Method for operating a particle beam apparatus, computer program product and particle beam apparatus for carrying out the method

A non-transitory computer readable medium containing software that, when loaded into a processor unit of a particle beam apparatus and executed, controls the particle beam apparatus, the software comprising:

• executable code that sets a control parameter to control an objective lens of the particle beam apparatus using a control unit of the particle beam apparatus to cause a particle beam from the particle beam apparatus to be focused onto a first region of at least one first unit, which is arranged in a sample chamber of the particle beam apparatus, using the objective lens;
• executable code that determines a first value of the control parameter, for which the particle beam is focused onto the first region of the at least one first unit;
• executable code that determines a first distance between an outer boundary of the objective lens and the first region of the at least one first unit using the first value of the control parameter and the processor unit;
• executable code that sets the control parameter to control the objective lens using the control unit to cause the particle beam from the particle beam apparatus to be focused onto a second region of at least one second unit, which is arranged in the sample chamber of the particle beam apparatus, using the objective lens;
• executable code that determines a second value of the control parameter, for which the particle beam is focused onto the second region of the at least one second unit;
• executable code that determines a second distance between the outer boundary of the objective lens and the second region of the at least one second unit using the second value of the control parameter and the processor unit of the particle beam apparatus;
• executable code that determines a difference between the first distance and the second distance using the processor unit;
• and
• executable code that outputs the difference and/or an absolute value of the difference on an output unit of the particle beam apparatus.

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

• at least one beam generator that generates at least one particle beam having charged particles;
• a sample chamber;
• at least one first unit and at least one second unit, wherein the at least one first unit and the at least one second unit are arranged in the sample chamber;
• at least one objective lens that focuses the at least one particle beam onto the object, onto the at least one first unit and/or onto the at least one second unit;
• a control unit that controls the objective lens;
• an output unit;
• and
• a processor unit coupled to a non-transitory computer readable medium containing software that, when executed by the processor unit, causes the particle beam apparatus to perform the following:
• setting of a control parameter to control the at least one objective lens using the control unit to cause the at least one particle beam to be focused onto a first region of the at least one first unit using the at least one objective lens;
• determining a first value of the control parameter, for which the at least one particle beam is focused onto the first region of the at least one first unit;
• determining a first distance between an outer boundary of the at least one objective lens and the first region of the at least one first unit using the first value of the control parameter;
• setting of the control parameter to control the at least one objective lens using the control unit to cause the at least one particle beam to be focused onto a second region of the at least one second unit using the at least one objective lens;
• determining a second value of the control parameter, for which the at least one particle beam is focused onto the second region of the at least one second unit;
• determining a second distance between the outer boundary of the at least one objective lens and the second region of the at least one second unit using the second value of the control parameter;
• determining a difference between the first distance and the second distance;
• and
• outputting the difference and/or an absolute value of the difference on the output unit.