METHOD OF CORRECTING ELECTRON PROXIMITY EFFECTS USING VOIGT TYPE SCATTERING FUNCTIONS

摘要

The present invention particularly applies to methods for projecting electron beams used in lithography by direct or indirect recording as well as electron microscopy. Particularly for critical dimensions or resolutions below 50 nm, the proximity effect created by the forward and backward scattering of electrons in the electron beam in interaction with the target needs to be corrected. This is typically done using the target geometry and the convolution of the point intensity distribution function. In the prior art, this point intensity distribution function uses the Gaussian distribution law. According to the invention, at least one component of the components of the point intensity distribution function is a linear combination of functions approximating the fork function, such as the fork function and / or the Pearson VII function. In some embodiments, some of these functions are centered on the back scattering peak of the radiation .