Optimization of an advanced positive DUV resist for 248 nm L S pattern printing

This paper reports on the results of a NA-sigma optimization study of an ad vanced positive DUV photoresist, AZO DX 2058P, on silicon substrate. The co ntribution starts with the dose-to-clear (Eo) swing curve on silicon and co ntinues with a resist thickness selection (E-max and E-min) according to th is swing curve. Dose-to-print versus dose-to-clear ratio is in the region o f 2.4. Process windows with regard to dense (1:1 L/S) versus isolated CD 0. 20 and 0.175 mu m patterns are determined and compared via top-down SEM ana lysis. Different NA and sigma settings are used in order to optimize the in dividual and overlapping process latitudes (exposure latitude, EL, and dept h-of-focus, DOF). Cross-section SEM pictures will support the results.