Electrical resistance of island-containing thin metal interconnects on polymer substrates under high strain

Abstract

We have deposited thin metal films that include a granular indium layer on polymer substrates and observed the resistance of the film changed by a factor of less than 2, even as the sample is uniaxially stretched to the point of rupture ͑ϳ38% strain͒. The presence of a discontinuous layer of indium islands in these films maintains the electrical conductivity by providing a bridging mechanism across the cracks formed in the underlying continuous film layers. A simple model is used to relate the applied strain to the electrical resistance of the metal films. Furthermore, we present the data for these films under cyclic loading around a cylindrical mandrel which show that there is no change in resistance under these fatigue testing conditions for 10 000 loading cycles.

Optimization and device application potential of oxide–metal–oxide transparent electrode structure

“…Such a stability of the OMO structure in terms of the sheet resistance under repeated bending is attributed to the presence of the Ag mid-layer. 28,29 On bending, it is possible that the crack initiated on the tensile side (convex outer surface) of the IZO layer and this crack can grow under repeated bending. 30 However, the Ag layer, which is highly resistant to fracture, can function as a crack stopper as in the case of the ber-reinforced or laminated composite materials.…”

Thickness dependent critical strain in submicron Cu films adherent to polymer substrate

“…Recently, the method of tensile testing the metal thin films on compliant substrates 6,7 has also been suggested to determine the yield strength of metal films, where the force of highly elastic compliant substrates could be subsequently subtracted from the total measured force of the compound to yield the real one of films. Both numerical simulations 12 and experimental investigations [13][14][15] have clearly shown that the polymersupported metal films, if well bonded to the substrate, could deform uniformly to a large strain. 9 Besides the yield strength, ductility is another important parameter in the mechanical property of the metal films.…”

High-Performance Flexible Organic Light-Emitting Diodes Using Amorphous Indium Zinc Oxide Anode

“…The increase in resistance is related to the number of cracks generated in the electrode, which depends on applied strain and film thickness. 1,3 For this reason, new transparent conducting materials have been explored to replace ITO for flexible OLED anodes. To achieve better performance of flexible OLEDs, Zn-based transparent conducting oxide ͑TCO͒ films, such as ZnSn 2 O 4 , ZnSnO 3 , Zn 2 In 2 O 5 , and Al͑Ga͒-doped ZnO, have been applied as the anode.…”

“…There has been increasing activity for flexible organic lightemitting diodes ͑OLEDs͒ over the past few years, and it has focused on developing indium tin oxide ͑ITO͒-coated polymer substrates, such as polyethylene terephthalate ͑PET͒, [1][2][3][4][5] polycarbonate ͑PC͒, 6,7 polyimide, 8 polyethersulfone ͑PES͒, 9 polyethylene naphthalate ͑PEN͒, 9 and polycyclic olefin ͑PCO͒. 9 However, ITO electrode comes with its own set of problems such as chemical instability in a reduced ambient, poor transparency in the blue region, release of oxygen and indium into the organic layer, imperfect work function alignment with typical hole-transport layers, and easy deterioration of ITO targets.…”