Apparatus for direct plating on resistive liners

Abstract

An apparatus for direct electroplating of a conductive material, such as copper, on resistive liners or substrates is provided. The apparatus includes an integrated in-situ measuring system to follow the actual progress of the front of the conductive material during plating. Feed-back of this information to a power supply allows for more precise control of the effective current density during plating.

1 . An apparatus for electroplating a conductive material on a resistive liner or substrate comprising: 
 (a) at least one auxiliary electrode, wherein the at least one auxiliary electrode provides a counter electrode to the liner or substrate, wherein the liner or substrate acts as a first electrode;    (b) a programmable power supply providing for the: 
 (i) generation of a current between the at least one auxiliary electrode and the liner or substrate, allowing for the conductive material to be electroplated onto the liner or substrate; and  
 (ii) adjustment of the current as a function of the change in the area of the conductive material as it is electroplated on the liner or substrate;  
   (c) a measuring device to detect the propagation of the front of the electroplated material over the surface of the said resistive liner or substrate; and    (d) a computer to process the output of the measuring device and calculate a new current to be applied by the programmable power supply as a function of the output of the measuring device.    
   
   
       2 . The apparatus of  claim 1 , wherein the measuring device comprises at least one reference electrode.  
   
   
       3 . The apparatus of  claim 2 , wherein the reference electrode is selected from the group consisting of Calomel, mercury sulfate, silver and silver/silver chloride.  
   
   
       4 . The apparatus of  claim 1 , wherein the measuring device comprises an array of reference electrodes positioned along the substrate surface.  
   
   
       5 . The apparatus of  claim 4 , wherein the reference electrodes are selected from the group consisting of Calomel, mercury sulfate, silver and silver/silver chloride, and combinations thereof.  
   
   
       6 . The apparatus of  claim 1 , wherein the measuring device comprises at least one light source and at least one photodiode to measure the reflectivity of the at least one light source.  
   
   
       7 . The apparatus of  claim 6 , wherein the light source comprises a laser or an array of light emitting diodes.  
   
   
       8 . The apparatus of  claim 1 , wherein the measuring device comprises an alternating current or voltage source.  
   
   
       9 . The apparatus of  claim 8 , wherein the measuring device further comprises an impedance analyzer selected from the group consisting of a frequency response analyzer and a lock-in amplifier.  
   
   
       10 . The apparatus of  claim 1 , wherein the measuring device comprised at least one Eddy-current inducing and sensing device.  
   
   
       11 . The apparatus of  claim 1 , wherein the conductive material comprises copper.  
   
   
       12 . The apparatus of  claim 1 , wherein the liner or substrate comprises a resistive metal selected from the group consisting of tantalum, tantalum nitride, titanium, titanium nitride, tungsten, tungsten nitride, ruthenium, rhenium, cobalt, molybdenum, chromium, indium, platinum, gold, thallium, lead, bismuth, vanadium, cobalt, iron, nickel, copper, aluminum, silicon, carbon, germanium, gallium, arsenic, selenium, rubidium, strontium, yttrium, zirconium, niobium, rhodium, palladium, silver, cadmium, tin, antimony, tellerium, hafnium, and osmium, and mixtures, alloys, and multilayers of the same.  
   
   
       13 . The apparatus of  claim 1 , wherein the current has a density ranging from about 10 μA/cm 2  to about 100 mA/cm 2 .  
   
   
       14 . The apparatus of  claim 1 , wherein the conductive material has a final thickness ranging from about 0.3 microns to about 10 micron.  
   
   
       15 . A method for electroplating a conductive material on a liner or substrate comprising using the apparatus of  claim 1 .  
   
   
       16 . The method of  claim 15 , wherein the measuring device comprises a reference electrode.  
   
   
       17 . The method of  claim 16 , wherein the reference electrode is selected from the group consisting of Calomel, mercury sulfate, silver and silver/silver chloride.  
   
   
       18 . The method of  claim 15 , wherein the measuring device comprises at least one light source and at least one photodiode to measure the reflectivity of the at least one light source.  
   
   
       19 . The method of  claim 18 , wherein the light source comprises a laser or an array of light emitting diodes.  
   
   
       20 . The method of  claim 15 , wherein the measuring device comprises an alternating current source.  
   
   
       21 . The method of  claim 20 , wherein the measuring device further comprises an analyzer selected from the group consisting of an impedance analyzer and a lock-in amplifier.  
   
   
       22 . The method of  claim 15 , wherein the measuring device measures an Eddy-current.  
   
   
       23 . The method of  claim 15 , wherein the conductive material comprises copper.  
   
   
       24 . The method of  claim 15 , wherein the liner or substrate comprises a resistive metal selected from the group consisting of tantalum, tantalum nitride, titanium, titanium nitride, tungsten, tungsten nitride, ruthenium, rhenium, cobalt, molybdenum, chromium, indium, platinum, gold, thallium lead, bismuth, vanadium, chromium, cobalt, iron, nickel, copper, aluminum, silicon, carbon, germanium, gallium, arsenic, selenium, rubidium, strontium, yttrium, zirconium, niobium, rhodium, palladium, silver, cadmium, tin, antimony, tellerium, hafnium, and osmium, and mixtures, alloys, and multilayers of the same.  
   
   
       25 . The method of  claim 15 , wherein the current has a density ranging from about 10 μA/cm 2  to about 100 mA/cm 2 .  
   
   
       26 . The method of  claim 15 , wherein the conductive material has a final thickness ranging from about 0.3 microns to about 1 micron.