Abstract: A charged particle beam is formed to a relatively larger area beam which is well-contained and has a beam area which relatively uniformly deposits energy over a beam target. Linear optics receive an accelerator beam and output a first beam with a first waist defined by a relatively small size in a first dimension normal to a second dimension. Nonlinear optics, such as an octupole magnet, are located about the first waist and output a second beam having a phase-space distribution which folds the beam edges along the second dimension toward the beam core to develop a well-contained beam and a relatively uniform particle intensity across the beam core. The beam may then be expanded along the second dimension to form the uniform ribbon beam at a selected distance from the nonlinear optics. Alternately, the beam may be passed through a second set of nonlinear optics to fold the beam edges in the first dimension.

Abstract: This invention relates to a fine focusing lens for charged particle beams. Since the field lines of the poles are additive, and the lens 50 can be made to be very small, the lens can be used inside of a coarse focusing lens 51. The lens 50 employs a plurality of poles 1-32, evenly spaced, circumferentially around the lens. The poles may be wires 38 for electromagnetic poles or plates 35 for electrostatic poles. Each pole can be tagged to induce a frequency, pulse, or phase signal on the charged particle beam 49, so that the effects of each pole on the beam can be separately detected. The beam can therefore be focused by seeing the effects of and adjusting each pole separately. As the number of poles increases, the ability to finely focus a charged particle beam increases. The lens 50 as shown in the figures has 32 poles, which is enough to very finely focus a charged particle beam.

Abstract: For the selection of a pure electron beam or ion beam from a mixed beam, use is made of a combined electrostatic/magnetic deflection system, the electrostatic deflection system being formed, for example, by a tilted electrode system of a cascade system of electrodes present in the apparatus. The pure beam is directed onto an object to be irradiated as near to the object as possible in order to prevent renewed mixing.

Abstract: An apparatus for directing a scanned electron beam to a sample along an axis. An objective magnetic lens of a single-pole type focusses the scanned electron beam onto the sample. The objective magnetic lens includes a central pole portion extending along the axis and having a central end face effective to generate a magnetic field for focusing the scanned electron beam onto the sample and a peripheral sleeve portion extending along the axis and having a peripheral edge face effective to form a magnetic circuit between the central end face and the peripheral edge face, the peripheral sleeve portion having an inner radius R. A magnetic shield member is disposed to surround the sample to magnetically shield the same.

Abstract: A lens system for a beam of energetic ions employs a focusing element in combination with a defocusing element. In a preferred embodiment, the focusing element is in the form of an electromagnetic lens, such as a solenoid, through which is propagated the beam of energetic ions. Also in the beam path is provided a defocusing element which also may be in the form of an electromagnetic element, such as a solenoid, or a magnetic element, such as a magnetic dipole. Alternatively, an electrostatic defocusing element may be employed in the practice of the invention. In a magnetic embodiment, defocusing is achieved by propagating the beam of energetic ions around the exterior of the defocusing element. The focusing element may be of the electrostatic variety, such as a radial an electric field lens. In other embodiments, a further focusing element, or a further defocusing element may be arranged in the beam path.

Abstract: An electron beam exposure apparatus scans an electron beam in a limited space for electron beam lithography. A magnetic object lens of the apparatus has a lower pole piece facing an object to be processed, which is placed on a continuously moving stage to be exposed to the electron beam. A bore is opened in the lower pole piece which faces the object, and has a stripe-like cross-section to allow the passage of the electron beam. The shape of the opening inhibits the passage of undesirable leakage magnetic flux issued from the magnetic lens toward the object, and guides the electron beam to land on the object perpendicularly. With this configuration, deflection aberration of the deflection apparatus which is caused by an eddy current induced in the moving stage due to the magnetic flux reaching the stage is substantially prevented, and normal landing of the electron beam on the object is realized.

Abstract: An arrangement for observing a surface using a charged particle beam irradiated on the surface of a specimen and detecting secondary electrons emitted. An exciting device produces a strong magnetic field substantially perpendicular to the surface of the specimen. Secondary electrons are extracted from a bottom or side surface of a recess, such as a through hole formed in the surface of the specimen, by an interaction between the emitted secondary electrons and the strong magnetic field. A focusing lens is arranged so as to focus the charged particles at a point on the specimen, even in the presence of a strong field. Thus, a secondary electron image on the surface of the specimen can be sharply obtained to thereby observe a secondary electron image at the bottom surface or side surface of the through hole.

Abstract: The invention relates to a double focusing mass spectrometer with a combination of an electric and of a magnetic field for directional and velocity focusing. In order to provide a compact and constructionally simple arrangement, it is proposed that a common magnet is used for the Wien filter (10) and the sector magnet (11). Preferably, this double focusing mass spectrometer is used in an MS/MS arrangement.

Abstract: A magnetic lens for use in an electron beam test probe system which includes an electron beam which travels along an electron beam column axis to reach the surface of a specimen which is to be examined. The magnetic lens focuses the electron beam to a selected point on the surface of the specimen. This magnetic lens also collects and collimates the secondary electrons produced in response to the electron beam bombardment of the specimen. The magnetic lens includes deflection coils for selecting the point on the specimen surface at which the electron beam is focused. The magnetic lens generates a magnetic field having a first region of intense magnetic flux substantially coincident with the selected point on the specimen surface and a second region of lesser uniform magnetic flux in which the magnetic flux lines are parallel to the electron beam column axis. This field is generated by the combination of a stationary magnetic field and a deflection magnetic field.

Abstract: A method for compensating for an eddy current effect due to leakage flux of a magnetic lens in a charged particle beam exposure system, and a system for exposing the beam on a substrate while a stage carrying the substrate is moving. By employing this method and system, a step and repeat system can be operated while the stage is moving, while improving the throughput of the system. A deviation in the path of the charged particle beam caused by the eddy current is proportional to the velocity of the stage. To compensate for this, a proportional constant relating the deviation to the velocity of the stage is measured in advance, and a correction term which is a product of the speed of the stage and the proportional constant, is fed back to a deflector of the charged particle beam. The proportional constant is obtained from a shift of an image of a test pattern viewed on a CRT in a SEM mode, from a first position at which the stage is stationary to a second position while the stage is moving at a constant speed.

Abstract: A circuit includes an inversely fedback operational amplifier having a saw tooth deflection signal applied at its input, as well as a coil pair and an output for deflecting the particle beam of a scanning microscope within a scanned field as established by the coil current. A plurality of resistor elements are selected by a switch and a constant current source for feeding a direct current is provided to effect the image displacement at a connection P between the coil pair and respective one of the resistor elements. Since the direct current flows only through the coils but not through the resistor elements as a consequence of the feedback amplifier, image displacement is independent of magnification established by the respective resistor element.

Abstract: By using an electrostatic magnetic dispersing field adapted for that purpose in a measuring space in an electron microscope it is possible to detect substantially all the electrons liberated by a primary beam from a surface of an object to be examined in which the measuring field can be increased without any error by using a variable axis lens system at the area. Auger electrons can be detected selectively by an adapted field strength variation of the magnetic field and superposition of an electrostatic braking field. A magnetic lens for generating the magnetic field may also be used with only small adaptations as an objective lens for the electron microscope.

Abstract: An objective lens of an electron beam apparatus in which an electron beam emitted from an electron gun is converged onto a specimen, the reflected electron from the specimen or the secondary electron emitted therefrom is detected, and a fine pattern on the specimen is measured, comprises: a magnetic circuit consisting of an upper magnetic pole member having an opening adapted to transmit the electron beam to be converted which was emitted from the electron gun, a lower magnetic pole member provided so as to face the upper magnetic pole member, and a magnetic path member to connect the outer peripheral edges of the upper and lower magnetic pole members; a coil, provided for a part of the magnetic circuit, for generating the magnetic fluxes passing through the upper and lower magnetic pole members, the magnetic path member, and the space between the opening edge and the lower magnetic pole member when this coil is excited; and a moving apparatus which is disposed on the surface of the lower magnetic pole member

Abstract: A multipole corrective element with the individual poles being electromagnetically energized individually and selectively to create a variable field around a charged particle beam projected through a mask and a lens system onto a substrate, e.g. an ion-beam or electron-beam microlithography. The corrective element is provided independently of the ion-optical lens system between the latter and the mask, preferably proximal to the mask.

Abstract: A two staqge, electron beam projection system includes a target, a source of an electron beam and means for projecting an electron beam towards the target with its upper surface defining a target plane. A magnetic projection lens has a principal plane and a back focal plane located between said means for projecting and the target. The means for projecting provides an electron beam directed towards the target. First stage means provides deflection of the beam from area to area within a field. Second stage means provides for deflection of the beam for providing deflection of the beam within an area within a field. The beam crossing the back focal plane produces a telecentric condition of the beam in the image plane with the beam substantially normal to the target plane from the principal plane to the target plane.

Abstract: An improved particle beam apparatus for imaging line-shaped subjects onto an image surface, for example, a row of perforations of an aperture diaphragm on a surface of a semiconductor member to be structured characterized by the isotropic and anisotropic distortions being compensated by the insertion of a first multi-pole optics into the beam path under the subject. Astigmatisms produced by the first multi-pole optics are compensated by a second multi-pole optic that is inserted in the beam path immediately above the imaging lens.

Abstract: Quadruple lenses 30, 31 and 32 and sextupole lenses 40, 41, 42, and 43 are interposed between a energy-dispersing device 17 and an electron imaging device 50 in an energy-selected electron imaging filter. The energy-dispersing device produces a focussed spectrum 21 of electron energies in the plane of an energy-selecting slit 20, and the quadrupole and sextupole lenses transform the spectrum into an energy-selecting slit may also be either removed or opened wide, and the quadrupole lenses may be refocussed, so that the electron imaging device directly observes a magnified spectrum of the electron energies.

Abstract: An electron beam source having a single electron optical axis is provided with two coplanar cathodes equally spaced on opposite sides from the electron optical axis. A switch permits selecting either cathode, and a deflection system comprised of electromagnets, each with separate pole pieces equally spaced from the plane of the cathodes and electron optical axis, first deflects the electron beam from a selected cathode toward the electron optical axis, and then in an opposite direction into convergence with the electron optical axis. The result is that the electron beam from one selected cathode undergoes a sigmoid deflection in two opposite directions, like the letter S, with the sigmoid deflection of each being a mirror image of the other.

Abstract: Provided herein is an electro-magnetic field former for controlling charged particle trajectories in a scanning charge particle source including a pair of induction coils and C-shaped ferromagnetic yokes which are positioned in the air space between the particle source and a target at the target edges to normalize the angle of incidence of the particles relatve to the target and to deflect scattered particles into the target edges. Also provided is a field former controller to compensate for induced flux variations caused by an oscillating particle beam.

Abstract: A detector objective forms a component of an electron-optical column of a scanning electron microscope, the detector objective being composed of an asymmetrical magnetic lens, an electrostatic immersion lens generating a substantially rotationally symmetrical field, and an annular detector disposed immediately above the magnetic lens body. An electrode of the electrostatic immersion lens is formed as a truncated cone and is arranged in insulated fashion in an upper pole piece of the magnetic lens. The lower pole piece forms the second electrode of the immersion lens. The first and second electrodes are charged with potentials that establish an electrical field for decelerating the primary electrons, the electrical field overlying the focusing magnetic field.

Abstract: An apparatus using a charged particle beam is disclosed which includes means for generating charged particles, means for accelerating the charged particles so that the charged particles have desired kinetic energy, lens means including at least one objective lens for focusing a charged particle beam formed of the accelerated, charged particles, on the surface of a specimen, scanning means for scanning the surface of the specimen two-dimensionally with the focused beam, detection means for detecting secondary electrons, reflected electrons, X-rays and light, all of which emerge from the surface of the specimen, objective lens moving means for moving an objective lens nearest to the specimen, and deflection means linked with the objective lens moving means for deflecting the charged particle beam so that the charged particle beam carries out parallel displacement at the objective lens by an amount corresponding to the moving distance of the objective lens.

Abstract: The electron beam 2 of the generator illuminates a first rectangular aperture 4 which is then imaged on a second rectangular aperture 10 by a magnetic lens 7 having reversible flux. The flux of the lens is chosen so that the focused image of the first aperture is rotated by 22.5+45n degrees where n=0,1,2 etc. One flux direction places the aperture image sides 8 parallel to the second aperture sides so that a rectangular shaped beam emerges. The other flux direction places the aperture image sides 8' at 45 degrees to the second aperture sides so that a triangular shaped beam emerges. A beam deflector 6 between the apertures allows rectangles or 45 degree isoceles triangles of a range of sizes to be produced. Thus triangles are produced without further generator components being needed.

Abstract: This invention provides for an integrated electron optical/differential pumping/imaging signal detection system for an environmental scanning electron microscope (ESEM). The ESEM includes a substantially cylindrical objective lens magnetic housing containing an axially disposed vacuum liner tube and containing means for magnetically focusing a beam of electrons passing through said liner tube. An annular ring comprised of magnetic materials abuts said magnetic housing at the lower end thereof and contains at least two pumping ports therein located axially with respect to one another. At least two annular nonmagnetic diaphragms and a final magnetic annular diaphragm are attached to the annular ring at different axial locations and extending inwardly therefrom. The diaphragms define at least two interior passages which each communicate with one of the pumping ports formed in the annular ring.

Abstract: In a beam shaper superpositions of a deformed first diaphragm and a deformed or non-deformed second diaphragm can be realized by means of a quadrupole system. As a result of this a great freedom for adapting the spot cross-section to the patterns to be formed is obtained, as a result of which the number of writing pulses per pattern and hence the writing time for, for example, a chip can be considerably reduced and in particular non-orthogonal and non-linear transistions in the patterns can be written with greater definition.

Abstract: A beam is redirected from an initial direction lying along an initial axis to a final direction lying in a plane which intersects the initial axis (the final direction being other than radially away from the axis) by first redirecting the beam from the initial direction to an intermediate direction lying in the plane, and then redirecting the beam within the plane from the intermediate direction to the final direction.

Abstract: A transmission electron microscope is disclosed, having an electron-energy spectrometer, a first imaging stage of four electron lenses in front of the spectrometer, and a second imaging stage of two more electron lenses following the spectrometer. The parts are so arranged, according to the disclosed structure, and so operated, according to the disclosed method, that a large range of magnifications can be obtained while the object or specimen to be examined remains in a fixed location, without having to refocus when the magnification is changed. The change in magnification occurs by changing the operation of the first imaging stage. The second imaging stage operates at a substantially fixed magnification, its magnification being changed, if at all, only to accommodate the size of the output image from the second stage to size of the available working area of the detector in the final image plane (fluorescent screen, photographic film, or electronic detector).

Abstract: A direct-imaging, monochromatic electron microscope includes an objective lens for collecting a substantial portion of emitted electrons from an area across a sample surface, a first transfer lens for collimating the electrons into beams, an energy filter receptive of the beams to transit monochromatic beams, and a second transfer lens receptive of the monochromatic beams for refocusing the same through a projection lens to effect an image of the plurality of spots in a projection plane. The objective lens is formed of a magnetic toroidal coil having a central hole therein with a dish-shaped magnetically permeable member cupped coaxially over the toroidal coil. The permeable member has a neck portion protruding through the central hole. The sample surface is interposed proximate the objective lens between the objective lens and the energy filter.

Abstract: A spectrometer objective is composed of a short focal length, asymmetrical objective lens comprising an integrated electrostatic opposing field spectrometer and a single-stage deflection system arranged within the magnetic lens. Since the deflection of primary electrons occurs within the spectrometer objective, the space for a two-state deflection system employed in conventional systems between a condenser lens and an objective lens can be eliminated. The extremely-short structural length of the electron beam measuring apparatus which is thereby obtainable, in turn, has a beneficial effect on the influence of the lateral Boersch effect on probe diameter, this influence increasing with the length of the electron-optical beam path.

Abstract: A magnetic lens system is provided for a beam of charged particles, comprising a pair of ring-shaped permanent magnets through which the beam passes, the axes of the rings lying coaxially along the beam direction, and the two rings being axially separated and axially oppositely magnetised. A pair of separated conducting focus coils are provided one for each ring, the axes of the focus coils lying coaxially along the beam direction, each focus coil lying within its associated ring, and the focus coils being connected in series opposition to carry an adjustable direct electric current for fine focusing of the beam by the lens without rotation of the focused beam. The lens may provide the fast fine focus adjustment needed to compensate for space charge defocussing produced by changes in beam current.

Abstract: An electron lens assembly comprises at least a pair of magnetic pole pieces disposed in opposition to each other and each having a bore allowing an electron beam to pass therethrough, an exciting coil for producing a magnetic field between the magnetic pole pieces, a yoke coupled to the magnetic pole pieces and constituted by two divided yoke members so that the exciting coil can be accommodated, at least one of the two yoke members being detachably coupled to one of the magnetic pole pieces, and a pipe disposed along the electron beam path for defining a passage for the electron beam except for a space formed between the magnetic pole pieces. A metal O-ring is disposed on a surface of the detachable yoke member so as to prevent the air from entering the space defined between the opposite magnetic pole pieces along the surface of the detachable yoke member from a space accommodating the exciting coil. The electron beam passage defining pipe is coupled integrally to the detachable yoke member.

Abstract: A deflecting electromagnet having bow-shaped pole pieces 7b,7a disposed at input and output side end surfaces 6b,6a, respectively, of a main pole piece 6 which deflects and focuses an ion beam 2 generated by an ion source 1. The respective bow-shaped pole pieces are rotatably contacted with the side end surfaces of the main pole piece. Wedge-shaped pole pieces 8b,8a, are disposed in freely slidable contact with the planar surfaces of each of the bow-shaped pole pieces, respectively. The deflecting electromagnet constructed as above can be used to easily establish and adjust the effective borders of the magnetic field to a desirable position to establish and adjust, as desired, and the angle of the faces of the deflecting electromagnet at which the ion beam is inputted and outputted.

Abstract: An electronic beam device is provided for projecting the image of an object on a sample, including two electromagnetic lens reduction stages. A single insulating tube is disposed between an object and the same plane, this tube having an inner metallized face.

Abstract: A technique for compensating for chromatic aberration in particle beams, caused by differing particle energy levels when a beam is deflected for beam steering or beam focusing. A compensating deflection is applied to the beam upstream of its intended point of deflection. When the particles reach the point of deflection, the effect of the compensating deflection is proportional to the energy level of each particle, and compensates for the aberration that would normally occur. The point at which the compensating deflection is applied is selected to be one-fourth of a cycle in longitudinal phase space and an integral number of half-cycles in transverse phase space. With this critical spacing, the compensating deflection at the point of its application is proportional to relative phase in longitudinal phase space, but is proportional to energy level at the intended point of deflection.

Abstract: An apparatus using an electron beam for repeatedly scanning a specimen. The apparatus has an xy stigmator equipped with x-axis and y-axis coils to which correcting currents I.sub.x and I.sub.y are respectively fed. The values of these correcting currents are systematically varied for every scan. The signal emanating from the specimen is converted into a signal D indicating the diameter of the beam moving in a direction during each scan. When the signal D indicates that the diameter of the beam assumes its minimum value, the values of the correcting currents fed to the x-axis and y-axis coils are determined about two perpendicular directions of scan. The combinations of these values are referred to as I.sub.xa, I.sub.ya and I.sub.xb, I.sub.yb. Finally, the correcting currents I.sub.x, I.sub.y fed to the coils are set to (I.sub.xa +I.sub.xb)/2 and (I.sub.ya +I.sub.yb)/2, respectively.

Abstract: A Wien filter for use in charged particle beam systems is disclosed, having two opposed resistive magnetic pole pieces separated from a set of excitation coils by an electrically insulating material. Two opposed electric pole pieces are positioned in orthogonal relationship to and in physical contact with the magnetic pole pieces to form a physical aperture through which the charged particles will pass. The resistivity of the magnetic pole pieces is such that sufficient current will flow through them between the electric pole pieces to establish a uniform electric field over the entire physical aperture.

Abstract: An electrostatic-magnetic lens is provided having either a symmetrical or asymmetrical magnetic lens which is overlaid with an electrostatic immersion lens. One electrode of the immersion lens is formed as a hollow cylinder, which is within an upper pole piece of the magnetic lens concentrically relative to the axis of symmetry thereof and extending into the region of the pole piece gap. The lower pole piece of the magnetic lens is preferably at a ground potential and clad with the beam guiding tube for protection against contamination and forming the lower electrode of the electrostatic immersion lens.

Abstract: A spectrometer-lens for particle beam apparatus is formed by a short focal length magnetic lens having an integrated electrostatic retarding field spectrometer and a single-stage deflection unit arranged within said lens. To avoid deflecting secondary particles that are triggered at a specimen by a primary particle beam, nearly uniform electrical and magnetic deflection fields are generated by the deflection unit oriented relative to one another such that their field vectors reside perpendicular to one another and respectively perpendicular to a velocity vector of the secondary particles attracted from the specimen.

Abstract: A method and an apparatus for irradiating a relatively large area with a charged particle beam. In the method, a pencil-like beam is generated and spread along a fan axis perpendicular to the beam axis. The fan axis is rotated around the beam axis so that finally a circular area is irradiated. The apparatus includes means for generating a pencil-like beam, a lens system for spreading the beam along the fan axis and means to rotate the fan axis around the beam axis. In a preferred embodiment, the beam is spread such that its transverse intensity distribution increases with increasing distance from the beam center so that the area swept by the beam is irradiated with an even intensity.

Abstract: An electron beam tester for fault detection and isolation in large and very large scale integrated circuits. An electron optical column focuses a primary beam of electrons on the surface of a circuit chip. An immersion extractor provides an electrical field to attract secondary electrons emitted from the irradiated surface. Secondary electrons are detected in an integral spectrometer. A wide bore final lens and integral high resolution double defection scan coils enable large area voltage contrast imaging as well as quantitative waveform measurement from internal nodes of the circuit chip.

Abstract: A method of correcting the aberration of an electron beam due to astigmatism and field curvature of focus by feeding a correction current through stigmator coils and a focus correction coil. The correction currents are determined by measuring a sharpness P of the electron beam. The sharpness P is defined as a product of p.sub.x, a sharpness measured when the electron beam is deflected in X direction, and p.sub.y, a sharpness measured when the electron beam is deflected in Y direction: P=p.sub.x .times.p.sub.y. The use of the sharpness P provides good convergence of the measurements and it becomes possible to calibrate the electron beam for many points in the scanning field. Thus, it is possible to attain maximum resolution over an entire scanning field.

Abstract: An image forming alpha filter having pole pieces with straight edges is disclosed which has good local resolution and very good energy resolution. It includes three deflection regions, which are separated from one another by relatively large interspaces.

Abstract: In an ion micro beam apparatus which consists of an ion source, a beam focusing system which accelerates, focuses, mass-separates and deflects the ions emitted from said ion source, and a specimen plate for finely moving the specimen, the improvement comprising a mass separator which is constituted by: at least two stages of focusing lenses in said beam focusing system; four stages of E.times.B deflectors arranged between the two stages of lenses, each of said E.times.B deflectors being comprised of a pair of electrodes and a pair of magnetic pole pieces to generate an electric field and a magnetic field in the directions perpendicular to an ion optical axis, wherein among the four stages of E.times.B deflectors, the electric fields and magnetic fields generated by the E.times.B deflectors of the second and third stages as counted from the side of the ion source are set to be in parallel with, but opposite to, the electric field and magnetic field generated by the E.times.

Abstract: An ion source provides ions that pass through an analyzing magnet, image slit, and magnetic quadrupole lenses before entering a beam deflector. The deflected ion beam enters a magnetic field established by a dipole magnetic lens of rectangular cross section in planes parallel to the beam plane including the scanned ion beam, and having a variable width gap in a plane perpendicular to the beam plane that provides a parallel scanned ion beam. The parallel scanned ion beam enters a slot-shaped acceleration columnn and then scans a target.

Abstract: Quadrupole electron lenses 21, 22, 23 and 24 are disposed between an energy-dispersing device 15 and a parallel detector 50 in an electron energy-loss spectrometer. The power and polarity of the quadrupole lenses may be adjusted to simultaneously provide the desired energy dispersion of the spectrum, and a precise match between the width of the spectrum and the width of the parallel detector. Additional quadrupole lenses may be interposed between quadrupole lens 24 and the detector 50 to further increase the energy dispersion.

Abstract: The invention is directed to an image forming omega filter having pole pieces with straight edges which has good local resolution and very good energy resolution. The omega filter includes four deflection regions, with deflection angles greater than 90.degree..

Abstract: A method and apparatus which uses combined quadrupole (Qx and Qy) and multipole magnet sets (Mx and My) to focus a charged particle beam from a point source is described. Primarily the multipole magnet sets are octupole magnets. The apparatus is particularly useful for providing a uniform intensity for ion implantation, in cancer therapy and in other fields where uniform charged particle irradiation of a surface is important.

Abstract: An electron beam gun generates an electron beam directed at a target. The gun comprises electrodes for creating an electric field along the direction of beam travel and focusing coils for creating a magnetic field along the direction of beam travel. The electrodes include a plurality of members each having a beam-shaping aperture therein for passage of the beam substantially without interception of the electrons in the beam. The electrodes and focusing coils are disposed for accelerating electrons in the beam in non-parallel paths through the beam-shaping apertures and for converging the electrons in the beam in at least one cross-sectional dimension of the beam to minimize that dimension at the target.

Abstract: An ultra-compact electrostatic electron gun includes integrated beam-modifying means for use in electron beam memory systems, electron microscopes, electron lithographic devices and the like. The gun is illustrated as comprising means forming a point source of electrons and means receiving electrons from the point source for defining an electron beam. Electrostatic lens means receives the beam and forms a beam focus. An integrated magnetic field-generating means establishes a field of magnetic flux through the electrostatic lens for modifying the position, cross-sectional shape or other characteristic of the beam.

Abstract: A method and apparatus for automatically focussing a specimen image in an electron microscope. Excitation currents for an objective lens of the microscope are previously determined in accordance with predetermined magnifications in one-to-one correspondence. When one of the magnifications is selected, the objective lens is automatically excited with the current corresponding to the magnification, whereby the specimen image is automatically properly focussed.

Abstract: An electron beam apparatus has a primary beam directed onto a point of a specimen to generate emerging secondary electrons that proceed to a detector after traversing an electrical extraction field. The extraction field is provided between electrodes arranged in a plane perpendicular to the optical axis of the electron beam device and a magnetic field is provided perpendicular to the electrical extraction field to compensate for the forces of the extraction field exerted on the primary beam yet to promote extraction of the secondary electrons.