ELECTROLESS PLATING LIQUID

PROBLEM TO BE SOLVED: To provide an electroless plating liquid which can form a cobalt based alloy on wiring of copper or the like as a protective film at high selectivity, can prevent the surface contamination of the exposed wiring and electromigration to an interlayer insulation film, can evade anxieties about the increase of wiring resistance and the deposition of plating metal to the part other than the wiring, further, does not include components as environmental hormones, and can suppress adverse influence on the using environment. SOLUTION: The electroless plating liquid is used for selectively forming a protective film on the surface of exposed wiring upon the fabrication of a semiconductor device having a wiring structure, and comprises: cobalt ions; the ions of a second metal different from cobalt; a chelating agent; a reducing agent; polyoxyethylene alkylether phosphate ester; and tetraalkyl ammonium hydroxide expressed by formula (1); wherein, R2, R3, R4and R5are each a group selected from alkyl groups and hydroxyalkyl groups. COPYRIGHT: (C)2007,JPO&INPIT