Localized doping and/or alloying of metallization for increased interconnect performance

Abstract

Methods and compositions are disclosed for modifying a semiconductor interconnect layer to reduce migration problems while minimizing resistance increases induced by the modifications. One method features creating trenches in the interconnect layer and filling these trenches with compositions that are less susceptible to migration problems. The trenches may be filled using traditional vapor deposition methods, or electroplating, or alternately by using electroless plating methods. Ion implantation may also be used as another method in modifying the interconnect layer. The methods and compositions for modifying interconnect layers may also be limited to the via/interconnect interface for improved performance. A thin seed layer may also be placed on the semiconductor substrate prior to applying the interconnect layer. This seed layer may also incorporate similar dopant and alloying materials in the otherwise pure metal.