Multi-channel current probe

Abstract

A current probe for measuring electrodeposition plating currents. The current monitoring probe includes a conductive layer located on a front face of the current monitoring probe, an insulating layer behind the conductive layer, and a plurality of current sensing circuits located behind the insulating layer. The insulating layer isolates the current sensing circuits from the conductive layer. A plurality of apertures are formed through the conductive layer and the insulating layer, each aperture exposing one of the plurality of current sensing circuits to metal ions incident to the aperture.

1 . A current probe for measuring electrodeposition plating currents, the current probe comprising: 
 a conductive layer located on a front face of the current probe;    an insulating layer located adjacent to the conductive layer;    a plurality of current sensing circuits located adjacent to the insulating layer, wherein the insulating layer is located between the conductive layer and the plurality of current sensing circuits; and    a plurality of apertures formed through the conductive layer and the insulating layer, wherein each of the plurality of apertures exposes one of the plurality of current sensing circuits.    
   
   
       2 . The current probe of  claim 1 , wherein the plurality of current sensing circuits have equal overall resistance.  
   
   
       3 . The current probe of  claim 1 , wherein each of the plurality of current sensing circuits includes: 
 a current sensing area, a portion of which is exposed by one of the plurality of apertures formed through the conductive layer and the insulating layer; and    a conductive line connecting the current sensing area to a current or voltage measuring device.    
   
   
       4 . The current probe of  claim 3 , wherein each of the plurality of apertures exposes an equal amount of the current sensing area.  
   
   
       5 . The current probe of  claim 1 , including an epoxy layer formed adjacent to the plurality of current sensing circuits opposite the insulating layer, the epoxy layer located on a back face of the current probe.  
   
   
       6 . The current probe of  claim 1 , wherein the conductive layer consists of copper.  
   
   
       7 . The current probe of  claim 1 , wherein the insulation layer consists of polyimide.  
   
   
       8 . The current probe of  claim 3 , wherein the conductive line and the current sensing area of each of the plurality of current sensing circuits consists of copper.  
   
   
       9 . An electrodeposition measuring system, comprising: 
 a plating cell for holding a metal salt bath;    an electrode located in the plating cell;    a current probe having a plurality of current sensing circuits, wherein each of the plurality of current sensing circuits senses a local electrodeposition plating current; and    a computer system connected to the current probe that determines an electrodeposition plating thickness based on the local electrodeposition plating currents sensed by the plurality of current sensing circuits.    
   
   
       10 . The electrodeposition measuring system of  claim 9 , including: 
 a plurality of plastic baffles that are adjustable to alter the electrodeposition plating currents.    
   
   
       11 . The electrodeposition measuring system of  claim 9 , wherein the computer system further comprises: 
 a data acquisition board operatively connected to the current probe that converts electrodeposition plating currents sensed by the plurality of current sensing circuits to a plurality of digital values;    a computer operatively connected to the data acquisition board that receives the plurality of digital values provided by the data acquisition board; and    a monitor operatively connected to the computer for displaying the plurality of digital values provided to the computer.    
   
   
       12 . The electrodeposition measuring system of  claim 9 , wherein the current probe further comprises: 
 a conductive layer located on a front face of the current probe;    a insulating layer formed adjacent to the conductive layer; and    a plurality of apertures formed through the conductive layer and the insulating layer, wherein each of the plurality of apertures exposes one of the plurality of current sensing circuits to local electrodeposition plating currents generated between the electrode and the current probe.    
   
   
       13 . The electrodeposition measuring system of  claim 12 , wherein each of the plurality of current sensing circuits include: 
 a current sensing region, wherein a portion of the current sensing region is exposed to electrodeposition plating currents by one of the plurality of apertures formed through the conductive layer and the insulating layer; and    a conductive line connecting the current sensing region to a current measuring device, wherein local electrodeposition plating currents incident to the portion of the current sensing region exposed by one of the plurality of apertures is sensed by the current sensing region and provided by way of the conductive line to the current measuring device.    
   
   
       14 . The electrodeposition measuring system of  claim 13 , wherein each of the plurality of apertures exposes an equal amount of the current sensing regions of the plurality of current sensing circuits, wherein the amount of the current sensing region exposed and the current measured by each of the plurality of current sensing circuits allows local electrodeposition plating current density to be determined at each of the plurality of apertures.  
   
   
       15 . The electrodeposition measuring system of  claim 12 , wherein the current probe further comprises: 
 an epoxy layer formed adjacent to the plurality of current sensing circuits, the epoxy layer located on a back face of the current monitoring probe, wherein the epoxy layer prevents electrodeposition plating currents incident to the back face of the probe from affecting the current sensing circuits.    
   
   
       16 . A method of providing real time analysis of electrodeposition plating currents, the method comprising: 
 A. placing a multi-channel current probe in a plating cell;    B. generating an electrodeposition plating current;    C. measuring the electrodeposition plating current at a plurality of locations on the multi-channel current probe using a plurality of current sensing circuits; and    D. adjusting the distribution of the electrodeposition plating current based on the measurements taken.    
   
   
       17 . The method of  claim 16 , wherein steps C and D are repeated until the distribution of the electrodeposition plating currents reaches a threshold level of uniformity.  
   
   
       18 . The method of  claim 16 , wherein measuring the electrodeposition plating current includes determining electrodeposition plating current density based on the electrodeposition plating current measured and a surface area of a current sensing region exposed to the electrodeposition plating currents.  
   
   
       19 . The method of  claim 16 , wherein adjusting the distribution of the electrodeposition plating current based on the measurements taken includes adjusting a plurality of plastic baffles.  
   
   
       20 . The method of  claim 16 , wherein measuring the electrodeposition plating current includes: 
 sensing the electrodeposition plating currents at a plurality of current sensing regions;    providing the sensed electrodeposition plating currents to a data acquisition board via a plurality of conductive lines; and    converting the sensed electrodeposition plating currents provided to the data acquisition board to a plurality of digital values representative of the electrodeposition plating currents sensed at the plurality of current sensing regions.