In-Line Optical Inspection System
The 2135/38 inspection systems are instrumental in nearly every modern fab for accelerating technology development and improving process yield. These systems, with their high-resolution brightfield inspection technology, enable accurate and consistent detection of all yield-relevant defect types on all process layers or current-generation devices. However, as design rules continue to shrink below 0.18 micron, wafer inspection systems must be capable of detecting ever smaller killer defects. Without the 2139 upgrade, achieving the required sensitivity for 0.18-micron inspection could mean running the inspection system at unacceptably low throughput. The 2139 systems incorporates a number of automation features and enhancements that improve the overall productivity of the tool, making it practical to use the highest sensitivity settings. The productivity features coupled with sensitivity enhancements enable IC manufacturers to inspect next-generation devices while reducing their overall cost of ownership.
The addition of numerous hardware and software features drive the 2139's new capabilities. All enhancements are based on a new user-friendly Windows NT operating system.
Featuring ultra-broadband (UBB) brightfield illumination and high numerical aperture (NA) optics, the 2139 extends raw sensitivity by up to 20 percent by introducing a new 0.16-micron pixel. Users can achieve additional sensitivity enhancement via the new AutoSAT feature. AutoSAT reduces the complexity and time associated with creating a SAT (Segmented Auto Threshold) inspection. Simplifying SAT setup increases the adoption of this powerful technology, which enables exceptional detection sensitivity on difficult-to-inspect layers that have process-induced noise such as color variation and grain. A new high-resolution camera and improved review optics provide higher sensitivity to critical defect types and improves the accuracy of automatic defect classification.
Productivity improvements include job queuing, fast edge-die inspection, and easy-to-use NT user interface and recipe management software. Job queuing improves tool utilization by up to 30 percent, thereby reducing tool idle time. Users can now set up one wafer lot while another lot is running. Fast edge-die inspection, referred to as MMED, enables edge-die inspection in a single pass. This improves full wafer inspection throughput by nearly 50 percent. The new NT user interface provides a number of ease-of-use features while maintaining the basic structure and flow of the previous interface, decreasing recipe setup time and minimizing the need for retraining. A new software module reduces the time to manage recipes, allowing more productive use of the inspection tool. Productivity is also improved by the reduced setup time enabled by AutoSAT and the 33 percent faster automatic defect classification enabled by improved review optics.
Also available on the 2139 is the company's RTC (Real Time Classification) solution, which classifies defects as the wafer is being inspected. RTC filters nuisance defects that have no impact on yield and reduces the number of defect samples that require subsequent high-resolution defect classification (HRDC) and costly scanning electron microscope (SEM) review.
KLA-Tencor Corporation, 160 Rio Robles, San Jose, CA 95134. Tel: 408-875-4200.