Design and fabrication of memory devices based on nanoscale polyoxometalate clusters

Busche, C. et al. (2014) Design and fabrication of memory devices based on nanoscale polyoxometalate clusters. Nature, 515(7528), pp. 545-549. (doi: 10.1038/nature13951) (PMID:25409147)

Abstract

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 memory1, 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 memory2, there are a number of significant barriers to the realization of devices using conventional MOS technologies3, 4, 5, 6, 7. Here we show that core–shell polyoxometalate (POM) molecules8 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)O3)2]4− as an oxidizable dopant in the cluster core allows the oxidation of the molecule to a [Se(V)2O6]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 behaviour9, 10, 11. This work suggests a route to the practical integration of configurable molecules in MOS technologies as the lithographic scales approach the molecular limit12.

• Item Type: Articles (Letter)
• Additional Information: Christoph Busche and Laia Vilá-Nadal contributed equally to this work.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Yan, Mr Jun and Busche, Dr Christopher and Mirza, Dr Muhammad M A and Vila-Nadal, Dr Laia and Moiras, Professor Haralampos and Georgiev, Professor Vihar and Pedersen, Mr Rasmus and Paul, Professor Douglas and Gadegaard, Professor Nikolaj and Asenov, Professor Asen and Long, Dr Deliang and Cronin, Professor Lee
• Authors: Busche, C., Vila-Nadal, L., Yan, J., Miras, H., Long, D.-L., Georgiev, V. P., Asenov, A., Pedersen, R. H., Gadegaard, N., Mirza, M. M., Paul, D. J., Poblet, J. M., and Cronin, L.
• Subjects: Q Science > QC Physics
• College/School: College of Science and Engineering > School of Chemistry; College of Science and Engineering > School of Engineering > Biomedical Engineering; College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Research Group: Semiconductor Devices
• Journal Name: Nature
• Publisher: Nature Publishing Group
• ISSN: 0028-0836
• ISSN (Online): 1476-4687

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
50329	1	Molecular-Metal-Oxide-nanoelectronicS (M-MOS): Achieving the Molecular Limit	Leroy Cronin	Engineering & Physical Sciences Research Council (EPSRC)	EP/H024107/1	CHEM - CHEMISTRY
56282	1	Innovative Manufacturing Research Centre for Continuous Manufacturing and Crystallisation (CMAC)	Leroy Cronin	Engineering & Physical Sciences Research Council (EPSRC)	EP/I033459/1	CHEM - CHEMISTRY
57739	1	Programmable Molecular Metal Oxides (PMMOs) - From Fundamentals to Application	Leroy Cronin	Engineering & Physical Sciences Research Council (EPSRC)	EP/J015156/1	CHEM - CHEMISTRY