| 摘要 |
The present invention is a bonding pad structure and method for making the same which can be connected at the metalization step to form passive or active devices in addition to forming a bonding pad. A P-doped region (24) is formed in an epitaxial layer (28) in the area of the bonding pad (30) at the perimeter of a chip. This P-doped region (24) allows the formation of a junction capacitance between it and the epitaxial layer (28). In addition, by adding an oxide layer (32) over the P-doped region (34) an oxide capacitor can be formed between the metal bonding pad (30) and the P-doped region (34) with the oxide (32) as the dielectric. The oxide layer (32) is a special sandwich of two layers, silicon dioxide (36) and silicon nitride (37). The sandwiched layers protects the components beneath the bonding pad (30). The P-doped region (34) can also be used as a resistance by providing metal connections to both ends. Finally, a vertical PNP transistor can be formed between the P-doped region (34), the epitaxial layer (28) and a P-doped substrate (26). |
