Determining a Position of a Defect in an Electron Beam Image

摘要

Methods and systems for determining a position of a defect in an electron beam image of a wafer are provided. One method includes determining a second position of a defect with respect to patterns imaged in a test image based on a first position of the defect in a difference image. The method also includes determining a third position of the defect with respect to the patterns in an electron beam image for the defect and determining an association between the first and third positions. In addition, the method includes determining a position of another defect in an electron beam image based on a first position of the other defect in a difference image and the determined association.

主权项

1. A system configured for determining a position of a defect in an electron beam image of a wafer, comprising:
an electron beam defect review subsystem comprising at least an electron beam source and a detector, wherein the electron beam source is configured to generate electrons that are directed to a wafer, and wherein the detector is configured to detect electrons from the wafer and to generate electron beam images responsive to the detected electrons; and a computer subsystem coupled to the electron beam defect review subsystem, wherein the computer subsystem comprises one or more processors that execute instructions from a memory medium, and wherein the computer subsystem is configured for:
determining a first position of a defect in a difference image generated for the wafer, wherein the difference image is generated by subtracting a reference image from a test image for an area on the wafer in which the defect is located, wherein the test image is generated for the wafer by an optical inspection system, and wherein the defect is detected on the wafer by the optical inspection system;determining a second position of the defect with respect to patterns formed on the wafer and imaged in the test image based on the first position of the defect in the difference image;determining a third position of the defect with respect to the patterns imaged in an electron beam image generated for the defect on the wafer by the electron beam defect review subsystem;determining an association between the first and third positions; anddetermining a position of another defect in an electron beam image generated for the other defect on the wafer by the electron beam defect review subsystem, wherein the position of the other defect is determined based on a first position of the other defect in another difference image generated for the wafer and the determined association, wherein the other defect is detected on the wafer by the optical inspection system, wherein the other difference image is generated by subtracting a reference image from a test image for an area on the wafer in which the other defect is located, and wherein the test image used to generate the other difference image is generated for the wafer by the optical inspection system.