Tools to measure CD-SEM performance

It is important to be able to quantify the imaging performance of CD-SEMs for such purposes as verifying the specification, rechecking after a routine maintenance, or for tool matching. To perform tests such as these it is necessary to have both appropriate software for image analysis and suitable test samples. A package of 2-D Fourier transform and analysis software, designed as a plug-in for the shareware IMAGE-Java program, has been developed and is freely available on line. The requirement for a reproducible and well characterized sample has been met by using direct-write electron beam lithography to fabricate suitable Fresnel zone plate structures.