Multi-parameter process and control method

Abstract

A method and system for generating control settings for a multi-parameter control system. The interdependencies of processing tools and the related effect on semiconductor wafers within a processing tool is factored into a mathematical model that considers desired and measured wafer quality parameters in the derivation of specific solutions of sets of possible quality parameter adjustments. A selection process determines a set of adjustments such as one that results in minimal changes to the process.

1 . A method for generating temperature control settings for a multi-zone semiconductor furnace, comprising: 
 measuring a measured film thickness change from a semiconductor wafer from each zone of said multi-zone semiconductor furnace; and    calculating temperature control settings for each zone of said multi-zone semiconductor furnace from a preferred set of temperature adjustments derived from said measured film thickness change and a desired film thickness change for each zone.    
   
   
       2 . The method, as recited in  claim 1 , wherein measuring a measured film thickness change is performed in situ.  
   
   
       3 . The method, as recited in  claim 1 , wherein measuring a measured film thickness change is performed ex situ.  
   
   
       4 . The method, as recited in  claim 1 , wherein calculating at least one set of temperature adjustments further includes modeling said measured film thickness change for each of said zones as a function of a temperature change from all of said zones of said multi-zone semiconductor furnace.  
   
   
       5 . The method, as recited in  claim 1 , wherein calculating at least one set of temperature adjustments includes calculating said at least one set of temperature adjustments from polynomial equations approximating transfer functions in which said measured film thickness change in each zone depends on each temperature change from all zones of said multi-zone semiconductor furnace.  
   
   
       6 . The method, as recited in  claim 1 , wherein selecting a preferred set of temperature adjustments comprise selecting said preferred set of temperature adjustments as one of said at least one set of temperature adjustments conforming to a predetermined criterion.  
   
   
       7 . The method, as recited in  claim 6 , wherein said predetermined criterion is a set of temperature adjustments having a smallest sum.  
   
   
       8 . The method, as recited in  claim 7 , wherein said smallest sum is a weighted smallest sum.  
   
   
       9 . The method, as recited in  claim 1 , further comprising applying a filter to said measured film thickness change to mitigate derived process and measurement noise.  
   
   
       10 . The method, as recited in  claim 1 , further comprising applying a filter to said temperature control settings to mitigate derived process and control noise.