SONOS电荷俘获型非挥发存储器与浮栅型存储器相比，工艺兼容性好，电荷不易丢失等优点使其浮栅存储器的有利替代者。然而SONOS存储器的可靠性尤其是其电荷保持特性是限制其应用与发展的瓶颈，可靠性退化机理也有待进一步研究；而非挥发存储器在空间领域的应用又要求其需要在辐照环境中保持高可靠性。因此，对SONOS存储器可靠性的研究以及辐照环境下器件及系统特性的研究就非常有意义。 本论文首先对电荷俘获型SONOS存储器在区域化操作下的可靠性退化的机制进行了探讨，分析了在多次编程擦除操作后的电荷分布特性，即在多次编程擦除周期后，由于CHE注入电子和BBHH注入空穴的不匹配导致了电子空穴的共存，空间上的不匹配导致了电荷的内建电场会影响电荷的再分布与复合，从而导致电荷保持特性的退化。基于此建立了内建电场增强电荷丢失模型，并在模型的基础上，对不同P/E周期后空穴激发能级进行了计算。结果表明，P/E周期对氮化层俘获空穴分布的影响可以加深空穴分布的能级，并使得俘获空穴的能级分布变窄。 针对存储器的辐照特性，本论文准备了不同尺寸的SONOS器件和阵列，对SONOS存储器器件损伤机理进行了分析，辐射导致的SONSO阈值电压漂移包括两个部分：一是初始存储电荷的丢失（被激发）。处于编程态的器件中存储电荷为电子，处于擦除态的器件中存储电荷为空穴。二是由于电子、空穴陷阱密度的不均衡导致了“净正电荷”积累。并对原有的辐射损伤模型进行了修改，大量辐照实验的结果符合修改后的模型，也证明SONOS器件具有较好的抗辐射能力。最后，论文还对深亚微米下的隔离结构和PN结的辐照特性进行了建模和分析，栅控二极管等效模型被用来解释PN结辐照后漏电流增加的现象。

Compared to conventional floating gate flash memories，SONOS has shown great advantages in better scaling capability, better immunity to defects in the tunnel oxide and higher storage density. It has a great chance to take part of the floating gate. However, the reliability of SONOS, especially in retention becomes the bottleneck of its development. The mechanism of the degradation needs to be studied further, too. For more, nonvolatile memories used in spaces need to be function in radiation environments and keeping reliability. So it is meaningful to conduct researches in reliability mechanisms and radiation characteristic of SONOS memory. In this thesis, the reliability degradation mechanisms of localized charge trapping memory have been discussed firstly. Distributions of trapped electrons and holes after 1, 100 and 10000 program/erase (P/E) cycles have been plotted. After P/E cycling, the mismatch between ejected electrons and holes would cause the coexistence of holes and electrons, leading to an internal electric field. That electric field enhances the redistribution and recombination, which comes to the retention degradation. A novel internal electric field enhanced retention model for localized charge trapping memory devices is proposed to explain the reliability degradation. According to the model, the excitation energy level distribution profiles of trapped holes after different P/E cycling stress are demonstrated for the first time.Next, the SONOS total dose radiation characteristic is studied. The radiation-caused threshold voltage shift consists of two parts. First is the trapped charge emission, electrons in PGM stage and holes in ERS stage; second is the accumulation of holes. The modified model is proposed and fit for the experimental result. Last, the isolation structures and PN junctions in deep submicron process are also been researched and explained the radiation characteristic using Gated-Diode method.