Fast sample height, AOI and POI alignment in mapping ellipsometer or the like
First Claim
Patent Images
1. A method of aligning a sample in an ellipsometer system, which ellipsometer system comprises:
- a source of a beam of electromagnetic radiation;
a polarizer;
a stage for supporting a sample;
an analyzer;
a data detector;
means for adjusting the relative “
height”
positioning between said stage for supporting a sample and, as a unit, said source of a beam of electromagnetic radiation and data detector;
as well as means for translating relative positioning of said sample with respect to said source of an ellipsometer beam of electromagnetic radiation and said data detector, along two orthogonal axes, and optionally means for adjusting the relative orientation of the ellipsometer systems with respect to said sample to set the angle and plane of incidence of said ellipsometer beam with respect to a surface of said sample;
said ellipsometer system optionally comprising at least one compensator and/or focusing means between said source of a beam of electromagnetic radiation and said data detector;
such that in use a beam of electromagnetic radiation from said source thereof approaches said sample at an oblique angle-of-incidence and reflects therefrom into said data detector;
said method comprising the steps of;
a) functionally mounting a sample alignment system to said ellipsometer system, which sample alignment system comprises;
an alignment source of an alignment beam of electromagnetic radiation;
a first alignment beam focusing means for focusing an alignment beam of electromagnetic radiation provided from said source thereof onto a sample on said ellipsometer system stage for supporting a sample;
a second alignment focusing means for focusing alignment beam electromagnetic radiation which reflects from said sample onto a two dimensional detector array; and
said two dimensional detector array;
such that in use an alignment beam of electromagnetic radiation from said source thereof is focused onto said sample at an oblique angle-of-incidence and reflects therefrom and is focused onto said two dimensional detector array;
said sample alignment system optionally further comprising;
between said second alignment focusing means and said two dimensional detector array a beam splitter which diverts a portion of the alignment beam electromagnetic radiation which reflects from said sample to a secondary two dimensional detector array, and said secondary two dimensional detector array;
said ellipsometer and alignment system being mounted with respect to one another such that the ellipsometer beam of electromagnetic radiation and said alignment beam of electromagnetic radiation impinge on said sample at substantially the same location;
said method further comprising;
prior to step e, performing steps b and c at least once, in which steps b and c are;
b) while monitoring output intensity from said data detector causing a beam of electromagnetic radiation from said source thereof to approach said sample at an oblique angle-of-incidence and reflect therefrom into said data detector, adjusting the means for adjusting the relative “
height”
positioning between said stage for supporting a sample, and, as a unit, said source of a beam of electromagnetic radiation and data detector, until output from said data detector is of a desirable intensity; and
c) causing the source of an alignment beam of electromagnetic radiation from said source thereof to approach said sample at an oblique angle-of-incidence and reflect therefrom onto said two dimensional detector array and identifying the location on said two dimensional detector array as an aligned position;
said method further comprising performing steps d, e and f a plurality of times, wherein steps d, e and f are;
d) using said means for translating relative positioning of said sample with respect to, as a unit, said source of an ellipsometer beam of electromagnetic radiation and said data detector, along two orthogonal axes, causing relative translation of said sample along at least one of said orthogonal axes so that a new spot on said sample is investigated by said ellipsometer beam, and such that the location at which the alignment beam reflected from said sample surface in step c appears on the two dimensional detector array, possibly at a different location than said aligned position;
e) if necessary, adjusting the means for adjusting the relative “
height”
positioning between said stage for supporting a sample and, as a unit, said source of a beam of electromagnetic radiation and data detector, until said alignment beam reflected from said sample surface in step c appears on the two dimensional detector array at said aligned position;
f) with the above adjustment set, acquiring ellipsometric data from said data detector.
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Abstract
A sample investigation system (ES) in functional combination with an alignment system (AS), and methodology of enabling very fast, (eg. seconds), sample height, angle-of-incidence and plane-of-incidence adjustments, with application in mapping ellipsometer or the like systems.
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Citations
29 Claims
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1. A method of aligning a sample in an ellipsometer system, which ellipsometer system comprises:
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a source of a beam of electromagnetic radiation; a polarizer; a stage for supporting a sample; an analyzer; a data detector; means for adjusting the relative “
height”
positioning between said stage for supporting a sample and, as a unit, said source of a beam of electromagnetic radiation and data detector;
as well as means for translating relative positioning of said sample with respect to said source of an ellipsometer beam of electromagnetic radiation and said data detector, along two orthogonal axes, and optionally means for adjusting the relative orientation of the ellipsometer systems with respect to said sample to set the angle and plane of incidence of said ellipsometer beam with respect to a surface of said sample;said ellipsometer system optionally comprising at least one compensator and/or focusing means between said source of a beam of electromagnetic radiation and said data detector; such that in use a beam of electromagnetic radiation from said source thereof approaches said sample at an oblique angle-of-incidence and reflects therefrom into said data detector; said method comprising the steps of; a) functionally mounting a sample alignment system to said ellipsometer system, which sample alignment system comprises; an alignment source of an alignment beam of electromagnetic radiation; a first alignment beam focusing means for focusing an alignment beam of electromagnetic radiation provided from said source thereof onto a sample on said ellipsometer system stage for supporting a sample; a second alignment focusing means for focusing alignment beam electromagnetic radiation which reflects from said sample onto a two dimensional detector array; and said two dimensional detector array; such that in use an alignment beam of electromagnetic radiation from said source thereof is focused onto said sample at an oblique angle-of-incidence and reflects therefrom and is focused onto said two dimensional detector array; said sample alignment system optionally further comprising; between said second alignment focusing means and said two dimensional detector array a beam splitter which diverts a portion of the alignment beam electromagnetic radiation which reflects from said sample to a secondary two dimensional detector array, and said secondary two dimensional detector array; said ellipsometer and alignment system being mounted with respect to one another such that the ellipsometer beam of electromagnetic radiation and said alignment beam of electromagnetic radiation impinge on said sample at substantially the same location; said method further comprising; prior to step e, performing steps b and c at least once, in which steps b and c are; b) while monitoring output intensity from said data detector causing a beam of electromagnetic radiation from said source thereof to approach said sample at an oblique angle-of-incidence and reflect therefrom into said data detector, adjusting the means for adjusting the relative “
height”
positioning between said stage for supporting a sample, and, as a unit, said source of a beam of electromagnetic radiation and data detector, until output from said data detector is of a desirable intensity; andc) causing the source of an alignment beam of electromagnetic radiation from said source thereof to approach said sample at an oblique angle-of-incidence and reflect therefrom onto said two dimensional detector array and identifying the location on said two dimensional detector array as an aligned position; said method further comprising performing steps d, e and f a plurality of times, wherein steps d, e and f are; d) using said means for translating relative positioning of said sample with respect to, as a unit, said source of an ellipsometer beam of electromagnetic radiation and said data detector, along two orthogonal axes, causing relative translation of said sample along at least one of said orthogonal axes so that a new spot on said sample is investigated by said ellipsometer beam, and such that the location at which the alignment beam reflected from said sample surface in step c appears on the two dimensional detector array, possibly at a different location than said aligned position; e) if necessary, adjusting the means for adjusting the relative “
height”
positioning between said stage for supporting a sample and, as a unit, said source of a beam of electromagnetic radiation and data detector, until said alignment beam reflected from said sample surface in step c appears on the two dimensional detector array at said aligned position;f) with the above adjustment set, acquiring ellipsometric data from said data detector. - View Dependent Claims (2, 8, 12, 13, 14, 15, 18, 24, 27)
in which said method further comprises, prior to step e; while causing a beam of electromagnetic radiation from said source thereof to approach said sample at an oblique angle-of-incidence and reflect therefrom into said data detector, monitoring the output from the data detector and adjusting the means for adjusting the relative orientation of the ellipsometer with respect to said sample to set the angle and plane of incidence of said ellipsometer beam with respect to a surface of said sample until the intensity of the data detector output is maximized, and so that electromagnetic radiation from said alignment source thereof reflects from said sample and, via said beam splitter, appears on said secondary two dimensional detector array, and identifying the location on said secondary two dimensional detector array as an aligned position; and in which said method, after practice of the step d causing of relative translation of said sample along at least one of said orthogonal axes so that a new spot on said sample is investigated by said ellipsometer beam, practice of step e, which step e further comprises; e) adjusting the means for adjusting the relative orientation of the ellipsometer with respect to said sample to set the angle and plane of incidence of said ellipsometric beam with respect to a surface of said sample until said alignment beam reflected from said sample surface in step c appears on the two dimensional detector array at said aligned position; followed by practice of step f.
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8. A method as in claim 1 in which the step of providing a source of a beam of electromagnetic radiation involves providing a spectroscopic source.
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12. A method of investigating a sample as in claim 1, which further comprises analyzing ellipsometric data acquired from said data detector in step f.
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13. A method of investigating a sample as in claim 12, in which the acquiring of ellipsometric data involves repeating steps b-f at least twice to obtain ellipsometric data from at least two spots on said sample, and in which the analysis comprises simultaneous regression onto data obtained from said at least two spots on said sample.
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14. A method of investigating a sample as in claim 2, which further comprises analyzing ellipsometric data acquired from said data detector in step f.
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15. A method of investigating a sample as in claim 14, in which the acquiring of ellipsometric data involves repeating steps b-f at least twice to obtain ellipsometric data from at least two spots on said sample, and in which the analysis comprises simultaneous regression onto data obtained from said at least two spots on said sample.
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18. A method as in claim 1, further comprising the step of calibrating the ellipsometer system by evaluating parameters in a mathematical model of said ellipsometer system using a regression procedure onto data obtained from said data detector while investigating at least one standard sample, having known physical and/or optical properties.
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24. A method as in claim 1, wherein step c, and optionally step b, is practiced each time steps d, e and f are practiced.
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27. A method as in claim 1 which further involves performing at least one selection from the group consisting of:
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storing at least some data provided by said data detector in machine readable media; analyzing at least some of the data provided by said data detector and storing at least some of the results of said analysis in machine readable media; displaying at least some data provided by said data detector by electronic and/or non-electronic means; analyzing at least some of the data provided by said data detector and displaying at least some of the results of said analysis by electronic and/or non-electronic means; causing at least some data provided by said data detector to produce a signal which is applied to provide a concrete and tangible result; analyzing at least some of the data provided by said data detector and causing at least some thereof to produce a signal which is applied to provide a concrete and tangible result.
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3. A method of aligning a sample in an ellipsometer system, which ellipsometer system comprises:
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a source of a beam of electromagnetic radiation; a polarizer; a stage for supporting a sample; an analyzer; a data detector; means for adjusting the relative “
height”
positioning between said stage for supporting a sample and, as a unit, said source of a beam of electromagnetic radiation and data detector;
as well as means for translating relative positioning of said sample with respect to said source of an ellipsometer beam of electromagnetic radiation and said data detector, along two orthogonal axes, and means for adjusting the relative orientation of the ellipsometer with respect to said sample to set the angle and plane of incidence of said ellipsometer beam with respect to a surface of said sample;said ellipsometer system optionally comprising at least one compensator and/or focusing means between said source of a beam of electromagnetic radiation and said data detector; such that in use a beam of electromagnetic radiation from said source thereof approaches said sample at an oblique angle-of-incidence and reflects therefrom into said data detector; said method comprising the steps of; a) functionally mounting a sample alignment system to said ellipsometer system, which sample alignment system comprises; an alignment source of an alignment beam of electromagnetic radiation; a first alignment beam focusing means for focusing an alignment beam of electromagnetic radiation provided from said source thereof onto a sample on said ellipsometer system stage for supporting a sample; a second alignment focusing means for focusing alignment beam electromagnetic radiation which reflects from said sample onto a two dimensional detector array; and said two dimensional detector array; such that in use an alignment beam of electromagnetic radiation from said source thereof is focused onto said sample at an oblique angle-of-incidence and reflects therefrom and is focused onto said two dimensional detector array; said sample alignment system further comprising; between said second alignment focusing means and said two dimensional detector array, a beam splitter which diverts a portion of the alignment beam electromagnetic radiation which reflects from said sample to a secondary two dimensional detector array, and said secondary two dimensional detector array; said ellipsometer and alignment system being mounted with respect to one another such that the ellipsometer beam of electromagnetic radiation and said alignment beam of electromagnetic radiation impinge on said sample at substantially the same location; in which said method further comprises, prior to step e, performing steps b and c at least once, wherein steps b and c are; b) while causing a beam of electromagnetic radiation from said source thereof to approach said sample at an oblique angle-of-incidence and reflect therefrom into said data detector, monitoring the output from the data detector and adjusting the means for adjusting the relative orientation of the ellipsometer with respect to said sample to set the angle and plane of incidence of said ellipsometer beam with respect to a surface of said sample until the intensity of the data detector output is maximized, and so that electromagnetic radiation from said alignment source thereof reflects from said sample and, via said beam splitter, appears on said secondary two dimensional detector array, and identifying the location on said secondary two dimensional detector array as an aligned position; and c) while monitoring output intensity from said data detector causing a beam of electromagnetic radiation from said source thereof to approach said sample at an oblique angle-of-incidence and reflect therefrom into said data detector, adjusting the means for adjusting the relative “
height”
positioning between said stage for supporting a sample, and, as a unit, said source of a beam of electromagnetic radiation and data detector until output from said data detector is of a desirable intensity and identifying the location on said two dimensional detector array as an aligned position; andsaid method further comprising performing steps d, e and f a plurality of times, wherein steps d, e and f are; d) using said means for translating relative positioning of said sample with respect to, as a unit, said source of an ellipsometer beam of electromagnetic radiation and said data detector, along two orthogonal axes, causing relative translation of said sample along at least one of said orthogonal axes so that a new spot on said sample is investigated by said ellipsometer beam, and such that the location at which the alignment beam reflected from said sample surface in step c appears on the two dimensional detector array, possibly at a different location than said aligned position; e) if necessary, adjusting the means for adjusting the relative “
height”
positioning between said stage for supporting a sample and, as a unit, said source of a beam of electromagnetic radiation and data detector, until said alignment beam reflected from said sample surface in step c appears on the two dimensional detector array at said aligned position and adjusting the means for adjusting the relative orientation of the ellipsometer with respect to said sample to set the angle and plane of incidence of said ellipsometric beam with respect to a surface of said sample until said alignment beam reflected from said sample surface in step c appears on the secondary two dimensional detector array at said aligned position;f) with the above adjustment set, acquiring ellipsometric data from said data detector. - View Dependent Claims (9, 16, 17, 19, 25, 28)
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4. A combination sample investigation system and alignment system comprising a sample investigation system selected from the group consisting of:
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ellipsometer; polarimeter; reflectometer; spectrophotometer; and Mueller Matrix measuring system; which comprises; a source of a sample investigation beam of electromagnetic radiation; a stage for supporting a sample; a data detector; means for adjusting the relative “
height”
positioning between said stage for supporting a sample and, as a unit, said source of a sample investigation beam of electromagnetic radiation and data detector;
as well as means for translating relative positioning of said sample with respect to said source of a sample investigation beam of electromagnetic radiation and said data detector, along two orthogonal axes, and optionally means for adjusting the relative orientation of the sample investigation system with respect to said sample to set the angle and plane of incidence of said sample investigation beam of electromagnetic radiation with respect to a surface of said sample;said ellipsometer system optionally comprising at least one polarizer, analyzer, compensator and/or focusing means between said source of a beam of electromagnetic radiation and said data detector; such that in use a sample investigation beam of electromagnetic radiation from said source thereof approaches said sample at an oblique angle-of-incidence and reflects therefrom into said data detector; and an alignment system comprising; an alignment source of an alignment beam of electromagnetic radiation; a first alignment beam focusing means for focusing an alignment beam of electromagnetic radiation provided from said source thereof onto a sample on said system stage for supporting a sample; a second alignment focusing means for focusing alignment beam electromagnetic radiation which reflects from said sample onto a two dimensional detector array; and said two dimensional detector array; such that in use an alignment beam of electromagnetic radiation from said source thereof is focused onto said sample at an oblique angle-of-incidence and reflects therefrom and is focused onto said two dimensional detector array; said sample alignment system optionally further comprising; between said second alignment focusing means and said two dimensional detector array a beam splitter which diverts a portion of the alignment beam electromagnetic radiation which reflects from said sample to a secondary two dimensional detector array, and said secondary two dimensional detector array; said sample investigation system and alignment system being mounted with respect to one another such that the sample investigation beam of electromagnetic radiation and said alignment beam of electromagnetic radiation impinge on said sample at substantially the same location. - View Dependent Claims (5, 6, 10, 20)
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7. A sample mapping system comprising a mounting frame which supports a combination ellipsometer and alignment system, said mounting frame projecting substantially vertically upward from a substantially horizontally oriented support, as viewed in elevation, said combination ellipsometer and alignment system comprising:
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an ellipsometer system comprising; a source of a beam of electromagnetic radiation; a polarizer; a stage for supporting a sample; an analyzer; a data detector; means for adjusting the relative “
height”
positioning between said stage for supporting a sample and, as a unit, said source of a beam of electromagnetic radiation and data detector;
as well as means for translating relative positioning of said sample with respect to said source of an ellipsometer beam of electromagnetic radiation and said data detector, along two orthogonal axes, and optionally means for adjusting the relative orientation of the ellipsometer with respect to said sample to set the angle and plane of incidence of said ellipsometer beam with respect to a surface of said sample;said ellipsometer system optionally comprising at least one compensator and/or focusing means between said source of a beam of electromagnetic radiation and said data detector; such that in use a beam of electromagnetic radiation from said source thereof approaches said sample at an oblique angle-of-incidence and reflects therefrom into said data detector; said system further comprising an alignment system comprising; an alignment source of an alignment beam of electromagnetic radiation; a first alignment beam focusing means for focusing an alignment beam of electromagnetic radiation provided from said source thereof onto a sample on said ellipsometer system stage for supporting a sample; a second alignment focusing means for focusing alignment beam electromagnetic radiation which reflects from said sample onto a two dimensional detector array; and said two dimensional detector array; such that in use an alignment beam of electromagnetic radiation from said source thereof is focused onto said sample at an oblique angle-of-incidence and reflects therefrom and is focused onto said two dimensional detector array; said sample alignment system optionally further comprising; between said second alignment focusing means and said two dimensional detector array a beam splitter which diverts a portion of the alignment beam electromagnetic radiation which reflects from said sample to a secondary two dimensional detector array, and said secondary two dimensional detector array; said ellipsometer and alignment system being mounted with respect to one another such that the ellipsometer beam of electromagnetic radiation and said alignment beam of electromagnetic radiation impinge on said sample at substantially the same location; said mounting frame having affixed thereto said means for adjusting the relative “
height”
positioning between said stage for supporting a sample and, as a unit, said source of an ellipsometer beam of electromagnetic radiation and data detector, as well as said means for translating relative positioning of said sample with respect to said source of an ellipsometer beam of electromagnetic radiation and said data detector, along two orthogonal axes, and said optional means for adjusting the relative orientation of the ellipsometer with respect to said sample to set the angle and plane of incidence of said ellipsometer beam with respect to a surface of said sample;and in which said stage for supporting a sample is oriented to secure a sample in a plane slightly offset from said vertically upward projected plane of said mounting frame so that a sample entered thereinto does not tend to fall back out thereof, said stage being of a construction to contact the edges of the sample only, there further being present a plurality of clamp means at the edges of said stage whereat the sample contacts said stage, and which clamp means secure the sample to the stage at said edges thereof to better secure said sample, and to decrease non-planar warping therein. - View Dependent Claims (11, 21)
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22. A method of aligning a sample in a sample investigation system selected from the group consisting of:
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ellipsometer; polarimeter; reflectometer; spectrophotometer; and Mueller Matrix measuring system; which system comprises; a source of a sample investigation beam of electromagnetic radiation; a stage for supporting a sample; a data detector; means for adjusting the relative “
height”
positioning between said stage for supporting a sample and, as a unit, said source of a sample investigation beam of electromagnetic radiation and data detector;
as well as means for translating relative positioning of said sample with respect to said source of a sample investigation beam of electromagnetic radiation and said data detector, along two orthogonal axes, and optionally means for adjusting the relative orientation of the systems with respect to said sample to set the angle and plane of incidence of said sample investigation beam with respect to a surface of said sample;said sample investigation system optionally comprising at least one polarizer, analyzer, compensator or focusing means between said source of a sample investigation beam of electromagnetic radiation and said data detector; such that in use a sample investigation beam of electromagnetic radiation from said source thereof approaches said sample at an oblique angle-of-incidence and reflects therefrom into said data detector; said method comprising the steps of; a) functionally mounting a sample alignment system to said system, which sample alignment system comprises; an alignment source of an alignment beam of electromagnetic radiation; a first alignment beam focusing means for focusing an alignment beam of electromagnetic radiation provided from said source thereof onto a sample on said system stage for supporting a sample; a second alignment focusing means for focusing alignment beam electromagnetic radiation which reflects from said sample onto a two dimensional detector array; and said two dimensional detector array; such that in use an alignment beam of electromagnetic radiation from said source thereof is focused onto said sample at an oblique angle-of-incidence and reflects therefrom and is focused onto said two dimensional detector array; said sample alignment system optionally further comprising; between said second alignment focusing means and said two dimensional detector array a beam splitter which diverts a portion of the alignment beam electromagnetic radiation which reflects from said sample to a secondary two dimensional detector array, and said secondary two dimensional detector array; said sample investigation system and alignment system being mounted with respect to one another such that the sample investigation beam of electromagnetic radiation and said alignment beam of electromagnetic radiation impinge on said sample at substantially the same location; said method further comprising; prior to step e, performing steps b and c at least once, wherein steps b and c are; b) while monitoring output intensity from said data detector causing a sample investigation beam of electromagnetic radiation from said source thereof to approach said sample at an oblique angle-of-incidence and reflect therefrom into said data detector, adjusting the means for adjusting the relative “
height”
positioning between said stage for supporting a sample, and, as a unit, said source of a sample investigation beam of electromagnetic radiation and data detector, until output from said data detector is of a desirable intensity; andc) causing the source of an alignment beam of electromagnetic radiation from said source thereof to approach said sample at an oblique angle-of-incidence and reflect therefrom onto said two dimensional detector array and identifying the location on said two dimensional detector array as an aligned position; said method further comprising performing steps d, e and f a plurality of times, wherein steps d, e and f are; d) using said means for translating relative positioning of said sample with respect to, as a unit, said source of a sample investigation beam of electromagnetic radiation and said data detector, along two orthogonal axes, causing relative translation of said sample along at least one of said orthogonal axes so that a new spot on said sample is investigated by said sample investigation beam, and such that the location at which the alignment beam reflected from said sample surface in step c appears on the two dimensional detector array, possibly at a different location than said aligned position; e) if necessary, adjusting the means for adjusting the relative “
height”
positioning between said stage for supporting a sample and, as a unit, said source of a beam of electromagnetic radiation and data detector, until said alignment beam reflected from said sample surface in step c appears on the two dimensional detector array at said aligned position;f) with the above adjustment set, acquiring data from said data detector. - View Dependent Claims (23, 26, 29)
in which said method further comprises, in prior to step e; while causing a sample investigation beam of electromagnetic radiation from said source thereof to approach said sample at an oblique angle-of-incidence and reflect therefrom into said data detector, monitoring the output from the data detector and adjusting the means for adjusting the relative orientation of the system with respect to said sample to set the angle and plane of incidence of said system beam with respect to a surface of said sample until the intensity of the data detector output is maximized, and so that electromagnetic radiation from said alignment source reflects from said sample and, via said beam splitter, appears on said secondary two dimensional detector array, and identifying the location on said secondary two dimensional detector array as an aligned position; and in which said method, after practice of the step d causing of relative translation of said sample along at least one of said orthogonal axes so that a new spot on said sample is investigated by said system beam, practice of step e, which step e further comprises; e) adjusting the means for adjusting the relative orientation of the system with respect to said sample to set the angle and plane of incidence of said beam with respect to a surface of said sample until said alignment beam reflected from said sample surface in step c appears on the two dimensional detector array at said aligned position; followed by practice of step f.
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26. A method as in claim 22, wherein step c, and optionally step b, is practiced each time steps d, e and f are practiced.
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29. A method as in claim 22 which further involves performing at least one selection from the group consisting of:
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storing at least some data provided by said data detector in machine readable media; analyzing at least some of the data provided by said data detector and storing at least some of the results of said analysis in machine readable media; displaying at least some data provided by said data detector by electronic and/or non-electronic means; analyzing at least some of the data provided by said data detector and displaying at least some of the results of said analysis by electronic and/or non-electronic means; causing at least some data provided by said data detector to produce a signal which is applied to provide a concrete and tangible result; analyzing at least some of the data provided by said data detector and causing at least some thereof to produce a signal which is applied to provide a concrete and tangible result.
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Specification