Fabrication of Ag micromaterials by utilizing stress-induced migration

Silver micromaterials are highly prospected for modern electronic industries, especially due to their high electrical conductivity. Up to now, the formation of Ag nanowires that has been reported is based on chemical techniques. The processes of the chemical techniques are sophisticated, but somewhat complicated. On the other hand, a physical technique for fabricating metallic nanowires in a simple and controlled way by utilizing stress-induced migration has recently been reported. In this approach, it is recognized that the gradient of compressive hydrostatic stress might be the driving force for atomic diffusion. In the technique utilizing stress-induced migration, heating is required and oxide layer is necessary for fabrication of nano/micro materials. When Ag is heated, the key material, namely the oxide layer, decomposes at high temperature. In the present paper, an approach for fabrication of Ag nano/micro materials based on stress-induced migration is proposed, in which SiO₂ layer is used as a passivation layer to overcome the drawback of the oxide layer.