| 摘要 |
The invention relates to a particle beam apparatus, in which very low target energies of the particles focused on the object can be set, with good imaging conditions. For this purpose, the beam guiding tube (5), from the anode (4) to behind the objective (6, 7) is at a high potential, which insures that the particles within the beam guiding tube have a high kinetic energy which is independent of the target energy. A braking electrode (9) arranged after the beam guiding tube, together with the object holder (10) and the object arranged thereon, is at a specimen potential UP which deviates from the ground potential and which has the same sign as the cathode potential UK. The specimen potential UP acts as the decelerating potential, by means of which the particles are braked to energies which can be below the energy value determined by the cathode potential UK. Thus even at the lowest target energies the object does not need to be brought to a high, high-voltage potential, so that object damage and high voltage flashovers are excluded. At the same time, the kinetic energy of the electrons within the beam guiding tube is largely independent of the target energy, so that the imaging relationships within the beam guiding tube are largely independent of the target energy.
|
