Operating a particle beam apparatus

A method for operating a particle beam apparatus comprising:

• at least one beam generator for generating a particle beam comprising charged primary particles,
• at least one objective lens for focusing the particle beam onto the object, wherein interaction particles and/or interaction radiation arise/arises in the case of an interaction of the particle beam with the object and wherein the objective lens has at least one termination electrode,
• at least one adjustable deflection unit for deflecting the particle beam and/or at least one adjustable aperture unit for forming the particle beam,
• at least one movable specimen stage for arranging the object in the particle beam apparatus,
• at least one detector for detecting the interaction particles and/or interaction radiation and for generating detector signals,
• at least one display device for displaying an image of the object, wherein the image is generated by means of the detector signals,
• at least one objective lens control unit for supplying the objective lens with an objective lens current and for setting the objective lens current, and
• at least one termination electrode control unit for supplying the termination electrode with a termination electrode voltage and for setting the termination electrode voltage,
• wherein the method comprises:
• setting the objective lens current to a current value by means of the objective lens control unit and periodically changing the current value of the objective lens current by means of the objective lens control unit;
• setting at least one of the following properties of the deflection unit and/or of the aperture unit during the periodic change of the objective lens current:
• (i) a position of the deflection unit and/or the aperture unit in the particle beam apparatus and (ii) at least one actuation variable for supplying the deflection unit and/or the aperture unit, wherein setting is implemented in such a way that either the image of the object displayed on the display device does not move or any such movement of the displayed image has a minimal deflection;
• setting the termination electrode voltage to a termination electrode voltage value by means of the termination electrode control unit and periodically changing the termination electrode voltage value of the termination electrode voltage by means of the termination electrode control unit;
• and
• moving the specimen stage to an aligned position of the object during the periodic change in the termination electrode voltage in such a way that either the image of the object displayed on the display device does not move or any such movement of the displayed image has a minimal deflection.

A method for operating a particle beam apparatus comprising:

• at least one beam generator for generating a particle beam comprising charged primary particles,
• at least one objective lens for focusing the particle beam onto the object, wherein interaction particles and/or interaction radiation arise/arises in the case of an interaction of the particle beam with the object, wherein the objective lens has at least one termination electrode,
• at least one movable specimen stage for arranging the object in the particle beam apparatus, wherein the specimen stage is rotatable about a first axis and/or a second axis and wherein the first axis is arranged perpendicular to the second axis,
• at least one detector for detecting the interaction particles and/or interaction radiation and for generating detector signals,
• at least one display device for displaying an image of the object on the basis of the detector signals, and
• at least one control unit for setting a beam parameter, wherein the method comprises:
• recording reference images in a reference position of the specimen stage, including the following steps:
• recording a first reference image of the object in the reference position of the specimen stage with a beam parameter having a value corresponding to a reference value;
• recording a second reference image of the object in the reference position of the specimen stage with the beam parameter having a beam parameter value, which differs from the reference value;
• calculating an image shift of the second reference image in relation to the first reference image;
• recording images in a first position of the specimen stage, including the following steps:
• recording a first image of the object in the first position of the specimen stage with the beam parameter having a value corresponding to the reference value;
• recording a second image of the object in the first position of the specimen stage with the beam parameter having the beam parameter value, which differs from the reference value;
• calculating an image shift of the first image in relation to the first reference image and calculating an image shift of the second image in relation to the first reference image;
• recording images in a second position of the specimen stage, including the following steps:
• recording a third image of the object in the second position of the specimen stage with the beam parameter having a value corresponding to the reference value;
• recording a fourth image of the object in the second position of the specimen stage with the beam parameter having the beam parameter value, which differs from the reference value;
• calculating an image shift of the third image in relation to the first reference image and calculating an image shift of the fourth image in relation to the first reference image;
• interpolating the image shifts of the first image and third image, each recorded at the reference value, in relation to the first reference image depending on the position of the specimen stage;
• interpolating the image shifts of the second reference image, the second image and the fourth image, each recorded at the beam parameter value, in relation to the first reference image depending on the position of the specimen stage, wherein the beam parameter value differs from the reference value;
• establishing a target position of the specimen stage, in which the interpolated image shifts at the reference value and at the beam parameter value, which differs from the reference value, are identical;
• and
• operating the particle beam apparatus with the beam parameter having a value corresponding to the reference value and with the specimen stage arranged in the target position.

A computer program product having program code, which may be loaded into a processor of a particle beam apparatus comprising:

• at least one beam generator for generating a particle beam comprising charged primary particles,
• at least one objective lens for focusing the particle beam onto the object, wherein interaction particles and/or interaction radiation arise/arises in the case of an interaction of the particle beam with the object, wherein the objective lens generates a magnetic field and an electric field at least partly between the beam generator and the object,
• at least one adjustable deflection unit for deflecting the particle beam and/or at least one adjustable aperture unit for forming the particle beam,
• at least one movable specimen stage for arranging the object in the particle beam apparatus,
• at least one detector for detecting the interaction particles and/or interaction radiation and for generating detector signals,
• at least one display device for displaying an image of the object, wherein the image is generated by means of the detector signals,
• at least one objective lens control unit for supplying the objective lens with an objective lens current and for setting the objective lens current, and
• at least one beam generator control unit for supplying the beam generator with an operating voltage and for setting the operating voltage,
• wherein the program code, when executed, controls the particle beam apparatus in such a way that a method is carried out, the method comprising:
• setting the objective lens current to a current value by means of the objective lens control unit and periodically changing the current value of the objective lens current by means of the objective lens control unit;
• setting at least one of the following properties of the deflection unit and/or of the aperture unit during the periodic change of the objective lens current:
• (i) a position of the deflection unit and/or the aperture unit in the particle beam apparatus and (ii) at least one actuation variable for supplying the deflection unit and/or aperture unit, wherein setting is implemented in such a way that either the image of the object displayed on the display device does not move or any such movement of the displayed image has a minimal deflection;
• setting the operating voltage to a voltage value by means of the beam generator control unit and periodically changing the voltage value of the operating voltage by means of the beam generator control unit;
• and
• moving the specimen stage into a position of the object during the periodic change in the voltage value of the operating voltage in such a way that either the image of the object displayed on the display device does not move or any such movement of the displayed image has a minimal deflection.

A particle beam apparatus for imaging and/or for processing an object, comprising:

• at least one beam generator for generating a particle beam comprising charged primary particles;
• at least one objective lens for focusing the particle beam onto the object, wherein interaction particles and/or interaction radiation arise/arises in the case of an interaction of the particle beam with the object, wherein the objective lens has at least one termination electrode;
• at least one adjustable deflection unit for deflecting the particle beam and/or at least one adjustable aperture unit for forming the particle beam;
• at least one movable specimen stage for arranging the object in the particle beam apparatus;
• at least one detector for detecting the interaction particles and/or interaction radiation and for generating detector signals;
• at least one display device for displaying an image of the object on the basis of the detector signals;
• at least one objective lens control unit for supplying the objective lens with an objective lens current and for setting the objective lens current;
• at least one beam generator control unit for supplying the beam generator with an operating voltage and for setting the operating voltage;
• at least one termination electrode control unit for supplying the termination electrode with a termination electrode voltage and for setting the termination electrode voltage;
• at least one deflection control unit for supplying the deflection unit and/or the aperture unit with an actuation variable and for setting the actuation variable;
• and
• a processor having program code of a computer program product being loaded therein, wherein the program code controls the particle beam apparatus in such a way that a method is carried out, the method comprising:
• setting the objective lens current to a current value by means of the objective lens control unit and periodically changing the current value of the objective lens current by means of the objective lens control unit;
• setting at least one of the following properties of the deflection unit and/or of the aperture unit during the periodic change of the objective lens current:
• (i) a position of the deflection unit and/or the aperture unit in the particle beam apparatus and (ii) at least one actuation variable for supplying the deflection unit and/or aperture unit, wherein setting is implemented in such a way that either the image of the object displayed on the display device does not move or any such movement of the displayed image has a minimal deflection;
• setting the operating voltage to a voltage value by means of the beam generator control unit and periodically changing the voltage value of the operating voltage by means of the beam generator control unit;
• and
• moving the specimen stage into a position of the object during the periodic change in the voltage value of the operating voltage in such a way that either the image of the object displayed on the display device does not move or any such movement of the displayed image has a minimal deflection.