Method and apparatus for inspecting pattern defects

An apparatus for inspecting pattern defects, the apparatus comprising:

• an image acquisition means which picks up an image of an inspection target, acquires a detected image signal and a reference image signal, and stores the acquired signals in an image memory;
• a defect candidate extraction unit which extracts defect candidate by comparing the detected image signal with the reference image signal, which are read from said image memory, and performs a process for storing in a memory a partial image containing the extracted defect candidate;
• and
• a defect detection unit which performs a defect detection process and a defect classification process based on a partial image containing a defect candidate that is read from said memory,
• wherein the process performed by said defect detection unit, the process performed by said defect candidate extraction unit, and an image acquisition process that is performed by said image acquisition means are performed asynchronously with each other.

A method for inspecting pattern defects, the method comprising:

• an image acquisition step of picking up the image of an inspection target, acquiring a detected image signal and a reference image signal, and storing the acquired signals in an image memory;
• a defect candidate extraction step of performing a defect candidate extraction process by comparing the detected image signal with the reference image signal, which are read from said image memory;
• and
• a defect detection step of performing a defect detection process and a defect classification process based on a partial image containing a defect candidate that is extracted in said defect candidate extraction step,
• wherein the processes performed in said defect candidate extraction step and/or said defect detection step are performed asynchronously with an image acquisition process that is performed in said image acquisition step.

A method for inspecting pattern defects, the method comprising:

• an image acquisition step of acquiring a detected image signal and a reference image signal from an inspection target, and storing the acquired signals in an image memory;
• a defect candidate extraction step of extracting defect candidates by comparing the detected image signal with the reference image signal, which are read from said image memory, and performing a process for storing in a memory a partial image containing the extracted defect candidate;
• and
• a defect detection step of performing a defect detection process and a defect classification process based on the partial image containing the defect candidate that is read from said memory,
• wherein the process performed in said defect detection step, the process performed in said defect candidate extraction step, and an image acquisition process that is performed in said image acquisition step are performed asynchronously with each other.