Method of burying a contact hole with a metal for forming multilevel interconnections

摘要

A method of burying a conductive metal into a contact hole formed in an insulation film formed over a silicon substrate. Within the contact hole a refractory metal silicide layer has been formed on the silicon substrate and a barrier metal layer has been formed on the refractory metal silicide layer and further a conductive metal film has been formed on the barrier metal layer. A top surface region of the conductive metal film is rapidly heated to a first temperature below a melting point of the conductive metal film and high enough so as to cause a semi-fluidization of only the top surface region of the conductive metal film so as to maintain an interface between the barrier metal layer and the conductive metal film at a second temperature which is lower than the first temperature and low enough so as to prevent any chemical reaction between the barrier metal layer and the conductive metal film and also maintain the refractory metal silicide layer and the silicon substrate to have temperatures lower than the second temperature so as to prevent silicon from being diffused through the barrier metal layer into the conductive metal film.