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ArF lithography is still applied to the majority of critical layers, even with increasing of extreme ultraviolet lithography in leading-edge production. As wafer design shrinks, conventional 6% phase shift mask (PSM) becomes hard to meet the ArF lithography requirements especially for array dot on mask (hole on wafer). Therefore, transmission dependency was evaluated by mask 3D simulation, and it was found that 30% transmission has the best lithographic performances for array dot. Based on these results, mask blank and mask making process for new 30% PSM were developed. Wafer printability test using negative tone development demonstrated that new 30% PSM has better process window and mask error enhancement factor (MEEF) than conventional 6% PSM for array dot (hole on wafer). To investigate further application of new 30% PSM, lithography performances of various patterns were evaluated by mask 3D simulation and aerial image measurement system (AIMSTM). The results indicated that new 30% PSM has larger lithography margin than 6% PSM for iso dot, iso line and logic pattern. Additionally, wafer printability test demonstrated that new 30% PSM has better process window than 6% PSM for iso dot. Defect control is also an important factor in high volume manufacturing. Therefore, it is necessary to evaluate the repairability and printability of the defects on new 30% PSM. We repaired various types of defects by electron-beam repair tool and confirmed the repairability by AIMS. And the defect printability of new 30% PSM and 6% PSM to critical dimension (CD) on wafer was evaluated by program defect mask that has pin dot, extrusion and intrusion defects.

Even with the increase in need for next-generation lithography, immersion ArF lithography is still applied to the majority of critical layers. However, as circuit designs shrink, conventional 6% phase-shift mask (PSM) will become difficult to meet the lithography requirements for dense dot pattern compared to dense line pattern. To enhance immersion ArF lithographic performances for dot pattern, high-transmission PSM (High-T PSM) is attracting attention because the transmission of PSM has a significant impact on lithographic performances. From results of transmission dependency evaluated by mask three-dimensional (3D) simulation, it was found that 30% transmission has the best lithographic performances for dense dot. Based on these results, mask blank and mask making process for the new 30% PSM were developed. The results 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 mask error enhancement factor for dense dots (holes on wafer). Finally, the potential for further application of new PSM was investigated by mask 3D simulation. The results showed that new PSM has lithographic benefits not only for dense dots but also other patterns.

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.