Comparison of PEC approaches for SCALPEL

SCALPEL is a projection electron lithography technology with resolution lim ited by aberrations and electron-electron interactions, not diffraction. Th e main CD control issue is adequate dose latitude, for image blur approachi ng the feature size in a high throughput scenario. This includes the effect of the unwanted electron back-scatter (EBS) proximity dose. Due to operati on at 100KeV, the back-scatter range is large (similar to 25 microns) and r esulting CD changes depend only on the density surroundings of a critical f eature. We compare mask pattern data biasing (adjustment of binary mask obj ect sizes) with our proposed GHOST scheme; both available as methods of pro ximity effect correction (PEC). We demonstrate data bias for a gate-level t est pattern with realistic features and density, using a very simple model. These CD control results are confirmed with CAPROX(TM), a complete device- pattern PEC calculation tool from Sigma-C.