Method for filling recessed micro-structures with metallization in the production of a microelectronic device

Abstract

A method for filling recessed micro-structures at a surface of a semiconductor wafer with metallization is set forth. In accordance with the method, a metal layer is deposited into the micro-structures with a process, such as an electroplating process, that generates metal grains that are sufficiently small so as to substantially fill the recessed micro-structures. The deposited metal is subsequently subjected to an annealing process at a temperature below about 100 degrees Celsius, and may even take place at ambient room temperature to allow grain growth which provides optimal electrical properties.

1 - 31 . (canceled)  
   
   
       32 - 54 . (canceled)  
   
   
       54 . A method of depositing a metal layer on a semiconductor wafer comprising: 
 depositing a seed layer on a surface of the wafer;    immersing the wafer in an electrolytic solution containing metal ions;    biasing the wafer negatively with respect to the electrolytic solution so as to create a current flow at a first current density between the electrolytic solution and the wafer and thereby deposit a plated layer electrolytically on the wafer; and    after a combined thickness of the seed and plated layers has reached a predetermined value, increasing the current flow to a second current density greater than the first current density.    
   
   
       55 . The method of  claim 54  wherein the plated and seed layers include copper.  
   
   
       56 . The method of  claim 54  wherein a top surface of the semiconductor wafer includes features to be filled with metal and the method includes applying a current flow at a third current density such that features are filled with metal.  
   
   
       57 . The method of depositing a metal layer on a semiconductor wafer comprising: 
 immersing a wafer having a seed layer on the surface thereof in an electrolytic solution containing metal ions;    biasing the wafer negatively with respect to the electrolytic solution so as to create a current flow at a first current density between the electrolytic solution and the wafer and thereby deposit a plated layer electrolytically on the wafer; and    after a predetermined time, increasing the current flow to a second current density greater than the first current density.    
   
   
       58 . The method of depositing a metal layer on a semiconductor wafer comprising: 
 contacting the wafer with a electrolytic solution containing metal ions;    applying a plating current to the wafer so as to create a current flow at a first current density between the electrolytic solution and the wafer and thereby deposit a plated layer electrolytically on the wafer; and    after a combined thickness of the seed and plated layers has reached a predetermined value, increasing the current flow to a second current density greater than the first current density.    
   
   
       59 . The method of depositing a metal layer on a semiconductor wafer comprising: 
 depositing a seed layer on the surface of the wafer;    contacting the wafer with a electrolytic solution containing metal ions;    applying a plating current to the wafer so as to create a current flow at a first current density between the electrolytic solution and the wafer and thereby deposit a plated layer electrolytically on the wafer;    after a predetermined time, increasing the current flow to a second current density greater than the first current density.