Abstract: There is provided an electron microscope capable of reducing variations of aberrations due to thermal variations. The electron microscope includes an electron optical system having a built-in aberration corrector equipped with multipole elements each for producing a multipolar field. Each multipole element includes a plurality of magnetic polepieces. Each polepiece includes a magnetic core, a first coil wound around the core, and a second coil wound around the core. The first coil and the second coil produce a first multipolar field and a second multipolar field, respectively, when energized. The first and second multipolar fields are identical in terms of symmetry.

Abstract: A method of adjusting a charged particle optical system in a charged particle beam apparatus provided with the charged particle optical system including an aberration corrector in which multipole elements disposed in three or more stages and transfer optical systems are alternately disposed. The method includes adjusting aberration using at least two of the multipole elements without using at least one of the multipole elements, and adjusting parameters of the charged particle optical system other than aberration using at least one of the transfer optical systems that is not disposed between the at least two of the multipole elements used.

Abstract: An aberration value estimator has a learned estimation model for estimating an aberration value set based on a Ronchigram. In a machine learning sub-system, a simulation is repeatedly executed while changing a simulation condition, and calculated Ronchigrams are generated in a wide variety and in a large number. By machine learning using the calculated Ronchigrams, the learned estimation model is generated.

Abstract: An electron microscope includes an irradiation optical system that focuses electron beams and scans a specimen with the focused electron beams; a deflector that deflects the electron beams transmitted through the specimen; a detector that detects the electron beams transmitted through the specimen; and a control unit that controls the irradiation optical system and the deflector The control unit causes the irradiation optical system to scan the specimen with the electron beams so that the electron beams have a plurality of irradiation positions on the specimen. The control unit causes the deflector to repeatedly deflect the electron beams transmitted through each of the irradiation positions, so that a plurality of electron beams which have the same irradiation position and different incident angle ranges with respect to the specimen are caused to sequentially enter the detector.

Abstract: A method of measuring an aberration in an electron microscope includes: acquiring an image for measuring the aberration in the electron microscope; and measuring the aberration by using the image. In measuring the aberration, a direction of defocusing is specified based on a residual aberration that is uniquely determined by a configuration of an optical system of the electron microscope and an optical condition of the optical system.

Abstract: An aberration correcting device includes a first multipole which generates a hexapole field; a second multipole which generates a hexapole field with a polarity opposite to a polarity of the hexapole filed generated by the first multipole; a third multipole which is disposed between the first multipole and the second multipole and generates an octupole field; a first transfer lens system disposed between the first multipole and the third multipole; and a second transfer lens system disposed between the third multipole and the second multipole. The first transfer lens system includes a plurality of fourth multipoles which generate a field in which an electromagnetic-field superposed quadrupole field and an octupole field are superposed; and the second transfer lens system includes a plurality of fifth multipoles which generate a field in which an electromagnetic-field superposed quadrupole field and an octupole field are superposed.

Abstract: An aberration corrector includes a first multipole element for producing a hexapole field, a second multipole element for producing a hexapole field, and a transfer lens system disposed between the first and second multipole elements. The first and second multipole elements are arranged along an optical axis. At least one of the hexapole fields respectively produced by the first multipole element and the second multipole element varies in strength along the optical axis.

Abstract: Prior to execution of primary correction, a first centering process, an in-advance correction of a particular aberration, and a second centering process are executed stepwise. In the first centering process and the second centering process, a ronchigram center is identified based on a ronchigram variation image, and is matched with an imaging center. In the in-advance correction and the post correction of the particular aberration, a particular aberration value is estimated based on a ronchigram, and the particular aberration is corrected based on the particular aberration value.

Abstract: An aberration value estimator has a learned estimation model for estimating an aberration value set based on a Ronchigram. In a machine learning sub-system, a simulation is repeatedly executed while changing a simulation condition, and calculated Ronchigrams are generated in a wide variety and in a large number. By machine learning using the calculated Ronchigrams, the learned estimation model is generated.

Abstract: A method of measuring an aberration in an electron microscope includes: acquiring an image for measuring the aberration in the electron microscope; and measuring the aberration by using the image. In measuring the aberration, a direction of defocusing is specified based on a residual aberration that is uniquely determined by a configuration of an optical system of the electron microscope and an optical condition of the optical system.

Abstract: In a scanning transmission electron microscope, a control unit performs: processing of calculating a first auto-correlation function that is an auto-correlation function of a first scanning transmission electron microscope image; processing of acquiring a first intensity profile along a straight line that passes through a center of the first auto-correlation function; processing of obtaining a position of an inflection point that is closest to the center of the first auto-correlation function in the first intensity profile and adopting an intensity at the position as a first reference intensity; processing of obtaining an aberration coefficient by fitting a first aberration function to an isointensity line that connects positions where intensity is equal to the first reference intensity in the first auto-correlation function and by fitting a second aberration function to an isointensity line that connects positions where intensity is equal to a second reference intensity in a second auto-correlation function;

Abstract: An aberration corrector includes: a first multipole, a second multipole, a third multipole, and a fourth multipole arranged along an optical axis A; a first transfer lens system arranged between the first multipole and the second multipole; a second transfer lens system arranged between the second multipole and the third multipole; and a third transfer lens system arranged between the third multipole and the fourth multipole, wherein each of the first multipole, the second multipole, the third multipole, and the fourth multipole generates a three-fold symmetric field.

Abstract: In a scanning transmission electron microscope, a control unit performs: processing of calculating a first auto-correlation function that is an auto-correlation function of a first scanning transmission electron microscope image; processing of acquiring a first intensity profile along a straight line that passes through a center of the first auto-correlation function; processing of obtaining a position of an inflection point that is closest to the center of the first auto-correlation function in the first intensity profile and adopting an intensity at the position as a first reference intensity; processing of obtaining an aberration coefficient by fitting a first aberration function to an isointensity line that connects positions where intensity is equal to the first reference intensity in the first auto-correlation function and by fitting a second aberration function to an isointensity line that connects positions where intensity is equal to a second reference intensity in a second auto-correlation function;

Abstract: An electron microscope includes: an optical system including an aberration correction device; and a control unit that controls the aberration correction device, wherein the control unit performs: processing for displaying, on a display unit, an image for designating a direction of aberration in superposition on an aberration pattern representing a state of aberration, processing for specifying the direction of aberration from the image that has been subjected to a rotation operation, and processing for controlling the aberration correction device to cause the aberration correction device to introduce an aberration in the specified direction.

Abstract: There is provided a method which is for use in a charged particle beam system including an illumination system equipped with an aberration corrector having a plurality of stages of multipole elements and a transfer lens system disposed between the multipole elements, the method being capable of correcting distortion in a shadow of an aperture of the illumination system. The method involves varying excitations of the transfer lens system to correct distortion in the shadow of the aperture of the illumination system.

Abstract: An aberration corrector includes: a first multipole, a second multipole, a third multipole, and a fourth multipole arranged along an optical axis A; a first transfer lens system arranged between the first multipole and the second multipole; a second transfer lens system arranged between the second multipole and the third multipole; and a third transfer lens system arranged between the third multipole and the fourth multipole, wherein each of the first multipole, the second multipole, the third multipole, and the fourth multipole generates a three-fold symmetric field.

Abstract: An electron microscope includes: an optical system including an aberration correction device; and a control unit that controls the aberration correction device, wherein the control unit performs: processing for displaying, on a display unit, an image for designating a direction of aberration in superposition on an aberration pattern representing a state of aberration, processing for specifying the direction of aberration from the image that has been subjected to a rotation operation, and processing for controlling the aberration correction device to cause the aberration correction device to introduce an aberration in the specified direction.

Abstract: An aberration computing device (100) includes a fitting section (48) for fitting line profiles of a diffractogram taken in radial directions to a fitting function and finding fitting parameters of the fitting function and a computing section (49) for finding at least one of an amount of defocus and two-fold astigmatism, based on the fitting parameters.

Abstract: A device which computes an angular range of illumination of an electron beam in which aberrations in an optical system can be measured efficiently by a tableau method. The device (100) includes an aberration coefficient information acquisition portion (112) for obtaining information about aberration coefficients of the optical system, a phase distribution computing portion (114) for finding a distribution of phases in the electron beam passed through the optical system on the basis of the information about the aberration coefficients, and an angular range computing portion (116) for finding the angular range of illumination on the basis of the distribution of phases found by the phase distribution computing portion (114).

Abstract: There is provided a method which is for use in a charged particle beam system including an illumination system equipped with an aberration corrector having a plurality of stages of multipole elements and a transfer lens system disposed between the multipole elements, the method being capable of correcting distortion in a shadow of an aperture of the illumination system. The method involves varying excitations of the transfer lens system to correct distortion in the shadow of the aperture of the illumination system.