Company Filing History:
Years Active: 2008-2013
Title: Innovations by Yongdong Liu
Introduction
Yongdong Liu is a prominent inventor based in Cupertino, CA, known for his contributions to optical metrology and measurement technologies. With a total of 2 patents, Liu has made significant advancements in the field, particularly in the area of asymmetry metrology and focus calibration.
Latest Patents
Liu's latest patents include innovative methods for scatterometry measurement of asymmetric structures. This technique utilizes Mueller matrix elements, including off-diagonal elements, to perform asymmetry metrology. The Mueller matrix can be generated using a spectroscopic or angle-resolved ellipsometer equipped with a rotating compensator. By analyzing the Mueller matrix elements, Liu's method allows for overlay analysis using in-chip devices, eliminating the need for special off-chip targets.
Another notable patent focuses on the correction of optical metrology for focus offset. This metrology system is designed to perform optical measurements while accommodating a sample with an unknown focus offset. Liu's approach involves fitting for the focus offset through model regression analysis, allowing for real-time adjustments based on the optical response of the metrology device. This innovative method enhances the accuracy of measurements and can store adjusted modeled data in a library for future reference.
Career Highlights
Yongdong Liu is currently employed at Nanometrics Inc., where he continues to develop cutting-edge technologies in optical metrology. His work has significantly impacted the industry, providing solutions that enhance measurement accuracy and efficiency.
Collaborations
Throughout his career, Liu has collaborated with notable colleagues, including Silvio J Rabello and William A McGahan. These partnerships have fostered innovation and contributed to the advancement of metrology technologies.
Conclusion
Yongdong Liu's contributions to the field of optical metrology through his patents and work at Nanometrics Inc. highlight his role as a leading inventor in the industry. His innovative approaches to measurement technologies continue to shape the future of metrology.