65nm NOR型闪存芯片RTS噪声研究

发布时间：2018-09-04 08:41

【摘要】：大数据时代的到来对大容量存储器带来了新的机遇,同时也提出了新的挑战。浮栅存储器是目前应用最为广泛的非易失性存储器之一,占据了非易失性半导体存储器90%以上的市场。研究表明存储器尺寸的减小与工艺的改进会带来器件可靠性问题,这其中随机电报信号(RTS)的噪声问题由于器件工艺进入纳米时代而更为突出,噪声会带来信号的抖动,从而会影响信息读取的正确性,甚至会引起芯片功能与性能上的失效。本论文针对65nm工艺下NOR型闪存的随机电报噪声及其对于器件的可靠性影响展开研究。主要研究内容包括:获取了NOR型闪存随机电报噪声的基本参数;通过随机电报噪声分析得到了RTS缺陷空间与能级分布;基于俘获/发射截面模型研究了不同的阈值电压状态对于RTS时间常数的影响。通过大量实验,得到结论:随着阈值电压的增加,器件RTS噪声的俘获时间增加,发射时间减小;针对该现象,提出了俘获/发射截面模型加以解释。该工作主要创新点在于:首次研究了阈值电压对于RTS信号以及相应的RTS缺陷的影响,并建立了基于俘获/发射截面的物理模型;对于陷阱俘获/发射电子的过程,以及RTS噪声对于器件阈值电压的依赖有了更深刻的理解。这些结果对于NOR型闪存RTS噪音的物理机理、可靠性退化机制有着一定的科学意义。同时,为改善NOR型闪存的可靠性提供参考。
[Abstract]:The arrival of the big data era brings new opportunities and challenges to large-capacity memory. Floating gate memory is one of the most widely used non-volatile memory, occupying more than 90% of the market of non-volatile semiconductor memory. Research shows that the reduction of memory size and the improvement of process will bring about devices. Reliability, of which random telegraph signal (RTS) noise problem is more prominent because of the device technology into the nano-era, noise will bring signal jitter, which will affect the correctness of information read, and even cause chip failure in function and performance. The main research contents are as follows: the basic parameters of NOR flash random telegraph noise are obtained; the defect space and energy level distribution of RTS are obtained by random telegraph noise analysis; and the influence of different threshold voltage states on RTS time constant is studied based on capture/emission cross section model. After a lot of experiments, it is concluded that with the increase of threshold voltage, the capture time of RTS noise increases and the emission time decreases, and a capture/emission cross section model is proposed to explain the phenomenon. The physical model of capture/emission cross section, the process of trapping/emission of electrons, and the dependence of RTS noise on the threshold voltage of the device have been deeply understood. These results have certain scientific significance for the physical mechanism of NOR flash RTS noise and the mechanism of reliability degradation. For reference.
【学位授予单位】：郑州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP333;TN40

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