CAD driven high precision E-beam positioning

To shorten the silicon debugging time of VLSI chips with design rules of 0.5 μ or less, an E-beam prober becomes an indispensable tool. However, the accuracy of E-beam positioning has to be greatly improved to the 0.1 μ level so the best waveform can be acquired. To achieve such high precision, we use image processing techniques to do pattern matching between the CAD layout database and the SEM image. We will discuss the methods to filter and segment the SEM image, the methods to do the registration between the CAD layout database and the SEM image, and the method for final beam positioning on the SEM image. We will also reveal some test results