| Popis: |
As reticle enhancement techniques (OPC, PSM) become more commonly used in multi-masking levels for 130nm node and below, the need for a better and more precise reticle specification will be even greater. OPC and sub-nominal assist feature like scattering bar represent a challenge for mask metrology tools. Consequentiy, defect inspection for advanced reticles has become a gating step for both Mask shops and Wafer Fabs alike. In this paper, a binary defect test reticle with and without OPC/SB features, manufactured by Dupont Photomask’s Reticle Technology Center, was used for the study. The reticle was made using the ALTA 3500 Laser Writer Tool and dry chrome etch process. Reticle inspection results from KLA363UV for 0. 13 um design rule patterns in both Clear and Dark polarities, with bump, divot and pinhole programmed defects between 0.1 and 0.6 um sizes (at 4x) were shown. These results were then compared to the wafer printability using ArF 193nm lithography. The impact of each defect type on 0.13 um Isolated, Semi-Dense and Dense lines was evaluated for 10% CD tolerance to provide an assessment on the KLA363UV inspection tool capability. A set of edge defects (bump and divot) and point defect (hole between line ends) from 0.1 to 0.6 um on the reticle (4x) were repaired using the Seiko SIR-3xxx tool at DPI-RTC. The printability of repairs on wafer at 193nm exposure wavelength was evaluated. CD of repaired features was compared to that of nominal feature for both reticle and resist wafer to evaluate the repair effectiveness. Finally, a defect specification for 0.13 um design rule binary reticle using ArF lithography is discussed. |
