Plating bath and method

摘要

Tin-silver alloy electroplating baths having certain amine-oxide surfactants and methods of electrodepositing a tin-silver-containing layer using these baths are disclosed. Such electroplating baths are useful to provide tin-silver solder deposits having reduced void formation and improved within-die uniformity.

主权项

1. An electroplating composition comprising: a water-soluble source of divalent tin ions; a water-soluble source of silver ions; water; acid electrolyte; and an alkoxylated amine oxide surfactant having the formulawherein Ra is selected from a (C6-C22)alkyl group and a substituted (C7-C22)aryl group; Rb is an alkoxylated unit; m is 0 to 7 and represents the number of moles of Rb; n is 0 or 1; and Rc and Rd are each at least one alkoxylated unit and the total number of alkoxylated units preresent in Rc and Rd is from 3 to 30.