Silver-gold alloy bump structure, method for fabricating the same, and semiconductor device

Abstract

The present invention provides a silver- gold alloy bump structure, method for fabricating the same, and semiconductor device. The method comprises: providing a semiconductor device; sequentially forming a TiW seed layer and an Au seed layer on a pad of the semiconductor device; forming a barrier layer on the Au seed layer; and forming a gold-silver alloy bump on the barrier layer. The barrier layer is configured to prevent metallic silver in the gold-silver alloy bump from diffusing into the Au seed layer. During the fabrication process of the gold-silver alloy bump structure, the barrier layer is formed on the Au seed layer before the gold-silver alloy bump is formed on the barrier layer. The barrier layer can block the diffusion of metallic silver from the gold-silver alloy bump into the Au seed layer, thereby ameliorating the issue of poor adhesion between the gold-silver alloy bump and the seed layer. This enhances the reliability of the gold-silver alloy bump structure, consequently improving the reliability of the semiconductor device.

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