Modeling the effect of defocus on the printability of submicrometer 5X reticle defects at g-line, i-line, and DUV wavelengths

Abstract

The effect of defocus on the printability of submicron 5X reticle defects at g-line, i-line and duv wavelengths is assessed. Imaging of a specifically designed test reticle incorporating defects whose size, and proximity to adjacent features, varies within submicron line/space arrays was studied using the simulation package SOLID. The results were assessed and initially presented by plotting minimum printed defect (MPD) vs. array linewidth (L/W) to compare with a previously reported practical study. Following this the results were replotted as curves of MPD vs. defocus at differing linewidth values. Finally, the resist modelling program has been used to create 3D images of the printed defects and thus demonstrate the effect caused by defocus on the resist profiles. Results on defect printability enable future reticle procurement specifications to be established.