应用负偏置温度不稳定性(negative bias temperature instability,NBTI),退化氢分子的漂移扩散模型,与器件二维数值模拟软件结合在一起进行计算,并利用已有的实验数据和基本器件物理和规律,分析直流应力NBTI效应随器件沟道长度、栅氧层...应用负偏置温度不稳定性(negative bias temperature instability,NBTI),退化氢分子的漂移扩散模型,与器件二维数值模拟软件结合在一起进行计算,并利用已有的实验数据和基本器件物理和规律,分析直流应力NBTI效应随器件沟道长度、栅氧层厚度和掺杂浓度等基本参数的变化规律,是研究NBTI可靠性问题发生和发展机理变化的一种有效方法.分析结果显示,NBTI效应不受器件沟道长度变化的影响,而主要受到栅氧化层厚度变化的影响;栅氧化层厚度的减薄和栅氧化层电场增强的影响是一致的,决定了器件退化按指数规律变化;当沟道掺杂浓度提高,NBTI效应将减弱,这是因为器件沟道表面空穴浓度降低引起的;然而当掺杂浓度提高到器件的源漏泄漏电流很小时(小泄露电流器件),NBTI效应有明显的增强.这些结论对认识NBTI效应的发展规律以及对高性能器件的设计具有重要的指导意义.展开更多
A simple standard reaction-diffusion（RD） model assumes an infinite oxide thickness and a zero initial interface trap density, which is not the case in real MOS devices.In this paper, we numerically solve the RD mode...A simple standard reaction-diffusion（RD） model assumes an infinite oxide thickness and a zero initial interface trap density, which is not the case in real MOS devices.In this paper, we numerically solve the RD model by taking into account the finite oxide thickness and an initial trap density.The results show that trap generation/ passivation as a function of stress/recovery time is strongly affected by the condition of the gate-oxide/poly-Si boundary.When an absorbent boundary is considered, the RD model is more consistent with the measured interfacetrap data from CMOS devices under bias temperature stress.The results also show that non-negligible initial traps should affect the power index n when a power law of the trap generation with the stress time, tn, is observed in the diffusion limited region of the RD model.展开更多
The exponent n of the generation of an interface trap （Nit）, which contributes to the power-law negative bias temperature instability （NBTI） degradation, and the exponent’s time evolution are investigated by simu...The exponent n of the generation of an interface trap （Nit）, which contributes to the power-law negative bias temperature instability （NBTI） degradation, and the exponent’s time evolution are investigated by simulations with varying the stress voltage Vg and temperature T. It is found that the exponent n in the diffusion-limited phase of the degradation process is irrelevant to both Vg and T. The time evolution of the exponent n is affected by the stress conditions, which is reflected in the shift of the onset of the diffusion-limited phase. According to the diffusion profiles, the generation of the atomic hydrogen species, which is equal to the buildup of Nit, is strongly correlated with the stress conditions, whereas the diffusion of the hydrogen species shows Vg-unaffected but T-affected relations through the normalized results.展开更多
The NBTI degradation phenomenon and the role of hydrogen during NBT stress are presented in this paper. It is found that PBT stress can recover a fraction of Vth shift induced by NBT1. However, this recovery is unstab...The NBTI degradation phenomenon and the role of hydrogen during NBT stress are presented in this paper. It is found that PBT stress can recover a fraction of Vth shift induced by NBT1. However, this recovery is unstable. The original degradation reappears soon after reapplication of the NBT stress condition. Hydrogen-related species play a key role during a device＇s NBT degradation. Experimental results show that the diffusion species are neutral, they repassivate Si dangling bond which is independent of the gate voltage polaxity. In addition to the diffusion towards gate oxide, hydrogen diffusion to Si-substrate must be taken into account for it also has important influence on device degradation during NBT stress.展开更多
The effect of the static negative bias temperature （NBT） stress on a p-channel power metal-oxide-semiconductor field-effect transistor （MOSFET） is investigated by experiment and simulation. The time evolution of t...The effect of the static negative bias temperature （NBT） stress on a p-channel power metal-oxide-semiconductor field-effect transistor （MOSFET） is investigated by experiment and simulation. The time evolution of the negative bias temperature instability （NBTI） degradation has the trend predicted by the reaction-diffusion （R-D） model but with an exaggerated time scale. The phenomena of the flat-roof section are observed under various stress conditions, which can be considered as the dynamic equilibrium phase in the R-D process. Based on the simulated results, the variation of the flat-roof section with the stress condition can be explained.展开更多
The impact of negative bias temperature instability （NBTI） can be ascribed to three mutually uncorrelated factors, including hole trapping by pre-existing traps （△ VHT） in gate insulator, generated traps （△ VOT...The impact of negative bias temperature instability （NBTI） can be ascribed to three mutually uncorrelated factors, including hole trapping by pre-existing traps （△ VHT） in gate insulator, generated traps （△ VOT） in bulk insulator, and interface trap generation （△ VIT）. In this paper, we have experimentally investigated the NBTI characteristic for a 40-nm complementary metal-oxide semiconductor （CMOS） process. The power-law time dependence, temperature activation, and field acceleration have also been explored based on the physical reaction-diffusion model. Moreover, the end-of-life of stressed device dependent on the variation of stress field and temperature have been evaluated. With the consideration of locking effect, the recovery characteristics have been modelled and discussed.展开更多
基金Supported by Major Program of National Natural Science Foundation of China(71490725)National Key Basic Research Program of China(2013CB329600)+1 种基金National Science Foundation of China(9154611,71371062)Key Project of Natural Science of Anhui Province Education Department(KJ2015A348)
文摘应用负偏置温度不稳定性(negative bias temperature instability,NBTI),退化氢分子的漂移扩散模型,与器件二维数值模拟软件结合在一起进行计算,并利用已有的实验数据和基本器件物理和规律,分析直流应力NBTI效应随器件沟道长度、栅氧层厚度和掺杂浓度等基本参数的变化规律,是研究NBTI可靠性问题发生和发展机理变化的一种有效方法.分析结果显示,NBTI效应不受器件沟道长度变化的影响,而主要受到栅氧化层厚度变化的影响;栅氧化层厚度的减薄和栅氧化层电场增强的影响是一致的,决定了器件退化按指数规律变化;当沟道掺杂浓度提高,NBTI效应将减弱,这是因为器件沟道表面空穴浓度降低引起的;然而当掺杂浓度提高到器件的源漏泄漏电流很小时(小泄露电流器件),NBTI效应有明显的增强.这些结论对认识NBTI效应的发展规律以及对高性能器件的设计具有重要的指导意义.
基金supported by the Micro/Nanoelectronics Science & Technology Innovation Platform,Fudan University
文摘A simple standard reaction-diffusion（RD） model assumes an infinite oxide thickness and a zero initial interface trap density, which is not the case in real MOS devices.In this paper, we numerically solve the RD model by taking into account the finite oxide thickness and an initial trap density.The results show that trap generation/ passivation as a function of stress/recovery time is strongly affected by the condition of the gate-oxide/poly-Si boundary.When an absorbent boundary is considered, the RD model is more consistent with the measured interfacetrap data from CMOS devices under bias temperature stress.The results also show that non-negligible initial traps should affect the power index n when a power law of the trap generation with the stress time, tn, is observed in the diffusion limited region of the RD model.
基金Project supported by the National Basic Research Program of China(Grant No.2011CBA00606)the National Natural Science Foundation of China(Grant No.61106106)the Fundamental Research Funds for the Central Universities,China(Grant No.K50511250008)
文摘The exponent n of the generation of an interface trap （Nit）, which contributes to the power-law negative bias temperature instability （NBTI） degradation, and the exponent’s time evolution are investigated by simulations with varying the stress voltage Vg and temperature T. It is found that the exponent n in the diffusion-limited phase of the degradation process is irrelevant to both Vg and T. The time evolution of the exponent n is affected by the stress conditions, which is reflected in the shift of the onset of the diffusion-limited phase. According to the diffusion profiles, the generation of the atomic hydrogen species, which is equal to the buildup of Nit, is strongly correlated with the stress conditions, whereas the diffusion of the hydrogen species shows Vg-unaffected but T-affected relations through the normalized results.
基金Project supported by the National Natural Science Foundation of China （Grant No 60206006）, the Hi-Tech Research ＆ Development Program of China （Grant No 2004AA1Z1070） and the Key Project of Chinese Ministry of Education （Grant No 104172）.
文摘The NBTI degradation phenomenon and the role of hydrogen during NBT stress are presented in this paper. It is found that PBT stress can recover a fraction of Vth shift induced by NBT1. However, this recovery is unstable. The original degradation reappears soon after reapplication of the NBT stress condition. Hydrogen-related species play a key role during a device＇s NBT degradation. Experimental results show that the diffusion species are neutral, they repassivate Si dangling bond which is independent of the gate voltage polaxity. In addition to the diffusion towards gate oxide, hydrogen diffusion to Si-substrate must be taken into account for it also has important influence on device degradation during NBT stress.
基金Project supported by the National Basic Research Program of China(Grant No.2011CBA00606)the National Natural Science Foundation of China(Grant No.61106106)
文摘The effect of the static negative bias temperature （NBT） stress on a p-channel power metal-oxide-semiconductor field-effect transistor （MOSFET） is investigated by experiment and simulation. The time evolution of the negative bias temperature instability （NBTI） degradation has the trend predicted by the reaction-diffusion （R-D） model but with an exaggerated time scale. The phenomena of the flat-roof section are observed under various stress conditions, which can be considered as the dynamic equilibrium phase in the R-D process. Based on the simulated results, the variation of the flat-roof section with the stress condition can be explained.
基金supported by the National Natural Science Foundation of China(Grant Nos.61574056 and 61204038)the Natural Science Funds of Shanghai,China(Grant No.14ZR1412000)+1 种基金the Fund from the Science and Technology Commission of Shanghai Municipality(Grant No.14DZ2260800)Shanghai Sailing Program(Grant No.17YF1404700)
文摘The impact of negative bias temperature instability （NBTI） can be ascribed to three mutually uncorrelated factors, including hole trapping by pre-existing traps （△ VHT） in gate insulator, generated traps （△ VOT） in bulk insulator, and interface trap generation （△ VIT）. In this paper, we have experimentally investigated the NBTI characteristic for a 40-nm complementary metal-oxide semiconductor （CMOS） process. The power-law time dependence, temperature activation, and field acceleration have also been explored based on the physical reaction-diffusion model. Moreover, the end-of-life of stressed device dependent on the variation of stress field and temperature have been evaluated. With the consideration of locking effect, the recovery characteristics have been modelled and discussed.
