Patent ID: 8119498
Filing Date: 2012-02-21
Classification: H01L

Abstract:
1. A wafer bonding process comprising: providing a first bonding site on a surface of a first wafer; depositing at least a first bonding stack on a surface of a second wafer; forming at least a first groove in the surface of the first wafer, the first groove either surrounding the first bonding site or lying entirely within the first bonding site; aligning and mating the first and second wafers so that the first bonding stack on the second wafer contacts the first bonding site on the first wafer, wherein if the first groove lies entirely within the first bonding site then the first bonding stack bridges the first groove after the first and second wafers are aligned and mated; and then heating the first and second wafers to reflow the first bonding stack on the second wafer, form a molten bonding material, cause at least a portion of the molten bonding material to flow into the first groove in the surface of the first wafer, and form a first bonding structure that bonds to the first bonding site of the first wafer and bonds the second wafer to the first wafer.