According to the ’434 patent, previous phase-detection inspection systems for semiconductor manufacturing utilized the spatial fringe technique which is ”susceptible to system noise, has higher costs for image processing, and is limited by the sampling of the fringe.” The system disclosed by the ’434 patent seeks to improve the interferometric contrast between the defects and the non-defective portions of the specimen by using a test beam and a reference beam both reflected from the specimen.
According to its website, KLA-Tencor is “the world’s leading supplier of process control and yield management solutions for the semiconductor and related microelectronics industries.” KLA-Tencor’s VisEdge™ wafer edge inspection and metrology systems are touted as “utiliz[ing] innovative technology to meet edge-defect inspection and edge metrology requirements for development and volume production of wafers and ICs,” and includes “[e]nhanced performance on low-contrast films.” This description sounds like it could be referring to the invention of the ’434 patent.
In 2010, the company received 131 U.S. patents, and in 2009 received 118 U.S. patents. So far in 2011, KLA-Tencor has been awarded 47 U.S. patents, including the ’434 patent and U.S. Pat. No. 7,924,892 (“Fiber amplifier based light source for semiconductor inspection”), which was issued on the same day.