HIGH ACCURACY BEAM PLACEMENT FOR LOCAL AREA NAVIGATION

摘要

An improved method of high accuracy beam placement for local area navigation in the field of semiconductor chip manufacturing. This invention demonstrates a method where high accuracy navigation to the site of interest within a relatively large local area (e.g. an area 200 µm x 200 µm) is possible even where the stage/navigation system is not normally capable of such high accuracy navigation. The combination of large area, high-resolution scanning, digital zoom and registration of the image to an idealized coordinate system enables navigation around a local area without relying on stage movements. Once the image is acquired any sample or beam drift will not affect the alignment. Preferred embodiments thus allow accurate navigation to a site on a sample with sub- 100 nm accuracy, even without a high-accuracy stage/navigation system.