TITLE

Direct evidence for abrupt postcrystallization germanium precipitation in thin phase-change films of Sb–15 at. % Ge

AUTHOR(S)
Cabral, C.; Krusin-Elbaum, L.; Bruley, J.; Raoux, S.; Deline, V.; Madan, A.; Pinto, T.
PUB. DATE
August 2008
SOURCE
Applied Physics Letters;8/18/2008, Vol. 93 Issue 7, p071906
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
We present evidence for the instability in the crystalline (metallic) state of binary Te-free phase-change Ge–Sb thin films considered for integration into nonvolatile nanosized memory cells. We find that while the amorphous (semiconducting) phase of eutectic Sb–15 at. % Ge is very robust until Sb crystallization at 240 °C, at about 350 °C, germanium rapidly precipitates out. Ge precipitation, visualized directly with transmission electron microscopy, is exothermic and is found to affect the films’ reflectivity, resistance, and stress. It converts melting into a two-step process, which may seriously impact the switching reliability of a device.
ACCESSION #
34135591

 

Related Articles

  • Low-temperature Al-induced crystallization of amorphous Ge. Zanatta, A. R.; Chambouleyron, I. // Journal of Applied Physics;5/1/2005, Vol. 97 Issue 9, p094914 

    This work reports on the low-temperature crystallization of hydrogenated amorphous germanium (a-Ge:H) films induced by aluminum. A series of aluminum-doped a-Ge:H films ([Al/Ge]∼10-6–10-2 range) were deposited onto crystalline silicon substrates at 220 °C by the cosputtering...

  • Crystallization of amorphous germanium in an Al/a-Ge bilayer film deposited on a SiO[sub 2] substrate. Katsuki, Futoshi; Hanafusa, Kenji; Yonemura, Mitsuharu; Koyama, Toshiyuki; Doi, Minoru // Journal of Applied Physics;4/15/2001, Vol. 89 Issue 8 

    The crystallization of amorphous Ge(a-Ge) in an Al (134 nm) and a-Ge (108 nm) thin-film bilayer deposited on a SiO[sub 2] substrate has been examined by a cross section transmission electron microscope technique. When crystallization of a-Ge begins at 125 °C, amorphous AlGe (a-AlGe) alloy is...

  • Mechanism of crystallization of oxygen-doped amorphous Ge1 Sb2 Te4 thin films. Rivera-Rodríguez, C.; Prokhorov, E.; Trapaga, G.; Morales-Sánchez, E.; Hernandez-Landaverde, M.; Kovalenko, Yu.; González-Hernández, J. // Journal of Applied Physics;7/15/2004, Vol. 96 Issue 2, p1040 

    The aim of this article is to study the mechanism of the amorphous-to-crystalline phase transformation in Ge1Sb2Te4 alloys doped by oxygen (in the range of 4-28 at %) using the electrical, optical, and x-ray measurements. Experimental results have shown that samples with oxygen in the range of...

  • Lead germanium telluride: a mechanically robust infrared high-index layer. Bin Li; Ping Xie; Suying Zhang; Dingquan Liu // Journal of Materials Science;Jun2011, Vol. 46 Issue 11, p4000 

    mechanically robust infrared high-index coating material is essential to the infrared interference coatings. Lead germanium telluride (PbGeTe) is a pseudo-binary alloy of IV-VI narrow gap semiconductors of PbTe and GeTe. In our investigation, the hardness and Young's modulus of thin films of...

  • Impurity-mediated one-dimensional crystallization of thin amorphous Ge films on Si (111). Hellman, Olof // Journal of Applied Physics;9/15/1994, Vol. 76 Issue 6, p3818 

    Presents information on a study which observed the peculiar low temperature crystallization dynamics of thin amorphous germanium films deposited on silicon substrates. Experimental details; Results and discussion; Conclusions.

  • Microstructural measurements of amorphous GeTe crystallization by hot-stage optical microscopy. Lu, Q. M.; Libera, M. // Journal of Applied Physics;1/15/1995, Vol. 77 Issue 2, p517 

    Presents a study which investigated the nucleation and growth kinetics of amorphous germanium telluride thin film crystallization by hot-stage optical microscopy. Theoretical background; Experimental procedure; Results and discussion.

  • A comparative study of Ge nanocrystals in SixGeyOz alloys and SiOx/GeOy multilayers. Zacharias, M.; Weigand, R. // Journal of Applied Physics;3/1/1997, Vol. 81 Issue 5, p2384 

    Presents a comparative study of germanium nanocrystals in SixGeuOz alloys and SiOx/GeOy multilayer films. Formation of the germanium nanocrystals in the alloy matrix; Similarity between alloy and multilayer films; Contraction and disappearance of the amorphous mode.

  • Thermal activation of dislocation array formation. Janzen, A.; Dumkow, I.; Horn-von Hoegen, M. // Applied Physics Letters;10/8/2001, Vol. 79 Issue 15, p2387 

    Surfactant-mediated epitaxy allows the growth of smooth, continuous, and relaxed Ge films on Si(111). The key process is the formation of an ordered array of misfit dislocations, which are confined to the Ge/Si interface and accommodate most of the lattice mismatch of 4.2%. Its formation...

  • Crystallization behavior of sputter-deposited amorphous Ge...Sb...Te... thin films. Jeong, Tae H.; Kim, Myong R. // Journal of Applied Physics;7/15/1999, Vol. 86 Issue 2, p774 

    Presents information on a study which investigated the crystallization behavior of amorphous germanium-antimony telluride thin films using differential scanning calorimetry and x-ray diffraction. Experimental procedure; Results and discussion; Conclusions.

Share

Read the Article

Courtesy of VIRGINIA BEACH PUBLIC LIBRARY AND SYSTEM

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics