Provided is a scanning electron microscope which can perform high-speed focus correction even when an electron beam having high energy is used. The scanning electron microscope includes an electron optical system including an electron source 100 that emits an electron beam and an objective lens 113, a sample stage 1025 which is disposed on a stage 115 and on which a sample 114 is placed, a backscattered electron detector 1023 which is disposed between the objective lens and the sample stage and is configured to detect backscattered electrons 1017 emitted due to interaction between the electron beam and the sample, a backscattered electron detection system control unit 138 which is provided corresponding to the backscattered electron detector and is configured to apply a voltage to the backscattered electron detector, and a device control calculation device 146. The objective lens has an opening in a stage direction, and the device control calculation device performs focus correction of the electron beam by controlling the voltage applied to the backscattered electron detector from the backscattered electron detection system control unit.

A multi-beam lens device is described, which includes: a first beam passage for a first charged particle beam formed along a first direction between a first beam inlet of the first beam passage and a first beam outlet of the first beam passage; a second beam passage for a second charged particle beam formed along a second direction between a second beam inlet of the second beam passage and a second beam outlet of the second beam passage, wherein the first direction and the second direction are inclined with respect to each other by an angle (α) of 5° or more such that the first beam passage approaches the second beam passage toward the first beam outlet; and a common excitation coil or a common electrode arrangement configured for focussing the first charged particle beam and the second charged particle beam. Further, a charged particle beam device as well as a method of operating a multi-beam lens device are described.

Provided is a charged particle beam device capable of detecting signal charged particles in a wide range of elevation angles from a large elevation angle to a small elevation angle and distinguishing detection signals between backscattered charged particles and secondary charged particles regardless of distribution of the signal charged particles. The charged particle beam device according to the disclosure includes a first detector that detects the secondary charged particles or the backscattered charged particles and a second detector that detects tertiary charged particles generated from the first detector, and generates an observation image of a sample using a signal value obtained by subtracting at least a part of a second detection signal output by the second detector from a first detection signal output by the first detector, or subtracting at least a part of the first detection signal from the second detection signal.

To improve detection efficiency of secondary particles without increasing a size of a charged particle beam apparatus, a charged particle beam apparatus according to the invention includes: a charged particle beam source configured to irradiate a sample with a primary particle beam; a scanning deflector configured to scan and deflect the primary particle beam to a desired position of the sample; and a detector configured to detect secondary particles emitted from the desired position. The charged particle beam apparatus further includes: a focusing lens electrode arranged coaxially with the primary particle beam and configured to generate a focusing electric field that is an electric field that focuses a trajectory of the secondary particles; and a mesh electrode configured to reduce leakage of the focusing electric field on a trajectory of the primary particle beam.

Provided is a charged particle beam control device having improved signal detection accuracy. The charged particle beam control device (detection block) includes: a detector provided in a charged particle beam device, and configured to detect secondary electrons emitted from a sample by irradiating the sample with a charged particle beam and output an electric signal based on the detected secondary electrons; a signal wiring configured to transmit the electric signal; a noise detection wiring configured to detect a noise signal generated in the charged particle beam device; and an arithmetic circuit configured to generate a signal obtained by subtracting the noise signal from the electric signal.

A scanning electron microscope is disclosed. The scanning electron microscope includes: an electron optical column, arranged to generate electron beams and focus the electron beams on a specimen; a first detector, arranged to receive electrons generated by the electron beams acting on the specimen; and a second detector, arranged to receive photons generated by the electron beams acting on the specimen. The second detector includes a reflector and a photon detector. The reflector is in a ring shape and is arranged to cover the perimeter of the specimen. The reflector reflects the photons generated on the specimen onto the photon detector. The scanning electron microscope provided by the present disclosure can collect photons in a wide range, and the photon detector has a high reception efficiency.

A multi-beam apparatus for observing a sample with high resolution and high throughput and in flexibly varying observing conditions is proposed. The apparatus uses a movable collimating lens to flexibly vary the currents of the plural probe spots without influencing the intervals thereof, a new source-conversion unit to form the plural images of the single electron source and compensate off-axis aberrations of the plural probe spots with respect to observing conditions, and a pre-beamlet-forming means to reduce the strong Coulomb effect due to the primary-electron beam.

When a high-performance retarding voltage applying power supply cannot be employed in terms of costs or device miniaturization, it is difficult to sufficiently adjust focus in a high acceleration region within a range of changing an applied voltage, and identify a point at which a focus evaluation value is maximum. To address the above problems, a scanning electron microscope is provided including: an objective lens configured to converge an electron beam emitted from an electron source; a current source configured to supply an excitation current to the objective lens; a negative-voltage applying power supply configured to form a decelerating electric field of the electron beam on a sample; a detector configured to detect charged particles generated when the electron beam is emitted to the sample; and a control device configured to calculate a focus evaluation value from an image formed according to an output of the detector. The control device calculates a focus evaluation value when an applied voltage is changed, determines whether to increase or decrease an excitation current according to an increase or a decrease of the focus evaluation value, and supplies the excitation current based on a result of the determination.

An object of the present invention is to reduce the possibility that a filament is broken during observation and a re-measurement is required, to reduce the running cost of an apparatus, and to improve the operating efficiency of the apparatus. The charged particle beam apparatus according to the present invention calculates an imaging time required to generate an observation image of a sample and estimates a remaining usable time of the filament, and when the imaging time is longer than the remaining usable time, presents the fact (see FIG. 3)

Even when the amount of overlay deviation between patterns located in different layers is large, correct measurement of the amount of overlay deviation is stably performed. The charged particle beam device includes a charged particle beam irradiation unit that irradiates a sample with a charged particle beam, a first detection unit that detects secondary electrons from the sample, a second detection unit that detects backscattered electrons from the sample, and an image processing unit that generates a first image including an image of a first pattern located on the surface of the sample based on an output of the first detection unit, and generates a second image including an image of a second pattern located in a lower layer than the surface of the sample based on an output of the second detection unit. A control unit adjusts the position of a measurement area in the first image based on a first template image for the first image, and adjusts the position of a measurement area in the second image based on a second template image for the second image.