An electron microscope is offered that is capable of achieving noise cancellation which results in a low level of noise and which can be implemented at high speed. An electron microscope (1) associated with the present invention includes: an electron beam source (11) for producing an electron beam; a noise detector (4) for detecting a part of the beam to thereby produce a beam detection signal and dividing a dividend by the beam detection signal; at least one image signal detector (6) for detecting an image signal obtained by making the beam impinge on a sample (A); and an arithmetic section (60) for performing a multiplication between an output signal of the image signal detector (6) and an output signal of the noise detector (4).

A method for measuring an electron signal or an electron induced signal may be provided. The method may include providing a threshold number of events or a threshold event rate for a pixel on a detector. The method may include collecting from the detector the threshold number of events or determining that the threshold event rate is achieved, wherein a signal at the detector is an electron signal or an electron induced signal from a sample. The method may include modulating an intensity of an electron source directed to the sample in response.

A beam current adjuster for an ion implanter includes a variable aperture device which is disposed at an ion beam focus point or a vicinity thereof. The variable aperture device is configured to adjust an ion beam width in a direction perpendicular to an ion beam focusing direction at the focus point in order to control an implanting beam current. The variable aperture device may be disposed immediately downstream of a mass analysis slit. The beam current adjuster may be provided with a high energy ion implanter including a high energy multistage linear acceleration unit.

An ion beam measuring device includes: a mask that is used for shaping an original ion beam into a measuring ion beam including a y beam part elongated in a y direction that is perpendicular to a traveling direction of the ion beam and an x beam part elongated in an x direction that is perpendicular to the traveling direction and the y direction; a detection unit that is configured to detect an x-direction position of the y beam part and a y-direction position of the x beam part; and a beam angle calculating unit that is configured to calculate an x-direction beam angle using the x-direction position and a y-direction beam angle using the y-direction position.

An ion source that includes a material delivery system to deliver a metal dopant in the form of a wire to the ion source is disclosed. The wire is introduced through an opening in one wall of the arc chamber and is sputtered or chemically etched by the plasma. The rate at which the wire is delivered may be controlled so as to maintain a desired beam current without causing any liquid metal to be spilled in the arc chamber. In some embodiments, the wire may be heated or cooled prior to entering the ion source. In some embodiments, a dopant power supply may be employed to supply a bias voltage to the wire. A controller may be used to control various parameters associated with the metal dopant, including delivery rate, dopant voltage and dopant temperature.

A multi charged particle beam writing apparatus of the present invention includes an aperture member to form multiple beams, a plurality of first deflectors to respectively perform blanking deflection of a corresponding beam, a second deflector to collectively deflect the multiple beams having passed through the plurality of openings of the aperture member so that the multiple beams do not reach the target object, a blanking aperture member to block each beam that has been deflected to be in the off state by the plurality of first deflectors, and a current detector, arranged at the blanking aperture member, to detect a current value of all beams in the on state in the multiple beams that have been deflected by the second deflector.

According to one aspect of the present invention, a multiple charged particle beam writing method includes: setting one of a plurality of weighting coefficients, for each beam of multiple charged particle beams according to arrangement positions of the multiple charged particle beams; and correcting, in a case where multiple writing is performed on a same position of a target object as a writing target with a plurality of beams at different arrangement positions, two or more kinds of weighting coefficients being set for the plurality of beams, among the multiple charged particle beams, a dose of a beam concerned obtained in advance, using the two or more kinds of weighting coefficients of the plurality of beams with which writing is performed on the position, for each beam of the plurality of beams with which the position is irradiated.

A method includes moving a plurality of sensors along a translation path with respect to an ion beam, acquiring sensor signals produced by the plurality of sensors, converting the acquired sensor signals into a data set representative of a two-dimensional (2D) profile of the ion beam, generating a plurality of first one-dimensional (1D) profiles of the ion beam from the data set, generating a plurality of second 1D profiles of the ion beam by spatially inverting each of the plurality of first 1D profiles, generating a plurality of third 1D profiles of the ion beam by superposing first current density values of each of the plurality of first 1D profiles with second current density values of a corresponding one of the plurality of second 1D profiles and determining whether to continue an implantation process with the ion beam in accordance with the plurality of third 1D profiles.

A particle beam column generates a particle beam of charged particles, for example electrons or ions, and direct it onto a sample. The particle beam column comprises a multi-aperture stop and a deflection system for selectively steering the particle beam through one of a plurality of apertures provided in the multi-aperture stop. The apertures have different sizes in order to limit the current strength of the particle beam to different values. The particle beam column furthermore comprises a lens for changing the divergence angle of the particle beam upstream of a first stop. The lens can comprise a magnetic lens, which comprises a magnetic core with a plurality of parts, which are electrically insulated from one another and can have substantially different electrical potentials during operation. Some of the parts of the magnetic core can have the same electrical potential as the first stop during operation.

Systems, non-transitory computer readable medium, and methods for determining one or more parameters used by an e-beam for an overlay measurement are disclosed. In some embodiments, the method comprises determining an acquisition time for the overlay measurement of a wafer stack based on a plurality of characteristics of the wafer stack and a plurality of backscattered electron (BSE) yields detected at a plurality of features on the wafer stack. The method also comprises determining the one or more parameters including a landing energy of the e-beam based on optimization of the acquisition time for the overlay measurement.