Korean Journal of Materials Research (한국재료학회지)

Materials Research Society of Korea (한국재료학회)
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Cu dry etching by the reaction of Cu oxide with H(hfac)

Cu oxide의 형성과 H(hfac) 반응을 이용한 Cu 박막의 건식식각

  • Yang, Hui-Jeong (School of Metallurgical and Materials Engineering, Kookmin University) ;
  • Hong, Seong-Jin (School of Metallurgical and Materials Engineering, Kookmin University) ;
  • Jo, Beom-Seok (School of Metallurgical and Materials Engineering, Kookmin University) ;
  • Lee, Won-Hui (School of Metallurgical and Materials Engineering, Kookmin University) ;
  • Lee, Jae-Gap (School of Metallurgical and Materials Engineering, Kookmin University)
  • 양희정 (국민대학교 금속재료공학부) ;
  • 홍성진 (국민대학교 금속재료공학부) ;
  • 조범석 (국민대학교 금속재료공학부) ;
  • 이원희 (국민대학교 금속재료공학부) ;
  • 이재갑 (국민대학교 금속재료공학부)
  • Published : 2001.06.01
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Abstract

Dry etching of copper film using $O_2$ plasma and H(hfac) has been investigated. A one-step process consisting of copper film oxidation with an $O_2$ plasma and the removal of surface copper oxide by the reaction with H(hfac) to form volatile Cu(hfac)$_2$ and $H_2O$ was carried but. The etching rate of Cu in the range from 50 to 700 /min was obtained depending on the substrate temperature, the H(hfac)/O$_2$ flow rate ratio, and the plasma power. The copper film etch rate increased with increasing RF power at the temperatures higher than 215$^{\circ}C$. The optimum H(hfac)/O$_2$ flow rate ratio was 1:1, suggesting that the oxidation process and the reaction with H(hfac) should be in balance. Cu patterning using a Ti mask was performed at a flow rate ratio of 1:1 on 25$0^{\circ}C$\ulcorner and an isotropic etching profile with a taper slope of 30$^{\circ}$was obtained. Cu dry patterning with a tapered angle which is necessary for the advanced high resolution large area thin film transistor liquid-crystal displays was thus successfully obtained from one step process by manipulating the substrate temperature, RF power, and flow rate ratio.

O$_2$plasma와 H(hfac)을 이용한 Cu 박막의 건식 식각을 조사하였다. 휘발성이 큰 Cu(hfac)$_2$와 $H_2O$를 탈착시키기 위하여 $O_2$ Plasma를 이용한 Cu 박막의 산화와 생성된 Cu 산화막을 H(hfac)과의 반응으로 제거하는 공정으로 식각을 수행하였다. Cu 박막의 식각율은 50-700 /min의 범위를 보였으며, 기판온도, H(hfac)/O$_2$ 유량비, plasma power에 따라 변하였다. Cu 박막의 식각율은 기판온도 215$^{\circ}C$보다 높은 온도구간에서 RF power가 증가함에 따라 증가하였고, 산화 공정과 H (hfac)과의 반응이 균형을 이루는 최적의 H (hfac)/O$_2$ 유량비는 1:1임을 확인하였다. Ti mask를 사용한 Cu Patterning은 유량비 1 : 1, 기판온도 25$0^{\circ}C$에서 실시하였고, 30$^{\circ}$외 taper slope를 갖는 등방성 etching profile을 얻을 수 있었다. Taper angle을 갖는 Cu 건식 patterning은 고해상도의 대면적 thin film transistor liquid-crystal(TFT-LCDs)를 위래 필요한 것으로써 기판온도, RF power, 유량비를 조절한 one-step 공정으로부터 성공적으로 얻을 수 있었다.

Keywords

References

  1. N. Awaya and Y. Arita, J. Electron. Mater., 21, (1992) 959 https://doi.org/10.1007/BF02684203
  2. A. Jain, T.T. Kodas, R. Jairath, and M.J. Hampden-Smith, J. Vac. Sci. & Technol. B, 11, (1993) 2107 https://doi.org/10.1116/1.586550
  3. J. Lin and M. C. Chen, Jpn. J. Appl. Phys., 38, (1999) 4863 https://doi.org/10.1143/JJAP.38.4863
  4. S. P. Murarka and S. Hymes, Solid State Mater. Sci., 20, (1995) 87
  5. Y.J. Park, V.K. Andleigh and C.V. Thompson, J. Appl. Phys., 85 (7), (1999) 3546 https://doi.org/10.1063/1.369714
  6. C. Whitman, M.M. Moslehi, A. Paranjpe, L. Velo, and T. Omstead, J. Vac. Sci. & Technol. A, 17(4), (1999) 1893 https://doi.org/10.1116/1.581700
  7. R. Liu, C.S. Pai, and E. Martinez, Solid State Electr., 43, (1999) 1003 https://doi.org/10.1016/S0038-1101(99)00015-5
  8. X. W. Lin and D. Pramanlk, Solid State Technology, October, (1998) 63
  9. K. Ohno, M. Sato, and Y. Arita, J. Electrochem. Soc., 143, (1996) 4089 https://doi.org/10.1149/1.1837341
  10. G.C. Schwartz and P. M. Schaible, J. Electrochem. Soc., 130, (1983) 1777 https://doi.org/10.1149/1.2120092
  11. K. Ohno, M. Sato, and Y. Arita, Jpn. J. Appl. Phys., 28, (1989) 1070 https://doi.org/10.1143/JJAP.28.L1070
  12. S.K. Lee, S.S. Chun, C.Y. Hwang, and W.J. Lee, Jpn. J. Appl. Phys., 36, (1997) 50 https://doi.org/10.1143/JJAP.36.50
  13. B.J. Howard and C.H. Steinbruchel, Appl. Phys. Lett., 59, (1991) 914 https://doi.org/10.1063/1.106299
  14. Y. Ohshita and N. Hosoi, Thin Solid Films, 262, (1995) 67 https://doi.org/10.1016/0040-6090(94)05803-2
  15. M.S. Kwon and J.Y. Lee, J. Electrochem. Soc., 146, (1999) 3119 https://doi.org/10.1149/1.1392441
  16. A. Jain, T.T. Kodas, and M.J. Hampden-Smith, Thin Solid Films, 269, (1995) 51 https://doi.org/10.1016/0040-6090(95)06877-5
  17. S.W. Kwang, H.U. Kim, and S.W. Rhee, J. Vac. Sci. Technol. B, 17, (1999) 1