Two Monte Carlo computer codes have been written to simulate the transmitted-, backscattered-, and secondary-electron signals from targets in a scanning electron microscope. The first discussed, MONSEL-II, is applied to semi-infinite lines produced lithographically on multi-layer substrates. The second discussed, MONSEL-III, is an extension to fully three-dimensional targets. Results are given for a 1 micrometer step etched in a silicon substrate and compared with experimental data. The comparisons show that it is possible to obtain edge locations to an uncertainty of less than 10 nm. Simulations are also given for photoresist lines on a silicon substrate coated with a layer of photoresist. Techniques are developed for simulating signals for finite beam diameter from those for zero beam diameter, and for extracting signals approximating zero beam diameter from those with finite beam diameter.
Proceedings Title: Proceedings of SPIE, Metrology, Inspection, and Process Control for Microlithography X, Susan K. Jones, Editor
Conference Location: Santa Clara, CA
Pub Type: Conferences