Method and apparatus for inspection of scattered hot spot areas on a manufactured substrate

摘要

One embodiment relates to a method of automated inspection of scattered hot spot areas on a manufactured substrate using an electron beam apparatus. A stage holding the substrate is moved along a swath path so as to move a field of view of the electron beam apparatus such that the moving field of view covers a target area on the substrate. Off-axis imaging of the hot spot areas within the moving field of view is performed. A number of hot spot areas within the moving field of view may be determined, and the speed of the stage movement may be adjusted based on the number of hot spot areas within the moving field of view. Another embodiment relates to an electron beam apparatus for inspecting scattered areas on a manufactured substrate. Other embodiments, aspects and features are also disclosed.

主权项

1. A method of automated inspection of scattered hot spot areas on a manufactured substrate using an electron beam apparatus, the method comprising:
moving a stage holding the substrate at variable speed along a swath path so as to move a field of view of the electron beam apparatus such that the moving field of view covers with dynamically varying speed a target area on the substrate, wherein the swath path is fixed in that the swath path does not vary depending on locations of the hot spot areas; and off-axis imaging of the hot spot areas within the moving field of view while the stage continues moving without deviation from the swath path; determining a number of hot spot areas within the moving field of view; adjusting the variable speed of the stage movement based on the number of hot spot areas within the moving field of view with a maximum speed corresponding to a zero hot spot density and multiple lower speeds corresponding to higher hot spot densities, wherein the variable speed as a function of stage position forms a profile that has sloped ramps in speed connecting constant speed levels; adjusting the variable speed of the stage movement such that the variable speed of the stage movement transitions in a downward sloped ramp from a first constant speed level to a second constant speed level, wherein the first constant speed level is higher than the second constant speed level, the first constant speed level is associated with a first hot spot density that is greater than zero, and the second constant speed level is associated with a second hot spot density that is greater than the first hot spot density; and adjusting the variable speed of the stage movement such that the variable speed of the stage movement transitions in an upward sloped ramp from a third constant speed level to a fourth constant speed level, wherein the third constant speed level is lower than the fourth constant speed level, the third constant speed level is associated with a third hot spot density, the fourth constant speed level is associated with a fourth hot spot density that is greater than zero and less than the third hot spot density.