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US 7,465,408 B1Granted
Solutions for controlled, selective etching of copper
AssigneeAdvanced Micro Devices, Inc.
InventorSteven C. Avanzino
Life of this patent
Estimating the term…
Abstract
Disclosed are methods and systems of etching copper containing materials so that they have smooth and/or planar surface. In this connection, the systems and methods employ two different solutions to accomplish the etching. The first solution oxidizes the surface of the copper containing material and forms a passivating film. The second solution removes the passivating film in a controlable manner.
Claims20
A method of etching a copper containing material, comprising:
- contacting the copper containing material comprising at least about 10% by weight copper with a first solution to convert at least a portion of the copper containing material to a passivating film, the first solution comprising a peroxide compound, a first organic acid, and water and having a pH from about 2 to about 6;
- and
- contacting the passivating film with a second solution to remove the passivating film, the second solution comprising a second organic acid and water.
A method of etching a copper structure, comprising:
- contacting the copper structure comprising at least about 25% by weight copper on a wafer with a first solution to convert at least a portion of the copper structure to a passivating film, the first solution comprising a peroxide compound, a first organic acid, and water and having a pH from about 2 to about 6;
- contacting the passivating film with a second solution to remove the passivating film, the second solution comprising a second organic acid and water, the second solution having a lower pH and a higher temperature than the pH and temperature of the first solution;
- and
- rinsing the wafer with water to provide an etched copper structure.
1 more element
A method of etching a copper containing material, comprising:
- contacting the copper containing material with a first solution to convert at least a portion of the copper containing material to a passivation layer, the first solution comprising a peroxide compound, a first organic acid, and water and having a pH from about 2 to about 6;
- contacting the passivation layer with a second solution to remove the passivation layer, the second solution comprising a second organic acid and water;
- and simultaneously
- monitoring the formation and removal of the passivation layer using a scatterometry system by generating a signature associated with forming and removing the layer, comparing the signature to a signature library to determine layer depth, and terminating forming and removing the passivation layer when a desired depth is attained.
1 more element
Dependencies are inferred from the claim text.