FinFET SRAM辐射效应仿真建模研究

发布时间：2018-03-10 11:10

本文选题：辐射效应　切入点：FinFET　出处：《西安电子科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着国防军事事业的快速发展,核辐射环境问题也越来越复杂而广泛存在,器件和系统的可靠性越来越被重视,因此,从长远来看,抗辐射问题必然要成为整个电子技术的一个基础,而对整个电子技术产生影响。例如,在对新电子器件的研制过程中,一开始就应该考虑到辐射的问题;而对于电子系统的设计,在设计开始时就要考虑如何提高抗辐射能力,这将成为一个设计原则。而由于难以在实验室中得到空间中各种真实的辐射环境,所以有必要对辐射效应的模拟仿真做深入研究,从而解决真实实验所不能解决的问题,模拟所得到的结果一样可以对器件或系统设计提供一定的数据参考。本文从辐射效应的角度出发,对影响器件正常工作的总剂量效应、单粒子翻转效应和瞬时辐射效应进行了研究,取得了下面三方面的研究成果:1、介绍了SOI FinFET器件的结构,并通过Silvaco TCAD对其进行了建模和仿真,研究了器件阈值电压随辐射剂量的影响,对比了宽Fin器件与窄Fin器件处在相同的辐射剂量下的阈值电压的漂移程度,由仿真结果可知:(1)当以200krad(Si)的辐射剂量入射时,SOI FinFET器件阈值电压的漂移现象就已经变的非常明显了,而当以超过400krad(Si)的辐射剂量入射时,SOI FinFET器件的阈值电压漂移量则逐渐趋于平缓;(2)当辐射剂量达到200 krad(Si)时,宽Fin器件的阈值电压就已经有了较大的漂移,几乎达到了窄Fin器件的4倍。2、研究了单粒子翻转的机理,电荷的收集模式,并继续基于Silvaco TCAD对SOI FinFET器件进行了单粒子翻转效应的仿真模拟,得到了漏极电流随时间的变化关系,并以Messenger提出的经典的双指数曲线模型为原型,通过最小二乘法拟合,得到了单粒子翻转效应的电流脉冲表达式,并将其带入用Cadence软件所画的基于SOI Fin FET的6T SRAM存储单元,从而进行电路模拟,得到了令此存储单元产生翻转的LET范围在40MeV·cm2/mg到50MeV·cm2/mg之间。3、对瞬时辐射效应和单粒子效应进行了区分,并简要介绍了蒙特卡罗工具包Geant4的内核结构和主要功能模块,并针对瞬时辐射效应、FinFET结构和粒子能量所对应的物理模型,对Geant4程序进行了编写;研究了瞬时辐射效应产生电流脉冲的模型,并将其带入用Cadence软件所画的基于SOI FinFET的6T SRAM中,从而模拟瞬时辐射效应,得到了令此存储单元产生翻转的电流峰值阈值为0.991mA,然后通过使用假定的电流脉冲模型,得到了SOI FinFET结构被质子(30MeV)、负电子(50keV)、X射线(10keV)分别从器件正向和背向入射时的“粒子数量阈值”,从而得出对于SOI FinFET结构抗质子和X射线瞬时辐射时,应该正面加固强于背面加固,而对于抗负电子瞬时辐射时,背面加固应该强于正面加固的结论;接着又对比了SOI FinFET结构和体硅FinFET结构的抗瞬时辐射能力,得到了SOI FinFET结构的抗瞬时辐射能力要远远好于体硅FinFET结构的结论。最后,通过考虑粒子入射的真实情况还有器件本身的双极放大效应后,对本文假定的瞬时辐射效应产生的电流脉冲模型进行了解释说明。
[Abstract]:With the rapid development of national defense and military industry, nuclear radiation environmental problems become more and more complex and widely exist, the reliability of devices and systems more and more attention, therefore, in the long run, anti radiation problem is bound to become a foundation of the electronic technology, the electronic technology and the impact. For example, in the development process the new electronic devices in the beginning should consider the issue of radiation; and for the design of electronic system, we must consider how to improve the anti radiation ability in the design at the beginning, it will become a design principle. And because of the difficulty to get the real space radiation environment in the laboratory, it is necessary to study of simulation on radiation effects, so as to solve the real problems that cannot be solved, simulation results on the device or system design can provide certain reference data. This paper from the perspective of radiation effects, the total dose effect of the device work, SEU effect and transient radiation effects were studied. The research results have been achieved the following three aspects: 1, introduces the structure of SOI FinFET device, and through the Silvaco TCAD modeling and Simulation of the influence of the threshold voltage. The device with the radiation dose of the contrast degree, drift wide Fin devices and Fin devices in a narrow threshold voltage under the same radiation dose, the simulation results show that: (1) to 200krad (Si) when the incident radiation dose, drift SOI threshold voltage of the FinFET device has become very clear and when, with more than 400krad (Si) of the incident radiation dose, the threshold voltage shift of SOI FinFET devices are gradually flatten; (2) when the radiation dose is 200 krad (Si), the threshold voltage of Fin devices have wide The large drift, almost 4 times the.2 narrow Fin devices, studies the mechanism of SEU, charge collection mode, and continue to Silvaco TCAD simulation of single eventupset effects on SOI FinFET devices based on the relationship between the drain current changes with time, and double exponential curve model based on Messenger's classic prototype, fitted by least square method, the current pulse expression of single eventupset effects are obtained, and bring it into 6T SRAM SOI Fin FET storage unit based on the painting by Cadence software, and in circuit simulation, has been to the memory cell flip in the range of 40MeV LET cm2/mg to 50MeV - cm2/mg between.3, the instantaneous radiation effect and single event effect were distinguished, and briefly introduces the kernel structure of Monte Carlo Geant4 toolkit and main function modules, and the instantaneous radiant Shot effect, physical model corresponding to FinFET structure and energy of particles, the Geant4 program was written; on the instantaneous radiation effect of current pulse model, and bring it into the picture with Cadence software based on SOI FinFET 6T SRAM, to simulate the transient radiation effect, the peak current of the threshold the storage unit flip is 0.991mA, and then through the pulse current using the assumed model, obtained the SOI FinFET structure by proton (30MeV), negative (50keV), X ray electronic (10keV) device respectively from the forward and back to the incident "the number of particles, so that the threshold for proton anti SOI structure and FinFET the instantaneous X ray radiation, should be positive reinforcement in the back reinforcement, and for the anti negative electron instantaneous radiation, the back reinforcement should be stronger than the positive reinforcement of the conclusion; then compared the SOI FinFET structure and bulk silicon FinFET junction Transient radiation ability structure, the transient radiation ability of SOI FinFET structure is much better than that of bulk silicon FinFET structure conclusions. Finally, by considering the real situation of the incident particle and the amplification effect of bipolar devices itself, the assumption of instantaneous radiation generated by the pulse current effect model were explained.

【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TP333

【共引文献】