Patterning Indium Tin Oxide and Indium Zinc Oxide Using Microcontact Printing and Wet Etching

We report a procedure that uses microcontact printing and wet chemical etching to fabricate patterned films of indium tin oxide (ITO) and indium zinc oxide (IZO). The procedure consists of three steps: (1) inking a patterned elastomeric stamp with an alkanephosphonic acid; (2) microcontact printing to form a patterned multilayer film of alkanephosphonic acid on the surface of an ITO or IZO film; (3) etching the unprotected regions of the ITO or IZO film using 0.05 M oxalic acid as the etchant. We demonstrate this procedure by fabricating patterned ITO and IZO films with areas as large as 15 cm 2 and minimum feature sizes of ∼2 μm. The key step in this procedure is applying the alkanephosphonic acid ink to the surface of the stamp. We present two different inking methods to illustrate the impact of stamp inking on the quality of printed and etched ITO and IZO films.