Transactions on Electrical and Electronic Materials

The Korean Institute of Electrical and Electronic Material Engineers (한국전기전자재료학회)
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Etch Properties of HfO2 Thin Films using CH4/Ar Inductively Coupled Plasma

  • Woo, Jong-Chang (School of Electrical and Electronic Engineering, Chung-Ang University) ;
  • Kim, Gwan-Ha (School of Electrical and Electronic Engineering, Chung-Ang University) ;
  • Kim, Dong-Pyo (School of Electrical and Electronic Engineering, Chung-Ang University) ;
  • Kim, Chang-Il (School of Electrical and Electronic Engineering, Chung-Ang University)
  • Published : 2007.12.31
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Abstract

In this study, we carried out an investigation of the etching characteristics(etch rate, selectivity) of $HfO_2$ thin films in the $CH_4/Ar$ inductively coupled plasma. It was found that variations of input power and negative dc-bias voltage are investigated by the monotonic changes of the $HfO_2$ etch rate as it generally expected from the corresponding variations of plasma parameters. At the same time, a change in either gas pressure or in gas mixing ratio result in non-monotonic etch rate that reaches a maximum at 2 Pa and for $CH_4(20%)/Ar(80%)$ gas mixture, respectively. The X-ray photoelectron spectroscopy analysis showed an efficient destruction of the oxide bonds by the ion bombardment as well as showed an accumulation of low volatile reaction products on the etched surface. Based on these data, the ion-assisted chemical reaction was proposed as the main etch mechanism for the $CH_4-containing$ plasmas.

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References

  1. K. Takahashi and K. Ono, 'Selective etching of high-k $HfO_{2}$ films over Si in hydrogen-added fluorocarbon ($CF_{4}/Ar/H_{2}$ and $C_{4}F_{8}/Ar/H_{2}$) plasmas', J. Vac. Sci. Technol. A, Vol. 24, p. 437, 2006 https://doi.org/10.1116/1.2187997
  2. K. J. Hubbard and D. G. Schlom, 'Thermodynamic stability of binary oxides in contact With silicon', J. Mater. Res., Vol. 11, p. 2757, 1996 https://doi.org/10.1557/JMR.1996.0251
  3. B. H. Lee, L. Kang, W.-J. Qi, R. Nieh, Y. Jeon, K Onishi, and J. C. Lee, 'Thermal stability and electrical characteristics of ultrathin hafuium oxide gate dielectric reoxidized with rapid thermal annealing', Appl. Phys. Lett., Vol. 76, p. 1926, 2000
  4. H. S. Kim, S. A. Campbell, and D. C. Gilmer, 'Charge trapping and degradation in high-permittivity $TiO_{2}$ dielectric films', IEEE Electron Device Lett., Vol. 18, p. 465, 1997
  5. D. Park, Y. C. King, Q. Lu, T. J. King, C. Hu, A. Kalnitsky, S. P. Tay, and C. C. Cheng, 'Transistor characteristics with $Ta_{2}O_{5}$ gate dielectric', IEEE Electron Device Lett., Vol. 19, p. 441, 1998
  6. U. Ehrke, A. Sears, L. Alff, and D. Reisinger, 'High resolution depth profiling of thin STO in high-k oxide material', Applied Surface Science, Vol. 231-232, p. 598, 2004
  7. R. J. Gaboriaud, F. Paumier, F. Pailloux, and P. Guerin, '$Y_{2}O_{3}$ thin films: internal stress and microstructure', Materials Science and Engineering B, Vol. 109, p. 34, 2004 https://doi.org/10.1016/j.mseb.2003.10.023
  8. T. Ngai, W. J. Qi, R. Sharma, J. Fretwell, X. Chen, J. C. Lee, and S. banerjee, 'Electrical properties of $ZrO_{2}$ gate dielectric on SiGe', Appl. Phys. Lett., Vol. 76, p. 502, 2000
  9. K. T. Kim and C. I. Kim, 'The effect of Cr doping on the microstructural and dielectric properties of $(Ba_{0.6}Sr_{0.4})TiO_{3}$ thin films', Thin Solid Films, Vol. 472, p. 26, 2005 https://doi.org/10.1016/j.tsf.2004.05.128
  10. S. W. Jeong, K. S. Kim, M. T. You, and Y. Roh, '$HfSi_{x}O_{y}-HfO_{2}$ gate insulator for thin film transistiors', J. Korean Phys. Soc., Vol. 47, p. S401, 2005
  11. C. T. Liu, 'Circuit Requirement and Integration Challenges of Thin Gate Dielectrics for Ultra Small MOSFETs', Tech. Dig. IEDM, p. 747, 1998
  12. B. Cheng, M. Cao, R. Rao, A. Inani, P. Noorde, W. M. Greene, J. M. C. Stork, Z. Yu, and P. M. Zeitzoff, 'The impact of high-k gate dielectrics and metal gate electrodes on Sub-100 nm MOSFET's', IEEE Tran. Electron Device, Vol. 46, p.1537, 1999
  13. J. H. Lee, Y. D. Ko, and I. Yun, 'Comparison of latin hypercube sampling and simple random sampling applied to neural network modeling of $HfO_{2}$ thin film fabrication', Trans. EEM., Vol. 7, No. 4, p. 210, 2006 https://doi.org/10.4313/TEEM.2006.7.4.210
  14. Y. Zhao and M. H. White, 'Modeling of direct tunneling current through interfacial oxide and high-k gate stacks', Solid-State Electronics, Vol. 48, p. 1801, 2004 https://doi.org/10.1016/j.sse.2004.05.016
  15. D. R. Lide, 'CRC Handbook of Chemistry and Physics', CRC Press, p. 4, 1998
  16. S. M. Gu, D. P. Kim, K. T. Kim, and C. I. Kim, 'The etching properties of MgO thin films in $Cl_{2}/Ar$ gas chemistry', Thin Solid Films, Vol. 475, p. 313, 2005 https://doi.org/10.1016/j.tsf.2004.08.037
  17. G. H. Kim and C. I. Kim, 'Dry etching of magnesium oxide thin films by using inductively coupled plasma for buffer layer of MFIS structure', Thin Solid Films, Vol. 515, p. 4955, 2007 https://doi.org/10.1016/j.tsf.2006.10.087
  18. J. Aarik, H. Mandar, M. Kirm, and L. Pung, 'Optical characterization of $HfO_{2}$ thin films grown by atomic layer deposition', Thin Solid Films, Vol. 466, p. 41, 2004 https://doi.org/10.1016/j.tsf.2004.01.110
  19. K. Nakamura, T. Kitagawa, K. Osari, K. Takahashi, and K. Ono, 'Plasma etching of high-k and metal gate materials', Vacuum, Vol. 80, p. 761, 2006 https://doi.org/10.1016/j.vacuum.2005.11.017
  20. D. Y. Kim, J. G. Kang, and K. J. Chang, 'Impact of Si impurities in $HfO_{2}$ threshold voltage problems in poly-Si/$HfO_{2}$ gate stacks', J. Korean Phys. Soc., Vol. 48, p. 1628, 2005