Even with the increasing need for next-generation lithography, ArF lithography is still applied to the majority of critical layers. However, as wafer design shrinks, conventional 6% phase shift mask (PSM) becomes unable to sufficiently meet the lithography requirements for dense dot pattern compared to dense line pattern. To enhance ArF lithographic performances for dot pattern, high-transmission phase shift mask (High-T PSM) is attracting attention because the transmission of PSM has a significant impact on lithographic performances[1-4]. From the evaluation results of transmission dependency by mask 3D simulation, it was found that 30% transmission has the best lithographic performances for dot pattern. Based on these results, mask blank and mask making process for the new 30% PSM were developed. The result showed good cross-section profile, mask pattern resolution and defect repairability. In addition, the durability against chemical cleaning and ArF irradiation were also improved. Wafer printability test using negative tone development demonstrated that new PSM has advantages in process window and MEEF for dense dots (holes on wafer). Finally, the potential for further application of new 30% PSM was investigated by mask 3D simulation. The results showed that new 30% PSM has lithographic benefits not only for dense dots but also for other patterns. The new 30% PSM is a strong candidate capable of enhancing ArF lithographic performances for 5nm node or hp 1Xnm and beyond.
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