Hostname: page-component-78c5997874-8bhkd Total loading time: 0 Render date: 2024-11-11T08:56:30.890Z Has data issue: false hasContentIssue false

Phase change materials: From structures to kinetics

Published online by Cambridge University Press:  31 January 2011

Wojciech Wełnic*
Affiliation:
I. Physikalisches Institut (IA), Rheinisch-Westfâlisch Technische Hochschule (RWTH) Aachen University of Technology, 52056 Aachen, Germany
Johannes A. Kalb
Affiliation:
I. Physikalisches Institut (IA), Rheinisch-Westfâlisch Technische Hochschule (RWTH) Aachen University of Technology, 52056 Aachen, Germany
Daniel Wamwangi
Affiliation:
I. Physikalisches Institut (IA), Rheinisch-Westfâlisch Technische Hochschule (RWTH) Aachen University of Technology, 52056 Aachen, Germany
Christoph Steimer
Affiliation:
I. Physikalisches Institut (IA), Rheinisch-Westfâlisch Technische Hochschule (RWTH) Aachen University of Technology, 52056 Aachen, Germany
Matthias Wuttig
Affiliation:
I. Physikalisches Institut (IA), Rheinisch-Westfâlisch Technische Hochschule (RWTH) Aachen University of Technology, 52056 Aachen, Germany
*
a)Address all correspondence to this author. Present address: Laboratoire des Solides Irradiés, CNRS-CEA, École Polytechnique, Palaiseau, France, European Theoretical Spectroscopy Facility (ETSF). e-mail: welnic@physik.rwth-aachen.de
Get access

Abstract

Phase change materials possess a unique combination of properties, which includes a pronounced property contrast between the amorphous and crystalline state, i.e., high electrical and optical contrast. In particular, the latter observation is indicative of a considerable structural difference between the amorphous and crystalline state, which furthermore is characterized by a very high vacancy concentration unknown from common semiconductors. Through the use of ab initio calculations, this work shows how the electric and optical contrast is correlated with structural differences between the crystalline and the amorphous state and how the vacancy concentration controls the optical properties. Furthermore, crystal nucleation rates and crystal growth velocities of various phase change materials have been determined by atomic force microscopy and differential thermal analysis. In particular, the observation of different recrystallization mechanisms upon laser heating of amorphous marks is explained by the relative difference of just three basic parameters among these alloys, namely, the melt-crystalline interfacial energy, the entropy of fusion, and the glass transition temperature.

Type
Outstanding Meeting Paper
Copyright
Copyright © Materials Research Society 2007

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1Ovshinsky, S.R.: Reversible electrical switching phenomena in disordered structures. Phys. Rev. Lett. 21, 1450 1968Google Scholar
2Zhou, G.: Material aspects in phase change optical recording. Mater. Sci. Eng., A 304–306, 73 2001Google Scholar
3Wuttig, M.: Phase-change materials—Towards a universal memory? Nat. Mater. 4, 265 2005CrossRefGoogle ScholarPubMed
4Yamada, N.: Erasable phase-change optical materials. MRS Bull. 21(9), 48 1996Google Scholar
5Friedrich, I., Weidenhof, V., Njoroge, W., Franz, P.Wuttig, M.: Structural transformations of Ge2Sb2Te5 films studied by electrical resistance measurements. J. Appl. Phys. 87, 4130 2000Google Scholar
6Lankhorst, M., Ketelaars, B.Wolters, R.: Low-cost and nanoscale non-volatile memory concept for future silicon chips. Nat. Mater. 4, 347 2005Google Scholar
7Philipp, H.R.Ehrenreich, H.: Optical properties of semiconductors. Phys. Rev. 129, 1550 1963Google Scholar
8Stuke, J.Zimmerer, G.: Optical properties of amorphous 3–5 compounds. 1. Experiment. Phys. Status Solidi B—Basic Res. 49, 513 1972CrossRefGoogle Scholar
9Wełnic, W., Botti, S., Reining, L.Wuttig, M.Origin of the optical contrast in phase change materials. Phys. Rev. Lett. 98, 236403 2007CrossRefGoogle ScholarPubMed
10Kolobov, A.V., Fons, P., Tominaga, J., Ankudinov, A.L., Yannopoulos, S.N.Andikopoulos, K.S.: Crystallization-induced short-range order changes in amorphous GeTe. J. Phys. Condens. Matter. 16, 5103 2004CrossRefGoogle Scholar
11Kolobov, A.V., Fons, P., Frenkel, A.I., Ankudinov, A.L., Tominaga, J.Urugal, T.: Understanding the phase-change mechanism of rewritable optical media. Nat. Mater. 3, 703 2004Google Scholar
12Kalb, J., Wuttig, M.Spaepen, F.: Calorimetric measurements of structural relaxation and glass transition temperatures in sputtered films of amorphous Te alloys used for phase change recording. J. Mater. Res. 22, 748 2007CrossRefGoogle Scholar
13Wełnic, W., Pamungkas, A., Detemple, R., Steimer, C., Blûgui, S.Wuttig, M.: Unraveling the interplay of local structure and physical properties in phase-change materials. Nat. Mater. 5, 56 2006Google Scholar
14Luo, M.Wuttig, M.: The dependence of crystal structure of Te-based phase-change materials on the number of valence electrons. Adv. Mat. 16, 439 2004Google Scholar
15Peierls, R.: Quantum Theory of Solids Oxford University Press Oxford, UK 1956Google Scholar
16Wuttig, M., Lüsebrink, D., Wamwangi, D., Wełnic, W., Gilleßen, M.Dronskowski, R.: The role of vacancies and local distortions in the design of new phase change materials. Nat. Mater. 6, 122 2007CrossRefGoogle ScholarPubMed
17Matsunaga, T., Kubota, Y.Yamada, N.: Structures of stable and metastable Ge2Sb2Te5, an intermetallic compound in the GeTe-Sb2Te3 pseudobinary systems. Acta Crystallogr. B 60, 685 2004Google Scholar
18Matsunaga, T., Kojima, R., Yamada, N., Kifune, K., Kubote, Y., Tabata, Y.Takata, M.: Single structure widely distributed in a GeTe-Sb2Te3 pseudobinary system: A rocksalt structure is retained by intrinsically containing an enormous number of vacancies within its crystal. Inorg. Chem. 45, 2235 2006Google Scholar
19Shamoto, S., Matsumaga, T., Yamada, N., Proffen, Th., Richardson, J.W. Jr., Chung, J.H.Egani, T.: Large displacement of germanium atoms in crystalline Ge2Sb2Te5. Appl. Phys. Lett. 86, 081904 2005Google Scholar
20El-Mellouhi, F., Mousseau, N.Ordejon, P.: Sampling the diffusion paths of a neutral vacancy in silicon with quantum mechanical calculations. Phys. Rev. B 70, 205202 2004Google Scholar
21Gaspard, J-P.Ceolin, R.: Hume-rothery rule in v-vi compounds. Solid State Comm. 84, 839 1992Google Scholar
22Gaspard, J-P., Pellegatti, A., Marinelli, F.Bichara, C.: Peierls instabilities in covalent structures I. Electronic structure, cohesion and the Z = 8−N rule. Philos. Mag. B 77, 727 1998CrossRefGoogle Scholar
23Yamada, N., Ohno, E., Nishiuchi, K., Akahira, N.Takao, M.: Rapid phase transitions of GeTe-Sb2Te3 pseudobinary amorphous thin films for an optical disk memory. J. Appl. Phys. 69, 2849 1991Google Scholar
24Hudgens, S.Johnson, B.: Overview of phase-change chalcogenide nonvolatile memory technology. MRS Bull. 29(11), 829 2004Google Scholar
25Christian, J.Transformation in Metals and Alloys 2 ed.Pergamon Press Oxford, UK 1975Google Scholar
26Herlach, D.: Non-equilibrium solidification of undercooled metallic melts. Mater. Sci. Eng., R 12, 177 1994CrossRefGoogle Scholar
27Kelton, K.: Crystal nucleation in liquids and glasses. Solid State Phys. 45, 75 1991CrossRefGoogle Scholar
28Kalb, J., Spaepen, F.Wuttig, M.: Kinetics of crystal nucleation in undercooled droplets of Sb- and Te-based alloys used for phase change recording. J. Appl. Phys. 98, 054910 2005Google Scholar
29Weidenhof, V., Friedrich, I., Ziegler, S.Wuttig, M.: Laser induced crystallization of amorphous Ge2Sb2Te5 films. J. Appl. Phys. 89, 3168 2001Google Scholar
30Ruitenberg, G., Petford-Long, A.Doole, R.: Determination of the isothermal nucleation and growth parameters for the crystallization of thin Ge2Sb2Te5 films. J. Appl. Phys. 92, 3116 2002Google Scholar
31Privitera, S., Bongiorno, C., Rimini, E.Zonca, R.: Crystal nucleation and growth processes in Ge2Sb2Te5. Appl. Phys. Lett. 84, 4448 2004Google Scholar
32Kooi, B.Hosson, J.D.: On the crystallization of thin films composed of Sb3.6Te with Ge for rewritable data storage. J. Appl. Phys. 95, 4714 2004Google Scholar
33Peng, C., Cheng, L.Mansuripur, M.: Experimental and theoretical investigations of laser-induced crystallization and amorphization in phase-change optical-recording media. J. Appl. Phys. 82, 4183 1997Google Scholar
34Senkader, S.Wright, C.: Models for phase-change of Ge2Sb2Te5 in optical and electrical memory devices. J. Appl. Phys. 95, 504 2004Google Scholar
35Sheila, A.Schlesinger, T.: Modeling thermal cross talk and overwrite jitter in growth dominant phase change optical-recording media at high data rates. J. Appl. Phys. 91, 2803 2002CrossRefGoogle Scholar
36Meinders, E., Borg, H., Lankhorst, M., Hellmig, J.Mijiritskii, A.: Numerical simulation of mark formation in dual-stack phase-change recording. J. Appl. Phys. 91, 9794 2002Google Scholar
37Coombs, J., Jongenelis, A., van Es-Spiekman, W.Jacobs, B.: Laser-induced crystallization phenomena in GeTe-based alloys. ii. Composition dependence of nucleation and growth. J. Appl. Phys. 82, 4183 1997Google Scholar
38Borg, H.J., Van Schijndel, M., Rijpers, J.C.N., Lankhoist, H.H.R., Zhou, G., Dekker, M.J., Ubbens, I.P.D.Kuijper, M.: Phase-change media for high-numericalaperture and blue-wavelength recording. Jap. J. Appl. Phys. 40, 1592 2001Google Scholar
39van Pieterson, L., van Schijndel, M., Rijpers, J.Kaiser, M.: Te-free, Sb-based phase-change materials for high-speed rewritable optical recording. Appl. Phys. Lett. 83, 1373 2003CrossRefGoogle Scholar
40Weidenhof, V., Friedrich, I., Ziegler, S.Wuttig, M.: Atomic force microscopy study of laser induced phase transitions in Ge2Sb2Te5. J. Appl. Phys. 86, 5879 1999Google Scholar
41Kalb, J., Spaepen, F.Wuttig, M.: Atomic force microscopy measurements of crystal nucleation and growth rates in thin films of amorphous Te alloys. Appl. Phys. Lett. 84, 5240 2004CrossRefGoogle Scholar
42Kalb, J., Wen, C., Spaepen, F., Dieker, H.Wuttig, M.: Crystal morphology and nucleation in thin films of amorphous Te alloys used for phase change recording. J. Appl. Phys. 98, 054902 2005CrossRefGoogle Scholar