Flash EEPROM threshold instabilities due to charge trapping during program/erase cycling
Flash EEPROM threshold instabilities due to charge trapping during program/erase cycling
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DOI：
10.1109/tdmr.2004.836721
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发表时间：
2004-12
影响因子：
2
通讯作者：
Neal Mielke;Hanmant Belgal;I. Kalastirsky;P. Kalavade;Andrew Kurtz;Qingru Meng;N. Righos;Jie Wu
中科院分区：
文献类型：
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作者：
Neal Mielke;Hanmant Belgal;I. Kalastirsky;P. Kalavade;Andrew Kurtz;Qingru Meng;N. Righos;Jie Wu
在闪存单元的编程/擦除循环中可能发生沟道上的电荷俘获，从而增加单元阈值电压并在电荷解除俘获时导致保持测试中的阈值偏移。这些影响的经验特征进行了讨论。陷印对编程/擦除周期计数具有平方根依赖性。脱陷比例与时间的对数，并与1.1至1.2 eV的活化能热加速。脱陷对电场的依赖性很弱。这些机制是内在的，但从一个细胞到另一个细胞的行为有很大的变化，与泊松统计变化有关。需要根据这一机制和其他机制的特点重新考虑常用的可靠性表征方法。特别地，执行周期之间没有延迟的广泛的编程/擦除循环对于这种机制是不现实的，并且提出了替代的分布式循环方案。
Charge trapping over the channel can occur from program/erase cycling of Flash memory cells, increasing the cell threshold voltage and causing threshold shifts in retention tests when charges detrap. The empirical characteristics of these effects are discussed. Trapping has a square-root dependence on program/erase cycle count. Detrapping scales with the logarithm of time and is thermally accelerated with an activation energy of 1.1 to 1.2 eV. Detrapping has only a weak dependence on electric field. These mechanisms are intrinsic, yet there is a wide variation in behavior from one cell to another related to Poisson statistical variations. Common reliability characterization methods need to be re-thought in light of the characteristics of this and other mechanisms. In particular, performing extensive program/erase cycling with no delays between cycles is unrealistic for this mechanism, and alternative distributed-cycling schemes are proposed.