Browse Prior Art Database

A Method to Inhibit Oxidation of Copper Silicide

IP.com Disclosure Number: IPCOM000119787D
Original Publication Date: 1991-Feb-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 1 page(s) / 46K

Publishing Venue

IBM

Related People

Aboelfotoh, MO: AUTHOR

Abstract

A method is disclosed to inhibit oxidation of copper silicide resulting from exposure to oxygen or air for an extended period of time that will cause degradation of its electrical transport properties.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 78% of the total text.

A Method to Inhibit Oxidation of Copper Silicide

      A method is disclosed to inhibit oxidation of copper silicide
resulting from exposure to oxygen or air for an extended period of
time that will  cause degradation of its electrical transport
properties.

      Copper, because of its low resistivity, has been proposed for
interconnect applications in VLSI and related technologies.  However,
Cu exhibits a high diffusivity in silicon and is generally believed
to be detrimental to the performance of Si devices due to Cu-induced
recombination centers which can reduce the minority carrier lifetime.
A possible solution to this problem is the use of copper silicide.
However, copper silicide reacts readily with oxygen upon exposure to
air and this results in degradation of its electrical transport
properties.

      A method has been discovered in which Cu-Pt or Cu-Pd alloys
containing 5 to 10 atomic percent Pt or Pd are deposited on a Si
substrate at room temperature, followed by heating at temperatures in
the range of 175 to 200@C, resulting in the formation of copper
silicide in contact with Si and a thin layer of Pt or Pd (silicide)
on top of the  copper silicide.  Experimental data show no detectable
oxygen in the bulk of the copper silicide upon exposing the structure
to air for  several months and essentially no change in its
electrical resistivity.

      An alternative structure which has been found to be effective
in inhibiting the oxidation of cop...