ENHANCEMENT OF ELECTROLYTE HYDRODYNAMICS FOR EFFICIENT MASS TRANSFER DURING ELECTROPLATING

摘要

The embodiments herein relate to methods and apparatus for electroplating one or more materials onto a substrate. In many cases the material is a metal and the substrate is a semiconductor wafer, though the embodiments are no so limited. Typically, the embodiments herein utilize a channeled plate positioned near the substrate, creating a cross flow manifold defined on the bottom by the channeled plate, on the top by the substrate, and on the sides by a cross flow confinement ring. During plating, fluid enters the cross flow manifold both upward through the channels in the channeled plate, and laterally through a cross flow side inlet positioned on one side of the cross flow confinement ring. The flow paths combine in the cross flow manifold and exit at the cross flow exit, which is positioned opposite the cross flow inlet. These combined flow paths result in improved plating uniformity.

主权项

1. An electroplating apparatus comprising:
(a) an electroplating chamber configured to contain an electrolyte and an anode while electroplating metal onto a substrate, the substrate being substantially planar; (b) a substrate holder configured to hold the substrate such that a plating face of the substrate is separated from the anode during electroplating; (c) an ionically resistive element comprising:
(i) a plurality of channels extending through the ionically resistive element and adapted to provide ionic transport through the ionically resistive element during electroplating;(ii) a substrate-facing side that is substantially parallel to the plating face of the substrate and separated from the plating face of the substrate by a gap, the gap forming a cross flow manifold between the ionically resistive element and the substrate; and(iii) a step positioned on the substrate-facing side of the ionically resistive element, wherein the step has a height and a diameter, wherein the diameter of the step is substantially coextensive with the plating face of the wafer, and wherein the height and diameter of the step are sufficiently small to allow electrolyte to flow under the substrate holder, over the step and into the cross flow manifold during plating; (d) an inlet to the cross flow manifold for introducing electrolyte to the cross flow manifold; and (e) an outlet to the cross flow manifold for receiving electrolyte flowing in the cross flow manifold,wherein the inlet and outlet are adapted to generate cross flowing electrolyte in the cross flow manifold to create or maintain a shearing force on the plating face of the substrate during electroplating.