Method for plating metal onto wafers

Abstract

A method for chemical plating a substrate is provided. Embodiments of the method include evacuating an enclosure having a substrate disposed therein under vacuum, filling the enclosure with an electrolyte solution having a pressure between about 0.5 atm and about 200 atm, chemical plating a metal layer on a surface of the substrate, and draining the electrolyte solution from the enclosure. In another aspect, the method includes energizing an ultrasonic source to agitate the electrolyte solution substantially simultaneous with the step of chemical plating a metal layer on a surface of the substrate. In still another aspect, the method includes varying the pressure of the plating cell to agitate the electrolyte solution. In yet another aspect, the method includes increasing a pressure of the electrolyte solution by heating the electrolyte solution.

What is claimed is:  
     
         1 . A method for chemical plating, comprising: 
 evacuating an enclosure having a substrate disposed therein to a pressure less than about 1 atm;    filling the enclosure with an electrolyte solution at a pressure between about 0.5 atm and about 200 atm; and    chemical plating a metal layer on at least a portion of a surface of the substrate.    
     
     
         2 . The method of  claim 1 , further comprising energizing one or more ultrasonic sources disposed within the enclosure to agitate the electrolyte solution.  
     
     
         3 . The method of  claim 1 , further comprising draining the electrolyte solution from the enclosure and venting the enclosure.  
     
     
         4 . The method of  claim 1 , wherein the enclosure has a variable operating pressure between about 0.5 atm and about 200 atm.  
     
     
         5 . The method of  claim 1 , wherein chemical plating of a metal layer on a surface of the substrate occurs at a temperature between about 15° C. and about 100° C.  
     
     
         6 . The method of  claim 1 , further comprising one or more ultrasonic sources disposed within the enclosure to agitate the substrate.  
     
     
         7 . The method of  claim 1 , wherein evacuating an enclosure comprises removing reactive compounds, contaminants, or both from the enclosure.  
     
     
         8 . The method of  claim 1 , further comprising varying the pressure to agitate the electrolyte solution.  
     
     
         9 . The method of  claim 8 , wherein varying the pressure of the electrolyte solution comprises increasing the pressure by about 5 to about 20 percent every 1 to about 30 seconds.  
     
     
         10 . The method of  claim 8 , wherein varying the pressure of the electrolyte solution comprises decreasing the pressure by about 5 to about 20 percent every 1 to about 30 seconds.  
     
     
         11 . The method of  claim 1 , further comprising energizing a power source connected to the substrate.  
     
     
         12 . A method for chemical plating, comprising: 
 opening a first valve to evacuate an enclosure having a substrate disposed therein,    pulling vacuum on the enclosure;    closing the first valve and opening a second valve to fill the enclosure with an electrolyte solution;    closing the second valve;    chemical plating a metal layer on at least a portion of a surface of the substrate;    opening the second valve to drain the electrolyte solution from the enclosure; and    closing the second valve and opening a fourth valve to vent the enclosure prior to removing the plated substrate from the enclosure.    
     
     
         13 . The method of  claim 12 , further comprising energizing one or more ultrasonic sources disposed within the enclosure to agitate the electrolyte solution.  
     
     
         14 . The method of  claim 12 , further comprising one or more ultrasonic sources disposed within the enclosure to agitate the substrate.  
     
     
         15 . The method of  claim 12 , wherein chemical plating occurs at pressure of about 0.5 atm to about 200 atm.  
     
     
         16 . The method of  claim 12 , wherein chemical plating occurs at a temperature of about 15° C. to about 100° C.  
     
     
         17 . The method of  claim 15 , further comprising varying the pressure to agitate the electrolyte solution in fluid contact with the substrate surface.  
     
     
         18 . The method of  claim 17 , wherein varying the pressure of the electrolyte solution comprises increasing the pressure by about 5 to about 20 percent every 1 to about 30 seconds.  
     
     
         19 . The method of  claim 17 , wherein varying the pressure of the electrolyte solution comprises decreasing the pressure by about 5 to about 20 percent every 1 to about 30 seconds.  
     
     
         20 . The method of  claim 18 , wherein increasing the pressure comprises increasing a temperature of the electrolyte solution to enhance the chemical plating.  
     
     
         21 . The method of  claim 12 , further comprising energizing a power source connected to the substrate.  
     
     
         22 . A method for chemical plating, comprising: 
 evacuating an enclosure having a substrate disposed therein under a vacuum sufficient to substantially purge gases from the enclosure;    filling the enclosure with a pressurized electrolyte solution;    energizing one or more ultrasonic sources disposed within the enclosure to agitate the electrolyte solution;    chemical plating a metal layer on a surface of the substrate; and    draining the electrolyte solution from the enclosure.    
     
     
         23 . The method of  claim 22 , further comprising venting the enclosure prior to draining the electrolyte solution from the enclosure.  
     
     
         24 . The method of  claim 22 , wherein chemical plating occurs at a variable operating pressure between about 100 mtorr and about 200 atm.  
     
     
         25 . The method of  claim 22 , wherein chemical plating occurs at a temperature of about 15° C. to about 25° C.  
     
     
         26 . The method of  claim 22 , further comprising energizing one or more ultrasonic sources disposed within the enclosure to agitate the substrate.  
     
     
         27 . The method of  claim 26 , wherein the substrate is agitated in both a vertical and horizontal direction.  
     
     
         28 . The method of  claim 22 , wherein the pressurized electrolyte solution has a pressure between about 1 atm and about 200 atm.  
     
     
         29 . The method of  claim 22 , further comprising varying the pressure of the electrolyte solution to agitate the electrolyte solution.  
     
     
         30 . The method of  claim 29 , wherein varying the pressure of the electrolyte solution comprises increasing the pressure by about 5 to about 20 percent every 1 to about 30 seconds.  
     
     
         31 . The method of  claim 29 , wherein varying the pressure of the electrolyte solution comprises decreasing the pressure by about 5 to about 20 percent every 1 to about 30 seconds.  
     
     
         32 . The method of  claim 30 , wherein increasing the pressure increases a temperature of the electrolyte solution.  
     
     
         33 . The method of  claim 22 , further comprising energizing a power source connected to the substrate.  
     
     
         34 . A method for chemical plating, comprising: 
 evacuating an enclosure having a substrate disposed therein under vacuum;    filling the enclosure with an electrolyte solution having a pressure sufficient to substantially collapse air bubbles in the electrolyte solution; and    chemical plating a metal layer on at least a portion of a surface of the substrate.    
     
     
         35 . The method of  claim 34 , further comprising energizing one or more ultrasonic sources to agitate the electrolyte solution.  
     
     
         36 . The method of  claim 35 , wherein the one or more ultrasonic sources are disposed within the chamber.  
     
     
         37 . The method of  claim 35 , wherein the one or more ultrasonic sources are adapted to agitate a substrate disposed within the enclosure.  
     
     
         38 . The method of  claim 34 , further comprising energizing a power source connected to the substrate.  
     
     
         39 . The method of  claim 34 , further comprising varying the pressure of the electrolyte solution to agitate the electrolyte solution.  
     
     
         40 . The method of  claim 39 , wherein varying the pressure of the electrolyte solution comprises increasing the pressure by about 5 to about 20 percent every 1 to about 30 seconds.  
     
     
         41 . The method of  claim 39 , wherein varying the pressure of the electrolyte solution comprises decreasing the pressure by about 5 to about 20 percent every 1 to about 30 seconds.  
     
     
         42 . A method for chemical plating, comprising: 
 evacuating an enclosure having a substrate disposed therein under vacuum;    filling the enclosure with an electrolyte solution having a pressure sufficient to substantially collapse air bubbles in the electrolyte solution;    varying the pressure of the electrolyte solution to agitate the electrolyte solution; and    chemical plating a metal layer on a surface of the substrate.    
     
     
         43 . The method of  claim 42 , further comprising energizing one or more ultrasonic sources to agitate the electrolyte solution.  
     
     
         44 . The method of  claim 43 , wherein the one or more ultrasonic sources are disposed within the chamber.  
     
     
         45 . The method of  claim 42 , further comprising energizing a power source connected to the substrate.  
     
     
         46 . The method of  claim 42 , wherein varying the pressure of the electrolyte solution comprises increasing the pressure by about 5 to about 20 percent every 1 to about 30 seconds.  
     
     
         47 . The method of  claim 42 , wherein varying the pressure of the electrolyte solution comprises decreasing the pressure by about 5 to about 20 percent every 1 to about 30 seconds.  
     
     
         48 . The method of  claim 42 , wherein varying the pressure of the electrolyte solution comprises increasing the pressure by about 5 to about 20 percent every 1 to about 30 seconds followed by decreasing the pressure by about 5 to about 20 percent every 1 to about 30 seconds.  
     
     
         49 . A method for chemical plating, comprising: 
 exposing a substrate surface to a vacuum that is sufficient to substantially remove gases from the substrate surface;    exposing the substrate surface to an electrolyte solution;    energizing one or more ultrasonic sources to agitate the electrolyte solution;    chemical plating a metal layer on at least a portion of the substrate surface at a variable pressure between about 1 atm and about 100 atm; and    draining the electrolyte solution from the enclosure.    
     
     
         50 . A method for chemical plating, comprising: 
 exposing a substrate surface to a vacuum that is sufficient to substantially remove gases from the substrate surface;    exposing the substrate surface to an electrolyte solution;    pressurizing the electrolyte solution; and    chemical plating a metal layer on at least a portion of the substrate surface.    
     
     
         51 . The method of  claim 50 , wherein pressurizing the electrolyte solution comprises increasing the pressure by about 5 to about 20 percent every 1 to about 30 seconds.  
     
     
         52 . The method of  claim 50 , further comprising decreasing the pressure of the electrolyte solution by about 5 to about 20 percent every 1 to about 30 seconds.  
     
     
         53 . The method of  claim 50 , wherein pressurizing the electrolyte solution comprises increasing the pressure by about 5 to about 20 percent every 1 to about 30 seconds followed by decreasing the pressure by about 5 to about 20 percent every 1 to about 30 seconds.  
     
     
         54 . The method of  claim 50 , wherein pressurizing the electrolyte solution increases a temperature of the electrolyte solution.  
     
     
         55 . The method of  claim 50 , further comprising compressing the electrolyte solution using a piston member.  
     
     
         56 . The method of  claim 55 , wherein compressing the electrolyte solution using a piston member pulsates the electrolyte solution across the substrate surface.  
     
     
         57 . The method of  claim 50 , further comprising energizing one or more ultrasonic sources to agitate the electrolyte solution.  
     
     
         58 . The method of  claim 50 , further comprising draining the electrolyte solution from the enclosure.  
     
     
         59 . A method for chemical plating, comprising: 
 exposing a substrate surface to a vacuum that is sufficient to substantially remove gases from the substrate surface;    exposing the substrate surface to an electrolyte solution;    energizing one or more ultrasonic sources to agitate the electrolyte solution; and    chemical plating a metal layer on at least a portion of the substrate surface.    
     
     
         60 . The method of  claim 59 , further comprising compressing the electrolyte solution using a piston member.  
     
     
         61 . The method of  claim 59 , further comprising pressurizing the electrolyte solution by increasing the pressure by about 5 to about 20 percent every 1 to about 30 seconds.  
     
     
         62 . The method of  claim 59 , further comprising varying a pressure of the electrolyte solution by increasing the pressure by about 5 to about 20 percent every 1 to about 30 seconds followed by decreasing the pressure by about 5 to about 20 percent every 1 to about 30 seconds.  
     
     
         63 . The method of  claim 59 , further comprising increasing a pressure of the electrolyte solution by heating the electrolyte solution.  
     
     
         64 . The method of  claim 59 , further comprising increasing a pressure of the electrolyte solution by heating the substrate surface.  
     
     
         65 . The method of  claim 63 , wherein the electrolyte solution is heated by the substrate surface.