A study of scaling effects on DRAM reliability
A study of scaling effects on DRAM reliability
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规模效应对 DRAM 可靠性的研究
DOI：
10.1109/rams.2011.5754522
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
J. Bernstein
中科院分区：
文献类型：
--
作者：
M. White;J. Qin;J. Bernstein
在这项研究中，商业512 Mb双数据速率同步动态随机存取存储器（DDR SDRAM）模块从三个渐进的技术-130纳米，110纳米和90纳米-被选中进行实验，以调查退化趋势作为缩放的函数。进行高温、高压加速应力测试以表征DRAM可靠性和故障率。还研究了保留时间随时间的降解作为强制降解的函数。对于每一代技术，观察到两个不同的软错误群体：尾部分布，其特征在于随机分布的弱位，Weibull斜率=1，以及Weibull斜率大于1的主分布。发现保留时间随时间呈指数下降。分析表明，保留时间退化涉及多种失效机制。活化能被发现与应力温度的所有三种技术。关于DRAM可靠性的缩放效应有几个观察结果。首先，工艺越小，高温、高压后工作电流增加的百分比越大，加速应力。第二，电池保留时间变化随着技术按比例缩小而减小。第三，90 nm DRAM在等效应力下，三种技术中软错误失效率最大，110 nm DRAM在55 ℃和75 ℃下的可靠性性能优于130 nm，130 nm DRAM在125 ℃下的可靠性性能最好。研究继续到渐进DRAM技术的可靠性的缩放效应。
In this study, commercial 512Mb Double Data Rate Synchronous Dynamic Random Access Memory (DDR SDRAM) modules from three progressive technologies — 130nm, 110nm and 90nm — were selected for experimentation to investigate degradation trends as a function of scaling. High temperature, high voltage accelerated stress testing was performed to characterize DRAM reliability and failure rates. Retention time degradation over time as a function of stress was also studied. For each technology generation, two distinct soft error populations were observed: Tail Distribution, characterized by randomly distributed weak bits with Weibull slope =1, and Main Distribution with Weibull slope greater than 1. Retention time was found to degrade exponentially with time. Analysis reveals multiple failure mechanisms are involved in retention tim e degradation. Activation energy was found to change with stress temperature for all three technologies. There are several observations with regard to scaling effects on DRAM reliability. First, the smaller the technology, the larger the operating current increases in percentage after high temperature, high voltage accelerated stress. Second, cell retention time variation decreases as technology scales down. Third, 90nm DRAM has the largest soft-error failure rate among three technologies under equivalent stress, 110nm DRAM has better reliability performance than 130nm at 55°C and 75°C, and 130nm DRAM is the best at 125°C. Studies con tinue into the scaling effects on reliability of progressive DRAM technologies.