Methods of multi-step electrochemical mechanical planarization of Cu

摘要

A method is provided for removing conductive material from a metal layer deposited on a wafer having die level thickness variations on its surface. The method includes contacting the metal layer with a composition capable of planarizing die level thickness variations while using a current having a current density within a range of between about 5 mA/cm² and about 40 mA/cm², applying a first current to the wafer having a current density within a range of between about 5 mA/cm² and about 20 mA/cm² to remove a first portion of the metal layer to thereby planarize the wafer surface, and administering a second current to the wafer having a current density within a range of between about 20 mA/cm² and about 40 mA/cm² to remove a second portion of the metal layer and to leave a third portion of the metal layer on the wafer having a predetermined thickness.