Via hole filling with metal melting by laser irradiation for submicron metallization

摘要

per discusses techniques with metal melting by laser irradiation for via hole filling and planarization of the metal film. In the planarization of metal film, a pure Al film has been melted by one optical pulse irradiation from an ArF excimer laser, resulting in realization of the planarization and via hole filling. A technique for producing metal plugs has been developed for via hole filling. In this technique, a thin metal film is patterned to be covering the entire via hole. The patterning controls the total amount of metal which is filled in the via hole. A metal cap is fabricated by this patterning, followed by melting with a XeCl excimer laser irradiation. The molten metal cap is drawn to the via during the mass transport procedure, resulting in formation of the metal plug. The mass transport mechanism of molten metal has been cleared up. The mass transport for the plug formation is attributed to the surface tension forces created by the three-dimensional geometry of the molten metal. The use of metal cap brings that the plug formation is performed easily and stably. And further, this technique is an effective method for submicron interconnection. The interconnects on contact check device are improved by the plug formation. The contact check device is composed of 60000 vias connected in series. These characteristics agree well with the results calculated using electrical resistivity of metal.