System and method for in-line metal profile measurement

Abstract

A system includes a measuring station for positioning an eddy current probe proximate to a substrate in a substrate holder. The probe can produce a time-varying magnetic field, in order to induce eddy currents in one or more conductive regions of a substrate either prior to or subsequent to polishing. The eddy current signals are detected, and may be used to update one or more polishing parameters for a chemical mechanical polishing system. The substrate holder may be located in a number places; for example, in a substrate transfer system, a factory interface module, a cleaner, or in a portion of the chemical mechanical polishing system away from the polishing stations. Additional probes may be used.

1 . A substrate processing system, comprising: 
 a processing module to process a substrate;    an interface module configured to accommodate at least one cassette for holding the substrate;    an eddy current monitoring system positioned in the interface module and configured to obtain information indicate of thickness of a conductive layer on the substrate;    a substrate transfer system configured to remove the substrate from and return the substrate to the at least one cassette, the substrate transfer system further configured to transfer the substrate to the eddy current monitoring system and to the processing module between removing the substrate from the at least one cassette and returning the substrate to the at least one cassette.    
   
   
       2 . The system of  claim 1 , wherein the processing module is a chemical mechanical processing module.  
   
   
       3 . The system of  claim 1 , wherein the system further includes an integrated cleaner, and wherein the substrate transfer system is configured to transfer the substrate from the process module to the integrated cleaner prior to returning the first substrate to the at least one cassette.  
   
   
       4 . The system of  claim 1 , wherein the eddy current monitoring system is configured to position the substrates substantially horizontally prior to obtaining the thickness data.  
   
   
       5 . The system of  claim 1 , wherein the eddy current monitoring system includes a probe and is configured to move the probe laterally across the surface of the substrate.  
   
   
       6 . The system of  claim 5 , wherein the eddy current monitoring system is configured to move the probe along a diameter of the substrate.  
   
   
       7 . The system of  claim 1 , wherein the substrate transfer mechanism is configured to transport a first substrate from the eddy current monitoring system to the processing module, and the eddy current monitoring system is configured to obtain information indicative of an initial thickness of a conductive layer on the first substrate, and wherein the system further comprises a controller configured to receive the information indicative of the initial thickness of the conductive layer on the first substrate, the controller further configured to determine process parameters for the processing module for the first substrate based on the information indicative of the thickness of the conductive layer of the first substrate.  
   
   
       8 . The system of  claim 1 , wherein the substrate transfer mechanism is configured to transport a first substrate from the processing module to the eddy current monitoring system, and the eddy current monitoring system is configured to obtain information indicative of an processed thickness of a conductive layer on the first substrate, and wherein the system further comprises a controller configured to receive the information indicative of the processed thickness of the conductive layer on the first substrate, the controller further configured to determine process parameters for the processing module for a subsequent substrate based on the information indicative of the thickness of the conductive layer of the first substrate.  
   
   
       9 . The system of  claim 1 , wherein the processing module is selected from the group consisting of a deposition module and an etch module.  
   
   
       10 . The system of  claim 1 , wherein the substrate transfer mechanism includes a factory interface robot to remove the substrate from and return the substrate to the at least one cassette.  
   
   
       11 . The system of  claim 10 , wherein the substrate transfer mechanism further includes a wet robot.  
   
   
       12 . A method of wafer processing, comprising: 
 removing a first substrate from one or more cassettes located in a interface module;    generating information indicative of a thickness of a conductive layer on the first substrate using an eddy current monitoring system which is positioned in the interface module;    transporting the first substrate to a processing module;    processing the first substrate in the processing module; and    returning the first substrate to the one or more cassettes.    
   
   
       13 . The method of  claim 12 , wherein processing the first substrate comprises polishing the first substrate.  
   
   
       14 . The method of  claim 12 , further comprising cleaning the first substrate after processing the first substrate and before returning the first substrate to the one or more cassettes.  
   
   
       15 . The method of  claim 12 , wherein the step of cleaning step is performed before the step of generating information.  
   
   
       16 . The method of  claim 13 , further comprising positioning the wafer substantially horizontally in the eddy current monitoring system while generating the information.  
   
   
       17 . The method of  claim 13 , wherein generating information includes scanning a probe along a diameter of the substrate.  
   
   
       18 . The method of  claim 13 , wherein the step of generating information is performed before the step of processing such that the information is indicative of an initial thickness of the conductive later, and the method further comprises determining processing parameters for the processing module for the first wafer based on the information.  
   
   
       19 . The method of  claim 13 , wherein the step of generating information is performed after the step of processing such that the information is indicative of a processed thickness of the conductive later, and the method further comprises determining processing parameters for the processing module for a subsequent wafer based on the information, and processing the subsequent wafer in the processing module using the processing parameters.  
   
   
       20 . The system of  claim 1 , wherein processing is selected from the group consisting of a depositing and etching.