| 摘要 |
PURPOSE:To realize a high-reliability bump electrode by a method wherein the top surface of a bump electrode is flattened owing to an element provided thereto, similar in shape to the opening and similar in thickness to a protective insulating film, between an insulating film just under an opening in a protective insulating film and a pad electrode. CONSTITUTION:On an Si substrate 9, a thermal oxide film 10 is provided for the selective formation of an polycrystalline Si film 11. An Al pad electrode 13 is built with an PSG layer 12 serving as an interlayer insulating film. A coating is provided of a protective insulating film 14 which is similar to the film 11 in thickness, a selective removal is accomplished of the film 11 and of a specified width (sum of the thickness of the film 12 and that of the electrode 13) from the region occupied by the film 11 and from its circumference. Next, a Ti contact layer 15 and Pd barrier layer 16 are provided in that order, and then a resist mask 17 is provided for the formation by Au plating of a bump electrode 24. The resist mask 17 is removed and, with the electrode 24 serving as a mask, the Pd barrier layer 16 and the Ti contact layer 15 are subjected to etching for the completion of the device. With the surface of the bump electrode 14 having been flattened, an uniform pressure may be applied in a process of lead bonding, damage is lessened of the damage a pad electrode 13 may be exposed to, cracks are reduced in the protective insulating film 14, all of which contribute to the improvement of reliability. |
