High integrity interconnection of silver submicron/nanoparticles on silicon wafer by femtosecond laser irradiation

Welding of nanomaterials is a promising technique for constructing nanodevices with robust mechanical properties. To date, fabrication of these devices is limited because of difficulties in restricting damage to the nanomaterials during the welding process. In this work, by utilizing very low fluence (∼900 μJ cm(-2)) femtosecond (fs) laser irradiation, we have produced a metallic interconnection between two adjacent silver (Ag) submicron/nanoparticles which were fixed on a silicon (Si) wafer after fs laser deposition. No additional filler material was used, and the connected particles remain almost damage free. Observation of the morphology before and after joining and finite difference time domain simulations indicate that the interconnection can be attributed to plasmonic excitation in the Ag submicron/nanoparticles. Concentration of energy between the particles leads to local ablation followed by re-deposition of the ablated material to form a bridging link that joins the two particles. This welding technique shows potential applications in the fabrication of nanodevices.