BUMP STRUCTURES AND PACKAGED STRUCTURES THEREOF

摘要

A bump structure for bonding two substrates together includes a composite structure. The composite structure is formed over a first substrate. The composite structure includes at least one first polymer layer and at least one first metal-containing layer. The bump structure also includes a second metal-containing layer at least partially covering a top surface of the composite structure and extending from the top surface of the composite structure to a surface of the first substrate, wherein the second metal-containing layer is thinner than the first metal-containing layer.