基于FinFET SRAM单粒子效应仿真研究

发布时间：2018-06-11 13:15

本文选题：FinFET + 单粒子翻转效应　；参考：《西安电子科技大学》2015年硕士论文

【摘要】：随着国防军事的迅速发展,IC芯片因辐射效应导致的问题也越来越严重,电子元器件及芯片系统在辐射环境下可靠性研究变得更加重要,从未来发展来看,抗辐射效应加固的问题可能成为影响整个半导体行业发展一个重要因素,对抗辐射问题的研究对半导体技术产生深刻影响。比如,当一个新型元器件研制出来后首先就要对它进行辐射可靠性测试,对芯片系统设计的过程当中提高它的抗辐射能力一直是此过程当中重要目标。因为在实验室中存在各种局限难以开展空间辐射效应的实验,所以对辐射效应进行模拟仿真变得很重要,仿真所得数据结论也可以对电子元器件或芯片系统设计提供一定参考。本文从介绍各种辐射效应环境角度出发,重点分析了单粒子辐射效应对FinFET新型器件的影响,通过对FinFET的单粒子效应的仿真分析得到了下面三个方面的研究成果:1、介绍了FinFET新型器件的工作原理及其优势,并利用Sentaurus TCAD软件建立了它的三维结构模型,基于重粒子轰击理论模型模拟了不同能量的重粒子轰击FinFET器件漏极而产生的单粒子效应,研究结果表明,当FinFET漏区受到重粒子轰击时,由于重粒子在穿透路径上沉积能量而产生电子空穴对,并在外电场的作用下分离,从而产生一个漏极脉冲电流,这个电流跟经典双指数脉冲电流一致,随粒子的LET值增加而变大。2、通过对比分析得知:体硅FinFET由于比平面MOSFET的敏感体积小因此它的抗单粒子翻转效应能力强;针对SOI和体硅两种不同结构的FinFET,SOI结构存在埋氧层隔离使得衬底里面产生的电荷不能被漏端收集,因而SOI结构比体硅结构抗辐射能力好;可以通过适当提高源端电压减弱寄生双极放大效应和降低鳍的高度来缩短单粒子在硅体中的径迹路径来提高抗辐射能力。由这些对比分析得知寄生双极晶体管对漏端脉冲电流的贡献不如忽视,用寄生双极放大因子α来衡量贡献大小,通过计算发现α随鳍高增加而非线性增加,提高源端电压α值变小,SOI结构的α值比体硅结构大。3、使用Hspice仿真软件对基于FinFET结构SRAM电路进行抗单粒子翻转效应的加固设计,首先简要介绍了BSIM-CMG库模型,这个spice模型库是标准FinFET模型;接着基于提高源端电压可减弱寄生双极放大效应的理论基础上提出了五种不同的SRAM存储单元;最后对比分析了类型A和类型E的抗单粒子翻转的能力以及这五种SRAM单元的静态噪声裕度、读噪声裕度和写噪声裕度,为设计具有抗单粒子翻转能力的SRAM单元提供了一定依据。
[Abstract]:With the rapid development of national defense and military, the problem of IC chip caused by radiation effect is becoming more and more serious. The research of reliability of electronic components and chip system in radiation environment becomes more and more important. The problem of anti-radiation effect reinforcement may become an important factor affecting the development of semiconductor industry, and the study of radiation resistance has a profound impact on semiconductor technology. For example, when a new type of component is developed, it is necessary to test its radiation reliability first, and it is an important goal to improve its anti-radiation ability in the process of chip system design. Because there are various limitations in the laboratory, it is difficult to carry out the experiment of space radiation effect, so it is very important to simulate and simulate the radiation effect. The conclusion of the simulation data can also provide some reference for the design of electronic component or chip system. In this paper, from the point of view of introducing various radiation effects, the influence of single particle radiation effect on FinFET novel devices is analyzed. Through the simulation analysis of single particle effect of FinFET, the following three aspects of research result: 1 are obtained. The principle and advantages of FinFET new device are introduced, and the three-dimensional structure model of FinFET is established by using Saurus TCAD software. Based on the theoretical model of heavy particle bombardment, the single particle effect caused by heavy particle bombarding FinFET devices with different energies is simulated. The results show that, when the FinFET leakage region is bombarded by heavy particles, Due to the deposition of energy on the penetration path by heavy particles, an electron hole pair is produced and separated by an external electric field, which generates a drain pulse current, which is consistent with the classical double exponential pulse current. With the increase of let value of particles, it becomes larger. 2. Through comparative analysis, it is found that bulk silicon FinFET has stronger anti-single particle flip effect because of its smaller sensitive volume than planar MOSFET. For the two different structures of SOI and bulk silicon, the buried oxygen layer exists in the SOI structure, so the charge generated in the substrate can not be collected by the drain end, so the SOI structure has better radiation resistance than the bulk silicon structure. The anti-radiation ability can be improved by properly increasing the source terminal voltage to reduce the parasitic bipolar amplification effect and to reduce the height of the fin to shorten the track path of single particle in the silicon body. It is found that the contribution of parasitic bipolar transistors to the leakage pulse current is not as good as that of the parasitic bipolar transistors. The contribution is measured by the parasitic bipolar amplification factor 伪. It is found by calculation that 伪 increases nonlinear with the increase of fin height. The 伪 value of SOI structure is larger than that of bulk silicon structure by increasing the source voltage. The SRAM circuit based on FinFET structure is strengthened with HSPICE simulation software. Firstly, the BSIM-CMG library model is introduced briefly. The spice model base is a standard FinFET model, and then five different memory cells are proposed based on the theory that increasing the source voltage can reduce the parasitic bipolar amplification effect. Finally, the ability of type A and type E to resist single particle flipping and the static noise margin, read noise margin and write noise margin of the five SRAM cells are compared and analyzed, which provides a basis for the design of SRAM cells with the ability to resist single particle flipping.
【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】：TN386

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