Browse Prior Art Database

METHOD TO ACHIEVE POLYIMIDE ADHESION TO Cr-Cu-Cr CONDUCTOR EDGES

IP.com Disclosure Number: IPCOM000046927D
Original Publication Date: 1983-Aug-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Horng, CT: AUTHOR [+2]

Abstract

Polyimide adhesion to Cr-Cu-Cr conductor edges is improved by depositing a thin layer of aluminum oxide on the copper conductor. Copper conductor, having high electrical conductivity and resistance to electromigration, is a desirable thin film metallurgy for use in microelectronic devices. Copper films, however, to not adhere well to dielectric passivation layers, such as SiO2, or polyimide. To utilize copper as a conductor metallurgy sandwich, structures such as Cr-Cu-Cr are formed. The chromium over- and under-coat layers in this sandwich structure serve as an adhesion promoter for passivation with a dielectric layer. However, in a Cr-Cu-Cr sandwich structure, copper is exposed at the conductor sidewalls. The following process can be used to solve the adhesion problem in passivating Cr-Cu-Cr conductor lines.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 99% of the total text.

Page 1 of 1

METHOD TO ACHIEVE POLYIMIDE ADHESION TO Cr-Cu-Cr CONDUCTOR EDGES

Polyimide adhesion to Cr-Cu-Cr conductor edges is improved by depositing a thin layer of aluminum oxide on the copper conductor. Copper conductor, having high electrical conductivity and resistance to electromigration, is a desirable thin film metallurgy for use in microelectronic devices. Copper films, however, to not adhere well to dielectric passivation layers, such as SiO2, or polyimide. To utilize copper as a conductor metallurgy sandwich, structures such as Cr-Cu-Cr are formed. The chromium over- and under-coat layers in this sandwich structure serve as an adhesion promoter for passivation with a dielectric layer. However, in a Cr-Cu-Cr sandwich structure, copper is exposed at the conductor sidewalls. The following process can be used to solve the adhesion problem in passivating Cr-Cu-Cr conductor lines. This is achieved by coating a thin layer of aluminum oxide over the Cr-Cu-Cr conductor lines prior to passivating the conductor patterns with a dielectric layer. Aluminum oxide adheres well to copper and dielectric layers, such as silicon dioxide or polyimide. Coating of aluminum oxide film over Cr-Cu-Cr conductor lines can be done with a sputtering process to achieve good step coverage. Alternately, an aluminum oxide film can be formed by a spin-on technique using a solution containing aluminum organic chelate. The aluminum oxide adhesion promoter is then formed by thermal curing at approxima...