Fabrication of RR-P3HT-based TFTs using low-temperature PECVD silicon nitride passivation


Regioregular poly(3-hexylthiophene) (RR-P3HT) is a commercially available semiconducting polymer. Its high processability makes it favorable for fabrication of organic thin film transistors (OTFTs). Depending on the processing technique and device configuration, the field effect mobility of this polymer ranges from 0.01 to 0.1 cm2/Vs. The mobility also shows a correlation with the choice of gate dielectric material. The most commonly reported dielectric materials for OTFTs are SiO2, Al2O3 and Ta2O5. In this work, we report a new fully encapsulated top-gate RR-P3HT-based TFT structure with a-SiNx implemented as the gate dielectric and passivation material. The fabrication process enables realization of discrete transistors and transistor circuits through four consecutive photolithographic steps. The process is compatible for various substrates including Corning glass, Si wafers, and any appropriate plastic substrates. This paper addresses a number of critical technological issues such as substrate surface treatment to improve film adhesion, optimal spin coating conditions for uniform polymer film formation, preparation of device quality a-SiNx films by plasma-enhanced chemical vapor deposition (PECVD) at 75°C substrate temperature, and a tailored etch process for patterning of the polymer film. Current-voltage characteristics of the fabricated transistors are analyzed to evaluate the quality of the polymer/a-SiNx interface.

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  1. 1

    H. Sirringhaus, N. Tessler and R. Friend, Science 280, 1741 (1998).

    CAS  Article  Google Scholar 

  2. 2

    Z. Bao, A. Dodabapalur, A. J. Lovinger. Appl. Phys. Lett. 69, 4108 (1996).

    CAS  Article  Google Scholar 

  3. 3

    L. Burgi, T. J. Richards, R. H. Friend, and H. Sirringhaus, J. Appl. Phys. 94, 6129 (2003).

    CAS  Article  Google Scholar 

  4. 4

    G. Wang, J. Swensen, D. Moses and A.J. Heeger, J. Appl. Phys. 93, 6137 (2003).

    CAS  Article  Google Scholar 

  5. 5

    D. J. Gundlach, Y. Y. Lin, T. N. Jackson, S. F. Nelson, D. G. Schlom, IEEE Electron Device Lett., 18, 87 (1997).

    CAS  Article  Google Scholar 

  6. 6

    Z. Bao, A. J. Lovinger, Chem. Matter. 11, 2607 (1999).

    CAS  Article  Google Scholar 

  7. 7

    S. Steudel, S. D. Vusser, S. D. Jonge, D. Janssen, S. Verlaak, J. Genow and P. Heremans, Appl. Phys. Lett. 85, 4400 (2004).

    CAS  Article  Google Scholar 

  8. 8

    A. Dodabapalur, L. Torsi, H. E. Katz, Science 268, 270 (1995).

    Article  Google Scholar 

  9. 9

    L. Torsi, A. Dodabapalur, H. E. Katz, J. Appl. Phys. 78, 1088 (1995).

    CAS  Article  Google Scholar 

  10. 10

    J. H. Shin, L. Y. Jung, S. W. Pyo, Y. K. Kim, Thin Solid Films 441, 284 (2003).

    Article  Google Scholar 

  11. 11

    S. Y. Park, M. Park and H. H. Lee, Appl. Phys. Lett. 85, 2283 (2004).

    CAS  Article  Google Scholar 

  12. 12

    G. Ashkenasy, D. Cahen, R. Cohen, A. Shanzer and A. Vilan, Acc. Chem. Res. 35, 121 (2002).

    CAS  Article  Google Scholar 

  13. 13

    H. Ishii, K. Sugiyama, E. Ito and K. Seki, Adv. Matter. 11, 605 (1999).

    CAS  Article  Google Scholar 

  14. 14

    S. Kobayashi, T. Nishikawa, T. Takenobu, S. Mori, T. Shimoda, T. Mitani, H. Shimotani, N. Yoshimoto, S. Ogawa, Y. Iwasa, Nature Materials 3, 317 (2004).

    CAS  Article  Google Scholar 

  15. 15

    A. Salleo, M. L. Chabinyo, M. S. Yang and R. A. Street, Appl. Phys. Lett. 81, 4383 (2002); S. Hayase, Pog. Poly. Sci. 28, 359 (2003).

    CAS  Article  Google Scholar 

  16. 16

    R. A. Street, Ed., Technology and Applications of Hydrogenated Amorphous Silicon, New York: Springer (2000).

  17. 17

    A. Sazonov and C. McArthur, J. Vac. Sci. Technol. A 22, 2052 (2004).

    CAS  Article  Google Scholar 

  18. 18

    S. Hoshino, M. Yoshida, S. Uemura, T. Kodzasa, N. Takada, T. Kamata and Kiyoshi Yase, J. Appl. Phys. 95, 5088 (2004).

    CAS  Article  Google Scholar 

  19. 19

    M. S. A. Abdou, F. P. Orfino, Z. W. Xie, M. J. Deen and S. Holdcroft, Adv. Mater. 6, 838 (1994).

    CAS  Article  Google Scholar 

  20. 20

    S. Wang, Fundamentals of Semiconductors: Theory and Device Physics, Englewood Cleffs, NJ: Prentice Hall (1989); R. F. Pierret, Field Effect devices, Reading, MA: Addison-Wesley (1990).

    Google Scholar 

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Koul, S., Vygranenko, Y., Li, F. et al. Fabrication of RR-P3HT-based TFTs using low-temperature PECVD silicon nitride passivation. MRS Online Proceedings Library 871, 94 (2005). https://doi.org/10.1557/PROC-871-I9.4

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