Imaging study of positive and negative tone weak phase-shifted 65 nm node contacts

CPL TM and aerial image mapping type contact designs for both negative and positive tones were created, built and tested for 100 nm and sub-100 nm contacts. Experimental results illustrated the need for electromagnetic-field corrections in the simulations. Resolution down to 80nm dense contacts were seen with both negative and positive resists with acceptable process windows though some process optimization is still required as unacceptable CD variation and a reentrant profile was observed. High MEEF requires strict CD control on the mask. Data volume for the isolated contact designs can also challenge the mask build.