Effect of carboxylic acid on sintering of inkjet-printed copper nanoparticulate films.

The reduction effect of various carboxylic acids on inkjet-printed copper film was investigated. Carboxylic acids were exposed to the film by nitrogen gas that was bubbled through the liquid acids during the annealing process. It was observed that in the case of saturated monocarboxylic acid (formic, acetic, propionic, butyric), the acids with shorter hydrocarbon chains perform better in reducing the surface copper oxides in the printed copper conductive film. The printed films exposed to formic acid vapor exhibited the lowest resistivity (3.10 and 2.30 μΩ cm when annealed at 200 and 250 °C, respectively). In addition, the oxalic acid more effectively reduces copper oxide than formic acid and its usage can shorten the annealing time for highly conductive printed copper film. This reductive annealing process allows fabrication of copper patterns with low resistivity, (3.82 μΩ cm annealed at 250 °C) comparable to the resistivity of bulk copper.

[1]  Jooho Moon,et al.  Solution processed invisible all-oxide thin film transistors , 2009 .

[2]  Jooho Moon,et al.  Highly Conductive Ink Jet Printed Films of Nanosilver Particles for Printable Electronics , 2005 .

[3]  Byron D. Gates Flexible Electronics , 2009, Science.

[4]  H. Wolf,et al.  Nanoparticle printing with single-particle resolution. , 2007, Nature nanotechnology.

[5]  David Voss,et al.  Cheap and cheerful circuits , 2000, Nature.

[6]  U. Schubert,et al.  Ink‐jet Printing and Microwave Sintering of Conductive Silver Tracks , 2006 .

[7]  M. Muccini A bright future for organic field-effect transistors , 2006, Nature materials.

[8]  Younan Xia,et al.  Controlling the Thickness of the Surface Oxide Layer on Cu Nanoparticles for the Fabrication of Conductive Structures by Ink‐Jet Printing , 2008 .

[9]  A. Yassar,et al.  All-Polymer Field-Effect Transistor Realized by Printing Techniques , 1994, Science.

[10]  H. Sirringhaus,et al.  Self-Aligned, Vertical-Channel, Polymer Field-Effect Transistors , 2003, Science.

[11]  Ying Wang,et al.  High‐Performance Organic Field‐Effect Transistors with Low‐Cost Copper Electrodes , 2008 .

[12]  Jooho Moon,et al.  Inkjet-printed Cu source/drain electrodes for solution-deposited thin film transistors , 2010 .

[13]  Jiyoul Lee,et al.  Printable ion-gel gate dielectrics for low-voltage polymer thin-film transistors on plastic. , 2008, Nature materials.

[14]  Youngil Lee,et al.  Large-scale synthesis of copper nanoparticles by chemically controlled reduction for applications of inkjet-printed electronics , 2008, Nanotechnology.

[15]  Yong-Young Noh,et al.  Downscaling of self-aligned, all-printed polymer thin-film transistors. , 2007, Nature nanotechnology.

[16]  U. Schubert,et al.  Inkjet Printing of Narrow Conductive Tracks on Untreated Polymeric Substrates , 2008 .

[17]  H. Sirringhaus,et al.  High-Resolution Ink-Jet Printing of All-Polymer Transistor Circuits , 2000, Science.

[18]  Jang Sub Kim,et al.  Direct writing of copper conductive patterns by ink-jet printing , 2007 .