Abbe offset reduction for a nanometre accurate moving scale measurement system

摘要

In this paper a method for aligning a moving scale measurement system to a point of interest with minimal Abbe offset is presented. A laser beam that is aligned with the point of interest is used as a reference for alignment. The position of this laser beam is measured by a combination of pinholes and photodiodes. An error budget has been made for this alignment method and it is evaluated by Monte Carlo simulations. Abbe offset can be reduced to 66μm, which results in a 5 nm Abbe error.