Charged particle beam device

An image acquiring method including the steps of:

• providing a charged particle source and generating a primary charged particle beam using the charged particle source;
• utilizing a plurality of convergent lenses for converging the primary charged particle beam which is emitted from the charged particle source along an optical axis of the charged particle beam device;
• providing a scan coil for scanning the primary charged particle beam on a sample;
• using an objective lens for converging the primary charged particle beam and for irradiating the primary charged particle beam on the sample;
• providing a sample table for receiving and supporting the sample;
• arranging a deflector above the objective lens and using the deflector for tilting the primary charged particle beam, the charged particle beam device being usable for acquiring a stereo pair image of the sample by irradiating on the sample;
• tilting the primary charged particle beam by using a swing-back action of the objective lens, the deflector moving a virtual crossover of the primary charged particle beam to a position out of the optical axis when tilting the primary charged particle beam,
• locating an aligner between the objective lens and the deflector with the aligner having a beam tilt field-of-view compensation function for compensating a tilt angle (ω0) of the primary charged particle beam by a compensation angle Δω0, such that a distance Δro between a virtual crossover of the primary particle beam and the optical axis is in a predetermined range, and makes a field-of-view of the left and right stereo pair image of a sample surface coincident by compensating the tilt angle of the primary charged particle beam,
• providing a tilting mechanism and using the tilting mechanism for tilting the sample on the sample table;
• utilizing a tilted focus compensation function for compensating a focus of the objective lens and simultaneously compensating the tilt angle (ω0) of the primary charged particle beam in response to a surface tilt of the sample on the sample table and using the aligner for compensating for a field-of-view deviation while the primary charged particle beam is scanned on one line on the sample;
• adapting the charged particle beam device for acquiring a stereo pair image of the sample tilted by the tilting mechanism;
• and
• increasing a first signal for the aligner, and decreasing a second signal for the objective lens as a function of the advancing of a deflection signal for the scan coil.