Hostname: page-component-586b7cd67f-dlnhk Total loading time: 0 Render date: 2024-11-20T23:08:03.840Z Has data issue: false hasContentIssue false
  • English
  • Français

Germanium supersaturation during the crystallization of amorphous Te–Ge–Sn thin films

Published online by Cambridge University Press:  31 January 2011

M. Libera ,
M. Chen  and
K. Rubin
M. Libera
Affiliation:
IBM Research Division, Almaden Research Center, San Jose, California 95120–6099
M. Chen
Affiliation:
IBM Research Division, Almaden Research Center, San Jose, California 95120–6099
K. Rubin
Affiliation:
IBM Research Division, Almaden Research Center, San Jose, California 95120–6099
Get access

Abstract

The structure and phase relations of Te–Ge–Sn thin films are examined with application to erasable optical storage media. Free energy data from the literature predict that the region of the Te–Ge–Sn phase diagram between Ge, Sn, and the TeGe–TeSn pseudobinary consists of one two-phase field [α–Ge and Te50 (GexSn1−x)50] and one three-phase field (α–Ge, β–Sn, and TeSn). Electron diffraction from five different Te–Ge–Sn films annealed at 623 K experimentally confirms this prediction. One composition from the two-phase field is deposited as a tri-layer film with the structure 150 nm SiO2/75 nm Te36.3Ge47.4Sn16.3/150 nm SiO2 on a grooved disk substrate, and the microstructure resulting from low-power (12 mW) CW and higher-power (∽50 mW) pulsed laser exposure is studied by transmission electron microscopy and electron diffraction. Of particular significance is that laser-induced crystallization produces a single-phase structure consisting of the Te–Ge–Sn compound phase which is supersaturated with respect to the excess Ge. This supersaturation leads to a disordering of the equilibrium NaCl-type structure of this phase. Crystallization of a micron-sized amorphous spot on a ∼200 ns time scale occurs by a diffusionless process. The fast erase times required by a phase-change optical recording application can thus be achieved in off-stoichiometric compound compositions by way of a nonequilibrium crystallization process.

Type
Articles
Information
Journal of Materials Research , Volume 6 , Issue 12 , December 1991 , pp. 2666 - 2676
Copyright
Copyright © Materials Research Society 1991

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

1.Libera, M. and Chen, M., MRS Bulletin XV, 40–45 (April 1990).CrossRefGoogle Scholar
2.Bouwhuis, G., Braat, J., Huijser, A., Pasman, J., Van Rosmalen, G., and Immink, K. Schouhamer, Principles of Optical Disc Systems (Adam Hilger, Bristol, 1985).Google Scholar
3.Bell, A. E., in CRC Handbook of Laser Science and Technology (CRC Press, 1987), p. 65.Google Scholar
4.Chen, M. and Rubin, K. A., Proc. SPIE 1078, San Diego, CA (1989).Google Scholar
5.Clemens, P. C., App. Opt. 22, 3165–3168 (1983).CrossRefGoogle Scholar
6.Chen, M., Rubin, K., Marello, V., Gerber, U., and Jipson, V., Appl. Phys. Lett. 46 (8), 734–736 (1985).CrossRefGoogle Scholar
7.van der Poel, C. J., Gravesteijn, D. J., Rippens, W. G. V. M., Srockx, H. T. L. P., and van Uijen, C. M. J., J. Appl. Phys. 59, 1819–1821 (1986).CrossRefGoogle Scholar
8.Chen, M., Rubin, K., and Barton, R., Appl. Phys. Lett. 49 (9), 502–504 (1986).CrossRefGoogle Scholar
9.Greer, A. L., Acta Metall. 30, 171–192 (1982).CrossRefGoogle Scholar
10.Libera, M., Chen, M., and Rubin, K., in Optical Materials: Processing and Science, edited by Poker, D. B. and Ortiz, C. (Mater. Res. Soc. Symp. Proc. 152, Pittsburgh, PA, 1989).Google Scholar
11.Ohta, T., Uchida, M., Yoshioka, K., Inoue, K., Akiyama, T., Furukawa, S., Kotera, K., and Nakamura, S., Proc. Soc. Photo-Opt. Inst. Eng., Technical Digest Series 1, p. 14 (1989).Google Scholar
12.Terao, M., Miyauchi, Y., Andoo, K., Yasuoka, H., and Tamura, R., Proc. SPIE 1078, 27 (1989).Google Scholar
13.Yamada, N., Takao, M., and Takenaga, M., Optical Mass Storage II, edited by Freese, R. P., Jamberdino, A. A., and de Haas, M., SPIE, Bellingham, WA, 79–85 (1986).Google Scholar
14.Ueno, F., Jpn. J. Appl. Phys. 26 Supplement 26–4, 55–60 (1987).CrossRefGoogle Scholar
15.Rhee, J. C., Okuda, M., and Matsushita, T., Jpn. J. Appl. Phys. 26, 102–105 (1987).CrossRefGoogle Scholar
16.Matsushita, T., Suzuki, A., Okuda, M., Rhee, J., and Naito, H., Jpn. J. Appl. Phys. 24, L504–L506 (1985).CrossRefGoogle Scholar
17.Bierly, J. N., Muldawer, L., and Beckman, O., Acta Metall. 11, 447–454 (1963).CrossRefGoogle Scholar
18.Goldak, J., Barrett, C. S., Innes, D., and Youdelis, W., J. Chem. Phys. 44 (9), 3323–3325 (1966).CrossRefGoogle Scholar
19.Clarke, R., Phys. Rev. B 18, 4920–4926 (1978).CrossRefGoogle Scholar
20.Brebrick, R. F., J. Phys. and Chem. Solids 24, 27–36 (1963).CrossRefGoogle Scholar
21.Zhukova, T. B. and Zaslavskii, A. I., Sov. Phys. Crystallogr. 12, 28–32 (1967).Google Scholar
22.Abrikosov, N. and Shelimova, L., Izv. Akad. Nauk SSSR, Neorg. Mater. 22, 1109–1114 (1986). Translated by Plenum Publishing Company (1987).Google Scholar
23.Barin, I., Knacke, O., and Kubaschewski, O., Thermochemical Properties of Inorganic Substances Supplement (Springer-Verlag, Berlin, 1977).CrossRefGoogle Scholar
24.Mills, K. C., Thermodynamic Data for Inorganic Sulphides, Selenides, and Tellurides (Butterworth's, London).Google Scholar
25.Gorman, G., IBM Almaden Research Center, unpublished research.Google Scholar
26.Riemer, L., Transmission Electron Microscopy (Springer-Verlag, Berlin, 1985).Google Scholar
27.Doyle, P. A. and Turner, P. S., Acta Crystallogr. A24, 390 (1968).CrossRefGoogle Scholar
28.Kelly, A. and Groves, G. W., Crystallography and Crystal Defects (Addison-Wesley, Reading, MA, 1970).Google Scholar
29.Baker, J. C. and Cahn, J. W., Acta Metall. 17, 575–578 (1969).CrossRefGoogle Scholar
30.Aziz, M. J., J. Appl. Phys. 53, 1158–1168 (1982).CrossRefGoogle Scholar