Sunday, July 13, 2014

IBM Zürich solves 40+ Year Old Challenge for Phase Change Materials

IBM Research reports in their News Blog on a breakthrough made in understanding and development of phase change memory cells by IBM Research in Zürich. "... for more than 40 years scientists have never measured the temperature dependence of crystal growth, due to the difficulties associated with the measurements which are taken at both a nanometer length and a nanosecond time scale. That was until earlier this year when, for the first time, IBM scientists in Zurich were able to take the measurements, which is today being reported in the peer-review journal Nature Communications."
The Binnig and Rohrer Nanotechnology Center is a unique facility for exploratory research. It is not a production or a pilot line with fixed processes or wafer sizes. Rather, it is a state-of-the-art exploratory cleanroom fabrication facility combined with "noise-free" labs shielded against external vibrations, acoustic noise, electromagnetic fields and temperature fluctuations.
Please see the abstract to the publication below and check out the blog more details including also an interview with the resreachers at The Binnig and Rohrer Nanotechnology Center in Zürich.
Abu Sebastian, Manuel Le Gallo und Daniel Krebs (Bild: IBM Research)

Abu Sebastian, Manuel Le Gallo, & Daniel Krebs,
Nature Communications Volume: 5, Article number: 4314 DOI:doi:10.1038/ncomms5314, 07 July 2014

In spite of the prominent role played by phase change materials in information technology, a detailed understanding of the central property of such materials, namely the phase change mechanism, is still lacking mostly because of difficulties associated with experimental measurements. Here, we measure the crystal growth velocity of a phase change material at both the nanometre length and the nanosecond timescale using phase-change memory cells. The material is studied in the technologically relevant melt-quenched phase and directly in the environment in which the phase change material is going to be used in the application. We present a consistent description of the temperature dependence of the crystal growth velocity in the glass and the super-cooled liquid up to the melting temperature.
The cross-sectional tunneling  electron microscopy (TEM) image of  a mushroom-type PCM cell  is shown in this photo.