Method for the etchback of a conductive material
AssigneeApplied Materials, Inc.
InventorsChris Ting, Janet Yu
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Abstract
The present disclosure provides a method for etchback of a conductive layer in a contact via (contact hole). The method described is typically used in the formation of a conductive plug within the contact hole. The method includes a first etchback in which the conductive layer is etched back; a buffer (i.e., transition) step during which the etch rate of the conductive layer is reduced; and a second etchback in which the amount of chemically reactive etchant is reduced from that used in the first etchback and a plasma species is added to provide additional physical bombardment, in an isotropic etch of the substrate surface surrounding the contact hole.
Claims25
A method for etchback of a conductive material layer within a semiconductor structure, wherein said semiconductor structure comprises a substrate including a conductive region to be connected, a dielectric layer formed over said substrate and defined with a contact hole therein which overlies said conductive region, and a conductive layer deposited within said contact hole, wherein said method comprises the steps of:
- a) a first etchback to remove a portion of said conductive layer;
- b) a buffer step to slow the etch rate of said conductive layer, wherein a plasma source power or a substrate bias power or both are reduced or discontinued;
- and
- c) a second etchback step to remove residues of said conductive layer from an upper surface of said substrate without significant additional etching of conductive layer material residing within said contact hole.
Dependencies are inferred from the claim text.