Design Based Sampling and Binning for Yield Critical Defects

Abstract

Methods and systems for design based sampling and binning for yield critical defects are provided. One method includes aligning each image patch in each inspection image frame generated for a wafer by an optical subsystem of an inspection system to design information for the wafer. The method also includes deriving multiple layer design attributes at locations of defects detected in the image patches. In addition, the method includes building a decision tree with the multiple layer design attributes. The decision tree is used to separate the defects into bins with different yield impacts on a device being formed on the wafer. The method also includes binning the defects with the decision tree.

What is claimed is: 
     
         1 . A wafer inspection system, comprising:
 an optical subsystem configured to scan a wafer thereby generating image patches in inspection image frames for the wafer; and   one or more computer subsystems coupled to the optical subsystem, wherein the one or more computer subsystems are configured for:
 aligning each of the image patches in each of the inspection image frames to design information for the wafer; 
 detecting defects in the image patches; 
 deriving multiple layer design attributes at locations of the defects from the image patches corresponding to the locations of the defects; 
 building a decision tree with the multiple layer design attributes, wherein the decision tree is used to separate the defects into bins with different yield impacts on a device being formed on the wafer; and 
 binning the defects with the decision tree.