Method for repairing copper diffusion barrier layers on a semiconductor solid substrate and repair kit for implementing this method.One subject of the present invention is a method for repairing a surface of a substrate coated with a discontinuous copper diffusion barrier layer of a titanium-based material.According to the invention, this method comprises: a) the contacting of the surface with a suspension containing copper or copper alloy nanoparticles for a time of between 1 s and 15 min; and b) the contacting of the thus treated surface with a liquid solution having a pH of between 8.5 and 12 and containing: at least one metal salt, at least one reducing agent, at least one stabilizer at a temperature of between 50° C. and 90° C., preferably between 60° C. and 80° C., for a time of between 30 s and 10 min, preferably between 1 min and 5 min, in order to thus form a metallic film having a thickness of at least 50 nanometers re-establishing the continuity of the copper diffusion barrier layer.