Evaluation on the Phase-Change Properties in W-doped Ge8Sb2Te11 Thin Films for Amorphous-to-Crystalline Reversible Phase-Change Device

비정질-결정질 가역적 상변환 소자용 Ge8Sb2Te11 박막의 W 도핑에 따른 상변환 특성 평가

  • Park, Cheol-Jin (Department of Advanced Chemicals and Engineering, Chonnam National University) ;
  • Yeo, Jong-Bin (The Research Institute of Catalysis, Chonnam National University) ;
  • Kong, Heon (Department of Advanced Chemicals and Engineering, Chonnam National University) ;
  • Lee, Hyun-Yong (School of Chemical Engineering, Chonnam National University)
  • 박철진 (전남대학교 신화학소재공학과) ;
  • 여종빈 (전남대학교 촉매연구소) ;
  • 공헌 (전남대학교 신화학소재공학과) ;
  • 이현용 (전남대학교 화학공학부)
  • Received : 2016.11.09
  • Accepted : 2017.01.31
  • Published : 2017.03.01


We evaluated the structural, electrical and optical properties of tungsten (W)-doped $Ge_8Sb_2Te_{11}$ thin films. In a previous work, GeSbTe alloys were doped with different materials in an attempt to improve thermal stability. 200 mm thick $Ge_8Sb_2Te_{11}$ and W-doped $Ge_8Sb_2Te_{11}$ films were deposited on p-type Si (100) and glass substrates using a magnetron co-sputtering system at room temperature. The fabricated films were annealed in a furnace in the $0{\sim}400^{\circ}C$ temperature range. The structural properties were analyzed using X-ray diffraction (X'pert PRO, Phillips). The results showed increased crystallization temperature ($T_c$) leading to thermal stability in the amorphous state. The optical properties were analyzed using an UV-Vis-IR spectrophotometer (Shimadzu, U-3501, range : 300~3,000 nm). The results showed an increase in the crystalline material optical energy band gap ($E_{op}$) and an increase in the $E_{op}$ difference (${\Delta}E_{op}$). This is a good effect to reduce memory device noise. The electrical properties were analyzed using a 4-point probe (CNT-series). This showed increased sheet resistance ($R_s$), which reduces programming current in the memory device.


Supported by : 한국연구재단


  1. T. Siegrist, P. Jost, H. Volker, M. Woda, P. Merkelbach, C. Scholickermann, and M. Wutting, Nature Mater., 10, 202 (2011). [DOI:]
  2. K. H. Song, S. C. Baek, and H. Y. Lee, J. Korean Phys. Soc., 61, 10 (2012). [DOI:]
  3. G. W. Burr, M. J. Breitwisch, M. Franceschini, D. Garetto, K. Goplalkrishnan, B, Jackson, B. Kurdi, C. Lam, L. A. Lastras, A. Padilla, B. Rajendran, S. Raoux, and R. S. Shenoy, J. Vac. Sci. Technol. B, 28, 223 (2010). [DOI:]
  4. M. H. Jang, S. J. Park, D. H. Lim, M. H. Cho, K. H. Do, D. H. Ko, and H. C. Sohn, Appl. Phys. Lett., 95, 012102 (2009). [DOI:]
  5. S. H. Kim, J. B. Park, W. T. Lee, J. Y. Woo, C. H. Cho, M. Siddik, J. H. Shin, S. S. Park, B. H. Lee, and H. S. Hwang, Appl. Phys. Lett., 99, 192110 (2011). [DOI:]
  6. B. Prasai, G. Chen, and D. A. Drabold, Appl. Phys. Lett., 102, 041907 (2011). [DOI:]
  7. J. H. Seo, K. H. Song, and H. Y. Lee, J. Appl. Phys., 47, 5337 (2008). [DOI:]
  8. S. W. Kim, W. S. Lim, T. W. Kim, and H. Y. Lee, Jpn. J. Appl. Phys., 47, 5337 (2008).
  9. A. Pirovano, A. L. Lacaita, A. Benvenuti, F. Pellizzer, and R. Bez, IEEE Trans on Electronic Devices., 51, 452 (2004).
  10. Y. Utsugi and Y. Mizushima, J. Appl. Phys., 51, 1773 (1980). []
  11. J. Kalb, F. Spaepen, and M. Wutting, Appl. Phys. Lett., 84, 5240 (2004). [DOI:]
  12. B. Gurbulak, S. Duman, and A. Ates, Czech, J. Phys., 55, 93 (2004). [DOI:]
  13. K. H. Song, J. H. Seo, J. H. Kim, and H. Y. Lee, J. Appl. Phys., 106, 123529 (2009). [DOI: ttps:// 1063/1.3273400]