Method and device for detecting defects on wafer surface

A method for detecting defects on a wafer surface, the method comprising:

• receiving a plurality of partial images obtained by dividing a wafer into a plurality of partial regions and capturing the plurality of partial regions;
• determining a uniformity of contrast distribution for a first partial image among the plurality of partial images;
• performing image binarization on the first partial image when it is determined that the contrast distribution of the first partial image is uniform;
• performing image equalization on the first partial image when it is determined that the contrast distribution of the first partial image is non-uniform;
• performing edge detection and line detection on the first partial image to detect a first scratch in the first partial image;
• determining a uniformity of contrast distribution for a second partial image different from the first partial image among the plurality of partial images;
• performing the image binarization on the second partial image when it is determined that the contrast distribution of the second partial image is uniform;
• performing the image equalization on the second partial image when it is determined that the contrast distribution of the second partial image is non-uniform;
• performing the edge detection and the line detection on the second partial image to detect a second scratch in the second partial image;
• and
• detecting a scratch on the surface of the wafer by merging the first scratch and the second scratch.

A device which detects defects on a wafer surface, the device comprising:

• one or more processors;
• memory storing instructions that, when executed by the one or more processors, cause the device to:
• receive a wafer image obtained by capturing a wafer in a grayscale or monochromatic expression;
• determine a uniformity of the contrast distribution of the wafer image;
• detect n detailed regions separated within the wafer image and perform adaptive image binarization on the n detailed regions when the contrast distribution of the wafer image is determined to be uniform, wherein n is a natural number;
• detect m detailed regions separated within the wafer image and perform adaptive image equalization on the m detailed regions when the contrast distribution of the wafer image is determined to be non-uniform, wherein m is a natural number;
• perform edge detection on the wafer image to detect an edge pixel;
• and
• perform line detection on the wafer image based on the edge pixel to detect a scratch on the surface of the wafer.