Methods for electroplating large copper interconnects

• US 6,699,396 B1
• Filed: 06/29/2001
• Issued: 03/02/2004
• Est. Priority Date: 06/29/2001
• Status: Active Grant

• Current Assignee: Novellus Systems Incorporated (LAM Research Corporation)
• Original Assignee: Novellus Systems Incorporated (LAM Research Corporation)
• Inventors: Drewery, John Stephen
• Primary Examiner(s): Mills, Gregory
• Assistant Examiner(s): CULBERT, ROBERTS P
• Application Number:
  US09/895,678
• Time in Patent Office: 977 Days
• Field of Search: 438/618-627, 438/631, 438/633, 438/634, 438/639, 438/667-680, 438/687, 216/13, 216/17, 216/18, 216/40
• US Class Current: 216/40
• CPC Class Codes: C25D 5/022 using masking means
• CPC Class Codes: C25D 7/123 Semiconductors first coated with a seed layer or a conductive layer
• CPC Class Codes: H01L 21/2885 using an external electrical current, i.e. electro-deposition
• CPC Class Codes: H01L 21/76802 by forming openings in dielectrics
• CPC Class Codes: H01L 21/76807 for dual damascene structures
• CPC Class Codes: H01L 21/76831 in via holes or trenches, e.g. non-conductive sidewall liners
• CPC Class Codes: H01L 21/76879 by selective deposition of conductive material in the vias, e.g. selective C.V.D. on semiconductor material, plating plating on semiconductors in general H01L21/288
• CPC Class Codes: H01L 21/7688 by deposition over sacrificial masking layer, e.g. lift-off lift-off per se H01L21/0272

Abstract

A method for forming conductive features in dielectric materials is disclosed which includes providing a dielectric layer and forming a release layer over the dielectric layer. Then a feature is defined into the each of the release layer and the dielectric layer and a conductive material is filled over the release layer and into the feature. The release layer is then removed where the removing serves to remove the conductive material from over the dielectric layer previously covered by the release layer.

Claims

1. A method for forming conductive features in dielectric materials, comprising:

providing a dielectric layer;

forming a release layer over the dielectric layer;

defining a feature into the release layer and the dielectric layer;

filling a conductive material over the release layer and into the feature; and

removing the release layer, the removing being configured to remove the conductive material from over the dielectric layer previously covered by the release layer, the removing of the release layer includes chemically dissolving the release layer, and the dissolving includes wet etching;

wherein the wet etching uses a combination of phosphoric acid, acetic acid and nitric acid, mixed with DI water.

2. A method for forming conductive features in dielectric materials as recited in claim 1, wherein the combination includes about 16 parts phosphoric acid, about 2 parts DI water, about 1 part acetic acid;

and about 1 part nitric acid.

3. A method for forming conductive features in dielectric materials, comprising:

providing a dielectric layer;

forming a release layer over the dielectric layer;

defining a feature into the release layer and the dielectric layer;

filling a conductive material over the release layer and into the feature; and

removing the release layer, the removing being configured to remove the conductive material from over the dielectric layer previously covered by the release layer, the removing of the release layer includes chemically dissolving the release layer, and the dissolving includes wet etching;

wherein the wet etching uses one of a sodium hydroxide solution in DI water and a trisodium phosphate solution in DI water.

4. A method for making copper features in a dielectric layer, comprising:

forming a release layer over the dielectric layer;

etching the release layer to define a location for a feature to be etched into the dielectric layer;

etching into the dielectric layer to define the feature in the dielectric layer;

applying a barrier layer over the release layer and into the feature;

applying a copper seed layer over the barrier layer;

apply a conformal dielectric layer over the copper seed layer;

directionally etching the conformal dielectric layer so as to remove the conformal dielectric layer from top surfaces of the dielectric layer, the top surfaces not including substantially vertical walls substantially in the feature defined in the dielectric layer, the directional etching exposing the copper seed layer over the top surfaces;

applying a copper material over the top surfaces so as to uniformly fill the feature and so as to apply the copper material throughout the dielectric layer in contact with the copper seed layer; and

removing the release layer, the removing of the release layer being configured to remove the barrier layer, the copper seed layer and the copper material from all regions other than in the feature.

5. A method for making copper features in a dielectric layer as recited in claim 4, wherein the release layer is selected from one of an aluminum material, a polymer material, and a dissolvable material.

6. A method for making copper features in a dielectric layer as recited in claim 4, wherein the removing the release layer may be accomplished by dissolving the release layer with a chemical.

7. A method for forming a conductive feature in a photo-sensitive dielectric material, comprising:

applying a photo-sensitive release layer over the photo-sensitive dielectric material;

exposing the photo-sensitive release layer and the photo-sensitive dielectric material so as to define a feature into the photo-sensitive dielectric material;

developing the photo-sensitive release layer and the photo-sensitive dielectric material so as to define the feature;

filling the feature with a conductive material; and

removing the release layer so as to remove the conductive material from over regions other than in the feature, the removing the release layer includes chemically dissolving the release layer;

wherein chemically dissolving the release layer includes wet etching with a combination of phosphoric acid, acetic acid and nitric acid, mixed with DI water.