| 摘要 |
The present invention provides a method for measuring aberration which has the simplicity of the Ronchigram method, can be employed even in an SEM using a reflection/secondary electron scanning image, and does not especially require a detector for imaging, or the present invention provides a method for acquiring aberration information which is supplied for aberration measurement. Beam scanning for obtaining a scanning image is performed by means of a scanning coil that is arranged above an object lens and an aberration corrector which comprises an aberration measurement-target lens, rather than by means of a scanning coil that is arranged directly above an ordinary object lens. As a result, distortion scanning reflecting the aberration of the aberration measurement-target lens is performed on a sample surface, and a scanning image is formed from scattered electron beams, transmission potential beams or reflection/secondary electron beams that are thereby generated. An aberration information pattern that is equivalent to a conventional Ronchigram can therefore be obtained by scanning. |
