Charged particle beam instrument comprising an aberration corrector

Abstract

A method for estimation of a probe shape, in a scanning electron microscope provided with an aberration corrector, and the method is designed so as to obtain a probe image, by inputting to a computer an image taken in a just-focused state and an image taken in a de-focused state, as an image data; preparing a correlation window by automatically determining a size of a correlation window image, based on an input data size and an output data size; executing cross-correlation calculation between the correlation window and a reference area; and repeating this calculation while shifting the reference area, so as to obtain a cross-correlation matrix, in order to stably obtain the probe image, without receiving effects of use conditions or noises.

1 . (canceled) 
     
     
         2 . A charged particle beam instrument comprising an aberration corrector provided with a charged particle beam to output the secondary particles as secondary particle signals by irradiating an aberration corrected convergent charged particle beam onto a specimen, and
 a computer for acquiring information on irradiation region of said convergent charged particle beam by processing of said secondary particle signals,   wherein said computer computes a brightness distribution data corresponding to said convergent charged particle beam by processing of said secondary particle signals and estimates aberration and species from said brightness distribution data corresponding to said convergent charged particle beam and calculates applied currents and voltages for the aberration corrector from estimated aberration amounts and species and sends information of applied currents and voltages to the aberration corrector and controls currents of voltages of the aberration corrector.   
     
     
         3 . A charged particle beam instrument comprising an aberration corrector according to  claim 1 ,
 wherein the instrument comprises a computer for iterating control of currents and voltages of the aberration corrector until estimated aberration amounts achieve target aberration amounts set in advance by comparing said estimated aberration amounts and said target aberration amounts.