Abstract:
In a retarding potential type energy analyzer including a front grid electrode 21, reference grid electrode 22 and rear grid electrode 23 sequentially arranged, with a predetermined amount of potential difference given between the reference grid electrode 22 and the front grid electrode 21 to form an upward potential gradient as well as a potential difference given between the reference grid electrode 22 and the rear grid electrode 23 to form a downward potential gradient, the grid electrodes are arranged so that the distance between the reference grid electrode 22 and the rear grid electrode 23 is shorter than the distance between the reference grid electrode 22 and the front grid electrode 21, or the potential difference between the reference grid electrode 22 and the rear grid electrode 23 is made to be greater than the potential difference between the reference grid electrode 22 and the front grid electrode 21.
Abstract:
Secondary electrons emitted by a body under electron beam bombardment into the magnetic field of a magnetic electron lens in which the body is placed are constrained and directed by the magnetic field so that the lens either focusses them to a small region at the centre of a hemispherical collector assembly so that the direction of the electrons do not affect their angle of incidence on the collector, or brings their paths to be within a small angle (5°) of the axis of the lens so that they impinge on a plane collector substantially normally. The invention is of particular value in the electron beam inspection of an integrated circuit when operating.
Abstract:
The invention is directed to mass spectrometer comprising an extraction system for secondary ions. The system (18) comprises: an inner spherical deflecting sector (42); an outer spherical deflecting sector (44); a deflecting gap (46) formed between the sectors (42; 44); a housing (38) in which the sectors (42; 44) are arranged. The deflecting sectors (42; 44) are biased at retarding potentials in order to reduce the energy of the ion beam (16) entering the deflecting gap (46). The system (18) further comprises an exit disc electrode (64) with an exit through hole (66) centred about the exit axis (24), said intermediate electrode (64) being biased at an intermediate voltage between the voltage of the housing (38) and the average voltage of the sectors (42; 44). The trajectories of the secondary ions become more parallel to the exit axis (24) and become closer to said axis.
Abstract:
An ion beam apparatus 1 and a method for providing an energy-filtered primary ion beam are described. Therein, a primary ion beam 14 having an asymmetric first energy distribution is generated by means of an ion source 10. The primary ion beam is energy filtered using, for example, a retarding lens 30.
Abstract:
An ion energy analyzer (100) having a micro-channel plate (104) where the geometric filtering characteristics of the micro-channel plate (104) are electrically controlled. The ion energy analyzer contains a metallic collector (116), a control grid (108) and a micro-channel plate (104), all formed into a cylindrical stack where the collector (116), control grid (108) and micro-channel plate (104) are separated by ceramic insulating washers. A control element is formed within each aperture (124) of the micro-channel plate (104) for controlling a critical angle of each aperture (124). A voltage is applied to the control element such that an electric field is generated within each micro-channel (124). By varying the magnitude of the electric field, the critical angle of the micro-channel plate (104) can be electrically controlled, and as such, certain ion trajectories can be selected for entry into the ion energy analyzer (100).
Abstract:
An ion energy analyzer (100) having a micro-channel plate (104) where the geometric filtering characteristics of the micro-channel plate (104) are electrically controlled. The ion energy analyzer contains a metallic collector (116), a control grid (108) and a micro-channel plate (104), all formed into a cylindrical stack where the collector (116), control grid (108) and micro-channel plate (104) are separated by ceramic insulating washers. A control element is formed within each aperture (124) of the micro-channel plate (104) for controlling a critical angle of each aperture (124). A voltage is applied to the control element such that an electric field is generated within each micro-channel (124). By varying the magnitude of the electric field, the critical angle of the micro-channel plate (104) can be electrically controlled, and as such, certain ion trajectories can be selected for entry into the ion energy analyzer (100).
Abstract:
A mass filter for an ion beam system includes at least two stages (306U,306L) and reduces chromatic aberration. One embodiment includes two symmetrical mass filter stages, the combination of which reduces or eliminates chromatic aberration, and entrance and exit fringing field errors. Embodiments can also prevent neutral particles from reaching the sample surface and avoid crossovers in the beam path. In one embodiment, the filter can pass a single species of ion from a source that produces multiple species. In other embodiments, the filter can pass a single ion species with a range of energies and focus the multi-energetic ions at the same point on the substrate surface.
Abstract:
The invention relates to a charged particle filter with an integrated energy filter. Where most filters used have a highly curved optical axis, and thus use parts with forms that are difficult to manufacture, the source according the invention uses electrodes surrounding a straight optical axis. Surprisingly the inventor found that it is well possible to deflect a beam of charged particles 106a quite far from the axis 104 showing respectable energy dispersion at an energy selecting slit 108 without introducing coma or astigmatism that cannot be corrected, provided that some of the electrodes (114, 116, 120, 122) are formed as 120°/60°/120°/60°. Such electrodes can be attached to each other by gluing or brazing of ceramic, and then series of a highly concentric bores can be formed by e.g. spark erosion.
Abstract:
The invention relates to a charged particle filter with an integrated energy filter. Where most filters used have a highly curved optical axis, and thus use parts with forms that are difficult to manufacture, the source according the invention uses electrodes surrounding a straight optical axis. Surprisingly the inventor found that it is well possible to deflect a beam of charged particles 106a quite far from the axis 104 showing respectable energy dispersion at an energy selecting slit 108 without introducing coma or astigmatism that cannot be corrected, provided that some of the electrodes (114, 116, 120, 122) are formed as 120°/60°/120°/60°. Such electrodes can be attached to each other by gluing or brazing of ceramic, and then series of a highly concentric bores can be formed by e.g. spark erosion.