Adjustable beam alignment compensator/retarder

The present invention relates to ellipsometer / polarimeter systems and more particularly to a compensator / retarder, which is set so may be that the introduction of significant distraction and / or displacement in the direction of propagation of a beam of electromagnetic waves, the thus brought in interaction is, even eliminated, if for example a compensator / retarder system constantly is rotated in a rotating compensator ellipsometer. The present invention also provides a method for calibrating an ellipsometer / Polarimetersystems which a compensator / retarder system having that while operation rotates continuously.

polarimeter and ellipsometer consist of optical elements such as polarizer and Verzögerersystemen. polarimeter can the polarization state of a polarized beam of electromagnetic waves notice and Ellipsometersysteme can change the polarization state a polarized beam of electromagnetic waves detect consisting of an interaction with a sample to be determined System result, the change in the polarization state optical assigned and physical properties of said sample system is. For general information should be noted that the Polarization state of a polarized beam of electromagnetic Waves is determined by: <ul><li>a. the ratio of orthogonal components (based on PSI);</li><li>b. the phase angle between the orthogonal components (based on DELTA);</li><li>c. the absolute value of an orthogonal component; and</li><li>d. the direction of rotation or handedness.</li></ul>

On ideal polarizer only allows the passage of linearly polarized electromagnetic radiation, the same along the fast axis is aligned and has all electromagnetic radiation into orthogonal orientation.

The called, the extinction ratio would be substantially infinity. The Mueller matrix for one ideal polarizer is shown below:

<img img-content="mf" img-format="tif" he="24" wi="73" file="00020001.tif" />

On ideal retarder would a phase delay between orthogonal components of the polarized electromagnetic bring radiation without preferably the intensity of a to modify any orthogonal component thereof. The Mueller matrix an ideal retarder is: <img img-content="mf" img-format="tif" he="24" wi="92" file="00020002.tif" />wherein "r" is the delay introduced.

There even very good compensator / retarder systems (including those which are presented in this disclosure) tend preferably an orthogonal component of an electromagnetic beam from to modify radiation, it is necessary, the Mueller matrix to modify so that this effect is taken into account. The Mueller matrix a Verzögerersystems, which a preferred modification of an orthogonal component a polarized beam of electromagnetic waves is taken into consideration: &lt;?page 3?&gt;<img img-content="mf" img-format="tif" he="29" wi="114" file="00020003.tif" />wherein "R" in turn the introduced delay is. It should be noted that if the PSI (Ψ) of the forty-five Verzögerersystems (45) degrees, the Mueller matrix to the ideal Mueller matrix reduced.

It is also found that the value of "r" should be in a range in which an ellipsometer in which it is a component, not strongly sensitive to changes This is, such as a function of wavelength. at rotating compensator ellipsometer is a value of "r" between ninety (90) and one hundred and fifty (150) degrees generally acceptable. Also show typical mass-produced Verzögerersysteme often a "r" with a (1 / wavelength) response, so that "r" values ​​not within of 90 to 150 ° range are viewed over a wavelength range two hundred and fifty of example (250) to one thousand (1000) nm.

at an ideal optical element, it is required that a jet of electromagnetic waves, the thus brought in interaction is a propagation direction has that not distracted by or is moved. This is especially critical when an optical member during the use must be rotated.

It is further desired, an optical element no sensitivity for the erasure ratio or a delay as a function of the beam alignment, this has regarding the between orthogonal components of an electromagnetic beam a radiation is introduced, the thus brought in interaction is.

It is also desired that optical elements are simple to prepare and that the production of Materials are, that are easy to relate.

furthermore requires the practice of ellipsometry, that data which a change the state of polarization of an electromagnetic beam of a reflected radiation from an interaction with Sample system results can be obtained and that these data Data are compared with that by use of a proposed mathematical model are generated. In such a mathematical model must all non-idealities of the optical elements, which present in the used ellipsometer are taken into account will. Thus, it is preferred that as little as possible non-idealities in the are optical elements available to the complexity of the mathematical To simplify the model.

In Relation to the present invention, a research patents executed. This research was aimed to polarizers and compensator / retarder systems, the one relatively stable over a delay Wavelength range can provide, without a beam of electromagnetic waves, which passed through this will deflect or move.

In Regarding compensator / retarder systems, U.S. Patents were found that have elements of a geometry, somehow similar to the geometry of the present compensator / retarder systems is. The present invention, however, was not found. especially the Patent Nos. 548.495 of Abbe, no. 4,556,292 of Mathyssek et al., no. 5,475,525 of Tournois et al., and no. 5,016,980 of Waldron, no. 3,817,624 of Martin is alerted and the Pat. No. 2,447,828 of West was also determined.

The by far the main patent, the use of compensators describes in Ellipsometersystemen, is no. 5,872,630 of Johs et al. The patent describes a rotating compensator ellipsometer system, wherein the use of non-achromatic compensator is made possible by a regression based calibration procedure. The PCT patent version of the serial number PCT / US98 / 02390 and the EP's version of the sequence number is 98907397.8. A additional Search for patents resulted in a patent of Dill, no. 4,053,232, describing a rotating compensator ellipsometer system, which is operated using monochromatic light. Also gefun&lt;?page 4?&gt;to have two patents, determine which systems, the polychromatic light in the study of material systems use and in Patent Nos. 5,596,406 and no. 4,668,086 Rosencwaig et al. or speakers are described. It has been found also a patent of Woollam et al., no. 5,373,359, which rotating a Analyzer ellipsometer describes in which white light is used. From the patent Woollam et al. 359 further patents Nos. 5,504,582 of Johs et al. and 5,521,706 of Green et al. The patent 582 of Johs et al, and 706 by Green et al. describe the use of polychromatic light in a rotating Analyzer ellipsometer system. A patent Bernoux et al., No. 5,329,357 was found which describes a ellipsometer, in which a polarizer during Use is rotated. A patent of Chen et al., No. 5,581,350 it has been found that the use of regression for the calibration describes of Ellipsometersystemen. An article by Johs, entitled "Regression Calibration Method for Rotating element ellipsometer ", which in Thin Film Solids, Volume 234, appeared in 1993, is also cited as he front of the Chen et al. Pat appeared and a substantially similar Walkthrough describes the Ellipsometerkalibrierung. An article by Jellison Jr., entitled "Data Analysis for Spectroscopic Ellipsometry " Thin Film Solids, 234, (1993) is cited because it is a process describes to determine the accuracy with which certain Data points can be measured, said information enabling that a weighting factor a curve fitting regression method added is that is applied to a plurality of data points, wherein the weighting factor serves the effect of more accurate and precise to emphasize data. In a book by Azzam and Bashara with entitled "Ellipsometry and Polarized Light "North-Holland, 1977 for referenced the general theory and this by reference added. An article by Collins, entitled "Automated Rotating Element ellipsometer: Calibration, operation, and Real-Time Applications "Rev. Sci Instrum.. 61 (8), August 1990, quoted because he insight into ellipsometer are rotating elements. An article by Kleim et al. With entitled "Systematic Errors in Rotating Compensator Ellipsometry ", published in J. Opt. Soc. Am./Vol. 11, no. 9, Sept. 1994 quoted because he calibration describes rotating compensator ellipsometer. An article of An and Collins entitled "Waveform Analysis with Optical Multichannel Detectors: applications for rapid scan spectroscopic ellipsometer "Rev. Sci. Instrum., 62 (8) August 1991 is also cited, since it Effects such Detection System Error characterization, stray light, Bildpersistenz etc., and discussed their calibration. Also pointed will describe products by Schubert et al., which "generalized ellipsometry". The first is entitled "Extension of Rotating-Analyzer Ellipsometry to Generalized Ellipsometry: Determination Of The Dielectric Function Tensor From uniaxial TiO2 ", J. Opt. Soc. Am. A. 13, (1996). The second article of this kind comes from M. Schubert alone and is entitled "Polarization Dependent Parameters of Arbitrary Anisotropic Homogenoeus Epitaxial Systems ", Phys. Rev. B 53, (1996). The third article of this kind is "Generalized Transmission Ellipsometry for Twisted Biaxially Dielectric Media: Application to Chiral Liquid Crystals " J. Opt. Soc. At the. A / Vol. 13, no. 9 (1996). Further relevant regarding Regression is a book entitled Numerical Recipes in "C", 1988, Cambridge University Press.

On Compensator / retarder system, which can be formed so that there is substantially no Deflection or shift in a beam of electromagnetic Waves introduced, which is brought in interaction with this, would use Find and appreciated will. An object of the present invention is to provide a optical compensator / retarder system provide that an acceptable ideal behavior over relatively size Wavelength ranges shows and used in rotating compensator / ellipsometer systems can be.

According to a first aspect of the present invention is a compensator or Retarder provided comprising: first and second elements with adjustable orientation, the reflective surfaces exhibit; and a third member, the first and second sides having projecting angularly from a common point from each other, wherein said third member is made of a material which inwardly at its first and second sides reflecting boundary surfaces providing; wherein the third member with respect to the first and second elements is aligned with an adjustable orientation so that in operation an incident electromagnetic beam of waves, of the first element is approximated with adjustable orientation, it is reflected and enters the third element and the substantially completely is internally reflected from the first side thereof, then essentially completely is internally reflected from the second side, and then further on tapers the second element with adjustable alignment and is reflected by the latter and along a propagation direction further runs, substantially not on the direction of said electromagnetic is the input beam is deflected or moved, the arrangement such is that a delay between orthogonal components of the electromagnetic input beam is produced. Preferably, the first and second elements are with adjustable alignment mirror elements and the electromagnetic Radiation is outside reflected thereto.

The Invention finds particular application when the system further having means to be&lt;?page 5?&gt;effect that during operation the system to the The propagation direction of the incident beam of electromagnetic waves rotates.

at a favorable Arrangement, the system is designed such that, in a vertical side view considered the third member includes first and second sides, the left and right and downward protrude from the top spot; wherein the third member with respect to the first and second elements is aligned with an adjustable orientation so that in operation the incident electromagnetic beam of waves to the first Element with adjustable alignment along a substantially horizontal direction approaches, thereof is reflected and extends along a direction is directed substantially vertically upwards, then in the third Element enters and substantially inside of the first side fully reflected is then extends along a substantially horizontal direction, and substantially completely reflected in the inside of the second side and is along a substantially downwardly directed vertical Direction runs, then reflected by the second element with adjustable alignment is along a substantially horizontal direction of propagation runs, the substantially non-substantially horizontal of the direction of propagation is deflected and displaced the incident beam.

According to the invention, a Spectroscopic Ellipsometer- or polarimeter with a or more compensator or Verzögerersystemen as stated above to be provided. In particular, a spectroscopic Ellipsometer- or polarimeter system may be provided which comprises in sequence: a source of electromagnetic radiation; a polarizer; one or more compensator or Verzögerersysteme as set forth above; an analyzer; and a detector system; in which the arrangement being such that in operation, a beam of electromagnetic provided waves from the source of electromagnetic radiation is and is passed through the polarizer, then in a functional sequence with a sample system and the compensator or retarder system or with the compensator or retarder and a sample system interacts and then through the analyzer and the detector system arrives.

It Note that the features of the invention herein with respect described to a device or a system according to the invention are also provided in reference to a method according to the invention could be and vice versa.

especially According to a Aspect of the invention, a method is provided for operating a spectroscopic Ellipsometer- or polarimeter system comprising in sequence: a source of electromagnetic radiation; a polarizer; on Compensator or retarder system; an analyzer, and a detector system; the method comprising the steps of: placing a sample in the system spectroscopic Ellipsometer- or polarimeter system; Cause, that the source of electromagnetic radiation to the sample system a Beam of electromagnetic waves supplies; and detecting of the beam of electromagnetic waves by its interaction with the sample system; wherein the beam of electromagnetic waves is directed so that He passes through the compensator or retarder system in steps, in which the electromagnetic beam of waves to a first reflective element with adjustable alignment approaches, by this is reflected and enters a third element, and which fully reflects substantially inward from a first side is then totally reflected thereof substantially inwardly from a second side is and then to a second reflective element with adjustable Alignment continues and is reflected by this and then along a propagation direction weiterverläuft, the substantially non from that of the electromagnetic beam Deflected by waves approaching the first reflecting element or is moved. The method may further comprise the step of that is causes the compensator or retarder system in operation to the propagation direction of the incident beam rotates.

According to a further aspect of the invention, a method for calibrating a spectroscopic Rotating Compensator Material System Investigation System be provided, comprising the steps of: <ul><li>a. Making bodies of a spectroscopic Rotating Compensator Material System Investigation System, comprising: a source of electromagnetic radiation; a polarizer; a compensator or retarder system as discussed above; a holder for a material system, an analyzer; and a detector system;</li><li>b. Developing a mathematical model of the spectroscopic Rotational Kompensatormaterialsystem-inspection system, which as Kalibrierparametervariable the Azimutalwinkelausrichtung of the polarizer, the present material system, the present material system DELTA, the Azimutalwinkelausrichtung (s) of the compensator, matrix components the compensator or Verzögerersystems, &lt;?page 6?&gt;Azimutalwinkelausrichtung the analyzer, and optionally detector element and Bildpersistenz Imperfections during read-out, wherein the mathematical model is effectively a transfer function is that a calculation of the intensity of the electromagnetic Beam as a function of the detected by a detector element Wavelength, a given intensity as a function of wavelength, provided from the source of a polychromatic beam of electromagnetic Waves, allows wherein the mathematical model alternatively equations for coefficients providing of terms in the transfer function, said coefficients the terms of calibration functions are;</li><li>c. Causing a polychromatic beam of electromagnetic Waves, generated by the source of a polychromatic beam of electromagnetic Waves passes through the polarizer, with a material system, which is on its way, interacts, through the analyzer extends and interacts with the dispersion optics, so that a plurality of substantially different wavelengths simultaneously in a corresponding Plurality of detector elements in the at least one detector system enters, said polychromatic beam of electromagnetic Waves by the compensator or retarder system runs, the is disposed at a location which is selected from: (prior to the mounting for a material system and after mounting for a material system, and both before and after, and / or support for a sample system;</li><li>d. obtaining a minimum two-dimensional data set of intensity values vs. wavelength and a parameter selected from: (angle of incidence of said polychromatic beam of electromagnetic Waves in relation to an existing material system and Azimutalwinkelrotation an element selected of: (said polarizer and analyzer)) over time, while causing the compensator or retarder system continuously rotated and optionally calculating numerical values ​​of the data set for coefficients of terms in the transfer function for said spectroscopic rotation Kompensatormaterialsystem-examination system;</li><li>e. applying a mathematical regression of mathematical Model to the at least two dimensional data set and / or on values Coefficients of terms in the transfer function for evaluating the calibration; said by the regression-based serve calibration evaluated calibration parameters to the mathematical model for non-achromatic characteristics and non-idealities of Compensator or Verzögerersystems and for Azimutalwinkelausrichtungen the polarizer, analyzer and compensator or Verzögerersystems compensate.</li></ul>

According to a further aspect of the invention, a method may be provided for performing Ellipsometry / polarimetry comprising the steps of: a provision. a spectroscopic Ellipsometer- or Polarimetersystems that successively comprising: a source of electromagnetic radiation; a polarizer; a compensator or retarder system, which as in of the upstanding side view is shown, comprising: first and second Mirrored elements with adjustable orientation, respectively reflective surfaces have, said compensator or retarder system further comprises a third The element, which, as shown in the upright side view is, having first and second sides, the left and right and protrude downward from an upper point, the third member is made of a material that is reflective interfaces inside providing on first and second sides, said third element in relation to the first and second mirror element with adjustable Orientation is aligned so that in operation, an incident electromagnetic beam of waves to one of said first and second mirror element with adjustable alignment along a essentially horizontally oriented locus approaches, the outside of this is reflected and passes along a locus, the is aligned essentially vertically upwards, then in the third element reaches and substantially completely inside is reflected by one of the first and second side, then along an essentially horizontal locus weiterverläuft and substantially completely internally reflected by the other of the first and second side is, and then along a substantially vertically downward aligned locus weiterverläuft, then from the other the first and second mirror element with adjustable alignment and is reflected along a substantially horizontally oriented Propagation curve weiterverläuft which essentially not from the substantially horizontally oriented propagation direction of curve of the incident beam of substantially horizontally aligned is deflected or moved electromagnetic radiation, even when rotation of the compensator or Verzögerersystems done; with the Result that a delay between orthogonal components of incident electromagnetic Beam of waves occurs; an analyzer and a detector system; b. Placing a sample system in the spectroscopic ellipsometer / polarimeter system; c. Causing the electromagnetic radiation source a beam electromagnetic wave supplying the sample system; and d. detecting the Beam of electromagnetic waves by its interaction with the sample system.

The The method may further comprise the step of adjusting the orientation the first and second mirror element with adjustable alignment include such that an electromagnetic beam, from which &lt;?page 7?&gt;the Compensator or retarder system exits, not electromagnetic of the locus of the incoming beam is deflected and displaced waves, even if the compensator rotated or retarder is.

According to a another feature, the method further comprises the step of altering the Alignment of the spectroscopic ellipsometer / polarimeter system include so that it incident beam of electromagnetic Waves not horizontally with respect to an external reference system is aligned, but so that relative relations between the first and second mirror element with adjustable alignment and the third member are maintained. The method may further comprise the step that the compensator or retarder system while use about the propagation direction of the incident curve Beam of electromagnetic waves, which is no longer horizontal is aligned with respect to the external frame of reference that rotates is.

in the Below will be a number of preferred and / or optional Characteristics and arrangements presented that in embodiments of the invention can be provided. It may be a compensator / retarder system be provided, which viewed in vertical side view, first and second mirror elements with adjustable focus has, each having reflective surfaces. The compensator / retarder system further comprises a third element which, as in the vertical shown side view, first and second sides, which after protrude left and right and down from a high point and the third element is made of a material which reflective interfaces having on first and second inner surfaces. The third element is in reference to the first and second mirror element with adjustable Orientation so arranged that in operation an entering electromagnetic Beam of radiation of one of the first and second mirror elements with adjustable alignment along a substantially horizontal approximately aligned locus is reflected externally thereto and along a locus migrates which is oriented substantially vertically upwardly, then enters the third element and substantially completely inside is reflected from a its first and second sides, then along an essentially horizontal locus weiterverläuft and substantially completely internally reflected by the other of the first and second sides and is aligned along a substantially vertically downward Locus weiterverläuft, then with the other of the first and second mirror elements adjustable alignment is reflected and then along a substantially horizontally oriented propagation direction of curve weiterverläuft, which essentially substantially horizontally aligned by the Propagation curve of the incoming beam of substantially not deflected horizontally oriented electromagnetic radiation and is not moved. This is even the case when the Compensator / retarder horizontally to the direction of propagation of the beam curve of substantially oriented electromagnetic radiation rotates. The result the use of the compensator / retarder is that a delay between the orthogonal components of the incoming electromagnetic Beam generated by radiation.

The Compensator / retarder system may also include a means for at least one of the first and second mirror elements with adjustable alignment at least one of the following: translation movement and rotational movement in at least one dimension to lend.

The Translational movement of at least one of the first and second Mirror elements with adjustable alignment can in any carried XYZ direction and the rotational movement may in accordance with done three dimensions, which by a ball joint-like device can take place. Since the first and second mirror element with adjustable Orientation have a dimension of depth, is a translational movement not necessary in a depth direction typically.

A primary relates to application of the present invention compensator / retarder spectroscopic Ellipsometer / polarimeter having successively: a Electromagnetic radiation source, a polarizer a Compensator / retarder; a analyzer; and a detector system.

On A method for performing ellipsometry / polarimetry may comprise the steps of: <ul><li>a. providing a spectroscopic ellipsometer / Polarimetersystems, having the sequence: &lt;?page 8?&gt;a source of electromagnetic Radiation; a polarizer; a compensator / retarder system according to the present Invention, as described further below; an analyzer; and a detector system;</li><li>b. Placing a sample system in the spectroscopic ellipsometer / polarimeter system;</li><li>c. Causing said source of electromagnetic radiation to the Sample system a beam of electromagnetic waves supplies; and</li><li>d. detecting the beam of electromagnetic waves by its Interaction with the sample system.</li></ul>

The A method for performing a ellipsometry / polarimetry may further comprise the step of cause the compensator / retarder system during the Use about the propagation direction of the incoming beam curve of essentially horizontally oriented electromagnetic radiation rotates.

The said method for performing ellipsometry / polarimetry may further comprise the step of the orientation of the first and second mirror element with adjustable adjust alignment so that an electromagnetic beam, which from the compensator / retarder system exits, not electromagnetic of the curve of the input beam is deflected and displaced waves, even if the compensator / retarder system is rotated.

The A method for performing ellipsometry / polarimetry may further comprise the step of the alignment of the spectroscopic ellipsometer / polarimeter system be amended to that a beam of electromagnetic waves entering this, not horizontally aligned with respect to an external reference system is, but so that the relative relationship between the first and second mirror elements with adjustable alignment and third element are maintained.

And said method for performing ellipsometry / polarimetry may further include the step that during operation a rotational the compensator / retarder system electromagnetic to the direction of propagation curve of the incoming beam Waves is caused, which is not more horizontal with respect to the external reference system is aligned.

A alternative form of embodiment, a compensator / retarder system the present invention first and second mirror elements have adjustable orientation, each reflecting surfaces have. The compensator / retarder system further includes a third member, said first and second Sides, at an angle in relation to each other from a common Point project and the third element consists of a material, which reflective interfaces at first and second pages has in its interior. The third element is in reference to the first and second mirror element with adjustable Orientation aligned so that, in operation, an incoming electromagnetic beam a radiation, the one of the first and second mirror elements is approximated with adjustable orientation, on the outside of this is reflected and enters the third element and substantially completely inside is reflected from a its first and second sides, then substantially completely internally reflected by the other of the first and second sides is and then to the other of the first and second mirror elements with proceeds adjustable alignment and reflected by this is and continues along a propagation direction of curve substantially non-electromagnetic from the direction of the incoming is deflected and displaced beam of radiation, even if the compensator / retarder is rotated, with the result that a delay between the orthogonal Components of the incoming electromagnetic beam of radiation arises.

And in turn, the compensator / retarder system further comprising means comprise at least one of the first and second mirror elements with adjustable alignment at least one translational movement and a rotational movement in at least one dimension to to lend. And the compensator / retarder system may further comprise means to cause that the compensator / retarder system while use about the propagation direction of the incoming curve Beam of electromagnetic waves is rotating.

Around hereinafter an insight into a particularly relevant application the present invention compensator / retarder system to give, it is noted that in general, while Ro&lt;?page 9?&gt;animal forming compensator material system investigation system have (eg rotating compensator ellipsometer) many advantages (Eg, the observation of material system PSI and DELTA limiting "dead-spots" not available) in the absence of substantially achromatic "ideal" compensators it difficult and prohibitively expensive would be a "spectroscopic" Rotating Compensator Material System Investigation System to build, calibrate and use. This has in view the fact is seen that compensators which substantially are achromatic (ie, substantially constant delay over a great Wavelength range deploy as 190-1000 NM) and not generally favorable as mass production goods available are.

embodiments the compensator / retarder system according to the present invention can However, just to be calibrated at an affordable, and to be used Spectroscopic Rotating Compensator Material System Investigation System electromagnetic with a source of polychromatic beam Waves, a polarizer, a holder for a material system, a Analyzer, a dispersive optics and at least one photo-detector element array system, which includes a plurality of detector elements, are applied, wherein the spectroscopic Rotating Compensator Material System Investigation System least comprising a compensator which is arranged at a location the selected is selected from the group: (in front of the holder for a sampling system and, after the holder for a sample and system both before and after the holder for a sampling system).

While it it is known that the expansion joints are generally available not exactly ninety (90) degrees delay at all wavelengths via a relatively large Wavelength range providing, in the present invention, as described above, a work based on regression calibration method used which is not ideal compensator delay characteristics compensated. And while it true that the sensitivity and accuracy of a Rotating Compensator Material System Investigation System deteriorates when the compensator used by a provided delay towards zero (0.0) or einhundertundachzig (180) degrees is, it has been found that compensators that a delay a The range of wavelengths used forty (40) show up one hundred and seventy (170) degrees, for use in the present invention are acceptable and very impressive results on a shown relatively large Wavelength range can achieve (eg at least two hundred and fifty (250) to one thousand (1000) nanometers).

If an embodiment the spectroscopic Rotating Compensator Material System Investigation System according to the present Invention is used to investigate a material system, the connected to the bracket a material system is in place, the analyzer and polarizer are essentially held in a fixed position and at least one the at least one expansion joints is continuously rotated, while a polychromatic beam of electromagnetic waves that of the source of a polychromatic beam of electromagnetic waves is produced, is caused by the polarizer and the / the Compensator / reach compensators. The polychromatic beam electromagnetic waves is also caused with the material system interacting, passes through the analyzer and comes into interaction with the dispersive optics such that a plurality of substantially simple wavelengths simultaneously into a corresponding plurality of detector elements enters the detector system Photo arrangement.

On A method of calibrating a spectroscopic Rotating Compensator Material System Investigation System according to the present Invention may include the following steps: <ul><li>a. Providing a spectroscopic Rotating Compensator Material System Investigation System, embodying the present invention, as described herein is.</li><li>b. Developing a mathematical model of the spectroscopic Rotating Compensator Material System Investigation System, which as Kalibrierparametervariable a polarizer Azimutalwinkelausrichtung, the present material system PSI, the present material system DELTA, compensator Azimutalwinkelausrichtung (s) Matrix components of the compensator or compensators, Analyzer Azimutalwinkelausrichtung, and optionally detector element Bildpersistenz and imperfections during read-out, wherein the mathematical model is effectively a transfer function is that a calculation of the electromagnetic beam intensity as a function of a detector element detected wavelength, a given intensity as a function of wavelength, provided from the source of a polychromatic beam of electromagnetic Waves, allows wherein the mathematical model alternatively equations for coefficients providing of terms in the transfer function, said coefficients of terms are functions of calibration;</li><li>c. Causing a polychromatic beam of electromagnetic Radiation generated by the source of a polychromatic beam electromagnetic radiation, passes through the polarizer, with a &lt;?page 10?&gt;Material system that is on its way, interacts, passes through the analyzer and interacts with the dispersive optics such that a multiplicity of substantially different wavelengths simultaneously in a corresponding Plurality of detector elements in the at least one detector system occurs, wherein said polychromatic beam of electromagnetic radiation also passes through the / the compensator / s, of / at a point is / are arranged, the selected is of (in front of the holder for a Material system and by the holder for a material system and both before and after the holder for a sample system);</li><li>d. obtaining a minimum two-dimensional data set of intensity values vs. wavelength and a parameter selected of: (angle of incidence of said polychromatic beam of electromagnetic radiation in relation to an existing material system and Azimutalwinkelrotation an element selected of: (said polarizer and analyzer) over a period of time, while causing at least one of the compensators continuously rotated and optionally calculation of numerical values ​​of the record for Coefficients of terms in the transfer function for said spectroscopic Rotational Kompensatormaterialsystem inspection system;</li><li>e. applying a mathematical regression of mathematical Model to the at least two dimensional data set and / or on values Coefficients of terms in the transfer function for evaluating the calibration; said by the regression-based serve calibration evaluated calibration parameters to the mathematical model for non-achromatic characteristics and non-idealities of Compensator / compensators and for Azimutalwinkelausrichtungen the polarizer, analyzer and compensator or Verzögerersystems compensate.</li></ul>

In addition, The evaluation included also in the mathematical model the detector system detector element Bildpersistenz and readout non-ideality compensation calibration parameters simultaneously are performed in the mathematical regression method.

It is noted that when two compensators are provided, each at substantially the same speed or different Speeds can be rotated.

That's why it is an object of embodiments of the present invention to provide a compensator / retarder system provide, which enables adjustment to the introduction of significant distraction and / or shift in the direction of propagation a beam of electromagnetic waves which interact with this is intended to eliminate.

A Another object of embodiments of the present invention is the use of a compensator / retarder in an ellipsometer / polarimeter system in which it during use is continuously rotated to provide.

A Another object of embodiments of the present invention is a method for calibrating an ellipsometer / provide Polarimetersystems which a Compensator / retarder system includes, embodying the present invention.

in the Below we will now embodiments of the invention by way of example with reference to the accompanying drawings described. Show it:

<figref idrefs="S31">1</figref> a diagrammatic view of a conventional Ellipsometersystems;

<figref idrefs="S31">2a</figref> a "shift" in a beam electromagnetic radiation (LB ') in comparison with an electromagnetic Beam (LB) of radiation;

<figref idrefs="S31">2 B</figref> electromagnetic a "deflected" Beam (LB ') a Radiation in comparison with an electromagnetic beam (LB) of radiation;

<figref idrefs="S31">3</figref> in upright side view of the retarder (<figref>3</figref>) According to the present Invention that any of the joints / retarder (C1) (C2) (C3) of <figref idrefs="S31">1</figref> can be; and

<figref idrefs="S32">4</figref> a enlarged version from <figref idrefs="S31">3</figref> with some additional attributes.

With Referring to the drawings, is in <figref idrefs="S31">1</figref> a general ellipsometer (<figref>1</figref>) Shown diagrammatically. functionally Sequence are shown: a source of electromagnetic radiation (LS); &lt;?page 11?&gt;a polarizer (P); at least one compensator (C1) (C2) (C3); an analyzer (A); and a detector system (DET); wherein the polarizer, compensator and analyzer in Operating alternately stationary, may be rotatable or rotating.

<figref idrefs="S31">1</figref> shows, that a beam of electromagnetic waves (LBI) (after interaction with the polarizer (P) and, if present with the compensator (C1)) is brought into interaction with a sample system (SS) and either of them is reflected (LB0) or by this sample system transfer (SS) through is (LB0 ') and in a detector (DET) occurs. Several compensators (C1) (C2) and (C3) are shown in dashed lines to indicate that one or more may be present. An electromagnetic Beam (EPCLB) is also shown, of the analyzers shown (A) (A ') and leaves in a detector (DET) occurs.

A embodiment the present invention provides a new compensator / retarder system which in (C1) and / or (C2) and / or (C3) can be applied, the in the system of <figref idrefs="S31">1</figref> are arranged.

Before The present embodiment shown the compensator according to the invention / retarder system is is for a better understanding the benefits of the compensator / retarder system the present embodiment, the <figref idrefs="S31">2a</figref> involved, a "shift" in a beam electromagnetic radiation (LB ') in comparison with an electromagnetic Beam (LB) to show radiation. <figref idrefs="S31">2 B</figref> is provided to electromagnetic a "deflected" Beam (LB ') of Radiation in comparison with an electromagnetic beam (LB) to show a radiation. It is thus clear that the terms "displaced" and "diverted" a change the propagation direction of a beam of electromagnetic radiation suggest. An important aspect of the compensator / retarder system the present embodiment, is that it is set by a manufacturer or user can be to set a state in which a distraction or shift between incoming and outgoing electromagnetic rays Radiation does not exist, but the exiting and entering Rays electromagnetic radiation directly to each other in a Propagation direction after the interaction with the compensator / retarder system according to the present embodiment are aligned. This is a very important result, in particular, a compensator / retarder system continuously during use is rotated, as in Rotating Compensator Ellipsometer- and Polarimetersystemen.

furthermore shows <figref idrefs="S31">3</figref> in a side view, that the compensator / retarder system (3) comprises a first member (P1) formed in an upright side view shown first (OS1) and second (OS2) mirror elements with adjustable having orientation, projecting at an angle relative to each other. The first element (P1), first (OS1) and second (OS2) mirror elements with adjustable alignment have reflective surfaces. The EXPANSION / RETARDER SYSTEM (3) further has a nominal triangular element (P2), which in side view considered first (IS1) and second (IS2) sides has the left and right and down from a high point (UP2) protrude, said substantially triangular element (P2) is made of a material which interior reflective, a phase delay transferring, interfaces having on its first (IS1) and second (IS2) sides. The nominal triangular element (P2) in relation to the first (OS1) and second (OS2) mirror element aligned with adjustable alignment so, that in operation an incoming electromagnetic beam a Radiation (LB) extending the first (OS1) mirror element with adjustable Orientation along a substantially horizontally oriented Propagation curve approaches, is shown as it is typically the same from an outer surface and is reflected as a beam of electromagnetic radiation along (R1) moves which is substantially vertically upwards is aligned. Thereafter, the electromagnetic beam is a Radiation (R1) inserted into the nominally triangular element (P2) and substantially completely internally reflected by the first (IS1) side and then runs continues along an essentially horizontal locus and is essentially completely inside of the second (IS2) page reflected and runs further as being substantially vertically oriented down electromagnetic Beam of radiation (R3). Thereafter, a reflection is typically from an outer surface of the second mirror element (OS2) with adjustable orientation of the first element (P1), so that the electromagnetic beam (LB ') of a radiation a substantially horizontally oriented propagation direction of curve follows, and substantially horizontally oriented direction of propagation curve of the input beam (LB) of essentially horizontally oriented electromagnetic radiation is not deflected and moved. This is the case even when the compensator / retarder system (3) is rotated. The result of the application of the described&lt;?page 12?&gt;Compensator / retarder system (3) is that a delay between orthogonal Components of the incoming electromagnetic beam of radiation (LB) is produced, where he met the second (P2) element for interaction is brought. Further, the second (P2) is typically element a right triangle (with a ninety (90) degree angle at (UP2)) in the side view of <figref idrefs="S31">3</figref>, However, it is clear that the lower IS3 another form simple as a straight face may have (eg see IS3 ') and the outer surfaces of the first (OS1) and second (OS2) mirror element with adjustable Orientation are typically, but not necessarily, reflective by applying a metal coating. A metal coating provides a high reflectance and a good throughput of radiation intensity of the electromagnetic Beam safely. Assuming that a nominal triangle with precision-machined right angles (P2) is used, this provides a training Compensator / retarder an inherent Compensation of angular, both and translatory misalignment of the incoming light beam (LB), in particular when the first (OS1) and second (OS2) mirror element with adjustable alignment as necessary about the pivot points (PP1) or (PP2) are rotated.

It is particularly noted that, while the totally substantially internal reflections from the first (IS1) and second (IS2) side of the substantially triangular shaped element (P2), the delay between the orthogonal components of the electromagnetic beam (LB) providing of radiation, a delay caused by reflections from the first (OS1) and second (OS2) mirror element with adjustable Orientation can be produced.

Also is the total delay provided for angular misalignments incoming electromagnetic beam compensated. That is, when the incoming electromagnetic beam (LB) is not aligned is that it with an entry angle of forty-five (45) degrees the first outer surface (OS1) forms, the reflected electromagnetic beam (R1) is inside to the first inner surface (IS1) of nominal triangular element (P2) at a larger (smaller) Angle reflected as would be the case if the entry angle Fourty five (45) degrees. This effect is, however, directly compensated by a smaller (Larger) angle of entry of the electromagnetic beam (R2), where it inwardly from the inner surface (IS2) of the second triangular element (P2) is reflected. It is further to explain, that due to the oblique angle of incidence the reflections from the external surface (OS1) and (OS2) of the mirror elements with adjustable alignment of (P1), a polarimeter / ellipsometer with the compensator / retarder (3) requires calibration to the PSI-like components thereof to characterize.

<figref idrefs="S32">4</figref> shows a larger version from <figref idrefs="S31">3</figref> with some additional details of acceptable Variations of the shape of the lower side of the nominally triangular Element (P2), (eg (IS3) (IS3), (IS3 '') (IS3 '' ')). Also indicated are adjustable modules (P1 ') (P1' ') instead of (P1) in <figref idrefs="S31">3</figref>, The nominally triangular element (P2) and the adjustable modules (P1 ') (P1') are acceptable to the (BACK SUPPORT) to generally Ask secured. It is clear that<figref idrefs="S32">4</figref> a Angle theta (θ₁) On top of the nominally triangular element (P2) shows and it is clear that while the angle typically ninety (90) degrees, this is not required and it must be clear that any functional Angle is within the scope of the present invention. The adjustable Modules (P1 ') (P1 ") have exemplified (Not restrictive) Facilities to the arrangement of the pivot points of the mirror elements with adjustable orientation to enable (OS1) (OS2) ((PP1) or (PP2) to which (OS1) can rotate and (OS2) in at least one plane) to in slots ((S1) &amp; (S2)) or ((S1 ') (S 2')) is set to will. (It should be noted that the pivot points (PP1) and / or (PP2) a rotational movement possibility can deploy in one or more planes) and functional equivalents, which one described and illustrated translational or rotational movement enable, are considered to be within the scope of the present invention. The setting by the basic arrangement of (P1 '), (P1') and (P2) on the (BACK SUPPORT) in combination with available standing translational and rotational adjustment of (OS1) and (OS2) within (P1 ') or (P1 '') allows a user, the compensator / retarder system of the present embodiment closely align so that the electromagnetic beam (LB ') of radiation the Compensator / retarder (3) of the present invention in substantially the same direction of propagation leaves as the electromagnetic beam (LB) of radiation enters this. <figref idrefs="S32">4</figref> shows a rotation means (RM) on the left and right sides, showing that the compensator / retarder system (3) according to the present embodiment the operability has that to the propagation direction of the undeflected and undisplaced outgoing and incoming beams of electromagnetic Waves (LB) &amp; (LB ') are rotated can.

It is to be noted that, while <figref idrefs="S31">3</figref> and <figref idrefs="S32">4</figref> electromagnetic Beam (LB) &amp; (LB ') of radiation show that externally from an "external" surface of the adjustable mirror elements (OS1) (OS2) are reflected, this widely to is interpreted, so that they have a functional system equivalentes beinhal&lt;?page 13?&gt;th, in which the mirror surface "internal" is thereby required that at least one of electromagnetic radiation (LB) &amp; (LB ') of radiation the Depth of an adjustable mirror element (OS1) (OS2) traversed by the "internal" "back" area it is reflected and the depth of an adjustable mirror element (OS1) (OS2) crosses when spread.

The Compensator / retarder system the present embodiment, as in <figref idrefs="S31">3</figref> and <figref idrefs="S32">4</figref> shown is preferred since additionally means that the present Rotating Compensator Material System Investigation System spectroscopy (ie, at the same time in at a number of wavelengths a beam is operated, contains a lot of electromagnetic wavelengths, over a Range of eg 190-1000 Nanometers, and a used therein compensator (C), (C ') (C' ') may provide a delay, for example, inversely with the wavelength can be varied and still used), has a compensator (C) (C ') (C' ') according to the present invention a passage of a polychromatic electromagnetic beam through those without a significant loss, to cause deflection or displacement in the direction of propagation, enable. If this is not the case, difficulties arise in the Detector elements (DES), the photo array detector system (DET) contained detector element output signals that are difficult to compensate are.

furthermore is the reason for that the present embodiment with a compensator (C), (C '), (C '') are operated can, of not even close a constant ninety (90) degrees delay over a range of wavelengths can provide (what ideal characteristics would be) that a regression based calibration procedure (see introduction of this description) is used which has a wavelength-dependent compensation providing, for the the calibration parameters required values ​​elicits, in a developed mathematical model of Rotationskompensatormaterialsystem inspection system according to the present embodiment, as in pending EPO Application Nos. 98907397.8, and submitted through PCT / US98 / 02390th

It Note also that the polychromatic electromagnetic Ray source of a combined majority / plurality of laser sources may exist and that a polychromatic electromagnetic Ray source may include an effective polarizer, thereby no separate polarizer is no longer required. These options are as in the scope of the claims lying to consider.

It is also understood that the terminology "achromatic" to understand so is that an uncertainty in the delay of a compensator of one (1.0) degrees is provided, an uncertainty of a quarter (1/4) degrees in a measured sample system (PSI) and a Uncertainty of one half (1/2) level in a measured sample system (DELTA) effected.

As mentioned, Find embodiments the compensator / retarder system of the present invention is particularly relevant, but non-limiting application in rotating compensator / Ellipsometer- and Polarimetersystemen, which no "blind Points "at DELTA'S from zero (0.00) or einhundertundachzig (180) degree show (characteristic of rotating Polarizer or Analysatorsysteme) or forty-five PSI (45) degrees (characteristic of Modulating element systems).

While hereby embodiments the present invention have been disclosed, it should be clear that Many modifications, substitutions and variations of the present Invention in view of possible are. It is clear that the present invention otherwise than as as specifically described and may be in its scope and breadth only by the appended claims limited should be.