US Patent 7223695 Methods to deposit metal alloy barrier layers

Metal alloy barrier layers formed of a group VIII metal alloyed with boron (B) and/or phosphorous (P) and an at least one element from glyoxylic acid, such as carbon (C), hydrogen (H), or carbon and hydrogen (CH) formed by electoless plating are described. These barrier layers may be used as a barrier layer over copper bumps that are soldered to a tin-based solder in a die package. Such barrier layers may also be used as barrier layer liners within trenches in which copper interconnects or vias are formed and as capping layers over copper interconnects or vias to prevent the electromigration of copper.