Method To Control Semiconductor Device Overlay Using Post Etch Image Metrology

摘要

A method of determining positioning error between lithographically produced integrated circuit patterns on at least two different lithographic levels of a semiconductor wafer comprising. The method includes exposing, developing and etching one or more lithographic levels to create one or more groups of marks comprising a target at one or more wafer locations. The method then includes exposing and developing a subsequent group of marks within the target on a subsequent lithographic level. The method then comprises measuring the position of the marks on each level with respect to a common reference point, and using the measured positions of the groups of marks to determine the relative positioning error between one or more pairs of the developed and etched lithographic levels on which the marks are located.