P4-13: 50 keV Electrons energy loss distribution in multi-layer targets

In shaped-beam lithography tools, a 50 keV electron beam is incident upon structures consisting of thin layers of resist and metal on the top of a massive silicon or quartz substrate. The desired result, resist exposure, is achieved by primary and secondary electrons losing energy in inelastic collisions with resist molecules. The exposure resolution depends on the electron energy loss distribution in the resist. We have modeled electron scattering in the mask with MONSEL software and developed an algorithm for extracting the energy loss distribution. Results obtained are in agreement with known resist exposure data.