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The Path Towards Woven Thin-film Transistors

Published online by Cambridge University Press:  01 February 2011

Kunigunde Cherenack  and
Gerhard Tröster
Kunigunde Cherenack
Affiliation:
[email protected], Swiss Federal Institute of Technology, Institute for Electronics, Zürich, Switzerland
Gerhard Tröster
Affiliation:
[email protected], Swiss Federal Institute of Technology, Institute for Electronics, Zürich, Switzerland
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Abstract

Electronic textiles (or e-textiles) have a wide range of potential applications in wearable computing and large-area applications, including medical monitoring, assistance to the disabled, and distributed sensor networks. We aim to integrate thin-film electronics directly into clothing during the weaving process. First, thin-film devices are fabricated on plastic substrates. Individual devices are separated by cutting the substrate into stripes which can then be woven into a textile. Devices on stripes need to survive high applied bending strains during weaving. As a first building block, we used atomic layer deposition (ALD) at a maximum temperature of 150oC to fabricate bottom-gate zinc-oxide thin-film transistors (TFTs) with a 25nm-thick Al2O3 gate dielectric, and a 15nm-thick ZnO semiconducting layer on 50μm-thick Kapton E substrates. These TFTs had average mobilities of 12cm2/Vs, threshold voltages around 1V and subthreshold slopes around 250mV/decade. However, after applying a tensile bending diameter of 1cm to the TFTs, ~80% of TFTs fail due to cracking of the brittle device layers. We studied causes of failure and investigated patterning holes in the brittle layers to prevent crack propagation though the channel. This reduced TFT failure to ~45% under the same applied bending conditions. In this paper, we will discuss failure mechanisms in our standard TFT structure when high tensile bending strains are applied and how the device structure was adjusted to decrease TFT failure.

Keywords

microelectronicsthin filmpolymer
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 1256: Symposium N – Functional Oxide Nanostructures and Heterostructures , 2010 , 1256-N11-19
Copyright
Copyright © Materials Research Society 2010

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References

[1] Hekmatshoar, B. Kattamis, A. Z. Cherenack, K. H. Wagner, S. and Sturm, J. C. A novel TFT-OLED integration for OLED-independent pixel programming in amorphous-Si AMOLED pixels, JSID, vol 16, no. 1, pp. 183–188, Jan. 2008.Google Scholar
[2] Bonderover, E. and Wagner, S. “A woven inverter circuit for e-textile applications,” IEEE Electron Device Lett., vol. 25, no. 5, pp. 295–297, May 2004.Google Scholar
[3] Someya, T. Sekitani, T. Iba, S. Kato, Y. Kawaguchi, H. and Sakurai, T. “A large-area, flexible pressure sensor matrix with organic field-effect transistors for artificial skin applications,” in PNAS, vol. 101, no. 27, Jul. 2004, pp. 9966–9970.Google Scholar
[4] Li, T. Huang, Z. Y. Xi, Z. C. Lacour, S. P. Wagner, S. and Suo, Z.”Delocalizing strain in a thin metal film on a polymer substrate,” Mech. Mater., vol. 37, pp. 261–273, 2005.10.1016/j.mechmat.2004.02.002Google Scholar
[5] Lu, N. Wang, X. Suo, Z. and Vlassak, J. “Metal films on polymer substrates stretched beyond 50%,” Appl. Phys. Lett., vol. 91, no. 22, Nov. 2007.Google Scholar
[6] Suo, Z. Ma, E. Y. Gleskova, H. and Wagner, S. “Mechanics of rollable and foldable filmon-foil electronics,” Appl. Phys. Lett., vol. 74, no. 8, pp. 1177–1179, Feb. 1999.10.1063/1.123478Google Scholar
[7] Mandlik, P. Lacour, S. P. Li, J. W. Chou, S. Y. and Wagner, S. “Fully elastic interconnects on nanopatterned elastomeric substrates,” IEEE Electron Device Lett., vol. 27, no. 8, pp. 650–652, Aug. 2006.10.1109/LED.2006.879029Google Scholar
[8] Lacour, S. Jones, J. Wagner, S. Li, T. and Suo, Z. “Stretchable interconnects for elastic electronics surfaces,” in Proc.of the IEEE, vol. 93, no. 8, Jul. 2005, pp. 1459–1467.Google Scholar
[9] Christiaens, W. Loeher, T. Pahl, B. Feil, M. Vandevelde, B. and Vanfleteren, J. “Embedding and assembly of ultrathin chips in multilayer flex boards,” Circuit World, vol. 34, no. 3, pp. 3–8, 2008.Google Scholar
[10] Cherenack, K. H. Kattamis, A. Z. Hekmatshoar, B. Sturm, J. C. and Wagner, S. “Amorphous silicon thin-film transistors fabricated at 300°C on a clear plastic substrate foil”, IEEE Electron Device Lett., vol. 28, no. 11, pp. 1004–1006, November 2007.10.1109/LED.2007.907411Google Scholar
[11] [Online] http://www2.dupont.com/Kapton/en_US/US/, downloaded 04.01.2010.Google Scholar
[12] [Online] http://www.cyantek.com/, com/, downloaded 10.03.2010.Google Scholar