The design of re-writeable ultra-high density scanning-probe phase-change memories

Wright, C. David, Wang, L., Shah, Purav ORCID: https://orcid.org/0000-0002-0113-5690, Aziz, Mustafa M., Varesi, E., Bez, R., Moroni, M. and Cazzaniga, F. (2010) The design of re-writeable ultra-high density scanning-probe phase-change memories. Nanotechnology, IEEE Transactions on . ISSN 1536-125X (doi:10.1109/TNANO.2010.2089638)

Abstract

A systematic design of practicable media suitable for re-writeable, ultra-high density (> 1Tbit/sq.in.), high data rate (> 1Mbit/s/tip) scanning probe phase-change memories is presented. The basic design requirements were met by a Si/TiN/GST/DLC structure, with properly tailored electrical and thermal conductivities. Various alternatives for providing re-writeability were investigated. In the first case amorphous marks were written into a crystalline starting phase and subsequently erased by re-crystallization, as in other already-established phase-change memory technologies. Results imply that this approach is also appropriate for probe-based memories. However, experimentally the successful writing of amorphous bits using scanning electrical probes has not been widely reported. In light of this a second approach has been studied, that of writing crystalline bits in an amorphous starting matrix, with subsequent erasure by re-amorphization. With conventional phase-change materials, such as continuous films of Ge_{2}Sb_{2}Te_{5}, this approach invariably leads to the formation of a crystalline “halo” surrounding the erased (re-amorphized) region, with severe adverse consequences on the achievable density. Suppression of the “halo” was achieved using patterned media or slow-growth phase-change media, with the latter seemingly more viable.

Item Type: Article
Keywords (uncontrolled): Conductivity, GeSbTe, Media, Probes, Thermal conductivity, TiN, Writing, phase-change RAM, phase-change materials, phase-change memories, scanning probe memories
Research Areas: A. > School of Science and Technology > Computer Science > SensoLab group
A. > School of Science and Technology > Computer and Communications Engineering
Item ID: 7538
Useful Links:
Depositing User: Purav Shah
Date Deposited: 12 Apr 2011 10:59
Last Modified: 13 Oct 2016 14:22
URI: https://eprints.mdx.ac.uk/id/eprint/7538

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