Interfacial phase-change memory - JSPS London.pdfVIP

LETTERS PUBLISHED ONLINE: 3 JULY 2011 | DOI: 10.1038/NNANO.2011.96 Interfacial phase-change memory 1 1,2 1,2 1 1 3 1 R. E. Simpson *, P. Fons , A. V. Kolobov , T. Fukaya , M. Krbal , T. Yagi and J. Tominaga * Phase-change memory technology relies on the electrical and necessary to determine the switching time between the covalently optical properties of certain materials changing substantially and resonantly bonded phases. The switching time for GST and when the atomic structure of the material is altered by IPCM samples was measured optically using a laser pump–probe heating1 or some other excitation process2–5. For example, static tester system (see Methods). Figure 1b shows the change in switching the composite Ge Sb Te (GST) alloy from its cova- the intensity of the probe light through laser RESET areas in the 2 2 5 lently bonded amorphous phase to its resonantly bonded meta- IPCM film as a function of time during and after the application stable cubic crystalline phase decreases the resistivity by three of a 100 ns pump pulse. Four different regions are discernible: (i) orders of magnitude6, and also increases reflectivity across the no change in transmission, (ii) a reduction in transmission (indica- visible spectrum7,8. Moreover, phase-change memory based on tive of a RESET to SET transition), (iii) an increase in transmission GST is scalable9–11