Detection of buried features by backscattered particles
AssigneeASML Netherlands B.V.
InventorsJoe WANG, Chia Wen LIN, Zhongwei CHEN, Chang-chun YEH
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Abstract
Disclosed herein an apparatus and a method for detecting buried features using backscattered particles. In an example, the apparatus comprises a source of charged particles; a stage; optics configured to direct a beam of the charged particles to a sample supported on the stage; a signal detector configured to detect backscattered particles of the charged particles in the beam from the sample; wherein the signal detector has angular resolution. In an example, the methods comprises obtaining an image of backscattered particles from a region of a sample; determining existence or location of a buried feature based on the image.
Claims15
An apparatus comprising:
- a source of charged particles;
- a stage;
- optics configured to direct a beam of the charged particles to a sample supported on the stage;
- and
- a signal detector configured to detect backscattered particles of the charged particles in the beam from the sample,
- wherein the apparatus is configured to detect a feature under a surface of the sample based on angular dependency of backscattered particles collected by the signal detector.
A method comprising:
- obtaining an image of backscattered particles from a beam of charged particles from a region of a sample, the image being formed with backscattered particles of different angles from the beam;
- and
- determining existence or location of a buried feature based on the angular dependency of the backscattered particles.
Dependencies are inferred from the claim text.