Plated article having metal thin film formed by electroless plating
View Patent ↗A plated article has an alloy thin film formed on a substrate and having a catalytically active metal (A) for electroless plating and a metal (B) capable of undergoing displacement plating with a metal ion contained in an electroless plating solution, and a metal thin film formed on the alloy thin film by electroless displacement and reduction plating. The alloy thin film of the catalytically active metal (A) and the metal (B) capable of displacement plating has a composition comprising 5 at % to 40 at % of the metal (A). The metal thin film formed by electroless displacement and reduction plating is a metal thin film having a thickness no greater than 10 nm and a resistivity no greater than 10 μΩ·cm. Preferably, the metal (B) has a barrier function with respect to a metal of the metal thin film.
1. A plated article comprising an alloy thin film formed on a substrate, the alloy thin film containing a catalytically active metal (A) for electroless plating and a metal (B) capable of undergoing displacement plating with a metal ion contained in an electroless plating solution, and a metal thin film formed on the alloy thin film by electroless displacement and reduction plating,
wherein the alloy thin film has a composition comprising 5 at. % to 40 at. % of the catalytically active metal (A),
the metal thin film has a thickness of no greater than 10 nm and a resistivity of no greater than 10 μΩ·cm,
an oxygen concentration at an interface between the alloy thin film and the metal thin film is no greater than 1 at. % as analyzed by Auger electron spectroscopy and the catalytically active metal (A) is at least one metal selected from the group consisting of Pd, Pt, Ag and Au, the metal (B) capable of undergoing displacement plating is at least one of W and Nb, the metal thin film is Cu and the catalytically active metal (A) is present in the alloy thin film in an amount of from 10-30 at. %.
2. The plated article according to claim 1 , wherein the metal thin film has a resistivity no greater than 5 μΩ·cm.
3. The plated article according to claim 1 , wherein a wiring portion is further formed on the metal thin film by plating.
4. The plated article according to claim 3 , wherein
the wiring portion is copper or an alloy having copper as a main component.
5. The plated article according to claim 4 , wherein the metal (B) capable of displacement plating has a barrier function of preventing diffusion of a metal of the metal thin film.
6. The plated article according to claim 4 ,
wherein the catalytically active metal (A) is at least one metal selected from among platinum and palladium.
7. The plated article according to claim 4 ,
wherein the catalytically active metal (A) is palladium,
the metal (B) capable of displacement plating is tungsten,
the metal thin film is a copper thin film, and
the wiring portion is copper.
8. The plated article according to claim 1 , wherein the metal thin film is a seed layer for damascene copper wiring.
9. The plated article according to claim 1 , wherein the alloy thin film is formed by sputtering.
10. A semiconductor element, comprising the plated article according to claim 1 .