A chip assembly includes a semiconductor chip, a bump and an external circuit. The semiconductor chip includes a semiconductor substrate, a transistor in and on the semiconductor substrate, multiple dielectric layers over the semiconductor substrate, a metallization structure over the semiconductor substrate, wherein the metallization structure is connected to the transistor, and a passivation layer over the metallization structure, over the dielectric layers and over the transistor. The bump is connected to the metallization structure through an opening in the passivation layer, wherein the bump includes an adhesion/barrier layer and a gold layer over the adhesion/barrier layer. The external circuit can be connected to the bump using a tape carrier package (TCP), a chip-on-film (COF) package or a chip-on-glass (COG) assembly.