Patent ID: 6852983

Claim:
Charged-particle beam apparatus equipped with an aberration corrector and adapted to direct a charged-particle beam probe at a specimen, said charged-particle beam apparatus comprising: said aberration corrector placed within an optical path of the charged-particle beam and acting to correct chromatic aberration, said aberration corrector consisting of four stages of electrostatic quadrupole elements, a first power supply for supplying voltages to the four stages of electrostatic quadrupole elements, two stages of magnetic quadrupole elements for superimposing a magnetic potential distribution on an electric potential distribution created by the two central electrostatic quadrupole elements, and a second power supply for exciting the two stages of magnetic quadrupole elements; a system of condenser lenses mounted upstream of said aberration corrector and acting to adjust probe current; a third power supply for said system of condenser lenses; an angular aperture control device placed between said system of condenser lenses and said aberration corrector, said angular aperture control device consisting of at least one angular aperture control lens and a fourth power supply for said angular aperture control lens, said angular aperture control device acting to control the angular aperture of the probe striking the specimen; an objective lens mounted downstream of said aberration corrector and acting to focus said probe onto the specimen; a fifth power supply for said objective lens; an objective lens aperture placed at least downstream of said system of condenser lenses; a manual input operation device permitting one to modify one of the operating parameters selected from the accelerating voltage on the charged-particle beam, the working distance between the objective lens and the specimen, and the probe current; and a controller for controlling the first through fifth power supplies in response to a manual input operation performed on said manual input operation device, such that when at least one of the accelerating voltage, working distance, and probe current is modified, the angular aperture of the probe is so controlled as to minimize the diameter of the probe striking the specimen.