Industry data suggests that Mask Inspection represents the second biggest component of Mask Cost and Mask Turn
Around Time (TAT). Ever decreasing defect size targets lead to more sensitive mask inspection across the chip, thus
generating too many defects. Hence, more operator time is being spent in analyzing and disposition of defects. Also, the
fact that multiple Mask Inspection Systems and Defect Analysis strategies would typically be in use in a Mask Shop or a
Wafer Foundry further complicates the situation. In this scenario, there is a need for a versatile, user friendly and
extensible Defect Analysis software that reduces operator analysis time and enables correct classification and disposition
of mask defects by providing intuitive visual and analysis aids.
We propose a new vendor-neutral defect analysis software, NxDAT, based on an open architecture. The open
architecture of NxDAT makes it easily extensible to support defect analysis for mask inspection systems from different
vendors. The capability to load results from mask inspection systems from different vendors either directly or through a
common interface enables the functionality of establishing correlation between inspections carried out by mask
inspection systems from different vendors. This capability of NxDAT enhances the effectiveness of defect analysis as it
directly addresses the real-life scenario where multiple types of mask inspection systems from different vendors co-exist
in mask shops or wafer foundries. The open architecture also potentially enables loading wafer inspection results as well
as loading data from other related tools such as Review Tools, Repair Tools, CD-SEM tools etc, and correlating them
with the corresponding mask inspection results.
A unique concept of Plug-In interface to NxDAT further enhances the openness of the architecture of NxDAT by
enabling end-users to add their own proprietary defect analysis and image processing algorithms. The plug-in interface
makes it possible for the end-users to make use of their collected knowledge through the years of experience in mask
inspection process by encapsulating the knowledge into software utilities and plugging them into NxDAT. The plug-in
interface is designed with the intent of enabling the pro-active mask defect analysis teams to build competitive
differentiation into their defect analysis process while protecting their knowledge internally within their company.
By providing interface with all major standard layout and mask data formats, NxDAT enables correlation of defect data
on reticles with design and mask databases, further extending the effectiveness of defect analysis for D2DB inspection.
NxDAT also includes many other advanced features for easy and fast navigation, visual display of defects, defect
selection, multi-tier classification, defect clustering and gridding, sophisticated CD and contact measurement analysis,
repeatability analysis such as adder analysis, defect trend, capture rate etc.