Abstract: Multilayer circuit devices include a plurality of metallized patterns thereon, said patterns being separated by a polymeric dielectric film. The various metallized patterns are interconnected by means of microvias through the polymeric film or films. Each of the metallizations is a composite including in succession from the substrate or from the polymeric film, a layer of titanium (Ti), a layer of titanium and palladium alloy (Ti/Pd), a layer of copper (Cu), and a layer of titanium and palladium alloy (Ti/Pd). The Ti-Ti/Pd-Cu-Ti/Pd composite is hereinafter referred to as TCT. The adhesion between the polymeric film and the top Ti/Pd layer is better than that between the polymer and gold (Au) and comparable to that between the polymer and an adhesion promoted Au layer. Use of the TCT metallization also results in additional cost reduction due to the elimination of Ni and Au layers on top of the Cu layer.

Abstract: Multilayer circuit devices include a plurality of metallized patterns thereon, said patterns being separated by a polymeric dielectric film. The various metallized patterns are interconnected by means of microvias through the polymeric film or films. Each of the metallizations is a composite including in succession from the substrate or from the polymeric film, a layer of titanium (Ti), a layer of titanium and palladium alloy (Ti/Pd), a layer of copper (Cu), and a layer of titanium and palladium alloy (Ti/Pd). The Ti--Ti/Pd--Cu--Ti/Pd composite is hereinafter referred to as TCT. The adhesion between the polymeric film and the top Ti/Pd layer is better than that between the polymer and gold (Au) and comparable to that between the polymer and an adhesion promoted Au layer. Use of the TCT metallization also results in additional cost reduction due to the elimination of Ni and Au layers on top of the Cu layer.

Abstract: A new metallization is described which is a composite of subsequent metal layers beginning with a layer of titanium and having in an ascending order the following composition: Ti--TiPd--Cu--Ni--Au. TiPd is an alloy of titanium and palladium containing from 0.3 to 14 weight percent Pd, by the weight of the alloy. The TiPd alloy is etchable in an aqueous HF solution containing from 0.5 to 2.0 and higher, preferably from 0.5 to 1.2 weight percent HF. The use of the TiPd alloy avoids the occurrence of Pd residues remaining after the etching of Ti layer and lift-off (rejection etching) of Pd layer in a prior art Ti--Pd--Cu--Ni--Au metallization. Ti and TiPd layers are present in a thickness ranging from 100 to 300 nm and from 50 to 300 nm, respectively, and in a total minimum thickness needed to maintain bonding characteristics of the metallization.

Abstract: A new metanization is described which is a composite of subsequent metal layers beginning with a layer of titanium and having in an ascending order the following composition: Ti - TiPd - Cu - Ni - Au. TiPd is an alloy of titanium and palladium containing from 0.3 to 14 weight percent Pd, by the weight of the alloy. The TiPd alloy is etchable in an aqueous BF solution containing from 0.5 to 2.0 and higher, preferably from 0.5 to 1.2 weight percent BF. The use of the TiPd alloy avoids the occurrence of Pd residues remaining after the etching of Ti layer and liftoff (rejection etching) of Pd layer in a prior art Ti-Pd-Cu-Ni-Au metanization. Ti and TiPd layers are present in a thickness ranging from 100 to 300 nm and from 50 to 300 nm, respectively, and in a total minimum thickness needed to maintain bonding characteristics of the metallization.