Abstract: For testing an interconnect network for shorts and interruptions, a point of the network to be tested is charged with a particle beam. Subsequently, a potential at least one further contact point is read with the same particle beam and an unaltered primary energy. An identification of potential occurs by documenting the secondary electrons triggered at the contact points. In order to avoid a disturbing change of potential during the measuring phase, the measuring time is only a fraction of the time for charging the network.

Abstract: An objective lens which is a component of a scanning electron microscope and wherein the electron source or the intermediate image of the electron source is reduced by condenser lenses is imaged onto a specimen (PR). The objective lens comprises an asymmetrical magnetic lens (ML), an electrostatic immersion lens (OE/UE) superimposed on the magnetic lens (ML), and electrode (ST) which is connected to a variable potential (U.sub.ST) so as to control the intensity of the current of secondary (SE) and back-scattered electrodes released from the specimen (PR), and a detector (DT) mounted immediately above the magnetic lens (ML). The electrodes (OE, UE) of the immersion lens are connected to potentials so that an electrical field which decelerates the primary electrons (PE) is formed inside the objective lens.

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: A spectrometer objective includes a generally asymmetrical objective lens having a short focal length, a deflection system disposed within the objective lens symmetrically relative to an optical axis, and an electrostatic retarding field spectrometer including an electrode arrangement for accelerating the secondary electrons generated on the specimen. The electrode arrangement of the retarding field spectrometer includes an electrode pair for establishing a spherically symmetrical retarding field. The electrode arrangement for extracting and accelerating the secondary particles includes a grid electrode disposed in a region of the lower pole piece of the objective lens and of a planar electrode disposed in the particle beam path immediately above the specimen, wherein the planar electrode is charged with a potential lying between the potential of the specimen and the potential of the grid electrode.

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: 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: There is disclosed a scanning particle microscope in which the adverse influence of the Boersch effect is reduced. This is achieved by providing an elastrostatic retardation element in the particle optics unit to decelerate the particle from a first energy, at which the particles are generated, to a second energy which is less than half of the first energy.

Abstract: A method and apparatus for measuring lengths in a scanning particle microscope employ a device for generating a particle beam directed toward a specimen stage on which a specimen is mounted. A second stage is placed over the specimen stage above the specimen, the second stage carrying a calibrated grid structure covering the region of the specimen to be measured. The grid structure is disposed a distance from the specimen which is less than or equal to the depth of focus of the apparatus. The grid structure is of known dimensions, and is utilized to provide bench marks for measuring distances on the specimen, and can be displaced as needed to measure longer distances.

Abstract: A beam generator in a scanning particle microscope reduces energetic Boersch effect on the probe diameter to improve resolution by enabling beam particles to traverse a first beam crossover point with low energy and subsequently reaccelerating the beam particles to high energies while traversing the microscope's electro-optical column for subsequent deceleration shortly before reaching a specimen. An extraction electrode is provided between a Wehnelt electrode and an anode at a positive potential relative to a cathode, wherein the positive potential of the extraction electrode is substantially less than a positive potential at the anode.

Abstract: An electron-optical system with a variable-shaped beam for generating and measuring microstructures, such as circuits on a semiconductor substrate, generates the variable-shaped electron beam by the use of electron-optical shadow projection imaging and has a remote focus multipole Wehnelt electrode for adjusting, focusing, and controlling the intensity of the electron beam. The system also has a ferrite polecylinder in the beam projections lens with field attenuation or may have a beam projection lens with an external air gap. The length of the electron beam is approximately 60 centimeters.

Abstract: A high current electron source with a narrow energy band of the type employed in an electron beam printer has a beam generating system consisting of a cathode and focusing electrodes and an anode with at least one electrode functioning to astigmatically focus at least one electron crossover in the low velocity range. For varying the position and shape of the crossover in a simple manner for adaptation to particular use conditions of the high current electron source, the Wehnelt electrode of the electron source consists of one or more cylinder lenses or of an electrostatic multipole element, or an electromagnetic multipole element is disposed in the plane of a conventional non-ferromagnetic Wehnelt electrode with a circular aperture for the electron beam. By pole reversal of the Wehnelt voltage or of the coil current and by changing the size of the current, the shape and azimuth position of the first crossover in the cathode space can be varied to any configuration.

Abstract: In an exemplary system, a two stage deflection system responds to a first control signal of low frequency such that extra-axial chromatic errors due to electrostatic and magnetic deflection are made equal and opposite. The magnetic and electrostatic deflection systems may be arranged in either order along the beam path just so the low frequency electrostatic deflection is one-half the magnetic deflection and is in an opposite direction at the target. A second higher frequency control signal controls only the electrostatic deflection system. Preferably the deflection velocities at the target produced by the two control signals are equal, with the higher frequency being an integral multiple of the lower frequency and with the control signals being poled to provide opposite deflections. When the two deflection velocities are superimposed, the resultant is then a step type deflection as a function of time.

Abstract: A method and device for correcting errors and setting the focus of an electron optical condenser of a microprojector which condenser produces a bundle of axially parallel electron rays for illuminating a large surface transmission mask to create an image which is projected by means of an electron optical lens system on a surface of a wafer characterized by placing an annular field stop or diaphragm which passes a bundle of rays having a ring-shaped or annular cross section and recording the image in a plane preferably adjacent the surface of the wafer. The recording can be accomplished by utilizing a photographic plate or by utilizing a detector arrangement. When the image on the recording unit is the same size and shape as the annular field stop, then the electron optical condenser has the correct focal length and the source is disposed on the front focal plane.