LONDON – Researchers from the Samsung Advanced Institute of Technology and the department of physics at Sejong University (Seoul, Korea) have reported on a non-volatile resistive RAM with a read-write endurance of more than one trillion cycles.
The passive switching memory is made using asymmetric Ta2O5−x/TaO2−x bilayer structures and has 10-ns switching times, according to the authors of a paper published by Nature Materials.
The devices are of the metal-insulator-metal type with platinum electrodes and experimental results are reported for cell sizes from 50 microns by 50 microns down to 30-nm by 30-nm. The team also prepared samples with double stacked ReRAM cells with linear dimensions of about 90-nm to judge from a scaled scanning electron micrograph and reported on 10 by 10 cell arrays with cell dimensions of 30-nm by 30-nm. The measured activation energy of 1.47-eV provides an estimated retention of greater than 10 years at 85 degrees Celsius.
By combining two devices anti-serially, one above the other, the authors have also circumvented the known problem with cross-bar devices of stray leakage without the need for rectifying diodes or access transistors.
The authors claim to have reduced power consumption compared with other reported ReRAMs and that the high endurance and fast switching make the device suitable for use as working memory as a potential replacement for flash memory.
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Article in Nature Materials
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