PLATING - ELECTRO CHEMICAL DEPOSITION (ECD)
Plating or ECD Electro-Chemical Deposition is a wet chemistry process. Primarily it is used to build the metal primary conductive wires in advanced integrated circuits where the different functional layers are connected with each other. Electrochemical deposition uses an electrolytic solution which creates lines and vias in layer which has been etched with a predefined pattern of the circuit. The process has a wide range of application in the Microelectronic Industry as
- Gold ECD (bonding pads, interconnects)
- Copper Damascene and Patterned Copper ECD
- Permalloy ECD (GMR heads)
- Solder ECD (bumping)
Uniformity and undefined outplating is of great concern to the plating process on silicon wafers. It is important that the over plating is kept to a minimum, as the CMP process following the metal deposition is very cost intensive.