Abstract: In a SEM it is desirable, in given circumstances, to acquire an image of the sample (14) by means of Auger electrons extracted from the sample and traveling back through the bore of the objective lens (8) in the direction opposing the direction of the primary beam. It is know to separate extracted electrons from the primary beam by positioning Wien filters (32, 34) in front of the objective lens (8), the filters being energized in such a way that they do not cause deflection of the primary beam but do not deflect the secondary electrons. This technique cannot be used for Auger electrons, considering their high energy and hence much stronger fields in the Wien filters, thus causing substantial imaging aberrations in the primary beam.

Abstract: A calibration mask having a plurality of marks previously formed thereon is loaded, and a deflector is used to control deflection of electron beams so that the electron beams are incident on a mark of the calibration mask. The electron beams, having passed through the mark, impinge on a first Faraday cup having a first mark and on a second Faraday cup having a second mark. Then, positional coordinates on an XY stage are detected when electrical quantities detected by the Faraday cups are largest. The positional coordinates on the above mentioned XY stage are detected for each of the marks of the calibration mask. Then, according to the positional coordinates on the XY stage detected in this manner and a difference in height between the marks, the inclination of the electron beams is calculated for the position input to each mark of the calibration mask. Thus, the inclination of electron beams can be accurately measured.

Abstract: A charged beam lithography system includes a charged particle gun for generating charged beams, a main deflecting system and a sub-deflecting system for deflecting the charged beams generated by the charged particle gun, and a control computer. The charged beam lithography system is designed to cause the surface of a substrate to be irradiated with the charged beams from the charged particle gun while continuously moving a stage, to write a desired pattern for each of stripes defined by the maximum deflection widths of the main deflecting system and the sub-deflecting system. The charged beam lithography system further comprises: a real time proximity effect correcting circuit for calculating an optimum dosage for each of the stripes by correcting the dosage of the electron beams in view of the influence of the proximity effect; and a cash memory for storing the optimum dosage data for at least two of the stripes.

Abstract: An ion source including an electron generating chamber and an ionization chamber adjacent the electron generating chamber and having an opening therebetween. The ionization chamber has a gas inlet opening and the electron generating chamber has a outlet. The gas inlet opening, the outlet and the opening between the two chambers are all on a common axis. The electron generating chamber has therein a cathode filament which extends completely around the axis and generates electrons, electrodes for directing the electrons transversely toward the axis and a deflection electrode for deflecting the electron flow along the axis and into the ionization chamber. An accelerator plate is adjacent the outlet and is adapted to attract ions generated in the ionization chamber along the axis and through the outlet.