Fogging effect correction method in high-resolution electron beam lithography

We report on a fogging effect correction (FEC) method to be used in high-resolution e-beam lithography (EBL). In the new version of the previously presented PROX-In software tool, originally developed to determine the numerical proximity parameters for the proximity effect correction (PEC), was now implemented also the possibility of correcting large-range pattern distortion effects in connection with the modified PROXECCOTM tool from PDF Solutions. This allows a complex exposure optimization by dose modulation of long-range fogging and/or loading effects with the standard PEC method using the same corrector. The presented approach is fast and effective, does not use any special additional technology steps and uses only standard high-resolution measuring techniques. The reviewed method was successfully implemented into mask production at different absorber stacks. It is also used for the determination of FEC input parameters and complex exposure optimization in e-beam direct write and step and flash imprint lithography (SFIL) template manufacturing with sub-50 nm resolution capability.