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Low-voltage organic transistors with an amorphous molecular gate dielectric

Abstract

Organic thin film transistors (TFTs) are of interest for a variety of large-area electronic applications, such as displays1,2,3, sensors4,5 and electronic barcodes6,7,8. One of the key problems with existing organic TFTs is their large operating voltage, which often exceeds 20 V. This is due to poor capacitive coupling through relatively thick gate dielectric layers: these dielectrics are usually either inorganic oxides or nitrides2,3,4,5,6,7,8, or insulating polymers9, and are often thicker than 100 nm to minimize gate leakage currents. Here we demonstrate a manufacturing process for TFTs with a 2.5-nm-thick molecular self-assembled monolayer (SAM) gate dielectric and a high-mobility organic semiconductor (pentacene). These TFTs operate with supply voltages of less than 2 V, yet have gate currents that are lower than those of advanced silicon field-effect transistors with SiO2 dielectrics. These results should therefore increase the prospects of using organic TFTs in low-power applications (such as portable devices). Moreover, molecular SAMs may even be of interest for advanced silicon transistors where the continued reduction in dielectric thickness leads to ever greater gate leakage and power dissipation.

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Figure 1: Chemical structures of organic materials, and cross-section and electrical characteristics of a TFT with molecular SAM gate dielectric.
Figure 2: Electrical characteristics of Si/SAM/Au capacitors.
Figure 3: Cross-section and electrical characteristics of a pentacene TFT with molecular SAM dielectric and photolithographically patterned source–drain contacts.

References

  1. Rogers, J. A. et al. Paper-like electronic displays: Large-area rubber-stamped plastic sheets of electronics and microencapsulated electrophoretic inks. Proc. Natl Acad. Sci. USA 98, 4835–4840 (2001)

    ADS  CAS  Article  Google Scholar 

  2. Sheraw, C. D. et al. Organic thin-film transistor-driven polymer-dispersed liquid crystal displays on flexible polymeric substrates. Appl. Phys. Lett. 80, 1088–1090 (2002)

    ADS  CAS  Article  Google Scholar 

  3. Huitema, H. E. A. et al. Plastic transistors in active-matrix displays. Nature 414, 599 (2001)

    ADS  CAS  Article  Google Scholar 

  4. Crone, B. K. et al. Organic oscillator and adaptive amplifier circuits for chemical vapor sensing. J. Appl. Phys. 91, 10140–10146 (2001)

    ADS  Article  Google Scholar 

  5. Bartic, C., Campitelli, A. & Borghs, G. Field-effect detection of chemical species with hybrid organic/inorganic transistors. Appl. Phys. Lett. 82, 475–477 (2003)

    ADS  CAS  Article  Google Scholar 

  6. Crone, B. et al. Large-scale complementary integrated circuits based on organic transistors. Nature 403, 521–523 (2000)

    ADS  CAS  Article  Google Scholar 

  7. de Leeuw, D. M. et al. Polymeric integrated circuits: fabrication and first characterisation. 2002 Int. Electron Device Meeting (IEDM) Tech. Dig., 293–296 (2002)

  8. Baude, P. et al. Pentacene-based radio-frequency identification circuitry. Appl. Phys. Lett. 82, 3964–3966 (2003)

    ADS  CAS  Article  Google Scholar 

  9. Klauk, H. et al. Pentacene organic transistors and ring oscillators on glass and on flexible polymeric substrates. Appl. Phys. Lett. 82, 4175–4177 (2003)

    ADS  CAS  Article  Google Scholar 

  10. Collet, J., Tharaud, O., Chapoton, A. & Vuillaume, D. Low-voltage, 30 nm channel length, organic transistors with a self-assembled monolayer as gate insulating films. Appl. Phys. Lett. 76, 1941–1943 (2000)

    ADS  CAS  Article  Google Scholar 

  11. Boulas, C., Davidovits, J. V., Rondelez, F. & Vuillaume, D. Suppression of charge carrier tunneling through organic self-assembled monolayers. Phys. Rev. Lett. 76, 4797–4800 (1996)

    ADS  CAS  Article  Google Scholar 

  12. Collet, J. & Vuillaume, D. Nano-field effect transistor with an organic self-assembled monolayer as gate insulator. Appl. Phys. Lett. 73, 2681–2683 (1998)

    ADS  CAS  Article  Google Scholar 

  13. Schütz, M. Self-Assembled Monolayers on Oxidized Surfaces—Anti-Corrosion and Insulation Behavior PhD thesis, 192–193, Univ. Stuttgart (2002)

    Google Scholar 

  14. Lenfant, S., Krzeminski, C., Delerue, C., Allan, G. & Vuillaume, D. Molecular rectifying diodes from self-assembly on silicon. Nano Lett. 3, 741–746 (2003)

    ADS  CAS  Article  Google Scholar 

  15. Kelley, T. W. et al. High-performance OTFTs using surface-modified alumina dielectrics. J. Phys. Chem. B 107, 5877–5881 (2003)

    CAS  Article  Google Scholar 

  16. Klauk, H. et al. High-mobility polymer gate dielectric pentacene thin film transistors. J. Appl. Phys. 92, 5259–5263 (2002)

    ADS  CAS  Article  Google Scholar 

  17. Halik, M. et al. Relationship between molecular structure and electrical performance of oligothiophene organic thin film transistors. Adv. Mater. 15, 917–922 (2003)

    CAS  Article  Google Scholar 

  18. Kelly, T. W. et al. High performance organic thin film transistors. MRS Symp. Proc. 771, 169–179 (2003)

    Google Scholar 

  19. Fontaine, P. et al. Octadecyltrichlorosilane monolayers as ultrathin gate insulating films in metal-insulator-semiconductor devices. Appl. Phys. Lett. 62, 2256–2258 (1993)

    ADS  CAS  Article  Google Scholar 

  20. Thompson, S. et al. A 90 nm logic technology featuring 50 nm strained silicon channel transistors, 7 layers of Cu interconnects, low k ILD, and 1 µm2 SRAM cell. 2002 Int. Electron Device Meeting (IEDM) Tech. Dig., 61–64 (2002)

  21. Sekine, K., Saito, Y., Hirayama, M. & Ohmi, T. Highly reliable ultrathin silicon oxide film formation at low temperature by oxygen radical generated in high-density krypton plasma. IEEE Trans. Electr. Dev. 48, 1550–1555 (2000)

    ADS  Article  Google Scholar 

  22. Lo, S. H., Buchanan, D. A., Taur, Y. & Wang, W. Quantum-mechanical modeling of electron tunneling current from the inversion layer of ultra-thin-oxide nMOSFETs. IEEE Electr. Dev. Lett. 18, 209–211 (1997)

    ADS  CAS  Article  Google Scholar 

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Acknowledgements

M.S. and S.M. were supported by the PhD Fellowship of the Deutsche Forschungsgemeinschaft.

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Correspondence to Marcus Halik.

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Supplementary information

Supplementary Data (DOC 32 kb)

Supplementary Figure S1

Tapping mode AFM height and phase images. (DOC 207 kb)

Supplementary Figure S2

STM images of a PhO-OTS monolayer. (DOC 600 kb)

Supplementary Figure S3

Electrical characteristics of an Eth-6T-Eth TFT with PhO-OTS gate dielectric. (DOC 43 kb)

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Halik, M., Klauk, H., Zschieschang, U. et al. Low-voltage organic transistors with an amorphous molecular gate dielectric. Nature 431, 963–966 (2004). https://doi.org/10.1038/nature02987

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