of dose rate behind various thickness of shielding using counting rates from the electron telescope EHD of the RADEM radiation hard electron monitor instrument onboard JUICE.

功率集成电路TID加固环栅器件研究现状综述

总结了标准工艺下功率集成电路中总剂量辐射(TID)加固环栅MOS器件与环栅功率器件的研究现状,归纳了不同结构形态的环栅器件的性能优劣,推荐8字形环栅MOS器件、华夫饼功率器件及回字形LDMOS器件结构用于功率集成电路的TID加固设计。同时,阐述了现有环栅MOS器件等效W/L的建模情况,提出保角变换是环栅MOS器件等效W/L精确建模的重要方法,最后还给出了环栅器件建库的基本流程。

存储单元抗TID/SEL电路加固技术面积代价研究

在太空辐射环境中,总剂量辐射(Total Ionizing Dose,TID)效应和单粒子闩锁(Single Event Latch,SEL)效应严重影响存储器的可靠性.由此讨论了存储单元TID效应和SEL效应的原理,探讨了基于电路的加固技术(RHBD),设计了4种新的抗TID/SEL存储单元加固方案,并和现有几种方案进行对比,研究了这些加固方案的面积代价.研究结果表明,抗TID/SEL RHBD方案普遍会使存储单元的版图面积增加87.5%以上.提出了一种加固方案,可以在加固性能和面积代价上得到较好的折衷.

Modeling operation amplifier based on VHDL-AMS for TID effect

A model of the operational amplifier based on VHDL-AMS is proposed. According to needs of simulating the total ionizing dose(TID) radiation effect, parameters of operational amplifier are taken into account when the performance is specified. The operational amplifier model used for the TID radiation effect simulation is completed after verifying each modeled parameter. And a parameter for describing the external environment is introduced to make the model combined with TID. Finally, an example is used to illustrate the TID effect on the operational amplifier of MC14573, proving the validity of the model.

集成电路和功率器件抗辐射工艺加固技术研究综述

随着我国空间装备的高速发展,尤其是深空探测器,微电子器件抗辐射性能得到广泛关注。抗辐射工艺加固是实现器件抗辐射性能提升的重要途径之一。本文围绕空间总剂量效应和单粒子效应,对近年来集成电路和功率器件辐射效应机理和工艺加固技术的研究进展进行了介绍和总结,为抗辐射工艺加固技术的发展与应用提供了有益参考。

SOI高压LDMOS器件氧化层抗总电离剂量辐射效应研究

绝缘体上硅(SOI)高压横向扩散金属氧化物半导体(LDMOS)器件是高压集成电路的核心器件,对其进行了总电离剂量(TID)辐射效应研究。利用仿真软件研究了器件栅氧化层、场氧化层和埋氧化层辐射陷阱电荷对电场和载流子分布的调制作用,栅氧化层辐射陷阱电荷主要作用于器件沟道区,而场氧化层和埋氧化层辐射陷阱电荷则主要作用于器件漂移区;辐射陷阱电荷在器件内部感生出的镜像电荷改变了器件原有的电场和载流子分布,从而导致器件阈值电压、击穿电压和导通电阻等参数的退化。对80 V SOI高压LDMOS器件进行了总电离剂量辐射实验,结果表明在ON态和OFF态下随着辐射剂量的增加器件性能逐步衰退,当累积辐射剂量为200 krad(Si)时,器件的击穿电压大于80 V,阈值电压漂移为0.3 V,器件抗总电离剂量辐射能力大于200 krad(Si)。