Combinational optical rule check on hotspot detection
The Calibre OPCverify tool can use additional limiters such as max intensity, contrast, and NILS checks in combination with normal CD-based checks such as bridge, pinch, or process window bands to achieve higher accuracy in failure locations.
Finding the true on-product hot spots (patterning defects) by high volume manufacturing inspection tools is increasingly challenging. Using optical rule checks is common, but may not be good enough. We propose a method of using addition limiters to achieve higher accuracy.