Charged particle beam device
Deflection of a secondary beam, and astigmatism correction of a primary beam or of the secondary beam are carried out using a multi-pole electromagnetic deflector which deflects the path of the secondary beam toward a detector.
1. A charged particle beam device comprising:
a charged particle gun that produces a primary beam;
a stage on which a sample is placed;
a detector that detects a secondary beam generated from the sample in response to the primary beam;
a multi-pole electromagnetic deflector that deflects a path of the secondary beam; and
a control circuit that controls the multi-pole electromagnetic deflector, wherein
the multi-pole electromagnetic deflector includes
electric field deflectors that generate an electric field, and
magnetic field deflectors of which number is the same as the number of the electric field deflectors and which generate a magnetic field,
the control circuit includes
electric field deflector drive circuits, each driving the electric field deflector,
a first astigmatism correction common voltage generating unit that controls the electric field deflector and outputs a first astigmatism correction voltage for carrying out astigmatism correction of the primary beam or the secondary beam,
magnetic field deflector drive circuits, each driving the magnetic field deflector,
a second astigmatism correction common voltage generating unit that controls the magnetic field deflector and outputs a second astigmatism correction voltage for carrying out astigmatism correction of the primary beam or the secondary beam,
an electric field-magnetic field common control voltage generating unit that outputs a deflection common voltage for deflecting a path of the secondary beam to the detector to the electric field deflector drive circuit and the magnetic field deflector drive circuit,
a first adder that adds the deflection common voltage and the first astigmatism correction voltage input directly or after adjustment and outputs a first added voltage to the electric field deflector drive circuit, and
a second adder that adds the deflection common voltage and the second astigmatism correction voltage input directly or after adjustment and outputs a second added voltage to the magnetic field deflector drive circuit.
2. The charged particle beam device according to claim 1 , wherein
each of the number of the electric field deflectors and the number of the magnetic field deflectors of the multi-pole electromagnetic deflector is N (but, N is a multiple of 4 which is 8 or more).
3. The charged particle beam device according to claim 2 , wherein
the electric field deflectors are arranged circumferentially,
the magnetic field deflectors are arranged circumferentially, and
the deflection common voltage is a direct or adjusted input of a predetermined first adder corresponding to a predetermined electric field deflector, and a predetermined second adder corresponding to a predetermined magnetic field deflector arranged at a position offset 90 degrees clockwise or counterclockwise from the predetermined electric field deflector.
4. The charged particle beam device according to claim 3 , wherein
the electric field deflector is an electrode, and
the magnetic field deflector is a coil in which the electrode is at least part of a core.