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AssigneeGeneral Phosphorix LLC
InventorsAlbert Sicignano, Dmitriy Yeremin, Tim Goldburt
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A method of diagnosing a parameter of a scanning electron microscope such as magnification, linearity and stability, includes loading a reference material into a microscope, setting a permissible limit of a value of the parameters, inputting a pitch of the reference material, inputting a magnification of the microscope, acquiring a set of digital images on the reference material, analyzing the digital image line after line with determination of a pitch of features of the image in each line, in mutually orthogonal directions, checking if all lines of the digital image has been analyzed, determining a mean value of the pitch of the features in each orthogonal direction, comparing the obtained value of the pitch of the image with a known value of the pitch of the reference material to determine a ratio indicative of a modification, and determining a precision of the measurements of the pitch by statistical analysis of the pitch measurements.
A method of diagnosing a parameter of a scanning electron microscope selected from the group consisting of magnification, linearity and stability, comprising the steps of loading a reference material Into a microscope;
A method of diagnosing a parameter of a scanning electron microscope selected from the group consisting of magnification, linearity and stability, comprising the steps of loading a reference material into a microscope;
A method of diagnosing a parameter of a scanning electron microscope selected from the group consisting of magnification, linearity and stability, comprising the steps of loading a reference material into a microscope;
Dependencies are inferred from the claim text.
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Electron or ion microscopes; Electron or ion diffraction tubes: with scanning beams
Electron or ion microscopes: determination of microscope properties
Electric discharge tubes or discharge lamps
Term ended 3 Jun 2021 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
The present invention relates to a method of diagnosing magnification, linearity and stability of a scanning electron microscope.
In scanning electron microscope it is very important to determine each major parameter, such as magnification, linearity, and stability. There are different methods of diagnosing a magnification with the use of reference material and interpretation of the results in a semi-manual form. No methods have been known for diagnosing of linearity and stability. It is therefore believed to be advisable to provide new methods for diagnosing of the above mentioned parameters.
Accordingly, it is an object of present invention to provide a new method of diagnosing magnification, linearity, and stability of a scanning electron microscope.
The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
FIG. 1 is a view schematically showing a flow chart of a new method of diagnosing magnification, linearity, and stability of a scanning electron microscope;
FIGS. 2a and 2b are views showing a change of the magnification of the scanning electron microscope across the field of view in the horizontal and vertical directions;
In accordance with the present invention at least one parameter selected from the group consisting of a magnification, a linearity and a stability of a scanning electron microscope is to be determined separately, or successively one after the other. The method is illustrated in FIG. 1.
In the first step a reference material with a corresponding pattern is loaded in a scanning electron microscope. The reference material is formed with repetitive pattern illustrated in FIGS. 5a, 5b and 5c and disclosed in our copending application Ser. No. 09/696,256.
In the step two, a corresponding parameter to be diagnosed, from the above mentioned three parameters, is selected.