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US 6,664,128 B2Granted
Bump fabrication process
AssigneeAdvanced Semiconductor Engineering, Inc.
InventorsHo-Ming Tong, Chun-Chi Lee, Jen-Kuang Fang, Min-Lung Huang, Jau-Shoung Chen, Ching-Huei Su, Chao-Fu Weng, Yu-Chen Chou, Tsung-Hua Wu, Su Tao
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Abstract
The present invention provides a bump fabrication process. After forming an under bump metallurgy (UBM) layer and bumps in sequence over the substrate, the under bump metallurgy layer that is not covered by the bumps is etched with an etchant. The etchant mainly comprises sulfuric acid and de-ionized water. The etchant can etch the nickel-vanadium layer of the UBM layer without damaging the bumps.
Claims15
A bump fabrication process, comprising:
- providing a substrate with a plurality of bonding pads thereon;
- forming an under bump metallurgy layer, the under bump metallurgy layer comprising a nickel-vanadium layer and at least a conductive layer;
- forming a plurality of bumps on the under bump metallurgy layer above the bonding pads;
- and
- etching the nickel-vanadium layer that is not covered by the bumps with an etchant, wherein the etchant comprises sulfuric acid and de-ionized water.
2 more elements
A bump fabrication process, comprising:
- providing a substrate with a plurality of bonding pads thereon;
- forming an under bump metallurgy layer, the under bump metallurgy layer comprising at least two conductive layers, wherein a material for forming the conductive layers is selected from the following group consisting of aluminum, copper and nickel-vanadium alloy;
- forming a plurality of bumps on the under bump metallurgy layer above the bonding pads;
- and
- etching the under bump metallurgy layer that is not covered by the bumps with an etchant, wherein the etchant comprises sulfuric acid and de-ionized water.
2 more elements
Dependencies are inferred from the claim text.