Applied Materials, Inc.

Gad Greenberg

Yair Eran

Ami Sade

Shirley Hemar

Amnon Joseph

A method and apparatus for inspecting a reticle measures line widths using an inspection tool that images the reticle and compares the image with a design database to detect errors in real time. The differences between the line widths of patterns on the reticle and the design database are stored during the inspection procedure. The difference (or 'bias') information is then processed off-line to create a map of all the local line-width deviation values (i.e., bias) of every feature on the reticle. The resultant local bias map can be used as a feedback mechanism to improve the reticle manufacturing process, as a 'go/no go' criteria for the validity of the reticle, and as a standard report shipped together with the mask to the wafer fabrication facility, where it can be used as a yield-enhancing tool.

Local bias map using line width measurements

In a system for real-time inspection of patterns formed on a base, the pattern including surfaces and edges. The system provides for a detector that includes: (i) two input channels for receiving streams of pixels representing the patterns. Each pixel representing the surface and/or edge of the pattern in sub-pixel boundary, (ii) two line width measurement devices being responsive to the streams of pixels for processing in real time the pixels in a manner that corresponds to a predetermined direction in the patterns, so as to measure, in sub-pixel boundary, line width data between two edges. This measurement is effected by executing the following steps: (i) detecting an opening edge, (ii) successively updating line width; and (iii) providing a line width measurement in response to detecting a closing edge. The detector further includes comparator being responsive to the line width data delivered from the two line width measurement devices, for comparing the line width data and obtaining difference between them, so as to generate a defect.backslash.no defect indication depending upon the difference.

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Tel Aviv, Israel

Gad Greenberg