| 摘要 |
PURPOSE:To prohibit occurrence of side etching phenomenon by suppressing the cathode reaction, by performing chemical etching using the bump electrode layer as the mask, and plating the surface of the bump electrode layer with metal such as Sn, Pb and Zn when removing the base metal layer. CONSTITUTION:A base SiO2 film 12 is deposited on Si substrate 10, and Al wire layer 14 of a specified pattern is formed thereon, and the contact part of wire layer 14 is coated with PSG passivation film 16 having windows. Next, a base metal layer consisting of Cr layer 18 and Cu layer 20 is laminated on the entire surface and evaporated, and Au bump electrode layer 22 is composed thereon. After this, excess base metal layers 18 and 20 are removed by etching, using the electrode layer 22 as the mask. At this time, a cathode reaction suppressive layer 24 of Sn, Pb, Zn or the like is deposited on the surface and sides of the electrode layer 20 by plating. Finally, the Cu layer 20 is etched in aqueous solution of ferric chloride, and the Cr layer 18 in aqueous solution of ammonium cerium (II) nitrate or others. |
