Complex, high-volume semiconductor manufacturing processes require advanced optical and EUV reticles. These reticles must be error-free, as reticle defects or pattern placement errors can be replicated in many die on production wafers, dramatically driving down semiconductor device yield. Multiple reticle inspection, metrology and review steps are needed during mask manufacturing to identify the reticle defects and pattern variations that could lead to yield loss. The challenge lies with how to distill this diverse and plentiful data to actionable results so that mask shop engineers can make appropriate process corrections or accurately disposition reticles. The KlearView™ centralized mask database solution, hosted on KLA’s Reticle Decision Center (RDC) platform, addresses this challenge by providing a robust application with an intuitive interface that helps engineers easily visualize reticle data.

Data Centralization. The range of process control tools used to qualify reticles generates multiple formats of raw data. A mask shop’s Data Management System (DMS) must utilize this data efficiently to reduce development cycle time, increase reticle manufacturing productivity, yield and quality. KlearView’s data consolidation enables engineers to optimize their process. Data in many different formats from production tools and manufacturing databases is imported and converted to a common format, which is centrally stored in the state-of-the-art database. This data consolidation step gives mask shops the flexibility required to take a more global view of their data.

Common Reviewer. The most devastating excursions related to reticle manufacture can include defects that were found at steps late in the process. These are most difficult to trace when there are no measurements between steps. KlearView’s centralized data management and advanced analytics enable engineers to carry out the advanced defect source analysis and cross-process correlation required to identify the root cause early. With defect data from all pattern and blank inspectors in one location, the common defect viewer makes it easy for operators to make decisions. Simultaneous views of reticle inspection, SEM review and design data allow for comprehensive defect dispositioning.

DSA and Overlay Analytics. Defect Source Analysis (DSA) displays all data associated with a defect to determine whether the defect showed up in an earlier inspection. DSA can be used to identify trends in outgoing quality control (OQC) and reticle requalification inspection, for example, finding haze growth at the site of what was identified as a nuisance defect at a previous inspection. By combining with Klarity^® Defect in the IC fab, KlearView DSA can perform wafer-to-reticle (W2R) mapping and repeater defect analysis in the mask shop. The W2R feature converts full wafer inspections to mask field view, which is used to match wafer-repeating defects to reticle defects. KlearView also includes an overlay analysis feature, providing a gallery view of all inspection, metrology and review data for a given reticle to help identify reticle anomaly progression.

Query and Report. Combining manufacturing database queries with KlearView’s integrated database gives reticle and IC manufacturers the capability to generate comprehensive defect reports and carry out detailed analyses of defects common to different inspection steps.

To learn more about how KlearView facilitates overall mask performance characterization, check out presentation 11518-21 in Session 9 of SPIE’s Photomask Technology and EUV Lithography digital forum.