An electron optical system includes an electromagnetic lens configured to include a yoke, and refract an electron beam passing through the yoke by generating a magnetic field, and a shield coil disposed along the inner wall of the yoke, and configured to reduce a leakage magnetic field generated by the electromagnetic lens.

According to one embodiment, a charged particle beam writing apparatus includes, a writing mechanism, a writing control circuit, a deflection operation control circuit configured to generate control data for controlling the blanking of each of the charged particle beams based on the shot data, a storage, a blanking control circuit configured to control the blanking based on the control data, and a detector. The writing control circuit is configured to, when the detector detects the abnormality during the writing, interrupt the writing, and generate interrupt position information at a position where the writing is interrupted based on the shot data which has been stored at the storage and is related to the control data that has not been used for controlling the blanking.

Electron-optical devices and associated methods are disclosed. In one arrangement, an electron-optical device projects a multi-beam of sub-beams of charged particles to a sample. A plurality of plates are provided in which are defined respective aperture arrays. The plates comprise an objective lens array configured to project the sub-beams towards the sample. The aperture arrays defined in at least two of the plates each have a geometrical characteristic configured to apply a perturbation to a corresponding target property of the sub-beams. A controller controls potentials applied to the plates having the geometrical characteristics such that the applied perturbations together substantially compensate for a variation in the target property over a range of a parameter of the device.

An ion beam etching method includes applying a positive voltage for extracting ions into a vacuum container to a first electrode, under a first condition where irradiation of a substrate with an ion beam is blocked off by a shutter, generating plasma in an internal space under the first condition, forming the ion beam by forming, under the first condition, a second condition where a positive voltage is applied to the first electrode and a negative voltage is applied to a second electrode, and moving the shutter and processing the substrate by irradiating the substrate with the ion beam.

One modified source-conversion unit and one method to reduce the Coulomb Effect in a multi-beam apparatus are proposed. In the modified source-conversion unit, the aberration-compensation function is carried out after the image-forming function has changed each beamlet to be on-axis locally, and therefore avoids undesired aberrations due to the beamlet tilting/shifting. A Coulomb-effect-reduction means with plural Coulomb-effect-reduction openings is placed close to the single electron source of the apparatus and therefore the electrons not in use can be cut off as early as possible.

One modified source-conversion unit and one method to reduce the Coulomb Effect in a multi-beam apparatus are proposed. In the modified source-conversion unit, the aberration-compensation function is carried out after the image-forming function has changed each beamlet to be on-axis locally, and therefore avoids undesired aberrations due to the beamlet tilting/shifting. A Coulomb-effect-reduction means with plural Coulomb-effect-reduction openings is placed close to the single electron source of the apparatus and therefore the electrons not in use can be cut off as early as possible.

In one embodiment, a multi charged-particle beam writing apparatus includes a plurality of blankers switching between ON and OFF state of a corresponding beam among multiple beams, a main deflector deflecting beams having been subjected to blanking deflection to a writing position of the beams in accordance with movement of a stage, a detector scanning a mark on the stage with each of the beams having been deflected by the main deflector and detecting a beam position from a change in intensity of reflected charged particles and a position of the stage, and a beam shape calculator switching an ON beam, scanning the mark with the ON beam, and calculating a shape of the multiple beams from a beam position. A shape of a deflection field of the main deflector is corrected by using a polynomial representing an amount of beam position shift that is dependent on a beam deflection position of the main deflector and then the mark is scanned with the ON beam. The polynomial is different for each ON beam.

A multi charged particle beams exposure method includes assigning, with respect to plural times of shots of multi-beams using a charged particle beam, each shot to one of plural groups, depending on a total current value of beams becoming in an ON condition in a shot concerned in the multi-beams, changing the order of the plural times of shots so that shots assigned to the same group may be continuously emitted for each of the plural groups, correcting, for each group, a focus position of the multi-beams to a focus correction position for a group concerned corresponding to the total current value, and performing the plural times of shots of the multi-beams such that the shots assigned to the same group are continuously emitted in a state where the focus position of the multi-beams has been corrected to the focus correction position for the group concerned.

Disclosed herein is an apparatus comprising: a source of charged particles configured to emit a beam of charged particles along a primary beam axis of the apparatus; a condenser lens configured to cause the beam to concentrate around the primary beam axis; an aperture; a first multi-pole lens; a second multi-pole lens; wherein the first multi-pole lens is downstream with respect to the condenser lens and upstream with respect to the second multi-pole lens; wherein the second multi-pole lens is downstream with respect to the first multi-pole lens and upstream with respect to the aperture.

A blanking device for multi charged particle beams includes a first substrate, in which plural first openings are formed in an array, to form multi-beams, a second substrate in which plural second openings are formed in an array, where a corresponding beam of the multi-beams passes through each of the plural second openings, plural control electrodes, which are on the second substrate and each of which is close to a corresponding one of the plural second openings and arranged not to be directly exposed to other second opening adjacent to the corresponding one of the plural second openings, to be switchably applied with first and second potentials, plural counter electrodes, each of which is facing a corresponding one of the plural control electrodes, to be applied with the second potential, and a shield film provided between the first substrate and the plural control electrodes.