A bump is formed on a semiconductor wafer which has a pad electrode thereon. The method includes the steps for coating a first organic film on a semiconductor water; drying the first organic film; applying an excimer laser to a portion of the first organic film substantially corresponding to the pad electrode to thereby form a first opening in the organic film; forming at least one metallic film on the first organic film and the opening; coating a second organic film on the metallic film; drying the second organic film; applying an excimer laser to a portion of the second organic film substantially corresponding to the first opening to thereby form a second opening in the second organic film; and providing and melting solder at the second opening to form a solder bump. Since the openings of the organic films are formed by the excimer laser, the openings can be formed in a short time with high accuracy. Thus, the bump with high quality can be formed at a low cost.
A conductive electrode pad is formed on a partial area of an insulating surface. An insulating film covers the electrode pad. The insulating film has an opening exposing at least a partial upper surface of the electrode pad. A barrier layer of conductive material is formed on the partial upper surface exposed on the bottom of the opening and on the surface of the insulating film near the opening. A conductive bump is adhered to the barrier layer. A step is formed on the surface of a layer under the barrier layer between an outer periphery of the barrier layer and an outer periphery of the opening.
The present invention discloses a substrate within a Ni/Au structure electroplated on electrical contact pads and a method for fabricating the same. The method comprises: providing a substrate with a circuit layout pattern and forming a conducting film on the surface of the substrate; depositing a first photoresist layer within an opening on said electrical conducting film surface to expose a portion of said circuit layout pattern to be electrical contact pads; removing the exposed conducting film uncovered by the first photoresist layer; depositing a second photoresist layer, covering the conducting film exposed in the openings of the first photoresist layer; electroplating Ni/Au covering the surface of the electrical contact pads; removing the first and second photoresists, and the conducting film covered by the photoresists; depositing solder mask on the substrate within an opening to expose said electrical contact pads. It improves the electrical coupling between gold wires and the electrical contact pads of the substrate, prevents the electrical contact pads from oxidation, and insurances the electrical interconnection performance.
A method of forming metal bumps on a wafer includes the steps of adhering a heat-resistant and steady synthetic tape on the top of the wafer, punching holes through the synthetic tape to form a blind hole on the synthetic tape above the under-bump-metallurgy layer (UBM), filling solder paste into the blind hole by a pusher, melting and then cooling the solder paste into a solder block removing the synthetic tape to expose the solder block, and melting the solder block to form a ball-shaped solder bump.
A method of forming a bump overlying the copper based contact pad to prevent oxidation of the copper based contact pad. A passivation blanket is deposited over a semiconductor device having a copper based contact pad, the passivation blanket includes a first layer overlying the top surface; a second layer overlying the first layer; a portion of the second layer overlying the copper based contact pad is removed leaving the first layer in place; depositing an under bump metallurgy over the semiconductor device, a portion of the first layer overlying the copper based contact pad is removed so that the copper based contact pad has limited exposure to oxygen; depositing an under bump metallurgy over the semiconductor device; removing excess under bump metallurgy; depositing an electrically conductive material over the under bump metallurgy; reflowing electrically conductive material to form a bump overlying the copper based contact pad.
A semiconductor device with under bump metallurgy (UBM) and a method for fabricating the semiconductor device are provided, wherein a passivation layer is deposited on a surface of the semiconductor device where a plurality of bond pads are disposed, and formed with a plurality of openings for exposing the bond pads. A first metal layer is deposited over part of each of the bond pads and a portion of the passivation layer around the bond pad; then, a second metal layer is formed over the first metal layer and part of the bond pad uncovered by the first metal layer; subsequently, a third metal layer is formed over the second metal layer to thereby fabricate a UBM structure. Finally, a solder bump is formed on the UBM structure so as to achieve good bondability and electrical connection between the solder bump and UBM structure.
