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Product Briefing Outline: KLA-Tencor has launched its latest-generation optical CD metrology system, the SpectraCD-XT, which provides inline CD and profile measurements of critical device structures that help enable early prediction of IC performance and yield at the 90-nm and 65-nm nodes. The only high-performance spectroscopic ellipsometry (SE)-based CD metrology tool with sub-two-second move-acquire-measure (MAM) time, SpectraCD-XT provides a two-fold increase in throughput (to more than 100 wph) compared to the previous-generation platform at comparable performance, according to the company.

Problem: Chipmakers face shrinking process windows and tighter process tolerances as they scale to smaller design rules. As a result, minute lithography process variations can significantly impact device performance and functional yields. This drives the need for increased measurement sampling early in the manufacturing cycle with minimal impact to fab productivity. In addition to requiring standard CD linewidth information, increasing hidden systematic errors in lithography today mandate the need for 3D profile information on device structures, including sidewall angle, and top and bottom CD, to obtain yield-relevant data that provides better correlation to back-end-of-line (BEOL) device performance tests.

Solution: SpectraCD-XT with SE technology offers leading precision on advanced applications where device structures are highly complex and require multiple types of measurements, such as shallow trench isolation (STI), gate and spacer. Unlike reflectometry-based metrology systems, which provide near-normal incidence (top-down) illumination, KLA-Tencor's SE optics uses oblique illumination to enable the identification of smaller structural anomalies-such as notching and footing of gate profiles-that more accurately correlate to end-of-line device performance and yield. Emerging optical CD metrology applications include:  contact holes; BEOL trenches and vias; and scanner qualification, where the SpectraCD-XT's sub-two-second MAM time makes it an ideal solution for measuring the tens of thousands of points per wafer
needed to characterize cross-field and cross-wafer CD uniformity.

As CD process control budgets shrink, tool matching has become increasingly critical for device manufacturability. The SpectraCD-XT offers excellent matching performance, both tool-to-tool and with KLA-Tencor's integrated CD module, enabling chipmakers to implement a comprehensive fab-wide CD control strategy. Improved model setup and analysis tools embedded on the SpectraCD-XT speeds library generation by 30 to 60x-providing significant savings in time and engineering resources, which in turn, help enable faster yield learning on new technologies. The system is also built on a platform with proven reliability in high-volume production.


Applications: Shallow trench isolation (STI), gate and spacer.

Platform: The system is built on a platform with proven reliability in high-volume production. Improved model setup and analysis tools embedded on the SpectraCD-XT speeds library generation by 30 to 60x.

Availability: February 2006 onwards