Design and fabrication of memory devices based on nanoscale polyoxometalate clusters
Design and fabrication of memory devices based on nanoscale polyoxometalate clusters
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DOI：
10.1038/nature13951
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发表时间：
2014-11-27
期刊：
影响因子：
64.8
通讯作者：
Cronin, Leroy
中科院分区：
文献类型：
--
作者：
Busche, Christoph;Vila-Nadal, Laia;Cronin, Leroy
闪速存储器设备（即，可以被电擦除和重新编程的非易失性计算机存储介质）对于便携式电子设备是至关重要的，但是将金属氧化物半导体（MOS）闪速存储器按比例缩小到每个数据单元小于十纳米的尺寸提出了挑战。已经提出用分子来代替MOS闪存（1），但是它们具有低电导率、高电阻、低器件成品率和有限的热稳定性，限制了它们集成到当前的MOS技术中。虽然在追求基于分子的闪存方面已经取得了很大的进步（2），但是使用传统MOS技术实现器件存在许多重大障碍（3-7）。在这里，我们表明核-壳聚氧乙烯酸盐（POM）分子（8）可以作为MOS闪存的候选存储节点。现实的，行业标准的设备模拟验证了我们的方法在纳米级，其中设备性能主要是由存储介质中的分子数量，而不是由它们的位置。为了探索核壳结构POM团簇的性质，我们在分子和器件水平上证明，在团簇核中嵌入[（Se（IV）O-3）（2）]（4-）作为可氧化的掺杂剂允许分子氧化成含有{Se（v）-Se（v）}键的[Se（V）（2）O-6]（2-）部分（其中花括号表示部分，而不是分子）并揭示了硒的新5 +氧化态。这种新的氧化态可以在器件水平上观察到，从而产生一种新型的存储器，我们称之为“一次写入擦除”。总之，这些结果表明，POM有可能被用作一个现实的纳米级闪存。此外，掺杂的POM芯的配置可能导致新类型的电行为（9-11）。这项工作提出了一条路线，以实际集成的可配置的分子在MOS技术的光刻规模接近分子的限制（12）。
Flash memory devices that is, non-volatile computer storage media that can be electrically erased and reprogrammed are vital for portable electronics, but the scaling down of metal-oxide-semiconductor (MOS) flash memory to sizes of below ten nanometres per data cell presents challenges. Molecules have been proposed to replace MOS flash memory(1), but they suffer from low electrical conductivity, high resistance, low device yield, and finite thermal stability, limiting their integration into current MOS technologies. Although great advances have been made in the pursuit of molecule-based flash memory(2), there are a number of significant barriers to the realization of devices using conventional MOS technologies(3-7). Here we show that core-shell polyoxometalate (POM) molecules(8) can act as candidate storage nodes for MOS flash memory. Realistic, industry-standard device simulations validate our approach at the nanometre scale, where the device performance is determined mainly by the number of molecules in the storage media and not by their position. To exploit the nature of the core-shell POM clusters, we show, at both the molecular and device level, that embedding [(Se(IV)O-3)(2)](4-) as an oxidizable dopant in the cluster core allows the oxidation of the molecule to a [Se(V)(2)O-6](2-) moiety containing a {Se(v)-Se(v)} bond (where curly brackets indicate a moiety, not a molecule) and reveals a new 5 + oxidation state for selenium. This new oxidation state can be observed at the device level, resulting in a new type of memory, which we call 'write-once-erase'. Taken together, these results show that POMs have the potential to be used as a realistic nanoscale flash memory. Also, the configuration of the doped POM core may lead to new types of electrical behaviour(9-11). This work suggests a route to the practical integration of configurable molecules in MOS technologies as the lithographic scales approach the molecular limit(12).