Patent ID: 8951837
Filing Date: 2015-02-10
Classification: H01L

Abstract:
1. A method for using a submicron connection layer to connect two wafers, comprising: Step (a): providing a first wafer and a second wafer; Step (b): forming a connection layer on a connection surface of each of said first wafer and said second wafer, wherein said connection layer comprises a top metal layer, an intermediary diffusion-buffer metal layer and a bottom metal layer, and wherein a melting point of said intermediary diffusion-buffer metal layer is higher than melting points of said top metal layer and said bottom metal layer, and wherein materials of said top metal layer and said bottom metal layer form a eutectic phase; and Step (c): bonding said connection layer of said first wafer to said connection layer of said second wafer, wherein said top metal layers, which are separated from said bottom metal layers by said intermediary diffusion-buffer metal layers, are joined to each other in a liquid state to melt; next said top metal layer and said bottom metal layer of each of said first wafer and said second wafer are melting; said intermediary diffusion-buffer metal layers are distributed uniformly into said top metal layers and said bottom metal layers having melted; then said bottom metal layer and said top metal layer of said first wafer diffuse to each other until said top metal layer of said first wafer is completely exhausted by said bottom metal layer of said first wafer, and said bottom metal layer and said top metal layer of said second wafer diffuse to each other until said top metal layer of said second wafer is completely exhausted by said bottom metal layer of said second wafer to form a eutectic intermetallic compound having said intermediary diffusion-buffer metal layers uniformly distributed in said eutectic intermetallic compound.