Patent ID: 6331347
Filing Date: 2001-12-18
Classification: H01L,H05K,Y10S,Y10T

Abstract:
A substrate comprising:a circuit pattern formed on a surface of said substrate;a nickel-containing barrier metal layer formed at a portion where an electrode of said circuit pattern is formed;a gold layer formed on said barrier metal layer by plating to a thickness of at least 5 nm and less than 100 nm,wherein said substrate is heated up to cause nickel contained in said gold layer to move toward a surface zone of said gold layer to deposit nickel compound in said surface zone of said gold layer so that the fineness of a remaining part of said gold layer is enhanced at, at least, an inside zone immediately below said surface zone, and said surface zone containing said nickel compound is removed to expose a purified gold surface of said inside zone of said gold layer having a ratio of nickel to gold concentration of less than 0.05.