High throughput multi-beam charged particle inspection system with dynamic control
OwnerDirk Zeidler, Ulrich Bihr +4inventors
InventorsDirk Zeidler, Ulrich Bihr, Andreas Adolf, Nicolas Kaufmann, Ingo Mueller, Michael Behnke
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Abstract
A multi-beam charged particle inspection system and a method of operating a multi-beam charged particle inspection system for wafer inspection can provide high throughput with high resolution and high reliability. The method and the multi-beam charged particle beam inspection system can be configured to extract from a plurality of sensor data a set of control signals to control the multi-beam charged particle beam inspection system and thereby maintain the imaging specifications including a movement of a wafer stage during the wafer inspection task.
Claims21
-16. (canceled)
A method, comprising:
- using a multi-beam charged particle microscope to acquire a first image acquisition of a first image patch during a first time interval;
- moving a wafer stage of the multi-beam charged particle microscope from a position of the first image patch to a second image patch during a third time interval;
- and
- using the multi-beam charged particle microscope to acquire a second image of the second image patch during a second time,
- further comprising:
- during the first time interval:
- determining a first error amplitude from a plurality of sensor signals;
- and
- during the first time interval, predicting a development of the first error amplitude at least over the third time interval;
- and
- at least during the third time interval, providing a control signal to control units of the multi-beam charged particle microscope to keep the predicted development of error amplitude during the second time interval below a predetermined threshold.
A method of operating of a multi-beam charged particle microscope, the method comprising:
- during a time period when the multi-beam charged particle microscope is used for an image acquisition of a sequence of image patches comprising first and second image patches, the second image patch being subsequent to the first image patch:
- expanding a data stream forming a plurality of sensor data into set of error amplitudes;
- extracting a set of drift control signals and a set of dynamic control signals;
- providing the set of drift control signals to slowly acting compensators of the multi-beam charged particle microscope;
- and
- provide the set of dynamic control signals to fast acting compensators of the multi-beam charged particle microscope.
A method of using a system comprising a charged-particle source, the method comprising:
- using the charged-particle source to generate a plurality of primary charged-particle beamlets;
- determining a lateral displacement of a stage of the system, the stage being movable along an axis;
- determining a lateral displacement of a line of sight of an object irradiation unit of the system;
- and
- deflecting the plurality of primary charged-particle beamlets incident on a sample to at least partly compensate for the lateral displacements.
Dependencies are inferred from the claim text.