Current collimation for thin seed and direct plating

Abstract

A method and apparatus for plating a conductive material onto a substrate is provided. The apparatus includes a fluid processing cell having a fluid basin configured to contain an electrolyte solution and having an opening configured to receive a substrate for processing, an anode assembly positioned in the fluid basin, and a collimator positioned in the fluid basin between the anode assembly and the opening.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] Embodiments of the invention generally relate to an electrochemical plating cell having an electric field collimator positioned between the anode and the substrate being plated. [0003] 2. Description of the Related Art [0004] In semiconductor processing, electrochemical plating (ECP) is generally the preferred technique for filling features formed onto substrates with a conductive material. A typical ECP process generally includes immersing a substrate into an electrolyte solution that is rich in ions of the conductive material (generally copper), and then applying an electrical bias between a conductive seed layer formed on the surface of the substrate and an anode positioned in the electrolyte solution. The application of the electrical bias between the seed layer and the anode facilitates an electrochemical reaction that causes the ions of the conductive material to plate onto the seed layer. [0005] However, with...

AI Technical Summary

Benefits of technology

The invention provides an electrochemical plating cell with a collimator that channels the electric field in a linear path, resulting in a more uniform plating of conductive materials onto a substrate. The cell also includes a zoned anode with non-concentrically shaped anode elements. The apparatus for plating includes a collimator and a cell body with an anode assembly and an electric field collimator. The method involves generating an electric field and collimating it in a linear direction between the anode and the substrate for plating. The technical effects include improved plating quality and efficiency.

Problems solved by technology

However, with conventional ECP processes and systems, the conductive seed layer formed on the substrate is generally very thin, and as such, is highly resistive.

This phenomenon is generally known as the “terminal effect”, and is an undesirable characteristic associated with conventional plating systems.

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