Cameca

Université De Paris—sud

Thomson-csf

Office National D'etudes Et De Recherches Aerospatiales

Office National D'etudes Et De Recherche Aerospatiales (onera)

Office National D'etudes Et De Recherches

Aerospatiales and Universite De Paris-sud

Centre De Recherche Public-gabriel Lippmann

Georges Slodzian

Tom Wirtz

Bernard Daigne

Francois Girard

Roger Dennebouy

Marcel Chaintreau

Francois Costa De Beauregard

Jean-Claude Lorin

Henri-Noël Migeon

An ion source is described, including a source of neutral particles which arrive at an ionization support positioned inside a chamber which is closed by a cap and which includes lateral walls. The cap includes an outlet orifice opposite which a plate defines a main ionization active surface. An electric field is applied between said device and by an electrode place downstream from the orifice in the direction of ion emission and fitted with a corresponding opening. Overall, the ionization support defines, by virtue of its active surface, and by virtue of holes surrounding said central active surface, a baffle assembly which prevents neutral atoms from passing directly to the outlet orifice, and which contributes to a high degree of ionization.

Ion source operating by surface ionization in particular for providing

To compensate for the charges created during the bombardment of a sample of insulating material, positively polarized by a beam of positive, primary ions, the method uses the secondary electrons emitted by the acceleration electrode under the impact of particles, emitted by the sample, which have not passed through the hole provided in this electrode for analysis. For this, an additional electrode, having a hole of a diameter greater than that of the acceleration electrode and carried to a potential which is greater than that of the same electrode by about 100 volts, is placed between the sample and this electrode, near the latter, to focus the secondary electrons on the imaged field of the sample.

Method and device to discharge samples of insulating material during ion

A sample (EC) is mounted on a sample carrier (PO). Vertically thereabove a common optical portion (5) receives a beam of primary ions derived from an ion source (S10) together with a beam of primary electrons derived from an electron source (S30). The secondary electrons and ions due to the sample (EC) being bombarded by said primary ions and electrons are retrieved by said common optical portion (5). The electrons are detected by electron detection means (D40). The secondary optical system (2) transmits the secondary ions to a mass spectrometer (SP20). This instrument is capable of providing ion and electron images of a single sample simultaneously.

Instrument for very high resolution ionic micro-analysis of a solid

Mass spectrometer having an ion source, acceleration means able to impart to the ions an energy essentially dependent on their electric charge, means for producing in a sector a magnetic field orthogonal to the plane of the trajectory of the ions in order to inwardly curve said trajectory and means for detecting the ions. At the inlet of the magnetic sector are provided electrostatic means able to modify the tangential velocity of the ions and consequently their energy, in such a way that ions with different masses can, at different times, follow the same inwardly curved trajectory in the magnetic sector.

Mass spectrometers

Between the electrostatic sector (SE 23) and the magnetic sector (SM 30) of a mass spectrometer, there is provided a quadrupole (QP 26) which applies parallel beams to the magnetic sector whose inclination depends on the energy dispersion of the particles. A slotted lens (LF 27) corrects the divergence of the quadrupole in the perpendicular plane. A suitable relationship between the angle of the inlet face of the magnetic sector (SM 30) and the deflection angle provided thereby ensures that the second order aperture aberrations of the magnetic sector are corrected. The chromatic aberrations may be corrected by means of a hexapole (HP 25) centered on the focus of the quadrupole (QP 26). Another hexapole (HP 22) placed upstream from the electrostatic sector (SE 23) level with a constriction in vertical section of the particle beam serves to correct second order aperture aberrations related to the electrostatic sector (SE 23).

High clarity mass spectrometer capable of multiple simultaneous detection

The invention provides a process and device for the ionic analysis of an insulating sample brought to a given negative potential, of the type in which a target on the surface of the sample to be analyzed is bombarded by means of a primary electron beam and negative ions emitted by the bombarded target are used for producing an ion image of the sample. An electron beam whose normal speed component cancels out just at level of the surface of the target is directed perpendicularly to the target. The device comprises for this purpose a filament, brought substantially to the same negative potential as the sample, which emits the electron beam. The electron beam, after emission, is deflected by a magnetic prism so as to be brought into coincidence with the optical axis of the negative ion beam emitted by the target.

Growing community of inventors

Sceaux, France

Georges Slodzian