Bottom gate organic field effect transistors made by laser structuring Ronald M. Meixner a, * , Rocco Wille a , Peter Schertling a , Holger Goebel a , H. Harde b , K.-H. Steglich b , F.A. Yildirim c , W. Bauhofer c , W. Krautschneider d a Helmut–Schmidt-University/University of the Federal Armed Forces Hamburg, Department of Electronics, Holstenhofweg 85, 22043 Hamburg, Germany b Helmut–Schmidt-University/University of the Federal Armed Forces Hamburg, Laser Engineering and Materials Science, Holstenhofweg 85, 22043 Hamburg, Germany c Institute of Optical and Electronic Materials, Hamburg University of Technology, Eissendorfer Strasse 38, D-21073 Hamburg, Germany d Institute of Nanoelectronics, Hamburg University of Technology, Eissendorfer Strasse 38, D-21073 Hamburg, Germany Received 8 June 2006; received in revised form 21 September 2006; accepted 26 September 2006 Available online 26 October 2006 Abstract This paper presents a process to manufacture all-polymer field effect transistors in a bottom gate configuration where all electrodes – including the gate electrode – are patterned using an excimer laser in combination with a scanning unit. This technique yields channel lengths of 10 lm between the source and the drain electrodes. Being a combination of a scanning and a single shot patterning process it is a promising candidate for an industrial process with a resolution of 10 lm and an operational throughput of at least 6 cm 2 /s. Ó 2006 Elsevier B.V. All rights reserved. Keywords: Laser patterning; P3HT; Thin-film transistors; Bottom gate 1. Introduction One of the most interesting features of organic electronics is the possibility to realize disposable electronics due to its low-cost potential. In order to fully enjoy the low-cost feature, simple and cost-effective process technologies are key require- ments for the fabrication of organic electronic devices. Since the first papers describing completely organic field effect transistors (FETs) [1] appeared in 1994, several all-organic thin-film transistors have been reported during the past decade. Based on these devices, interesting applications like ring-oscil- lators [2,3], a four-bit parallel-to-serial converter [4] or RFID-tags [5] were presented. Most of these organic field effect transistors (OFETs) are realized with simple and cheap patterning techniques, for example screen-printing [6], ink-jet printing [7], micro-contact printing [8], laser-induced thermal imaging [9] or direct laser patterning [10], represent- ing the required simple and cheap key technologies 1566-1199/$ - see front matter Ó 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.orgel.2006.09.005 * Corresponding author. Tel.: +49 40 6541 2228/2456; fax: +49 40 6541 3518. E-mail address: meixner@unibwh.de (R.M. Meixner). Organic Electronics 7 (2006) 586–591 www.elsevier.com/locate/orgel