Embodiments may include methods, systems, and apparatuses for correcting a response function of an electron beam tool. The correcting may include modulating an electron beam parameter having a frequency; emitting an electron beam based on the electron beam parameter towards a specimen, thereby scattering electrons, wherein the electron beam is described by a source wave function having a source phase and a landing angle; detecting a portion of the scattered electrons at an electron detector, thereby yielding electron data including an electron wave function having an electron phase and an electron landing angle; determining, using a processor, a phase delay between the source phase and the electron phase, thereby yielding a latency; and correcting, using the processor, the response function of the electron beam tool using the latency and a difference between the source wave function and the electron wave function.

Systems and methods to focus and align multiple electron beams are disclosed. A camera produces image data of light from electron beams that is projected at a fiber optics array with multiple targets. An image processing module determines an adjustment to a voltage applied to a relay lens, a field lens, or a multi-pole array based on the image data. The adjustment minimizes at least one of a displacement, a defocus, or an aberration of one of the electron beams. Using a control module, the voltage is applied to the relay lens, the field lens, or the multi-pole array.

A calibration method for calibrating the position error in the point of interest induced from the stage of the defect inspection tool is achieved by controlling the deflectors directly. The position error in the point of interest is obtained from the design layout database.

A multiple-electron-beam-image acquisition apparatus includes an electromagnetic lens to receive and refract multiple electron beams, an aberration corrector, disposed in a magnetic field of the electromagnetic lens, to correct aberration of the multiple electron beams, an aperture-substrate, disposed movably at the upstream of the aberration corrector with respect to an advancing direction of the multiple electron beams, to selectively make an individual beam of the multiple electron beams pass therethrough independently, a movable stage to dispose thereon the aberration corrector, a stage control circuit, using an image caused by the individual beam selectively made to pass, to move the stage to align the position of the aberration corrector to the multiple electron beams having been relatively aligned with the electromagnetic lens, and a detector to detect multiple secondary electron beams emitted because the target object surface is irradiated with multiple electron beams having passed through the aberration corrector.

A multi-charged particle beam inspection apparatus includes a movable stage to place thereon an inspection substrate where plural dies each with the same pattern are arranged in a predetermined direction, a pitch acquisition circuit to acquire an arrangement pitch of plural dies, a magnification control circuit to control, when imaging the inspection substrate with multi-charged particle beams while continuously moving the stage, magnification of the multi-charged particle beams to be a controlled magnification such that the arrangement pitch of the plural dies becomes a natural number (2 or greater) multiple of an imaging region cycle in the predetermined direction of plural imaging regions to be individually imaged by each beam at each arrangement position of the multi-charged particle beams, and an acquisition mechanism to acquire inspection images of the plural dies on the inspection substrate, using the multi-charged particle beams whose magnification has been controlled to be the controlled magnification.

A method for calibrating a scanning charged particle microscope, such as a scanning electron microscope (SEM), is provided. The method includes dividing a wafer into a plurality of regions; preparing, on each of the plurality of regions, a pattern including a first periodic structure interleaved with a second periodic structure, the first and second periodic structures having an induced offset; determining an actual pitch the first and second periodic structures and thereby determining actual induced offset on each of the plurality of regions; selecting a plurality of regions from among the plurality of regions; measuring, by the SEM, a pitch of first and second periodic structures on each of the plurality of regions; and performing linearity calibration on the SEM based on the determining and the measuring.

Provided is a measurement device including: an irradiation optical system which emits a primary charged quantum beam to a sample for scanning; a detector which detects secondary charged particles generated from the sample; and a signal processing unit which processes an output signal from the secondary charged particle detector which has detected the secondary charged particles, in which the signal processing unit includes a measurement unit which measures widths of a first pattern group calibrated with a well-known first dimension and a second pattern group calibrated with a well-known second dimension, and an operation unit which defines a relationship between the well-known dimensions of the first and second pattern groups and length measurement values of the first and second pattern groups as a function. Accordingly, it is possible to control device performance with high accuracy, by controlling a device state so that the measured value described above is within an acceptable range by comparing to a predetermined value provided in advance.

A multi charged particle beam inspection apparatus includes a plurality of sensors, arranged inside or on a periphery of a secondary electron image acquisition mechanism, to measure a plurality of interfering factors, a determination circuit to determine, for each interfering factor, whether change exceeding a corresponding threshold is a first case which returns to the original state within a predetermined time period, or a second case which does not return to the original state even if the predetermined time period has passed, and a comparison circuit to input a reference image of a region corresponding to the secondary electron image acquired, and compare the secondary electron image with the reference image, wherein in the case where change of the second case occurs, the secondary electron image acquisition mechanism suspends the acquisition operation of the secondary electron image, and calibrates a change amount of the multiple charged particle beams.

Methods and systems for quantifying and correcting for non-uniformities in images used for metrology operations are disclosed. A metrology area image of a wafer and a design clip may be used. The metrology area image may be a scanning electron microscope image. The design clip may be the design clip of the wafer or a synthesized design clip. Tool distortions, including electron beam distortions, can be quantified and corrected. The design clip can be applied to the metrology area image to obtain a synthesized image such that one or more process change variations are suppressed and one or more tool distortions are enhanced.

A multiple beam inspection apparatus includes a multi-detector to detect multiple secondary electron beams generated because a target object is irradiated with multiple primary electron beams, and to include plural detection pixels each receiving irradiation of a corresponding one of the multiple secondary electron beams, and having a region which receives irradiation of a corresponding secondary electron beam and is larger than the irradiation spot size of the corresponding secondary electron beam, a shifting mechanism to shift irradiation positions of the multiple secondary electron beams irradiating the plural detection pixels, a determination circuitry to determine whether sensitivity of at least one of the plural detection pixels is degraded, and a setting circuitry to set, when sensitivity of at least one detection pixel is degraded, irradiation position shifting destinations of multiple secondary electron beams, irradiating the plural detection pixels, to be within respective corresponding same detection pixels.