Driving imaging and overlay performance to the limits with advanced lithography optimization

摘要

Immersion lithography is being extended to 22-nm and even below. Next to generic scanner system improvements,application specific solutions are needed to follow the requirements for CD control and overlay. Starting from theperformance budgets, this paper discusses how to improve (in volume manufacturing environment) CDU towards 1-nmand overlay towards 3-nm. The improvements are based on deploying the actuator capabilities of the immersion scanner.The latest generation immersion scanners have extended the correction capabilities for overlay and imaging, offeringfreeform adjustments of lens, illuminator and wafer grid. In order to determine the needed adjustments the recipegeneration per user application is based on a combination wafer metrology data and computational lithography methods.For overlay, focus and CD metrology we use an angle resolved optical scatterometer.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.