Analysis of short-channel effects in organic field-effect transistors

We present a comprehensive study of short channel effects in organic field-effect transistors by measuring the electrical characteristics of devices with fixed channel width and varying channel length. Our studies are conducted on a p-type organic semiconductor, (E,E-2,5-bis-{4'-bis-(4''-methoxy-phenyl)amino-styryl}-3,4-ethylenedioxy-thiophene that is spin-coated from solution to form bottom contact organic field-effect transistors. Drain-source currents from transistors with a channel length of 50 μm show excellent agreement with the square law equations derived for crystalline Si MOSFETs in both the linear and saturation regimes. As the channel length is incrementally reduced to 1 μm, device characteristics such as saturation regime channel conductance, sub-threshold current and threshold voltage, behave in a manner similar to Si MOSFETs of decreasing channel length. Results of these studies indicate the presence of non-destructive current punch-through and in addition, both channel-length modulation and threshold-voltage roll-off, neither of which have previously been reported in OFETs.

[1]  Theodor Doll,et al.  Organic field-effect transistors with nonlithographically defined submicrometer channel length , 2004 .

[2]  M. B. Barron.  Low level currents in insulated gate field effect transistors , 1972 .

[3]  I. Shih,et al.  Fabrication of short channel organic thin film transistors by Si-etching method , 2004 .

[4]  Gilles Horowitz,et al.  Organic thin film transistors: From theory to real devices , 2004 .

[5]  Aaas News,et al.  Book Reviews , 1893, Buffalo Medical and Surgical Journal.

[6]  C. M. Sotomayor Torres,et al.  Nanoimprinted organic field-effect transistors: fabrication, transfer mechanism and solvent effects on device characteristics , 2004 .

[7]  L. D. Yau,et al.  A simple theory to predict the threshold voltage of short-channel IGFET's , 1974 .

[8]  Toshihisa Tsukada,et al.  Analysis of Effective Channel Length in Amorphous Silicon Thin-Film Transistors , 1992 .

[9]  Luigi Mariucci,et al.  Short-channel effects in 0.2 μm channel length a-Si:H thin-film transistors fabricated by electron beam lithography , 1991 .

[10]  W. Fichtner,et al.  Generalized guide for MOSFET miniaturization , 1980, IEEE Electron Device Letters.

[11]  K. Steinhubl.  Design of Ion-Implanted MOSFET'S with Very Small Physical Dimensions , 1974 .

[12]  John A. Rogers,et al.  Low-voltage 0.1 μm organic transistors and complementary inverter circuits fabricated with a low-cost form of near-field photolithography , 1999 .

[13]  Kevin Barraclough,et al.  I and i , 2001, BMJ : British Medical Journal.

[14]  Ute Zschieschang,et al.  Low-voltage organic transistors with an amorphous molecular gate dielectric , 2004, Nature.

[15]  Dominique Vuillaume,et al.  Low-voltage, 30 nm channel length, organic transistors with a self-assembled monolayer as gate insulating films , 2000 .

[16]  G. G. Stokes.  "J." , 1890, The New Yale Book of Quotations.

[17]  Paul R. Berger,et al.  High electric-field effects on short-channel polythiophene polymer field-effect transistors , 2004 .

[18]  Y. Tsividis.  Operation and modeling of the MOS transistor , 1987 .

[19]  Robert A. Street,et al.  Short channel effects in regioregular poly(thiophene) thin film transistors , 2004 .

[20]  Takao Someya,et al.  Nanoscale organic transistors that use source/drain electrodes supported by high resolution rubber stamps , 2003 .