Patent ID: 8420535

Claim:
A method for forming a copper interconnection structure, the method comprising the steps of: forming an opening in an insulating layer, wherein the opening comprises an inner surface side facing the insulating layer; forming a copper alloy layer including manganese having an atomic concentration of not less than 1.0 atom % and not more than 25 atom % on the inner surface side; forming a buried copper over the copper alloy layer so as to substantially fill the opening; and applying a heat treatment under a predetermined condition after the burying step, wherein the predetermined condition includes: a temperature of not less than 150° C. and not more than 450° C., and oxygen partial pressure being adjusted to be less than an atomic concentration of oxygen (N o ) in the copper alloy layer according to: N o =N Mn *D o /D Mn , wherein: N Mn : atomic concentration of manganese contained in the copper alloy layer, D o : diffusion coefficient of oxygen atom in the copper alloy layer, and D Mn : diffusion coefficient of manganese in the copper alloy layer.