Cu surface plasma treatment to improve gapfill window

Abstract

A method and apparatus for selectively controlling deposition rate of conductive material during an electroplating process. Dopants are predominantly incorporated into a conductive seed layer on field regions of a substrate prior to filling openings in the field regions by electroplating. A substrate is positioned in one or more processing chambers, and barrier and conductive seed layers formed. A dopant precursor is provided to the chamber and ionized, with or without voltage bias. The dopant predominantly incorporates into the conductive seed layer on the field regions. Electrical conductivity of the conductive seed layer on the field regions is reduced relative to that of the conductive seed layer in the openings, resulting in low initial deposition rate of metal on the field regions during electroplating, and little or no void formation in the metal deposited in the openings.