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Electronics and Telecommunications Research Institute (한국전자통신연구원)
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Channel Protection Layer Effect on the Performance of Oxide TFTs

  • KoPark, Sang-Hee (Convergence Components & Materials Research Laboratory, ETRI) ;
  • Cho, Doo-Hee (Convergence Components & Materials Research Laboratory, ETRI) ;
  • Hwang, Chi-Sun (Convergence Components & Materials Research Laboratory, ETRI) ;
  • Yang, Shin-Hyuk (Convergence Components & Materials Research Laboratory, ETRI) ;
  • Ryu, Min-Ki (Convergence Components & Materials Research Laboratory, ETRI) ;
  • Byun, Chun-Won (Convergence Components & Materials Research Laboratory, ETRI) ;
  • Yoon, Sung-Min (Convergence Components & Materials Research Laboratory, ETRI) ;
  • Cheong, Woo-Seok (Convergence Components & Materials Research Laboratory, ETRI) ;
  • Cho, Kyoung-Ik (Convergence Components & Materials Research Laboratory, ETRI) ;
  • Jeon, Jae-Hong (School of Electronics, Telecommunications, and Computer Engineering, Korea Aerospace University)
  • Received : 2009.05.17
  • Accepted : 2009.10.19
  • Published : 2009.12.31
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Abstract

We have investigated the channel protection layer (PL) effect on the performance of an oxide thin film transistor (TFT) with a staggered top gate ZnO TFT and Al-doped zinc tin oxide (AZTO) TFT. Deposition of an ultra-thin PL on oxide semiconductor films enables TFTs to behave well by protecting the channel from a photo-resist (PR) stripper which removes the depleted surface of the active layer and increases the carrier amount in the channel. In addition, adopting a PL prevents channel contamination from the organic PR and results in high mobility and small subthreshold swings. The PL process plays a critical role in the performance of oxide TFTs. When a plasma process is introduced on the surface of an active layer during the PL process, and as the plasma power is increased, the TFT characteristics degrade, resulting in lower mobility and higher threshold voltage. Therefore, it is very important to form an interface using a minimized plasma process.

Keywords

References

  1. K. Nomura et al., "Room-Temperature Fabrication of Transparent Flexible Thin-Film Transistors Using Amorphous Oxide Semiconductors," Nature, vol. 432, no. 7016, 2004, pp. 488-492. https://doi.org/10.1038/nature03090
  2. J. Wager, "Transparent Electronics," Science, vol. 300, no. 5623, 2003, pp. 1245-1246. https://doi.org/10.1126/science.1085276
  3. E.M.C. Fortunato et al., "Fully Transparent ZnO Thin Film Transistor Produced at Room Temperature," Adv. Mater., vol. 17, no. 5, 2005, pp. 590-594. https://doi.org/10.1002/adma.200400368
  4. H.N. Lee et al., "3.5 Inch QCIF+ AM-OLED Panel Based on Oxide TFT Backplane," Tech. Dig. SID07, California, USA, 2007, pp. 1826-1829.
  5. H. Ohta and H. Hosono, "Transparent Oxide Optoelectronics," Material Today, vol. 7, no. 6, 2004, pp. 42-51.
  6. I. Song et al., " Short Channel Characteristics of Gallium–Indium–Zinc–Oxide Thin Film Transistors for Three-Dimensional Stacking Memory," IEEE Electron Device Letters, vol. 29, no. 6, 2008, pp. 549-552. https://doi.org/10.1109/LED.2008.920965
  7. S.-H. K. Park et al., "Transparent and Photo-Stable ZnO Thin-Film Transistors to Drive an Active Matrix Organic-Light-Emitting-Diode Display Panel," Adv. Mater., vol. 21, no. 6, 2009, pp. 678-682. https://doi.org/10.1002/adma.200801470
  8. J. Lee et al., "World's Largest (15-inch) XGA AMLCD Panel Using IGZO Oxide TFT," Tech. Dig. SID08, California, USA, 2008, pp. 625-628.
  9. M. Ito et al., "Amorphous Oxide TFT and Their Applications in Electrophoretic Displays," Physica Status Solidi (a), vol. 205, no. 8, 2008, pp. 1885-1894. https://doi.org/10.1002/pssa.200778910
  10. R.B.M. Cross and M.M. De Souza, "Investigating the Stability of Zinc Oxide Thin Film Transistors," Appl. Phys. Lett., vol. 89, no. 26, 2006, pp. 263513-263515. https://doi.org/10.1063/1.2425020
  11. J.K. Jeong et al., "High Performance Thin Film Transistors with Cosputtered Amorphous Indium Gallium Zinc Oxide Channel," Appl. Phys. Lett., vol. 91, no. 11, 2007, pp. 113505-113507. https://doi.org/10.1063/1.2783961
  12. E.M.C. Fortunato et al., "High Mobility Indium Free Amorphous Oxide Thin Film Transistors," Appl. Phys. Lett., vol. 92, no. 22, 2008, pp. 222103-222105. https://doi.org/10.1063/1.2937473
  13. J.K. Jeong et al., "Impact of Device Configuration on the Temperature Instability of Al-Zn-Sn-O Thin Film Transistor," Appl. Phys. Lett., vol. 95, no. 12, 2009, pp. 123505-123507. https://doi.org/10.1063/1.3236694
  14. N.L. Dehuff et al., "Transparent Thin-Film Transistors with Zinc Indium Oxide Channel Layer," J. Appl. Phys., vol. 97, no. 6, 2005, pp. 64505-64508 https://doi.org/10.1063/1.1862767
  15. S.-H. K. Park et al., "Transparent ZnO-TFT Arrays Fabricated by Atomic Layer Deposition," Electrochemical and Solid-State Letters, vol. 11, no. 1, 2008, pp. H10-H14. https://doi.org/10.1149/1.2801017
  16. J.H. Shin et al., "Light Effects on the Bias Stability of Transparent ZnO Thin Film Transistors," ETRI Journal, vol. 31, no. 1, 2009, pp. 62-64. https://doi.org/10.4218/etrij.09.0208.0266
  17. C.J. Kim et al., "Characteristics and Cleaning of Dry-Etching-Damaged Layer of Amorphous Oxide Thin-Film Transistor," Electrochemical and Solid-State Letters, vol. 12, no. 4, 2009, pp. H95-H97. https://doi.org/10.1149/1.3067838
  18. I. Yagi, K. Tsukagoshia, and Y. Aoyagi, "Modification of the Electric Conduction at the Pentacene/$SiO_2$ Interface by Surface Termination of $SiO_2$," Appl. Phys. Lett., vol. 86, no. 10, 2005, pp. 103502-103504. https://doi.org/10.1063/1.1875749
  19. A.R. Hepburn et al., "Metastable Defects in Amorphous-Silicon Thin Film Transistors," Physical Review Letters, vol. 56, no. 20, 1986, pp. 2215-2217. https://doi.org/10.1103/PhysRevLett.56.2215
  20. S.-H. K. Park et al., "Characteristics of ZnO Thin Films by Means of Plasma-Enhanced Atomic Layer Deposition," Electrochemical and Solid-State Letters, vol. 9, no. 10, 2006, pp. G299-G301. https://doi.org/10.1149/1.2221770
  21. J.W. Lim and S.J. Yun, "Electrical Properties of Alumina Films by Plasma-Enhanced Atomic Layer Deposition," Electrochemical and Solid-State Letters, vol. 7, no. 8, 2004, pp. F45-F48. https://doi.org/10.1149/1.1756541
  22. D.-H. Cho et al., "Transparent Al–Zn–Sn–O Thin Film Transistors Prepared at Low Temperature," Appl. Phys. Lett., vol. 93, no. 14, 2008, pp. 142111-142113. https://doi.org/10.1063/1.2998612
  23. S.J. Yun et al., "Dependence of Atomic Layer-Deposited $Al_2O_3$ Films Characteristics on Growth Temperature and Al Precursors of $Al(CH_3)_3$ and $AlCl_3$," J. Vac. Sci. Technol. A, vol. 15, no. 6, 1997, pp. 2993-2997. https://doi.org/10.1116/1.580895
  24. C.G. Van de Walle, "Hydrogen as a Cause of Doping in Zinc Oxide," Phys. Rev. Lett., vol. 85, no. 5, 2000, pp. 1012-1015. https://doi.org/10.1103/PhysRevLett.85.1012
  25. R.L. Hoffman, "ZnO-Channel Thin Film Transistor: Channel Mobility," J. Appl. Phys., vol. 95, no. 10, 2004, pp. 5813-5819. https://doi.org/10.1063/1.1712015
  26. J.S. Park et al., "Electronic Transport Properties of Amorphous Indium-Gallium-Zinc Oxide Semiconductor upon Exposure to Water," Appl. Phys. Lett., vol. 92, no. 7, 2008, pp. 72104-72106. https://doi.org/10.1063/1.2838380
  27. J.K. Jeong et al., "Origin of Threshold Voltage Instability in Indium-Gallium-Zinc Oxide Thin Film Transistors," Appl. Phys. Lett., vol. 93, no. 12, 2008, pp. 123508-123510. https://doi.org/10.1063/1.2990657
  28. H. Yin et al., "Bootstrapped Ring Oscillator with Propagation Delay Time below 1.0 nsec/stage by Standard 0.5 $\mu$m Bottom-Gate Amorphous Ga2O3-In2O3-ZnO TFT Technology," Electron Device Meeting, IEEE International, 15-17, Dec. 2008, pp. 1-4.

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