Patent ID: 6258710
Filing Date: 2001-07-10
Classification: H01L

Abstract:
A method for forming multilevel interconnections of copper lines isolated from one another by dielectric insulation for making contacts to electrical features in a substrate, the method comprising the steps of:(a) preparing a substrate having a dielectric insulation layer to receive copper lines in a defined pattern;(b) optionally depositing a metallic liner in said pattern;(c) depositing in said pattern a layer of an element capable of forming an intermetallic compound with copper, wherein said element has less than two atomic percent solubility copper, and wherein the intermetallic forming element is selected from the group consisting of hafnium, lanthanum, tin and zirconium;(d) subsequently depositing in said pattern a chemical vapor deposition layer of copper; and(e) depositing over the chemical vapor deposition copper layer by a different process a layer of copper to substantially fill said pattern; and(f) heating the substrate to react the intermetallic forming element with said layer of copper which substantially fills said pattern to form a layer of intermetallic compound.