Abstract: A method of imaging single molecules, comprises the steps of: a) providing an assembly comprising a carrier substrate having a substrate face with an aperture, the aperture being covered with a receiving layer attached to the substrate face, the receiving layer being substantially transparent for low-energy electrons with a kinetic energy of 5 to 1,000 eV; b) depositing single molecules onto said receiving layer by means of soft-landing electrospray ion deposition, whereby a single molecule loaded receiving layer is formed; c) acquiring an in-line low-energy electron transmission pattern of said single molecule loaded receiving layer; and d) applying a reconstruction procedure to said electron transmission pattern to obtain at least one image of a single molecule on said single molecule loaded receiving layer. The above steps a) to c) are conducted under vacuum conditions.

Abstract: A method of imaging single molecules, comprises the steps of: a) providing an assembly comprising a carrier substrate having a substrate face with an aperture, the aperture being covered with a receiving layer attached to the substrate face, the receiving layer being substantially transparent for low-energy electrons with a kinetic energy of 5 to 1,000 eV; b) depositing single molecules onto said receiving layer by means of soft-landing electrospray ion deposition, whereby a single molecule loaded receiving layer is formed; c) acquiring an in-line low-energy electron transmission pattern of said single molecule loaded receiving layer, said single molecule loaded receiving layer. The above steps a) to c) are conducted under vacuum conditions.

Abstract: Ion sources or generators for focused ion beam emission (FIB) applications emitting ion beams into vacuum or a gas are used in industry and research for the characterization and processing of surfaces. With appropriate focusing, such ion beams can be confined to diameters of a few nanometers. The tip of technical FIB generators for producing such focused beams consists of a liquid metal, gallium in general, which tends to fluctuate during operation. This has a negative influence on the stability of the emission current and the focus definition. It is also possible to generate an FIB with solid tips, consisting of a solid metal, but such tips deteriorate rapidly during operation due to erosion of material from the tip apex. The present invention concerns a novel FIB source generating free space ion beams from a solid source but does not exhibit the above-mentioned erosion effect at the apex.

Abstract: A source for intense coherent electron pulses of an energy below 1 keV comprises an ultrasharp electron-emitting tip and an anode both arranged in mutual alignment inside a vacuum envelope A pulsed potential with an amplitude in the range between 100 V and 500 V and with a variable pulse rate is applied between said tip and said anode. The tip is maintained negative with respect to said anode, the tip having a sharpness such that the electric field at its surface exceeds 10.sup.7 V/cm at said pulsed potential.

Abstract: The Delta-Phi microlens consists of a first foil (3) of a metal or alloy from the group of transition metals and a second foil (4) of a metal or alloy from the group comprising the elements of IA or IIA groups of the periodic system of elements, the second foil (4) being coated onto one surface of said first foil (3). A hole (2) extends through both foils (3, 4) in precise alignment with the axis (6) of a sharply pointed tip (1) made of conductive material and placed at a distance of the order of 1 .mu.m from that surface of said first foil (3) opposite said second foil (4). With the first foil (3) connected to ground and a potential on the order of -30 V applied at said tip (1), at ultra-high vacuum conditions, a beam of low-energy electrons will have trajectories (5) deviated towards a focal point (7).

Abstract: This source for charged particles comprises a sharply pointed tip (1) and an aperture (2) in a thin sheet of material. If the point of the tip (1) is made sharp enough, i.e., if it ends in a single atom or a trimer of atoms, the electric field existing between the tip (1) and the aperture (2) will cause a stream of electrons to be emitted from the tip (1), pass the aperture (2) and to continue as a beam (4) of free electrons beyond said aperture (2). The sheet (3) carrying the aperture (2) may, for example, be a carbon foil or a metallic foil, including gold. The distance of the tip (1) from the aperture (2) is in the submicron range, and so is the diameter of said aperture (2). The distance is being held essentially constant by means of a feedback loop system. The divergence of the beam (4) is <2.degree..

Abstract: A method for fabricating exactly aligned apertures for use in electron and ion microscopy involves the placing of a very sharply pointed tip (1) in front of a set of extremely thin, precisely spaced metal foils (3,5) in an atmosphere of heavy gas atoms. The application of an elevated voltage at the tip (1) will result in a sputtering operation to commence and erode the metal foils (3,5) at a location underneath the facing tip (1). The sputtering operation is continued until the first ions are detected to emerge on the far side of the lens structure (2).

Abstract: An atto amperemeter includes a shop tip (1) correctable to a voltage source (18) providing a known potential (U') via a sample conductor measured, the tip (1) faces a particle detector such as an electron multiplier (4). The count of the free electrons being emitted from the tip (1), multiplied by the electron multiplier (4) and counted by an electronic current (i) passing through the sample conductor (17). Calibration of the arrangement is performed by temporarily connecting the tip (1) to ground and applying a calibration potential (U cal) to a calibrated electrode (3) aligned with the tip (1) and the channel electron multiplier (4).