A method for making a semiconductor memory device comprising a plurality of memory cells for storing one or more data values, the method comprising: exposing a pattern on a wafer for creating structures for a plurality of memory cells for the semiconductor memory device, wherein the pattern is exposed by means of one or more charged particle beams; and varying an exposure dose of the one or more charged particle beams during exposure of the pattern to generate a set of one or more non-common features in one or more structures of at least one of the memory cells, so that the structures of the at least one memory cell differ from the corresponding structures of other memory cells of the semiconductor memory device.

A method for making a semiconductor memory device comprising a plurality of memory cells for storing one or more data values, the method comprising; exposing a pattern on a wafer for creating structures for a plurality of memory cells for the semiconductor memory device, wherein the pattern is exposed by means of one or more charged particle beams; and varying an exposure dose of the one or more charged particle beams during exposure of the pattern to generate a set of one or more non-common features in one or more structures of at least one of the memory cells, so that the structures of the at least one memory cell differ from the corresponding structures of other memory cells of the semiconductor memory device.

The mark position is measured with a multi-beam with high accuracy. A multi charged particle beam writing method includes forming a multi-beam (30a-30e) in which charged particle beams are arranged with a predetermined pitch, irradiating a mark (M) with beams in an on-beam region while shifting irradiation positions of the charged particle beams by sequentially changing the on-beam region in which beams in a partial region of the multi-beam (30a-30e) are set to ON, the mark (M) being provided at a predetermined position and having a width greater than the predetermined pitch, detecting a reflected charged particle signal from the mark (M), and calculating a position of the mark (M), and adjusting the irradiation positions of the multi-beam based on the calculated position of the mark (M), and writing a pattern.

A photocathode emitter can include a transparent substrate, a photocathode layer, and a plasmonic structure array disposed between the transparent substrate and the photocathode layer. The plasmonic structure can serve as a spot-confining structure and an electrical underlayer for biasing the photocathode. The plasmonic structure can confine the incident light at subwavelength sizes.

A multi-charged particle beam writing apparatus includes a circuit to allocate an additional dose to a position inside a writing target pattern in order to change a first dose distribution by an excessive dose, generated on the target object by applying, in the multi-charged particle beams, an excessive dose defective beam, to a second dose distribution whose center is located inside the writing target pattern and for which beam irradiation canceling out the excessive dose and being in a range of the first dose distribution exists; and a circuit to perform correction by subtracting an increased dose amount, generated at the center of the second dose distribution because of the additional dose being allocated, from a dose with which one of the center of the second dose distribution and a vicinity of the center of the second dose distribution is irradiated.

A multiple-charged particle-beam irradiation apparatus includes a shaping aperture array substrate that causes a charged particle beam to pass through a plurality of first apertures to form multi-beams, a plurality of blanking aperture array substrates each provided with a plurality of second apertures, which enable corresponding beams to pass, and including a blanker arranged at each of the second apertures, a movable table on which the blanking aperture array substrates are mounted so as to be spaced apart from each other in a second direction, which is orthogonal to a first direction along an optical axis, and that moves in the second direction to position one of the blanking aperture array substrates on the optical axis, and an alignment mechanism that performs an alignment adjustment between the blanking aperture array substrate on the optical axis and the shaping aperture array substrate.

A scanning electron microscopy (SEM) system is disclosed. The SEM system includes an electron source configured to generate an electron beam and a set of electron optics configured to scan the electron beam across the sample and focus electrons scattered by the sample onto one or more imaging planes. The SEM system includes a first detector module positioned at the one or more imaging planes, wherein the first detector module includes a multipixel solid-state sensor configured to convert scattered particles, such as electrons and/or x-rays, from the sample into a set of equivalent signal charges. The multipixel solid-state sensor is connected to two or more Application Specific Integrated Circuits (ASICs) configured to process the set of signal charges from one or more pixels of the sensor.

A multi-electron beam image acquisition apparatus includes a multiple-beam forming mechanism to form multiple primary electron beams, a primary-electron optical system to irradiate 1a sample with the multiple primary electron beams, a beam separator, arranged at a position conjugate to an image plane of each of the multiple primary electron beams, to form an electric field and a magnetic field to be mutually perpendicular, to separate multiple secondary electron beams, emitted from the sample due to irradiation with the multiple primary electron beams, from the multiple primary electron beams by using actions of the electric field and the magnetic field, and to have a lens action on the multiple secondary electron beams in at least one of the electric field and the magnetic field, a multi-detector to detect the multiple secondary electron beams, and a secondary-electron optical system to lead the multiple secondary electron beams to the multi-detector.

In one embodiment, a multi-charged-particle-beam writing method includes performing a tracking operation such that, while a substrate placed on a stage moving continuously is being irradiated with multiple beams including a plurality of charged particle beams, deflection positions of the multiple beams follow movement of the stage, and applying the multiple beams to the substrate having a writing area including a plurality of rectangular regions arranged in a mesh during the tracking operation such that each of the plurality of rectangular regions is irradiated with the multiple beams. Each rectangular region includes a plurality of pixels each having a predetermined size and arranged in a mesh. At least one subset of the plurality of pixels is irradiated with the multiple beams in a first shot order and is then irradiated with the multiple beams in a second shot order different from the first shot order.

In one embodiment, a multi-charged-particle-beam writing method includes dividing a data path into a plurality of first blocks based on at least either one of each of a plurality of input/output circuits and a plurality of wiring groups, and calculating a first shift amount for multiple beams for each of the plurality of first blocks. The data path is for inputting control data to a cell array on a blanking aperture array substrate. The control data is for controlling ON/OFF of each beam of the multiple beams. Each of the plurality of wiring groups includes a plurality of pieces of wiring connected to the plurality of input/output circuits and grouped together based on inter-wiring distance. The first shift amount is due to at least one of an electric field and a magnetic field for each of the plurality of first blocks. An irradiation position or a dose of the multiple beams is corrected based on the first shift amount, and irradiation is performed.