Variable rate scanning in an electron microscope
AssigneeApplied Materials Israel Ltd.
InventorsAmir Shoham, Benzion Sender, Alon Litman
Life of this patent
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Abstract
A method for imaging a surface, including scanning a first region of the surface with a primary charged particle beam at a first scan rate so as to generate a first secondary charged particle beam from the first region, and scanning a second region of the surface with the primary charged particle beam at a second scan rate faster than the first scan rate so as to generate a second secondary charged particle beam from the second region. The method also includes receiving the first secondary charged particle beam and the second secondary charged particle beam at a detector configured to generate a signal in response to the beams, and forming an image of the first and the second regions in response to the signal.
Claims12
A method for imaging a surface of an object, comprising:
- scanning at least one region of the surface with a charged particle beam, wherein during a portion of the scanning, the charged particle beam is scanned in one direction along a one-dimensional beam path;
- during the scanning in the one direction along the one-dimensional beam path, changing a scan rate of the charged particle beam from a first non-zero scan rate to a second non-zero scan rate, the first scan rate being different than the second scan rate;
- detecting a secondary electron beam comprising secondary electrons generated from an interaction between the charged particle beam and the surface;
- and
- generating an image of the at least one region of the surface in response to the detected secondary electron beam,
- wherein during the scanning along the one-dimensional beam path, the scanning transitions from the first scan rate to the second scan rate at a point on the one-dimensional beam path, and a location of the point is based on a current transition in the secondary electron beam, the current transition measured prior to the scanning along the one-dimensional beam path.
An apparatus for imaging a surface of an object, comprising:
- an irradiation module configured to scan at least one region of the surface with a charged particle beam, wherein (i) during a portion of the scan, the charged particle beam is scanned in one direction along a one-dimensional beam path, and (ii) during the scan in the one direction along the one-dimensional beam path, the charged particle beam is scanned at a first non-zero scan rate and a second non-zero scan rate, the first scan rate being different than the second scan rate;
- a detector configured to detect a secondary electron beam comprising secondary electrons generated from an interaction between the charged particle beam and the surface;
- and
- a processor configured to form an image of the at least one region of the surface in response to the detected secondary electron beam,
- wherein during the scanning along the one-dimensional beam path, the irradiation module is further configured to switch from the first scan rate to the second scan rate at a point on the one-dimensional beam path, and a location of the point is based on a current transition in the secondary electron beam, the current transition measured by the processor prior to the scanning along the one-dimensional beam path.
Dependencies are inferred from the claim text.