Method for the formation of diffusion barrier

Abstract

Electronic components such as semiconductor wafer VLSI and ULSI integrated circuit devices are provided having a robust barrier layer in the device interconnects. The robust barrier layer provides excellent step coverage, low resistance and enhanced adhesion to CVD copper and the interconnect has a double structure of a layer of a barrier material and a metal layer thereon. The metal layer is preferably tungsten and is formed by replacing silicon or other such atoms on the surface of the barrier layer with tungsten metal. A layer of silicon can be formed on the barrier layer, silicon atoms can be formed on the surface by reacting the barrier layer with a silicon containing reactant or a silicon containing barrier layer can be used.

1 . An interconnect structure in a multilayer electronic component for connecting metallization layers, the interconnect structure having excellent step coverage, uniformity, low resistance and adhesion to CVD-copper comprising: 
 a dielectric layer having a through opening to a conductor in another layer;    a diffusion barrier layer in the through opening in the dielectric layer;    a metallic layer on the diffusion barrier layer; and    copper filling the opening to form the interconnect structure.    
     
     
         2 . The interconnect structure of  claim 1  wherein the diffusion barrier has metal replaceable atoms on the surface thereof which are replaced by the metallic layer.  
     
     
         3 . The interconnect structure of  claim 2  wherein the metal replaceable atoms are silicon atoms.  
     
     
         4 . The interconnect structure of  claim 3  wherein the silicon atoms are formed by surface treating the diffusion barrier layer.  
     
     
         5 . The interconnect structure of  claim 3  wherein a layer of silicon is deposited on the diffusion barrier layer.  
     
     
         6 . The interconnect structure of  claim 3  wherein the diffusion barrier material contains silicon atoms.  
     
     
         7 . The interconnect structure of  claim 3  wherein the metallic layer is tungsten.  
     
     
         8 . A multilayer electronic component integrated circuit device comprising: 
 a plurality of dielectric layers having metallization therein;    openings in the form of a trench and/or via extending through at least one layer and connecting metallization in another layer;    a diffusion barrier in the opening on the dielectric layer;    a metallic layer on the diffusion barrier layer; and    copper filling the opening to electrically connect the metallization in the dielectric layers.    
     
     
         9 . The device of  claim 8  wherein the diffusion barrier has metal replaceable atoms on the surface thereof which are replaced by the metallic layer.  
     
     
         10 . The device of  claim 9  wherein the metal replaceable atoms are silicon atoms.  
     
     
         11 . The device of  claim 10  wherein the silicon atoms are formed by surface treating the diffusion barrier layer.  
     
     
         12 . The device of  claim 10  wherein a layer of silicon is deposited on the diffusion barrier layer.  
     
     
         13 . The device of  claim 10  wherein the diffusion barrier material contains silicon atoms.  
     
     
         14 . The device of  claim 10  wherein the metallic layer is tungsten.  
     
     
         15 . A method for making multilayer electronic component integrated circuit devices wherein interconnects in the devices have excellent step coverage, uniformity, low resistance and adhesion to CVD-copper comprising the steps of: 
 forming a multilayer electronic component layer by layer with dielectric layers having openings therein with metallization formed in the openings to provide electrical connections between the layers;    forming a diffusion barrier layer in the opening on the dielectric layer;    forming a metallic layer on the diffusion barrier layer by reacting the barrier layer with a metal containing reactant; and    filling the opening with copper to provide a conductor which contacts the metallization in the dielectric layer to another layer.    
     
     
         16 . The method of  claim 15  wherein the diffusion barrier layer is surface treated to form silicon atoms on the surface thereof.  
     
     
         17 . The method of  claim 16  wherein the diffusion barrier layer is surface treated by contacting the barrier layer with a silicon containing reactant to form silicon atoms on the surface thereof.  
     
     
         18 . The method of  claim 17  wherein the silicon containing reactant is SiH 4 .  
     
     
         19 . The method of  claim 15  wherein a layer of silicon is deposited on the diffusion barrier layer.  
     
     
         20 . The method of  claim 15  wherein the diffusion barrier material contains metal replaceable atoms.  
     
     
         21 . The method of claim  20  wherein the metal replaceable atoms are silicon.