Apparatus for barrier interface preparation of copper interconnect

Abstract

An integrated system for processing a substrate to improve electromigration performance of a copper interconnect, including: a lab-ambient transfer chamber capable of transferring the substrate from a substrate cassette coupled to the lab-ambient transfer chamber into the integrated system; a vacuum transfer chamber operated under vacuum at a pressure less than 1 Torr; a vacuum process module for depositing a metallic barrier layer, wherein the vacuum process module for depositing the metallic barrier layer is coupled to the vacuum transfer chamber, and is operated under vacuum at a pressure less than 1 Torr; a controlled-ambient transfer chamber filled with an inert gas selected from a group of inert gases; and, a deposition process module used to deposit a functionalization layer on the surface of the metallic barrier layer, wherein the deposition process module used to deposit the functionalization layer is coupled to the controlled-ambient transfer chamber.

What is claimed is: 
     
         1 . An integrated system for processing a substrate in a controlled environment to enable deposition of a functionalization layer over a metallic barrier layer of a copper interconnect to improve electromigration performance of the copper interconnect, comprising:
 a lab-ambient transfer chamber capable of transferring the substrate from a substrate cassette coupled to the lab-ambient transfer chamber into the integrated system;   a vacuum transfer chamber operated under vacuum at a pressure less than 1 Torr;   a vacuum process module for depositing the metallic barrier layer, wherein the vacuum process module for depositing the metallic barrier layer is coupled to the vacuum transfer chamber, and is operated under vacuum at a pressure less than 1 Torr;   a controlled-ambient transfer chamber filled with an inert gas selected from a group of inert gases; and   a deposition process module used to deposit the functionalization layer on the surface of the metallic barrier layer, wherein the deposition process module used to deposit the functionalization layer is coupled to the controlled-ambient transfer chamber.   
     
     
         2 . The integrated system of  claim 1 , further comprising:
 an electroless copper deposition process module used to deposit a thin layer of copper seed layer in the copper interconnect after the functionalization layer is deposited on the surface of the metallic barrier layer, wherein the electroless copper deposition process module is coupled to the controlled-ambient transfer chamber.   
     
     
         3 . The integrated system of  claim 2 , wherein the electroless copper deposition process module is also used to deposit a gap-fill copper layer over the thin copper seed layer. 
     
     
         4 . The integrated system of  claim 2 , further comprising:
 an electroless copper deposition process module used to deposit a gap-fill copper layer over the thin copper seed layer.   
     
     
         5 . The integrated system of  claim 1 , further comprising:
 a vacuum process module for cleaning an exposed surface of a metal oxide of an underlying metal, wherein the underlying metal is part of an underlying interconnect, the copper interconnect is electrically connected to the underlying interconnect, and the vacuum process module for cleaning is coupled to the vacuum transfer chamber, and is operated under vacuum at a pressure less than 1 Torr.   
     
     
         6 . The integrated system of  claim 1 , further comprising:
 a hydrogen-containing reduction process module used to reduce metal oxide or metal nitride on a surface of the metallic barrier to make the surface metal-rich before the functionalization layer is deposited on the surface of the metallic barrier layer, wherein the hydrogen-containing reduction process module is coupled to the vacuum transfer chamber, the hydrogen-containing reduction process module is operated under vacuum at a pressure less than 1 Torr.   
     
     
         7 . The integrated system of  claim 1 , further comprising:
 a substrate cleaning process module used to clean the substrate surface after depositing the functionalization layer over the metallic barrier layer, wherein the substrate cleaning process module is coupled to the controlled-ambient transfer module.   
     
     
         8 . The integrated system of  claim 1 , further comprising:
 a first loadlock coupled to the vacuum transfer chamber and the controlled-ambient transfer chamber, wherein the first loadlock assists the substrate to be transferred between the vacuum transfer chamber and the controlled-ambient transfer chamber, the first loadlock being configured to be operated under vacuum at pressure less than 1 Torr or to be filled with an inert gas selected from a group of inert gases; and   a second loadlock coupled to the vacuum transfer chamber and the lab-ambient transfer chamber, wherein the second loadlock assists the substrate to be transferred between the vacuum transfer chamber and the lab-ambient transfer chamber, the second loadlock being configured to be operated under vacuum at pressure less than 1 Torr or at lab ambient or to be filled with an inert gas selected from a group of inert gases.   
     
     
         9 . The integrated system of  claim 1 , wherein the vacuum transfer chamber and the vacuum process module coupled to the vacuum transfer chamber are operated at a pressure less than 1 Torr to control the exposure of the substrate to oxygen. 
     
     
         10 . The integrated system of  claim 1 , wherein the controlled-ambient transfer chamber and the deposition process module coupled to the controlled-ambient transfer chamber are filled with one or more inert gases selected from the group of inert gases to control the exposure of the substrate to oxygen. 
     
     
         11 . The integrated system of  claim 1 , wherein substrate is transferred and processed in the integrated system to limit a duration the substrate is exposed to oxygen. 
     
     
         12 . The integrated system of  claim 11 , wherein limiting the exposure of the substrate surface to oxygen enables the functionalization layer being deposited on the surface of the metallic barrier layer. 
     
     
         13 . The integrated system of  claim 1 , wherein the at least one process module coupled to the controlled-ambient transfer module enables a dry-in/dry-out processing of the substrate, wherein the substrate goes in and comes out of the at least one process module in a dry state. 
     
     
         14 . An integrated system for processing a substrate in a controlled environment to enable deposition of a functionalization layer over a metallic barrier layer of a copper interconnect to improve electromigration performance of the copper interconnect, comprising:
 a lab-ambient transfer chamber capable of transferring the substrate from a substrate cassette coupled to the lab-ambient transfer chamber into the integrated system;   a vacuum transfer chamber operated under vacuum at a pressure less than 1 Torr;   a vacuum process module for depositing the metallic barrier layer, wherein the vacuum process module for depositing the metallic barrier layer is coupled to the vacuum transfer chamber, and is operated under vacuum at a pressure less than 1 Torr;   a controlled-ambient transfer chamber filled with an inert gas selected from a group of inert gases;   a deposition process module used to deposit the functionalization layer on the surface of the metallic barrier layer, wherein the deposition process module used to deposit the functionalization layer is coupled to the controlled-ambient transfer chamber; and   an electroless copper deposition process module used to deposit a copper layer over the functionalization layer in the copper interconnect, wherein the electroless copper deposition process module is coupled to the controlled-ambient transfer chamber, and wherein the material used for the functionalization layer comprises a complexing group with at least two ends, one end of the complexing group forming a bond with the metallic bather layer and another end of the complexing group forming a bond with the copper layer.   
     
     
         15 . The integrated system of  claim 14 , further comprising one or more of the following:
 a vacuum process module for cleaning an exposed surface of a metal oxide of an underlying metal, wherein the underlying metal is part of an underlying interconnect, the copper interconnect is electrically connected to the underlying interconnect, and the vacuum process module for cleaning is coupled to the vacuum transfer chamber, and is operated under vacuum at a pressure less than 1 Torr;   a hydrogen-containing reduction process module used to reduce metal oxide or metal nitride on a surface of the metallic barrier to make the surface metal-rich before the functionalization layer is deposited on the surface of the metallic barrier layer, wherein the hydrogen-containing reduction process module is coupled to the vacuum transfer chamber, the hydrogen-containing reduction process module is operated under vacuum at a pressure less than 1 Torr; and/or   a substrate cleaning process module used to clean the substrate surface after depositing the functionalization layer over the metallic barrier layer, wherein the substrate cleaning process module is coupled to the controlled-ambient transfer module.   
     
     
         16 . The integrated system of  claim 14 , further comprising:
 a first loadlock coupled to the vacuum transfer chamber and the controlled-ambient transfer chamber, wherein the first loadlock assists the substrate to be transferred between the vacuum transfer chamber and the controlled-ambient transfer chamber, the first loadlock being configured to be operated under vacuum at pressure less than 1 Torr or to be filled with an inert gas selected from a group of inert gases; and   a second loadlock coupled to the vacuum transfer chamber and the lab-ambient transfer chamber, wherein the second loadlock assists the substrate to be transferred between the vacuum transfer chamber and the lab-ambient transfer chamber, the second loadlock being configured to be operated under vacuum at pressure less than 1 Torr or at lab ambient or to be filled with an inert gas selected from a group of inert gases.   
     
     
         17 . The integrated system of  claim 14 ,
 wherein the vacuum transfer chamber and the at least one vacuum process module coupled to the vacuum transfer chamber are operated at a pressure less than 1 Torr to control the exposure of the substrate to oxygen;   wherein the controlled-ambient transfer chamber and each one the at least one process module coupled to the controlled-ambient transfer chamber are filled with one or more inert gases selected from the group of inert gases to control the exposure of the substrate to oxygen;   wherein substrate is transferred and processed in the integrated system to limit a duration the substrate is exposed to oxygen;   wherein limiting the exposure of the substrate surface to oxygen enables the functionalization layer being deposited on the surface of the metallic barrier layer.   
     
     
         18 . The integrated system of  claim 14 , wherein the at least one process module coupled to the controlled-ambient transfer module enables a dry-in/dry-out processing of the substrate, wherein the substrate goes in and comes out of the at least one process module in a dry state. 
     
     
         19 . An integrated system for processing a substrate in a controlled environment to enable deposition of a functionalization layer over a metallic barrier layer of a copper interconnect to improve electromigration performance of the copper interconnect, comprising:
 a vacuum transfer chamber operated under vacuum;   a vacuum process module for depositing the metallic barrier layer, wherein the vacuum process module for depositing the metallic barrier layer is coupled to the vacuum transfer chamber, and is operated under vacuum;   a controlled-ambient transfer chamber filled with one or more inert gases;   a deposition process module used to deposit the functionalization layer on the surface of the metallic barrier layer, wherein the deposition process module used to deposit the functionalization layer is coupled to the controlled-ambient transfer chamber; and   an electroless copper deposition process module used to deposit a copper layer over the functionalization layer in the copper interconnect, wherein the electroless copper deposition process module is coupled to the controlled-ambient transfer chamber, and wherein the material used for the functionalization layer comprises a complexing group with at least two ends, one end of the complexing group forming a bond with the metallic bather layer and another end of the complexing group forming a bond with the copper layer, the functionalization layer facilitating the deposition of the copper layer and improving adhesion between the metallic barrier layer and the copper layer.   
     
     
         20 . The integrated system of  claim 19 , further comprising one or more of the following:
 a vacuum process module for cleaning an exposed surface of a metal oxide of an underlying metal, wherein the underlying metal is part of an underlying interconnect, the copper interconnect is electrically connected to the underlying interconnect, and the vacuum process module for cleaning is coupled to the vacuum transfer chamber, and is operated under vacuum at a pressure less than 1 Torr;   a hydrogen-containing reduction process module used to reduce metal oxide or metal nitride on a surface of the metallic barrier to make the surface metal-rich before the functionalization layer is deposited on the surface of the metallic barrier layer, wherein the hydrogen-containing reduction process module is coupled to the vacuum transfer chamber, the hydrogen-containing reduction process module is operated under vacuum at a pressure less than 1 Torr; and/or   a substrate cleaning process module used to clean the substrate surface after depositing the functionalization layer over the metallic barrier layer, wherein the substrate cleaning process module is coupled to the controlled-ambient transfer module.   
     
     
         21 . The integrated system of  claim 19 , further comprising:
 a loadlock coupled to the vacuum transfer chamber and the controlled-ambient transfer chamber, wherein the loadlock assists the substrate to be transferred between the vacuum transfer chamber and the controlled-ambient transfer chamber, the loadlock being configured to be operated under vacuum at pressure less than 1 Torr or to be filled with an inert gas selected from a group of inert gases.   
     
     
         22 . The integrated system of  claim 19 ,
 wherein the vacuum transfer chamber and the vacuum process module coupled to the vacuum transfer chamber are operated at a pressure less than 1 Torr to control the exposure of the substrate to oxygen;   wherein the controlled-ambient transfer chamber and the deposition process module coupled to the controlled-ambient transfer chamber are filled with one or more inert gases to control the exposure of the substrate to oxygen;   wherein substrate is transferred and processed in the integrated system to limit a duration the substrate is exposed to oxygen, wherein limiting the exposure of the substrate surface to oxygen enables the functionalization layer being deposited on the surface of the metallic barrier layer.   
     
     
         23 . The integrated system of  claim 19 , wherein the at least one process module coupled to the controlled-ambient transfer module enables a dry-in/dry-out processing of the substrate, wherein the substrate goes in and comes out of the at least one process module in a dry state.