Product Briefing Outline: KLA-Tencor has announced XP, a new upgrade package for 28xx broadband brightfield inspection systems. The XP package is the first commercially available product to give an inspection system access to standard IC design layout files. With access to this information, the inspection system can use knowledge of the defect’s location within the circuit to better estimate its probability of affecting device yield. In addition, XP can use the results of the design-aware wafer inspection to identify features on the mask that may be particularly sensitive to process variations during printing. These and other features of the XP upgrade package are designed to improve the sensitivity and productivity of existing 28xx inspectors and raise the information content of defect results, helping to accelerate identification and resolution of defect issues.
Problem: As chip complexity and price pressure increase in our consumer-driven markets, engineers are asking for tools to facilitate root-cause defect analysis, improve their productivity, and effect faster, more efficient ramps. Today leading-edge fabs have to cope with advanced lithography techniques that enable 193nm ArF lithography to print features with dimensions nearly one-tenth the illumination wavelength, dimensions that can now be measured in countable atoms. In this environment, even the smallest defect on a wafer or marginal pattern on a mask can have an enormous yield impact.
Solution: The new XP package includes several features designed to improve inspection results or inspector productivity, including: Preferential capture of yield-relevant defects — during inspection — based on the density of the circuit pattern at the defect site;
Optimization of defect capture throughout all areas of interest within the die by using circuit design information to set highly localized defect detection thresholds according to pattern group; Early detection of marginal lithography conditions, enabled by close monitoring of pattern types having the smallest process margins; and Offline generation of derivative “recipes” — the optical, mechanical and algorithm parameters settings that govern the inspection — for new layers or new devices. This feature, one of several recipe acceleration features, can significantly reduce time and labor required for recipe setup, thereby increasing inspector productivity and making recipe optimization feasible even for small lots or rapid prototyping of devices.
Applications: Defect inspection of photomasks.
Platform: Offered as an upgrade to the 281x and 282x brightfield inspection systems, the XP package has been shipped to multiple foundry, memory and logic fabs.
Availability: July 2009 onwards.