US Patent 7952083 Ion beam system and machining method

An ion beam system includes a sample stage which holds a sample, an ion source which generates an ion beam so that the ion beam is extracted from the ion source along an extraction axis, an irradiation optical system having an irradiation axis along which the ion beam is irradiated toward the sample held on the sample stage, and a charged particle beam observation system for observing a surface of the sample which is machined by the irradiated ion beam. The extraction axis along which the ion beam is extracted from the ion source and the irradiation axis along which the sample is irradiated are inclined with respect to one another.