| 摘要 |
PURPOSE:To increase production recovery rate by improving covering performance at stepped section remarkably and stabilizing etching of conductor wiring layer, when forming a solder bump electrode, by forming only metallic membrane on the topmost layer selectively by electroplating process. CONSTITUTION:A first layer wiring 22, which is formed through an SiO2 membrane 20 on an Si substrate 21, is covered with an SiO2 membrane 23 and provided with a window 24. Ti25 and Cu26 are brazed in turn and provided with a resist mask 27. Cr29 (or Fe or Ti) is plated on Cu with Cu26 as a cathode, and the resist 27 is removed. By providing another resist mask 30 and plating Ni31, Sn32 and Pb33, a projecting electrode is formed. By eliminating the resist 30 and etching Cu26 and Ti25 with Cr29 as a mask, the second layer wiring is formed. And then, by heating it for approximately 30 seconds at 350 deg.C, the projecting electrode is melted and turned into a hemispherical solder bump 34. It is possible, by using this mechanism, to prevent the thin second layer wiring from breakage even at the time when it is laid on a stepped section on an element, and therefore, a solder electrode can be formed in a given region. |
