| 摘要 |
PURPOSE:To eliminate an influence due to the difference in level at a substratum insulating film and to flatten a bonding face by a method wherein a pump is formed by an electrolytic plating method using a voltage whose phase is inverted periodically. CONSTITUTION:A pad electrode 3 is formed on a semiconductor substrate 1 via a first insulating film 2; then, a second insulating film 4 is formed in such a way that it overlaps with the pad electrode 3. Furthermore, after an opening has been made selectively on the pad electrode 3 by using a photoresist, two or more metal layers 5, 6 (e.g. chromium-copper, titanium-palladium) which function as adhesion layers or barrier layers are formed. In succession, a window whose size is bigger than the opening on the pad electrode 3 is opened on the metal layers 5, 6 by using a photoresist 7; an electrolytic plating process of a bump material is executed by applying a pulse electric current which is inverted alternately to be positive and negative. If a bump is formed on the window of the metal layers 5, 6, the bump 8 is shaped to be flat without having a hollow in the central part. At this stage, a surface metal layer having the suitable bonding performance is coated on the bump 8; the metal layers 5, 6 are removed by etching by making use of the bump 8 as a mask.
|
