DOI QR코드

DOI QR Code

Amorphous-to-Crystalline Phase Transition of (InTe)x(GeTe) Thin Films

(InTe)x(GeTe) 박막의 비정질-결정질 상변화

  • 송기호 (전남대학교 신화학소재공학과) ;
  • 백승철 (전남대학교 신화학소재공학과) ;
  • 이현용 (전남대학교 응용화학공학부)
  • Published : 2010.03.01

Abstract

The crystallization speed (v) of amorphous (InTe)$_x$(GeTe) (x = 0.1, 0.3 and 0.5) films and their thermal, optical and electrical behaviors have been investigated using nano-pulse scanner (wavelength = 658 nm, laser beam diameter < 2 ${\mu}m$), X-ray diffraction (XRD), 4-point probe and UV-vis-IR spectrophotometer. These results were compared with those of $Ge_2Sb_2Te_5$ (GST) film, comprehensively utilized for phase-change random access memory (PRAM). Both v-value and thermal stability of (InTe)$_{0.1}$(GeTe) and (InTe)$_{0.3}$(GeTe) films could be enhanced in comparison with those of the GST. Contrarily, the v-value in the (InTe)$_{0.5}$(GeTe) film was so drastically deteriorated that we could not quantitatively evaluate it. This deterioration is thought because amorphous (InTe)$_{0.5}$(GeTe) film has relatively high reflectance, resulting in too low absorption to cause the crystallization. Conclusively, it could be thought that a proper compositional (InTe)$_x$(GeTe) films (e.g., x < 0.3) may be good candidates with both high crystallization speed and thermal stability for PRAM application.

References

  1. N. Yamada, E. Ohno, K. Nishiuchi, N. Akahira, and M. Takao, “Rapid-phase transitions of GeTe-$Sb_2Te_3$ pseudobinary amorphous thin films for an optical disk memory", J. Appl. Phys., Vol. 69, p. 2849, 1991. https://doi.org/10.1063/1.348620
  2. Stanford R. Ovshinsky, “Reversible electrical switching phenomena in disordered structures", Phys. Rev. Lett., Vol. 21, Issue 20, p. 1450, 1968. https://doi.org/10.1103/PhysRevLett.21.1450
  3. S. J. Yang, J. M. Lee, K. Shin, and H. B. Chung, “The phase transition with electric field in ternary chalcogenide thin films", Trans. Electr. Eletron. Mater., Vol. 5, No. 5, p. 185, 2004. https://doi.org/10.4313/TEEM.2004.5.5.185
  4. J. M. Lee, K. Shin, C. H. Yeo, and H. B. Chung, “Electrical switching studies of amorphous $Ge_1Se_1Te_2$ thin film for a high-performance nonvolatile phase-change memory", Jpn. J. Appl. Phys., Vol. 45, p. 5467, 2006. https://doi.org/10.1143/JJAP.45.5467
  5. H. B. Chung, K. Shin, and J. M. Lee, “Phase-change characteristics of chalcogenide $Ge_1Se_1Te_2$ thin films for use in nonvolatile memories", J. Vac. Sci. Technol. A, Vol. 25, p. 48, 2007. https://doi.org/10.1116/1.2388956
  6. H. Tanaka, T. Nishihara, T. Ohisuka, K. Morimoto, N. Yamada, and K. Morita, “Electrical switching phenomena in a phase change material in contact with metallic nanowires", Jpn. J. Appl. Phys., Vol. 41, p. L1443, 2002. https://doi.org/10.1143/JJAP.41.L1443
  7. F. Rao, Z. Song, K. Ren, X. Li, L. Wu, W. Xi, and B. Liu, “$Sn_{12}Sb_{88}$ material for phase change memory", Appl. Phys. Letter., Vol. 95, p. 032105, 2009. https://doi.org/10.1063/1.3184787
  8. K. Nakayama, K. Kojima, F. Hayakawa, Y. Imai, A. Kitagawa, and M. Suzuki, “Submicron nonvolatile memory cell based on reversible phase transition in chalcogenide glasses", Jpn. J. Appl. Phys., Vol. 39, p. 6157, 2000. https://doi.org/10.1143/JJAP.39.6157