Abstract: An electron gun having a field emission cathode is provided with a focusing magnetic lens. In the vicinity of the cathode, a pole piece is defined by two parts. The orifice of the part closer to the cathode is smaller than that positioned downstream. The air gap between the two parts is small and the filament of the cathode extends up to a distance of from about 1.5 to 3 mm from the median plane of the air gap. The excitation of the coil of the focusing magnetic lens is provided such that the image of the electronic source is substantially positioned at the level of the orifice of an intermediate electrode surrounding at least the magnetic lens.

Abstract: An apparatus for the potential measuring technique has an objective lens for focusing primary electrons onto an object, and also has a spectrometer for the energy selection of secondary electrons to provide an improvement of the quantitative potential measurement on printed conductors of integrated microelectronic components with improved local resolution, higher probe current, and improved potential resolution. The objective lens is a magnetic lens in which the lens field lies largely outside the lens body, and the spectrometer is an electrostatic retarding field spectrometer arranged in the magnetic field of the lens.

Abstract: Benchmark detector (46) has two light pipe fingers (48, 50) which lie adjacent to each other at an acute angle to the orthogonal axes of movement of the stage on which the benchmark is positioned. The light pipe fingers have notches which define a rectangular opening therebetween through which a benchmark (52) can be excited to produce secondary electrons. Scintillator material adjacent the notches produces photons in the light pipes so that the position of the benchmark with respect to the detector can be established.

Abstract: An electrospray ion source for a mass spectrometer capable of generating ions from samples dissolved in a solution comprises a capillary tube through which the said solution is pumped into a first chamber maintained substantially at atmospheric pressure and in which an inert gas is flowing in a direction counter to the flow of the solution, and a small orifice in the end wall of the chamber opposite to and aligned with the capillary. A high potential difference is applied between the capillary and the end wall so that the solution is electrosprayed into the chamber and ions characteristic of the sample are formed. These ions are desolvated to a controllable extent by the inert gas, which may also be heated to improve the efficiency of the process and increase the maximum permissible flow rate of solution. The ions so formed pass through the small orifice into a second chamber maintained at a reduced pressure, and into a mass spectrometer.

Abstract: The invention comprises a high vacuum compatible electron beam stage having an X/Y and theta coordinate positioning drive mechanism mounted from below the stage. The stage comprises four plates: A base plate, an X plate slidably mounted thereon and constrained to slide in an X direction, a Y plate slidably mounted on the X plate and constrained to slide in a Y direction, and a theta plate mounted on the Y plate and constrained to translate in the Z direction. Two rotary capstans, mounted on drive shafts, are coupled on each to the X and Y plates by a metallic band looped around the capstan and attached at opposite ends to the plate. Rotation of the capstan causes the respective plates to slide in their constrained direction. The theta plate drive shaft is limited to vertical motion. The Y and theta drive shafts couple to universal joints. All three drive shafts couple to bellows joints. This permits the drive shafts to deflect at small angles.

Abstract: A gas is introduced into a discharge chamber of an ion source apparatus, and a gas discharge is performed between a thermionic cathode and an anode. Ions are extracted from the plasma formed in this gas discharge by a grid electrode. The thermionic cathode has a hollow cylindrical shape. A cathode chamber is defined by the thermionic cathode and a cylindrical partition wall supporting it. A columnar auxiliary electrode is coaxially inserted in the thermionic cathode. An A.C. voltage from a power source unit is supplied between the thermionic cathode and the auxiliary electrode such that effective power for keeping the thermionic cathode at a positive potential with respect to the auxiliary electrode is higher than that for keeping the auxiliary electrode at a positive potential with respect to the thermionic cathode.