Systems and methods for focusing charged-particle beams

A charged-particle beam system, comprising:

• a stage configured to hold a sample and is movable along at least one of X-Y axes or Z-axis;
• and
• a controller having circuitry and configured to:
• manipulate an electromagnetic field associated with the sample to adjust a focus of the charged-particle beam with reference to the sample;
• form a plurality of focal planes substantially perpendicular to a primary optical axis of the charged-particle beam based on the manipulation of the electromagnetic field;
• generate a plurality of image frames from the plurality of focal planes, wherein an image frame of the plurality of image frames is associated with a corresponding focal plane of the plurality of focal planes;
• and
• generate a 3D image of the sample from the plurality of image frames and corresponding focal plane information.

A non-transitory computer readable medium comprising a set of instructions that is executable by one or more processors of an apparatus to cause the apparatus to perform operations, wherein the apparatus includes a charged-particle source to generate a charged-particle beam, and the operations comprising:

• manipulating an electromagnetic field associated with a sample to adjust a focus of the charged-particle beam with reference to the sample;
• forming a plurality of focal planes substantially perpendicular to a primary optical axis of the charged-particle beam based on the manipulation of the electromagnetic field;
• generating a plurality of image frames from the plurality of focal planes of the sample, wherein an image frame of the plurality of image frames is associated with a corresponding focal plane of the plurality of focal planes;
• and
• generating a 3D image of the sample from the plurality of image frames and corresponding focal plane information.

A charged-particle beam system, comprising:

• a stage configured to hold a sample and is movable along at least one of X-Y axes or Z-axis;
• and
• a controller having circuitry and configured to:
• adjust, using a first component of the charged-particle beam system, a location of a first focal point of the charged-particle beam with reference to the sample;
• and
• manipulate, using a second component of the charged-particle beam system, an electromagnetic field associated with the sample to form a second focal point by adjusting the first focal point of the charged-particle beam with reference to the sample, wherein the second component is located downstream of a focusing component of an objective lens of the charged-particle beam system.