Method and system for on-line controlling of solder bump deposition

Abstract

By evaluating a dynamic failure signal, such as a voltage signal and/or a current signal, obtained during an electroplating operation for forming solder bumps, an inline control system with a responsiveness on a substrate basis may be established. Thus, the electroplating tool may be controlled on a single wafer basis to improve process uniformity and also significantly reduce yield loss.

1 . A method, comprising: 
 forming a plurality of bumps on a first substrate by an electrochemical deposition process in an electroplating tool;    obtaining a dynamic status signal during the processing of said first substrate, said dynamic status signal representing a dynamic behavior of at least one tool parameter during the electrochemical deposition process;    estimating a current tool status on the basis of said dynamic status signal; and    releasing said electroplating tool for forming a plurality of bumps on at least one subsequently processed substrate on the basis of said estimated tool status.    
   
   
       2 . The method of  claim 1 , wherein estimating said current tool status comprises providing reference data for at least one reference status of said electroplating tool and comparing said dynamic status signal of said first substrate with said reference data.  
   
   
       3 . The method of  claim 2 , wherein providing said reference data comprises defining one or more fault conditions for said at least one process parameter.  
   
   
       4 . The method of  claim 3 , wherein each fault condition is associated with a specific fault procedure for the further handling of the electroplating tool.  
   
   
       5 . The method of  claim 4 , wherein each fault procedure comprises establishing an updated tool status for the processing of said subsequent substrate by at least one of adapting at least one manipulated variable of a process recipe to be applied to said plurality of substrates and initiating a specific maintenance action.  
   
   
       6 . The method of  claim 1 , further comprising predicting an expected time to failure of at least one hardware component of said electroplating tool.  
   
   
       7 . The method of  claim 1 , wherein estimating said current tool status comprises extracting a plurality of key values from said dynamic status signal and comparing said key values with reference key values.  
   
   
       8 . The method of  claim 7 , wherein extracting said plurality of key values comprises processing raw data of said dynamic status signal by at least one of compressing said raw data and filtering said raw data.  
   
   
       9 . The method of  claim 8 , wherein at least some of said key values are directly calculated from said raw data.  
   
   
       10 . The method of  claim 1 , wherein said dynamic status signal represents a voltage signal obtained from an anode of said electroplating tool.  
   
   
       11 . The method of  claim 1 , wherein said dynamic status signal represents a current flowing through an anode of said electroplating tool.  
   
   
       12 . A method, comprising: 
 processing a first substrate in an electroplating tool that operates on a single substrate basis;    monitoring a failure status of said electroplating tool on the basis of a dynamic status signal obtained during the processing of said first substrate; and    comparing said failure status with at least one reference status prior to processing an additional substrate.    
   
   
       13 . The method of  claim 12 , further comprising at least one of releasing said electroplating tool for processing said additional substrate and initiating a maintenance action on the basis of said comparison.  
   
   
       14 . The method of  claim 12 , further comprising obtaining reference data and defining a plurality of reference statuses that represent one or more fault conditions for at least one tool parameter.  
   
   
       15 . The method of  claim 14 , wherein each fault condition is associated with a specific fault procedure for the further handling of the electroplating tool.  
   
   
       16 . The method of  claim 15 , wherein each fault procedure comprises establishing an updated tool status for the processing of said next substrate by at least one of adapting at least one manipulated variable of a process recipe to be applied to said plurality of substrates and initiating a specific maintenance action.  
   
   
       17 . The method of  claim 12 , further comprising predicting an expected time to failure of at least one hardware component of said electroplating tool on the basis of said failure status.  
   
   
       18 . The method of  claim 12 , wherein monitoring said failure status comprises extracting a plurality of key values from said dynamic status signal that represent said failure status.  
   
   
       19 . The method of  claim 18 , wherein extracting said plurality of key values comprises processing raw data of said dynamic status signal by at least one of compressing said raw data and filtering said raw data.  
   
   
       20 . The method of  claim 19 , wherein at least some of said key values are directly calculated from said raw data.  
   
   
       21 . The method of  claim 12 , wherein said dynamic status signal represents at least one of a voltage signal and a current signal obtained from an anode of said electroplating tool.  
   
   
       22 . The method of  claim 12 , wherein processing said substrate comprises forming a plurality of bumps above respective contact areas, said bumps being configured for a direct contact to contact regions of a carrier substrate.  
   
   
       23 . A system, comprising: 
 an electroplating tool having an anode assembly; and    a failure detection unit connected to said electroplating tool, said failure detection unit being configured to indicate a failure status of said electroplating tool for each process run on the basis of a dynamic status signal.    
   
   
       24 . The system of  claim 23 , wherein said dynamic status signal represents at least one of a voltage signal and a current signal obtained from said anode assembly of said electroplating tool.  
   
   
       25 . The system of  claim 24 , wherein said anode assembly comprises a plurality of anode segments and said dynamic status signal is obtained from each of said anode segments.  
   
   
       26 . The system of  claim 23 , further comprising a control unit operatively coupled to said electroplating tool and said failure detection unit, said control unit being configured to control operation of said electroplating tool on the basis of said failure status supplied by said failure detection unit.  
   
   
       27 . The system of  claim 26 , wherein said failure detection unit is further configured to indicate a type of maintenance action on the basis of said failure status so as to re-establish a valid tool status prior to starting a process run.