Semiconductor device comprising fine bump electrode having small side etch portion and stable characteristics

A semiconductor device having a bump electrode comprising:

• a substrate;
• a first conductive layer on a predetermined portion of said substrate;
• an insulating layer on said substrate and said first conductive layer, and said insulating layer having an opening portion via which a predetermined portion of said first conductive layer is exposed;
• a second conductive layer formed on said first conductive layer, the opening portion of said insulating layer, and an upper surface of said insulating layer;
• a third conductive layer covering said second conductive layer along said opening portion and extending onto said insulating layer beyond an edge of said second conductive layer sufficiently to improve adhesion between said third conductive layer and said insulating layer and adhesion between said third conductive layer and said fourth conductive layer;
• and
• a fourth conductive layer provided on said third conductive layer.

A semiconductor device having a bump electrode comprising:

• a substrate;
• a first conductive layer on a predetermined portion of said substrate;
• an insulating layer on said substrate and said first conductive layer, and said insulating layer having an opening portion via which a predetermined portion of said first conductive layer is exposed;
• a second conductive layer of successive laminar layers of titanium and nickel formed on said first conductive layer, the opening portion of said insulating layer, and an upper surface of said insulating layer;
• a third conductive layer of copper covering said second conductive layer along said opening portion and extending onto said insulating layer beyond said second conductive layer;
• and
• a fourth conductive layer of gold provided oil said third conductive layer.