Thin Solid Films, Vol.612, 350-357, 2016
Transparent conductive Ta/Al/Ta-grid electrode for optoelectronic and electromagnetic interference shielding applications
Ta/Al/Ta multilayer grid electrodes were fabricated by combining DC magnetron sputtering with a photolithography process. The optical transparency and sheet resistance were investigated for the electrode when the thickness of Al was changed from 20 to 150 nm. Predicted and measured sheet resistance and transmittance are in good agreement. The electrode shows insignificant increase in sheet resistance after annealing at 250 degrees C for 2 h in air. It also exhibits excellent adhesion, showing no increase in sheet resistance after repeated scotch tape tests and ultrasonic treatment in acetone for 30 min. With 150 nm Al thickness, the electrode has sheet resistance of 10.2 Omega/sq and transmittance of 86% in the whole investigated Vis-NIR spectral range, and the figure of merit is 21.7x10(-3)Omega(-1) which is comparable to ITO. Furthermore, the EMI shielding effectiveness simulations for all the samples were performed over the frequency range of 1 to 12 GHz. It was observed that the shielding effectiveness was enhanced with increased thickness of Al and at 6 GHz shielding effectiveness was 48 dB with 150 nm Al thickness. (C) 2016 Elsevier B.V. All rights reserved.
Keywords:Transparent conductor;EMI shielding