A golden-template self-generating method for patterned wafer inspection

This paper presents a novel golden-template self-generating technique for detecting possible defects in periodic two-dimensional wafer images. A golden template of the patterned wafer image under inspection can be obtained from the wafer image itself and no other prior knowledge is needed. It is a bridge between the existing self-reference methods and image-to-image reference methods. Spectral estimation is used in the first step to derive the periods of repeating patterns in both di r ections. Then a building block representing the structure of the patterns is extracted using interpolation to obtain sub-pixel resolution. After that, a new defect-free golden template is built based on the extracted building block. Finally, a pixel-to-pixel comparison is all we need to find possible defects. A comparison between the results of the proposed method and those of the previously published methods is presented. Received: 19 May 1999 / Accepted: 20 May 2000