Barrier process/structure for transistor trench contact applications

Abstract

A barrier architecture is provided that includes different materials that are selected to be employed in connection with copper contact applications. Some of the barrier material is formed over trench contact sidewalls, and other different barrier material is formed over trench contact bottoms. By selecting the appropriate barrier materials, electromigration can be improved while, at the same time, interconnect and contact resistances can be kept low and array leakage can be mitigated.

1 . A method comprising:
 forming a trench contact over a substrate region with which electrical connection is desired;   forming a first barrier layer from a first barrier layer material within the trench contact;   forming a second barrier layer from a second barrier layer material within the trench contact; and   forming copper within the trench contact and in electrical communication with the substrate region.   
   
   
       2 . The method of  claim 1 , wherein the first and second barrier layer materials are different materials. 
   
   
       3 . The method of  claim 1 , wherein the first and second barrier layer materials have different metallurgical consistencies. 
   
   
       4 . The method of  claim 1 , wherein the act of forming the first barrier layer comprises:
 forming the first barrier layer over trench contact sidewalls and a trench contact bottom; and   removing first barrier layer material from over the trench contact bottom.   
   
   
       5 . The method of  claim 4 , wherein the act of forming the first barrier layer comprises depositing the first barrier layer using a high bias resputter process, wherein the first barrier layer comprises a metal and/or nitrogen containing material. 
   
   
       6 . The method of  claim 5 , wherein the act of removing the first barrier layer material comprises employing a sputter etch to remove the first barrier layer material. 
   
   
       7 . The method of  claim 6 , wherein the act of forming the second barrier layer comprises using a low bias resputter process. 
   
   
       8 . The method of  claim 7 , wherein the second barrier layer material comprises a metal material. 
   
   
       9 . The method of  claim 4 , wherein the first barrier layer material comprises a metal nitride.