System for improving thermal stability of copper damascene structure

Abstract

Disclosed is a system for fabricating a semiconductor device ( 100 ). An interconnect structure ( 110 ) is formed on the semiconductor device ( 100 ) and a cap ( 112 ) is deposited over the interconnect structure ( 110 ). The interconnect structure ( 110 ) is annealed with the overlying cap ( 112 ) in place. The cap ( 112 ) is then removed after the interconnect structure ( 110 ) is annealed.

1 - 10 . (canceled)  
   
   
       11 . A method of fabricating a semiconductor device, comprising the steps of: 
 forming an interconnect structure;    depositing a cap over the interconnect structure;    annealing the interconnect structure; and    depositing an interlevel dielectric on the cap.    
   
   
       12 . The method of  claim 11  wherein the interconnect structure is formed from copper.  
   
   
       13 . The method of  claim 11  wherein the interconnect structure is formed by electrochemical deposition.  
   
   
       14 . The method of  claim 11  wherein the cap is deposited at a temperature about or less than 200° C.  
   
   
       15 . The method of  claim 11  wherein the cap is deposited by chemical vapor deposition.  
   
   
       16 . The method of  claim 11  wherein the step of annealing the interconnect structure is annealing at a temperature above 200° C.  
   
   
       17 . The method of  claim 11  wherein the step of annealing the interconnect structure is annealing at 780° C.  
   
   
       18 . The method of  claim 11  wherein the step of depositing an interlevel dielectric on the cap is by chemical vapor deposition.  
   
   
       19 . The method of  claim 11 , wherein the step of depositing the cap comprises depositing a cap from a material chosen from the group of silicon nitride, silicon oxide, silicon dioxide or organic silicon glass.  
   
   
       20 . The method of  claim 11 , wherein the cap has a thickness of between about 50 nm and 200 nm.