| 摘要 |
PURPOSE:To fabricate the bump electrode suitable for face-down bonding by a method wherein a solder layer is formed on a base metal by performing alloy plating, and after the solder layer has been fused and formed into a spherical shape, the exposed base metal is removed by etching. CONSTITUTION:An Al wiring 3 is formed on an si substrate 1 through the intermediary of an oxide film 3, and after an aperture has been formed on a bump forming region by providing a nitride film 4, a Ti film 5 and a Cu film 6 are laminated on the whole surface. Then, after an Ni plated layer 7 has been provided using a resist film 11 as a mask, alloy plating is performed on layer 7 using a phenol sulfonic acid solution, for example, and a Pb-Sn solder layer 14 is formed. Subsequently, the resist film 11 is removed, a reflowing process is performed, and after the composition of the solder layer 14 has veen uniformalized and a bump 8 has been formed spherically, the exposed part of the Cu film 6 and the Ti film 5 are removed by etching. Accordingly, a bump electrode 8 of excellent external appearance having no defect can be formed, and the reliability of a flip-chip type device can be improved. |
