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Dendritic growths during Cu plating

Our site is involved in electroplating interconnect structures and are currently experiencing a problem with our Cu plating. We plate 4.5um thick Cu on a sputtered 4000A Cu seedmetal using a sulphate bath. We are sporatically finding that we are getting very unusual growths on are metal structures. This problem seems similar to other problems associated with tin-lead type growths but I can find little documentation on Cu growths. Our growths are spiral in shape (like a corkscrew) and can grow to hundreds of microns in size. It also appears that this growth is occurring entirely during the plating which takes about 21min. Cross-sections show them to be madeup entirely of Cu and we also believe them to have a grain structure the same as the metal we are plating. No foreign material has been detected inside them. If anyone could give me help in finding references or articles discussing this type of problem, I would greatly appreciate it. Thanks

Clinton Hilliard
- Columbia, Maryland
1999

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Hi Clinton ,

Usually the brighyeners take care of the drndritic growths if you are using a proprietary system , demand some explanations $ help or go elsewhere . However if you are using no brighteners or a "home Brew" system then please supply a complete inorganic chemical analysis , the type of " home brew" brightener you use , an indication of the type of anode material you are using , the anode current density you are using , the mode and rate of filtration you are using as well as the method of agitation and finally the method of racking . With this info a good answer can be provided . Best regards

John Tenison - Woods
- Victoria Australia
1999