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Browse Prior Art Database

Enhanced Copper Metallurgy for Beol Application

IP.com Disclosure Number: IPCOM000102060D
Original Publication Date: 1990-Oct-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 2 page(s) / 44K

Publishing Venue

IBM

Related People

Ahn, KY: AUTHOR [+2]

Abstract

Disclosed is a combination of materials and process for copper-based metallurgy suitable for applications in back-end of line (BEOL) technology.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 95% of the total text.

Enhanced Copper Metallurgy for Beol Application

       Disclosed is a combination of materials and process for
copper-based metallurgy suitable for applications in back-end of line
(BEOL) technology.

      Preliminary results of electromigration tests of copper
conductors show early fails.  There may be several approaches to
solve this problem, but we believe the method disclosed herein
appears to be most practical to protect copper conductors.  The
method involves wrapping the copper conductor with tungsten film.
The tungsten film is formed by selective deposition using the mixture
of WF6 and SiH4 in the presence of hydrogen in a typical cold-wall
single-wafer reactor with typical gas flow rates of 6, 6, and 200
sccm, respectively.  Under this condition, thin-wall tungsten "shell"
for the conductor and doughnut- shaped tungsten deposit for via holes
are obtained.

      These tungsten shells and doughnuts are then filled with
copper, either by physical vapor deposition or chemical vapor
deposition to the desired thickness, followed by a capping layer of
tungsten, by physical vapor deposition or chemical vapor deposition,
as shown in the figure.

      Most elegant method will be to employ the selective deposition
of copper followed by selective deposition of tungsten capping layer,
which will not require further processing.  However, if a blanket
deposition of copper and tungsten capping layers are used, an
etchback method is needed for planarization....