Patent Number: 6,426,555

Title: Bonding pad and method for manufacturing it

Abstract: A bonding pad that has low parasitic capacitance and that transmits little or no stress to the underlying metal layer during bonding, along with a process for manufacturing it, is described. A key feature of this structure is that the damascene wiring directly below the bonding pad has been limited to its outer edges, that is it is formed in the shape of a hollow square. This limits overlap by the aluminum pad of the damascene wiring to the via hole area only. After a passivation layer, including suitable diffusion barriers, has been laid over the structure, it is over-filled with a suitable soft metal (typically copper or one of its alloys) and then planarized in the usual way. A via hole for communicating with the damascene wiring is then formed. This via can take the shape of a somewhat smaller hollow square or it can be formed from a series of individual vias arranged in the shape of a broken hollow square.

Inventors: Hsia; Chin Chiu (Taipei, TW), Tsui; Bing-Yue (Hsinchu, TW), Yang; Tsung-Ju (Hsinchu, TW), Chu; Tsung Yao (Taipei, TW)

Assignee: Industrial Technology Research Institute

International Classification: H01L 21/60 (20060101); H01L 23/48 (20060101); H01L 23/485 (20060101); H01L 21/02 (20060101); H01L 021/44 ()

Expiration Date: 07/30/2019