Back to results
US 7,095,031 B2Granted
Method of automatically correcting aberrations in charged-particle beam and apparatus therefor
AssigneeJEOL Ltd.
InventorShinobu Uno
Life of this patent
Estimating the term…
Abstract
The present invention provides method and apparatus for automatically correcting aberrations in a charged-particle beam. The apparatus extracts line profiles from the probe profile of the charged-particle beam. Features indicative of the line profile, i.e., μ, σ, and ρ indicating left-and-right asymmetry, width, and unevenness around the center, respectively, are extracted. An aberration amount calculator calculates amounts of aberrations corresponding to aberrations, respectively, in the charged-particle beam from the amounts of features μ, σ, and ρ. An aberration corrector corrects the aberrations in the beam.
Claims7
A method of automatically correcting aberrations in a charged-particle beam, comprising:
- a step for extracting line profiles from a probe profile of the charged-particle beam when it has been defocused;
- a step for calculating amounts of features μ, σ, and ρ from the extracted line profiles, the μ, σ, and ρ indicating features of the line profiles, i.e., left-and-right asymmetry, width, and unevenness around the center;
- a step for calculating amounts of aberrations in the charged-particle beam from the a mounts of features μ, σ, and ρ;
- a step for making a decision as to whether a total amount of aberration in the charged-particle beam calculated based on the amounts of aberrations is less than a given threshold value;
- and
- a step for specifying at least one of the amounts of aberrations, calculating an amount of feedback for reducing the specified amount of aberration, and correcting the aberrations in the charged-particle beam based on the amount of feedback when the total amount of aberration has been judged to be greater than the threshold value by the step for making a decision.
3 more elements
An apparatus for automatically correcting aberrations in a charged-particle beam, said apparatus comprising:
- a line profile extractor means for extracting line profiles from a probe profile of the charged-particle beam when it has been defocused;
- a line profile feature amount extractor means for calculating amounts of features μ, σ, and ρ from the extracted line profiles, the μ, σ, and ρ indicating features of the line profiles, i.e., left-and-right asymmetry, width, and unevenness around the center;
- an aberration amount calculator means for calculating amounts of aberrations in the charged-particle beam from the amounts of features μ, σ, and ρ;
- an aberration amount decision-making means for making a decision as to whether a total amount of aberration in the charged-particle beam calculated based on the amounts of aberrations is less than a given threshold value;
- a feedback amount-setting means for specifying at least one of the amounts of aberrations and calculating an amount of feedback for reducing the specified amount of aberration;
- and
- an aberration corrector means for correcting the aberrations in the charged-particle beam based on the amount of feedback.
4 more elements
A method of automatically correcting aberrations in a charged-particle beam, comprising:
- a step for extracting line profiles from a probe profile of the charged-particle beam when it has been defocused;
- a step for calculating amounts of features μ, σ, and ρ from the extracted line profiles, the μ, σ, and ρ indicating features of the line profiles, i.e., left-and-right asymmetry, width, and unevenness around the center;
- a step for calculating amounts of aberrations in the charged-particle beam from the a mounts of features μ, σ, and ρ;
- a step for making a decision as to whether a total amount of aberration in the charged-particle beam calculated based on the amounts of aberrations is less than a given threshold value;
- and
- a step for specifying at least one of the amounts of aberrations, calculating an amount of feedback for reducing the specified amount of aberration, and correcting the aberrations in the charged-particle beam based on the amount of feedback when the total amount of aberration has been judged to be greater than the threshold value by the step for making a decision, wherein the amount of feedback is a linear combination of the amounts of aberrations indicated by the step for calculating the amounts of aberrations.
3 more elements
A method of automatically correcting aberrations in a charged-particle beam, comprising:
- a step for extracting line profiles from a probe profile of the charged-particle beam when it has been defocused;
- a step for calculating amounts of features μ, σ, and ρ from the extracted line profiles, the μ, σ, and ρ indicating features of the line profiles, i.e., left-and-right asymmetry, width, and unevenness around the center;
- a step for calculating amounts of aberrations in the charged-particle beam from the a mounts of features μ, σ, and ρ;
- a step for making a decision as to whether a total amount of aberration in the charged-particle beam calculated based on the amounts of aberrations is less than a given threshold value;
- and
- a step for specifying at least one of the amounts of aberrations, calculating an amount of feedback for reducing the specified amount of aberration, and correcting the aberrations in the charged-particle beam based on the amount of feedback when the total amount of aberration has been judged to be greater than the threshold value by the step for making a decision, wherein the amount of feedback is calculated using fields which make a feedback gain matrix a diagonal matrix, the feedback gain matrix indicating relations between the amount of feedback and the amounts of aberrations.
3 more elements
Dependencies are inferred from the claim text.