Method & apparatus for monitoring plasma processing operations

Abstract

The invention generally relates to various aspects of a plasma process, and more specifically the monitoring of such plasma processes. One aspect relates in at least some manner to calibrating or initializing a plasma monitoring assembly. Another aspect relates in at least some manner to various types of evaluations which may be undertaken of a plasma process which was run, and more typically one which is currently being run, within the processing chamber. Yet another aspect associated with the present invention relates in at least some manner to the endpoint of a plasma process (e.g., plasma recipe, plasma clean, conditioning wafer operation) or discrete/discernible portion thereof (e.g., a plasma step of a multiple step plasma recipe). A final aspect associated with the present invention relates to how one or more of the above-noted aspects may be implemented into a semiconductor fabrication facility, such as the distribution of wafers to a wafer production system.

What is claimed is:  
     
         1 . A plasma monitoring system for a plasma process performed on a first product in a processing chamber, wherein said plasma process comprises first and second plasma steps, wherein a first endpoint of said first plasma step is when a first predetermined result of said first plasma step has been achieved on said first product, and wherein a second endpoint of said second plasma step is when a second predetermined result of said second plasma step has been achieved on said first product, wherein said second predetermined result is different from said first predetermined result, said system comprising: 
 a computer-readable storage medium comprising: 
 means for receiving data on said plasma process and including data on each of said first and second plasma steps;  
 means for identifying an occurrence of said first endpoint from data on said first plasma step provided to said means for receiving data; and  
 means for identifying an occurrence of said second endpoint from data on said second plasma step provided to said means for receiving data.  
   
     
     
         2 . A system, as claimed in  claim 1 , wherein: 
 said first product comprises at least one wafer.    
     
     
         3 . A system, as claimed in  claim 1 , wherein: 
 said means for receiving data comprises means for receiving data representative of optical emissions of said plasma in said processing chamber within a first wavelength range extending from about 250 nanometers to about 1,000 nanometers, from at least a plurality of different times during each of said first and second plasma steps, and at least at every 1 nanometer throughout said first wavelength range.    
     
     
         4 . A system, as claimed in  claim 3 , wherein: 
 a spacing between each pair of adjacent wavelengths obtained at each of said plurality of different times provided to said means for receiving is selected from the group consisting of equal spacings, unequal spacings, and a combination of equal spacings and unequal spacings.    
     
     
         5 . A system, as claimed in  claim 1 , wherein: 
 said means for identifying said first and second endpoints each comprise, and for said first and second plasma steps, respectively: 
 means for receiving data representative of optical emissions of said plasma in said processing chamber at least a plurality of different times during the respective said plasma step;  
 means for comparing said optical emissions at each of said plurality of different times with said optical emissions from an earlier of said plurality of different times; and  
 means for determining when said optical emissions from said means for comparing are within a predetermined amount of each other and equating this with the respective said endpoint.  
   
     
     
         6 . A system, as claimed in  claim 5 , wherein: 
 said means for comparing compares said optical emissions at a first time with said optical emissions from an immediately preceding time.    
     
     
         7 . A system, as claimed in  claim 5 , wherein: 
 said optical emissions from said means for receiving have an associated pattern, wherein said means for comparing comprises means for comparing said patterns of said optical emissions from said means for comparing, and wherein said predetermined amount of said means for determining defines when said patterns of said optical emissions from said means for comparing are considered a match.    
     
     
         8 . A system, as claimed in  claim 1 , wherein: 
 said means for identifying said first and second endpoints each comprise, and for said first and second plasma steps, respectively: 
 means for receiving data representative of optical emissions of said plasma in said processing chamber at a plurality of different times during the respective said plasma step;  
 means for comparing said optical emissions at each of said plurality of different times with at least one standard; and  
 means for determining when said optical emissions from at least one of said plurality of different times is within a predetermined amount of said at least one standard.  
   
     
     
         9 . A system, as claimed in  claim 8 , wherein: 
 said at least one standard is different for each of said first and second plasma steps, wherein said at least one standard associated with said first plasma step was obtained from a previous execution of the same said first plasma step in the same said processing chamber, and wherein said at least one standard associated with said second plasma step was obtained from a previous execution of the same said second plasma step in the same said processing chamber.    
     
     
         10 . A system, as claimed in  claim 8 , wherein: 
 said at least one standard associated with said first and second plasma steps, respectively, are stored on said computer-readable storage medium.    
     
     
         11 . A system, as claimed in  claim 8 , wherein: 
 said optical emissions from each of said plurality of different times have an associated pattern, wherein said at least one standard has a standard pattern, wherein said means for comparing comprises means for comparing said pattern of said optical emissions from each of said plurality of different times with said standard pattern, and wherein said predetermined amount of said means for determining defines when said patterns from said means for comparing are considered a match.    
     
     
         12 . A system, as claimed in  claim 1 , wherein: 
 said means for identifying said first endpoint comprises means for monitoring said first plasma step for an occurrence of said first endpoint using at least two different techniques, and wherein said first endpoint is identifiable by at least one of said at least two different techniques associated with said first endpoint; and    said means for identifying said second endpoint comprises means for monitoring said second plasma step for an occurrence of said second endpoint using at least two different techniques, and wherein said second endpoint is identifiable by at least one of said at least two techniques associated with said second endpoint.    
     
     
         13 . A system, as claimed in  claim 12 , wherein: 
 said at least two different techniques associated with said first and second endpoints, respectively, are each selected from the group consisting of means for determining when there is at least a first change in an impedance of said processing chamber, means for evaluating optical emissions of said plasma in said processing chamber over a first wavelength range at least a plurality of times during the respective said plasma step, and means for evaluating at least one individual wavelength of said plasma in said processing chamber at least a plurality of times during the respective said plasma step.    
     
     
         14 . A system, as claimed in  claim 1 , wherein: 
 said means for identifying said first and second endpoints each comprises means for determining if there is at least a first change in an impedance of said processing chamber.    
     
     
         15 . A system, as claimed in  claim 14 , wherein: 
 said means for determining is based upon a change in at least a portion of optical emissions of said plasma in said processing chamber during the respective said plasma step.    
     
     
         16 . A system, as claimed in  claim 1 , wherein: 
 said means for identifying said first and second endpoints each comprise means for evaluating at least one individual wavelength of said plasma in said processing chamber at least a plurality of times during the respective said plasma step.    
     
     
         17 . A method, as claimed in  claim 16 , wherein: 
 said means for evaluating at least one individual wavelength comprises using a technique selected from the group consisting of means for determining when a plot of intensity versus time of said at least one individual wavelength deviates by more than a predetermined amount from a predetermined equation, means for determining when a time rate of change of a slope of said plot of intensity versus time of said at least one individual wavelength deviates by more than a predetermined amount, and combinations thereof.    
     
     
         18 . A system, as claimed in  claim 16 , wherein: 
 said means for evaluating at least one individual wavelength comprises using a technique selected from the group consisting of means for determining when a plot of intensity versus time of said at least one individual wavelength deviates by more than a predetermined amount from a predetermined function, means for determining when an output of a first derivative of said predetermined function deviates by more than a predetermined amount, means for determining when an output of a second derivative of said predetermined function deviates by more than a predetermined amount, and combinations thereof.    
     
     
         19 . A method, as claimed in  claim 16 , wherein: 
 said at least one individual wavelength associated with said first and second endpoints are different.    
     
     
         20 . A system, as claimed in  claim 1 , wherein said computer-readable storage medium further comprises: 
 means for evaluating a condition of said plasma during each of said first and second plasma steps from data on said first and second plasma steps, respectively, provided to said means for receiving data, wherein said condition is a cumulative result of all parameters having an effect on said plasma in said processing chamber.    
     
     
         21 . A system for running a plasma process on a first product in a processing chamber, wherein said plasma process comprises first and second plasma steps, wherein a first endpoint of said first plasma step is when a first predetermined result of said first plasma step has been achieved on said first product, and wherein a second endpoint of said second plasma step is when a second predetermined result of said second plasma step has been achieved on said first product, wherein said second predetermined result is different from said first predetermined result, said system comprising: 
 a processing chamber comprising a product access and a window, wherein product may be transferred between an interior and exterior of said processing chamber through said product access;    a first gas inlet and a first gas outlet fluidly interconnected with said processing chamber;    a plasma generator in said plasma chamber, wherein said first and second plasma steps may be run on said first product in said processing chamber after activation of said plasma generator; and    a computer-readable storage medium comprising: 
 means for identifying when said first endpoint of said first plasma step has occurred; and  
 means for identifying when said second endpoint of said second plasma step has occurred.