Patent Number: 
Section: claims

1. A method of automatically correcting aberrations in a charged-particle beam, comprising the steps of:storing image data into a memory, the image data being obtained by scanning a specimen with the charged-particle beam;reading the image data from said memory and blurring regions close to four sides of an image represented by the image data;extracting a profile of a probe formed by said charged-particle beam from the image that has been blurred by the immediately preceding step;extracting line profiles from the extracted profile of the probe;performing extraction of amounts of features, calculations of aberrations, judgments on corrections of the aberrations, and setting of an amount of feedback about the obtained line profiles; andcorrecting conditions under which an aberration corrector is driven, based on the obtained amount of feedback, the aberration corrector acting to correct the aberrations in the charged-particle beam. 2. An apparatus for automatically correcting aberrations in a charged-particle beam, said apparatus comprising:an aberration corrector for correcting the aberrations in the charged-particle beam;a memory for storing image data obtained by scanning a specimen with the charged-particle beam;a four-sided region-blurring device for reading the image data from said memory and blurring regions close to four sides of an image represented by said image data;a probe profile extractor for extracting a probe profile of the charged-particle beam from the image which has been blurred by the immediately preceding step;a line profile extractor for extracting line profiles from the extracted probe profile;correction amount-calculating means for performing extraction of amounts of features, calculations of aberrations, judgment on corrections of the aberrations, and setting of an amount of feedback about the extracted line profiles; andcorrecting means for correcting conditions under which the aberration corrector is driven, based on the amount of feedback obtained by said correction amount-calculating means. 3. A method for automatically correcting aberrations in a charged-particle beam as set forth in claim 1, wherein background noise contained in the probe profile is removed by automatically adjusting an amount by which the regions close to the four sides are blurred by said four-sided region-blurring device.