Patent Number: 040244024
Section: summary

Our invention relates to specimen cartridges for particle beam devices, such as electron microscopes or the like. To bring specimens into the interior of a particle beam device, specimen cartridges are used. Specimen cartridges include a conical member with which the specimen cartridge is insertable into the specimen table of the microscope in a direction parallel to the axis of the particle beam. The specimen table is transversely adjustable in the interior of the electron microscope relative to a table carrier, to permit various surface regions of the inserted specimen to be investigated. The table carrier can, for example,s be made from the pole shoe to the magnetic objective lens of an electron beam microscope. The specimen cartridge often includes a specimen holder for receiving the specimen to be investigated. This specimen received by the specimen holder is readily exchangeable for other specimens. Each specimen to be investigated is first secured by means of the specimen holder and then, with the conical member, is placed into the microscope through an air lock, the microscope being connected with an operating pump. After this preparatory step, the specimen regions of interest are investigated. In many cases, it is desired to compare the specimen under investigation with other specimens. In this connection, difficulties arise because of the necessary preparation associated with insertion of the specimen or comparison specimens into the microscope. It is an object of our invention to provide a specimen cartridge for a particle beam apparatus, such as an electron microscope or the like. Subsidiary to this object, it is an object of our invention to provide a specimen cartridge which is insertable into a transversely adjustable specimen table along an axis parallel to the beam axis. The specimen cartridge of the invention includes a cartridge cone or conical member, as well as a specimen holder connected to the latter. In this connection, it becomes a further object of our invention to provide a specimen cartridge which permits and facilitates the simultaneous insertion of a plurality of specimens into the interior of the electron microscope, thereby preventing the above-mentioned difficulties. According to a feature of the invention, the specimen holder of the specimen cartridge is provided with a plurality of openings for receiving specimens and, according to a further feature, the specimen holder is secured to the conical member and is rotatable about an axis of rotation extending eccentric to the longitudinal axis of the conical member. In applying the specimen cartridge of the invention, it is possible to bring a plurality of specimens simultaneously into the interior of an electron microscope and to place the specimens individually by means of a rotation of the specimen holder into the path of the particle beam. According to a preferred embodiment of the invention, the specimen holder is configured so as to be in the form of a circular disk. According to another embodiment of the invention, the openings of the circular shaped disk are configured for receiving special specimen carriers. These object carriers are tightly held in place by means of a plate which is tensioned against the disk. These specimen carriers are for example, formed from ring apertures receiving the specimens and have a centric bore for leaving the specimen surfaces to be investigated free. In an alternate embodiment of the invention, the openings are configured as slits extending concentric to the rotating axis of the disk. With this embodiment, investigations of large surface areas of the specimens is possible. In an advantageous embodiment of the invention, the specimen holder is joined with a gear wheel via a shaft. The gear wheel is rotatably borne on, the end face of the cartridge cone. by means of the arrangement of the shaft, the specimen holder is directed at a distance from the end face of the cartridge cone. To insure a precise positioning of the specimen holder free of tipping, the gear wheel has a radius which extends beyond the longitudinal axis of the cone, whereby the gear wheel is provided with pass-through openings for the electron beam which correspond to the openings of the circular shaped disk. This embodiment affords the additional advantage that the gear wheel has a correspondingly large diameter to accommodate a large drive arrangement. The gear wheel is advantageously joined with a pinion positioned on a drive shaft which is directed in the cartridge cone parallel to the longitudinal axis of the cone. This drive shaft has a toothed drive wheel which has a diameter extending beyond the periphery of the cartridge cone. The toothed drive wheel meshes with a corresponding toothed wheel borne in the specimen table. The toothed wheel in the specimen table is driven from outside the electron microscope by means of appropriate linkages. By adjusting these linkages, the specimen holder is turned about an axis extending eccentric to the longitudinal axis of the cartridge cone, thereby permitting the specimens to be sequentially placed in the path of the electron beam.