Cu surface plasma treatment to improve gapfill window

摘要

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.

主权项

1. A method of controlling the rate of an electrochemical deposition process in openings formed in the field regions on a substrate, sequentially comprising:
depositing a conductive seed layer in the openings and on the field regions of the substrate; exposing the substrate to a nitrogen-containing plasma to incorporate nitrogen into a surface of the conductive seed layer on the field regions, wherein the concentration of nitrogen incorporated into the surface of the conductive seed layer on the field regions is higher than a concentration of nitrogen incorporated into the conductive seed layer in the openings, and wherein the substrate has a weak bias of between about 5 W and 200 W; and performing a post-treatment to remove excess dopant.