Hostname: page-component-586b7cd67f-vdxz6 Total loading time: 0 Render date: 2024-11-23T14:18:09.107Z Has data issue: false hasContentIssue false
  • English
  • Français

In situ Transmission Electron Microscopy Study of the Crystallization of Fast-growth Doped SbxTe Alloy Films

Published online by Cambridge University Press:  01 July 2005

Bart J. Kooi ,
R. Pandian ,
J.Th.M. De Hosson  and
Andrew Pauza
Bart J. Kooi*
Affiliation:
Department of Applied Physics, Materials Science Centre and Netherlands Institute for Metals Research, University of Groningen, 9747 AG Groningen, The Netherlands
R. Pandian
Affiliation:
Department of Applied Physics, Materials Science Centre and Netherlands Institute for Metals Research, University of Groningen, 9747 AG Groningen, The Netherlands
J.Th.M. De Hosson
Affiliation:
Department of Applied Physics, Materials Science Centre and Netherlands Institute for Metals Research, University of Groningen, 9747 AG Groningen, The Netherlands
Andrew Pauza
Affiliation:
Plasmon Data Systems Ltd., Hertsfordshire, SG8 6EN, United Kingdom
*
a)Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

Crystallization of amorphous thin films composed of doped SbxTe with x = 3.0, 3.6, and 4.2 and constant dopant level was studied by in situ heating in a transmission electron microscopy. Magnetron sputtering was used to deposit 20-nm-thick films sandwiched between two types of 3-nm-thick dielectric layers on 25-nm-thick silicon-nitride membranes. One type of dielectric layer consists of ZnS–SiO2 (ZSO), the other of GeCrN (GCN). Crystallization was studied for temperatures in-between 150 and 190 °C. The type of dielectric layer turned out to strongly influence the crystallization process. Not only did the nucleation rate appear to depend sensitively on the dielectric layer type, but also the growth rate. The velocity of the crystalline/amorphous interface is about 5 times higher for the x = 4.2 film than for the x = 3.0 film if ZSO is used. In case of GCN, the interface velocity is about 2 times higher for the x = 4.2 film than for the x = 3.0 film. The activation energy for crystal growth is not significantly dependent on the Sb/Te ratio but is clearly different for ZSO and GCN—2.9 eV and 2.0 eV, respectively. The incubation time for the crystal nuclei formation is longer for ZSO than for GCN. Although the effects of the Sb/Te ratio and the dielectric layer type on the growth rates are strong, their effects on the nucleation rate are even more pronounced. A higher Sb/Te ratio results in a lower nucleation rate and the use of GCN instead of ZSO leads to higher nucleation rates.

Keywords

KineticsThin filmTransmission electron microscopy (TEM)
Type
Articles
Information
Journal of Materials Research , Volume 20 , Issue 7 , July 2005 , pp. 1825 - 1835
Copyright
Copyright © Materials Research Society 2005

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

1Ohta, T., Yamada, N., Yamamoto, H., Mitsuyu, T., Kozaki, T., Qiu, J. and Hirao, K. Progress of the phase-change optical disk memory, in Applications of Ferromagnetic and Optical Materials, Storage and Magnetoelectronics, edited by Borg, H.J., Bussmann, K., Egelhoff, W.F. Jr., Hesselink, L., Majetich, S.A., Murdock, E.S., Stadler, B.J.H., Vázquez, M., Wuttig, M., and Xiao, J.Q. (Mater. Res. Soc. Symp. Proc. 674, Warrendale, PA, 2001), V1.1.Google Scholar
2Zhou, G-F.: Materials aspects in phase change optical recording. Mater. Sci. Eng. A304–306, 73 (2001).CrossRefGoogle Scholar
3Borg, H., Lankhorst, M., Meinders, E., Leibrandt, W.: Phase-change media for high-density optical recording, in Applications of Ferromagnetic and Optical Materials, Storage and Magnetoelectronics, edited by Borg, H.J., Bussmann, K., Egelhoff, W.F. Jr., Hesselink, L., Majetich, S.A., Murdock, E.S., Stadler, B.J.H., Vázquez, M., Wuttig, M., and Xiao, J.Q. (Mater. Res. Soc. Symp. Proc. 674, Warrendale, PA, 2001), V1.2.Google Scholar
4Borg, H.J., Blom, P.W.M., Jacobs, B.J.A., Tieke, B., Wilson, A.E., Ubbens, I.P.D. and Zhou, G.: AgInSbTe materials for high speed phase-change recording. Proc. SPIE 3864, 191 (1999).Google Scholar
5Kooi, B.J. and De Hosson, J.Th.M.: On the crystallization of thin films composed of Sb3.6Te with Ge for rewritable data storage. J. Appl. Phys. 95, 4714 (2004).CrossRefGoogle Scholar
6Kooi, B.J., Groot, W.M.G. and De Hosson, J.Th.M.: In-situ transmission electron microcopy study of the crystallization of Ge2Sb2Te5. J. Appl. Phys. 95, 924 (2004).CrossRefGoogle Scholar
7Pandian, R., Kooi, B.J., J.Th.M. De Hosson, Pauza, A. (unpublished).Google Scholar
8Kolosov, V.Yu. and Thölen, A.R.: Transmission electron microcopy studies of the specific structure of crystals formed by phase transition in iron oxide amorphous films. Acta Mater. 48, 1829 (2000).CrossRefGoogle Scholar
9Ruitenberg, G., Petford-Long, A.K. and Doole, R.C.: Determination of the isothermal nucleation and growth parameters for the crystallization of thin Ge2Sb2Te5 films. J. Appl. Phys. 92, 3116 (2002).CrossRefGoogle Scholar
10Privitera, S., Bongiorno, C., Rimini, E., Zonca, R., Prirovano, A. and Bez, R.: Amorphous-to-polycrystal transition in GeSbTe thin films, in Advanced Data Storage Materials and Characteriztion Techniques, edited by Ahner, J.W., Levy, J., Hesselink, L., and Mijiritskii, A. (Mater. Res. Soc. Symp. Proc. 803, Warrendale, PA, 2004), HH1.4, p. 83.Google Scholar
11Kalb, J., Spaepen, F. and Wuttig, M.: Atomic force microscopy measurements of crystal nucleation and growth rates in thin films of amorphous Te alloys. Appl. Phys. Lett. 84, 5240 (2004).CrossRefGoogle Scholar
12Morilla, M.C., Afonso, C.N., Petford-Long, A.K. and Doole, R.C.: Influence of the relaxation state on the crystallization kinetics of Sb-rich SbGe amorphous films. Philos. Mag. A 73, 1237 (1996).CrossRefGoogle Scholar
13Ohshima, N.: Crystallization of germanium-antimony-tellurium amorphous thin film sandwiched between various dielectric layers. J. Appl. Phys. 79, 8357 (1996).CrossRefGoogle Scholar
14Friedrich, I., Weidenhof, V., Njoroge, W., Franz, P. and Wuttig, M.: Structural transformations of Ge2Sb2Te5 films studied by electrical resistance measurements. J. Appl. Phys. 87, 4130 (2000).CrossRefGoogle Scholar
15Kooi, B.J.: Monte Carlo simulations of phase transformations caused by nucleation and subsequent anisotropic growth: Extension of the Johnson–Mehl–Avrami–Kolmogorov theory. Phys. Rev. B 70, 224108 (2004).CrossRefGoogle Scholar
16Martens, H.C.F., Vlutters, R. and Prangsma, J.C.: Thickness dependent crystallization speed in thin phase change layers for optical recording. J. Appl. Phys. 95, 3977 (2004).CrossRefGoogle Scholar
17Porter, D.A. and Easterling, K.E.: Phase Transformations in Metals and Alloys (Van Nostrand Reinhold Company, New York, 1981), pp. 132–136.Google Scholar