January 1, 2001
      
                  
        
  Author(s)
  Richard M. Silver,   Jay S. Jun,   S  Fox,   Edward A. Kornegay
 
       
            
    
    
        As devices shrink and clock speeds continue to increase, process control and measurement of I critical dimension linewidths and the essential overlay of features from different photolithographic levels become increasingly important. Improved manufacturing