Metallic boride and phosphide barrier layers for via linings

摘要

A material lining a via comprises either cobalt XY or nickel XY where X may be tungsten, tin or silicon, and Y is phosphorous or boron, in particular an embodiment disclosing cobalt tungsten phosphide is described. Multilayer linings including TaN are also envisaged. The layers are formed by an electroless plating method. The compounds when used to line a via opening act as a barrier to prevent material (eg copper) from wiring layers diffusing into the surrounding dielectric material.