Phase-shift mask pattern accuracy requirements and inspection technology

摘要

Computer simulations and i-line phase shift lithography experiments with programmed 5$MUL phase shift reticle defects were used to investigate the effect of opaque and phase-shift layer defects on sub-half-micron lines. Both the simulations and the experiments show that defects in the phase shift layer print larger than corresponding opaque defects, with 0.3-0.4 $mu@m defects affecting sub-half-micron critical dimensions by more than the allowable 10%. Inspection of programmed phase shift defects with a prototype mask inspection system confirmed that the system finds the 0.3-0.4 $mu@m phase shift defects critical to sub-half-micron lithography.