Company Filing History:
Years Active: 2009-2010
Title: Joan Williams Casey - Innovator in Photolithography Mask Repair
Introduction
Joan Williams Casey is a distinguished legal representative and inventor based in West Roxbury, MA. She has made significant contributions to the field of photolithography mask repair, holding a total of 3 patents. Her innovative work has advanced the technology used in the semiconductor industry.
Latest Patents
One of her latest patents focuses on electron beam processing for mask repair. This invention restores transmissivity to a gallium-stained substrate by directing an electron beam to the substrate in the presence of an etching gas. For higher concentrations of implanted gallium, transparency can be substantially restored without reducing the thickness of the substrate. For lower doses of implanted gallium, the transmission is restored to 100%, although the thickness of the substrate is reduced. This invention is particularly suitable for the repair of photolithography masks.
Another notable patent involves the repair of photolithography masks by creating structures that differ from the original design while producing the same aerial image. For instance, missing opaque material can be replaced by implanting gallium atoms to reduce transmission, and quartz can be etched to an appropriate depth to produce the proper phase. Additionally, a laser or other means can be used to remove an area of a mask around a defect, allowing for the construction of mask structures using charged particle beam deposition and etching.
Career Highlights
Joan works at Fei Company, where she continues to innovate and contribute to advancements in her field. Her expertise in electron beam processing and photolithography mask repair has positioned her as a key figure in the industry.
Collaborations
Joan collaborates with talented coworkers, including Diane Stewart and John Beaty, who contribute to her projects and enhance the innovative environment at Fei Company.
Conclusion
Joan Williams Casey is a remarkable inventor whose work in photolithography mask repair has made a significant impact on the semiconductor industry. Her patents reflect her dedication to innovation and her ability to solve complex challenges in technology.