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US 2001/0032931 A1Published application
Charged particle beam instrument
AssigneeJEOL Ltd.
InventorMiyuki Matsuya
Life of this patent
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Abstract
A charged particle beam instrument capable of reducing the spread of the probe diameter while maintaining the probe current constant. An electrical current Id is detected by a detection aperture to create a feedback signal. The feedback signal is supplied to a condenser lens control and to an objective lens control via a signal adjuster. The objective lens control portion controls the objective lens such that the charged particle probe is in focus.
Claims6
A charged particle beam instrument comprising:
- a charged particle beam source for producing a charged particle beam having a probe current;
- a first focusing means for focusing the charged particle beam and varying the probe current of the charged particle beam impinging on a specimen;
- a second focusing means for varying the degree of focus of said charged particle beam impinging on the specimen;
- a first control portion for controlling said first focusing means;
- means for detecting a part of the current of the charged particle beam from the charged particle beam source to thereby produce a detected signal, controlling the control portion for said first focusing means to maintain constant the probe current of the charged particle beam impinging on the specimen, and controlling the control portion for said second focusing means according to the detected signal to adjust focus of said charged particle beam.
2 more elements
Dependencies are inferred from the claim text.