Patent ID: 8124932
Filing Date: 2012-02-28
Classification: H01J

Abstract:
1. A charged particle beam apparatus comprising: a charged particle source that emits a charged particle beam; an aperture that narrows the charged particle beam to a predetermined diameter; an object lens that focuses the charged particle beam narrowed by the aperture to irradiate the focused charged particle beam to a sample; observing means for acquiring an image of a surface of the sample; an aperture driving portion that moves a center axis of the aperture in an X direction and a Y direction constituting two axes substantially orthogonal to each other relative to the center axis; and a control portion that adjusts a position of the center axis of the aperture relative to a center axis of the object lens by moving the aperture by the aperture driving portion; wherein the control portion includes: spot pattern forming means for forming a plurality of spot patterns on the surface of the sample by irradiating the charged particle beam to the sample a plurality of times by moving the aperture to a position different in the X direction and the Y direction by the aperture driving portion; analyzing means for calculating positions of spot centers constituting centers of the respective spot patterns formed at the sample and a geometrical center position of a halo constituting an outer edge thereof from the image acquired by the observing means; and adjusting position determining means for calculating an adjusting position of the center axis of the aperture based on a position of intersecting lines connecting the positions of the spot centers of the respective spot patterns and the center position of the halo calculated by the analyzing means; and wherein a position of the aperture is adjusted by moving the center axis of the aperture to the adjusting position calculated by the adjusting position determining means.