KR20230133961A - Reflectometer, spectrophotometer, ellipsometer, and polarimeter systems including wavelength modifiers - Google Patents

Abstract

The present invention, an ellipsometer, A polarimeter, reflectometer, and spectrophotometer system comprising at least one wavelength modifier that converts the wavelengths provided by a source of electromagnetic radiation into different wavelengths for use in sample irradiation.

Description

Reflectometer, spectrophotometer, ellipsometer, and polarimeter systems including wavelength modifiers

This invention claims priority of provisional application 63/143,187 filed on January 29, 2021, and provisional application 63/259,830 filed on August 17, 2021.

The present invention relates to ellipsometers, polarimeters, reflectometers, and spectrophotometer systems, comprising one or more converting wavelengths provided to a source of electromagnetic radiation into other wavelengths detectable by its detector and/or for use in irradiating a sample. Contains a wavelength modifier.

The use of electromagnetic radiation to irradiate samples, including reflectometers, spectrophotometers, ellipsometers, polarimeter systems, for example a direct beam of electromagnetic radiation (in reflection and/or transmission) to interact with a sample with which the beam is incident on a detector. This is well known. Changes in detected intensity (reflectometer and spectrophotometer systems) and polarization state (ellipsometer and polarimeter systems) provide insight into the properties of the sample as a result of these interactions. Properties such as absorption constant, Psi and Delta are usually evaluated by performing mathematical regression of the accumulated data against a mathematical model of the sample.

It has been common practice to provide a source of electromagnetic radiation containing the desired wavelength and direct the beam so that it interacts with the sample and then enters a detector. However, if a given wavelength is for example in the IR or THZ range, then special detector systems (e.g. Golay Cells or Bolometers, etc.) are needed to detect it, detectors for IR and THZ wavelengths e.g. For example, they are much more difficult to use than solid-state detectors suitable for detecting wavelengths in the visible range. The present invention recognizes this and provides a wavelength modifier that receives, for example, IR or THZ wavelengths and provides visible range wavelengths derived, for example, from the IR and THZ wavelengths. Additionally, investigators using systems that provide IR or THZ wavelengths may wish to easily extend the survey to include visual wavelengths. In these cases, a wavelength modifier can be applied prior to the sample. An example of a currently available wavelength modifier that converts MIR range wavelengths to near-visible wavelengths is produced by the Danish company NLIR. Therefore, a data sheet is provided for information disclosure.

For patentability purposes, the present invention focuses on the use of wavelength modifiers in ellipsometers, polarimeters, reflectometers, and spectrophotometer systems, while incidentally considering topics such as sources of electromagnetic radiation and their detectors. Regarding up-conversion, the wavelength modifier clearly exploits the surface state properties of the semiconductor. In a recent press release, Mona Jarrahi of UCLA's Department of Computer and Electrical Engineering reported that electrons in a semiconductor lattice experience an increase in energy when struck by incoming light, causing them to jump within the lattice. The electric field further enhances the energy. When electrons release energy through photon emission, the wavelengths are different.

Continuing, it is always beneficial to irradiate the sample with multiple angles of incidence of the beam on the sample surface and with as many wavelengths as possible. Although no source has been identified as preferred here (except those determined to be suitable for use with wavelength modifiers), the latter point can be addressed using a source of electromagnetic radiation beams called supercontinuum lasers. . For more insight into Supercontinuum Sources, see patent 11/035,729 to Van Derslice. Although the formation of supercontinuum laser spectra is the result of many complex nonlinear effects, it does not depend on the way the supercontinuum is created, simply that the supercontinuum can be created and applied as a reflectometer, spectrophotometer, elepsometer, or polarimeter. It need not be related in connection with the present invention. Again, the present invention relates to the use of wavelength modifiers in such sample irradiation systems.

A patent search for applying wavelength modifiers to ellipsometer, polarimeter, reflectometer, and spectrophotometer systems found nothing. However, patents were found in closely related areas and are disclosed herein. for example:

Patent No. 8,422,519 (Knight et al.);

Patent No. 8,718,104 (Clowes et al.);

Application Publication No. 2014/0233091 (Clowes et al.);

Patent No. 7,345,762 (Liphardt et al.);

Patent No. 6,104,488 (LeVan);

is disclosed. A computer search found additional patent references:

In a search for (supercontinuous laser and ellipsometer), 5 patents Nos. 9,080,971, 8,873,054, 8,441,639, 8,031,337 and 7,570,358, and 6 application publication nos. 2015/0323316, 2015/0036142, 2013/0222795, 2011/0069312, 2009/0262366, and 2008/0239265 are provided; and

In the search for (supercontinuum & laser and ellipsometer & spot), no patents were provided, but 4 applications were published, Nos. Only 2015/0058813, 2015/0046121, 2015/0046118 and 2015/0330770 were provided.

Additionally, known patent and application publications related to spot reduction include: 6,895,149 (Jacob et al.); 7,522,331 (Lapchuk et al.); US 2013/0027673 (Moussa); US 2006/0238743 (Lizotte et al.) and US 2013/0010365 (Curtis).

Additionally, during examination of patent application 14/757,280, the examiner discovered the following documents:

US2012/0057158 (Hilfiker et al.);

US2013/0026368 (Herzinger);

US2013/0304408 (Pandev);

US2015/0219497(Johs);

US2009/0267003 (Moriva et al.);

US2014/0304963 (Grejeda);

US2013/0063700 (Yamaguchi et al.).

Also titled "A New Spectrometer Using the Multiple Gratings With A Two-Dimensional Charge-Coupled Diode Array Detector" (Review of Scientific The paper, Instruments, Han et al., Volume 74, Issue 6, June 2003, describes a special grating consisting of three laterally stacked sub-gratings to generate three wavelength ranges.

It should be understood that a wavelength modifier may be applied after a step in the sample irradiation system to change the wavelength provided by the source to a wavelength that can be detected by the detector after interaction with the sample. It should also be understood that a wavelength modifier may be placed in front of the stage of the sample irradiation system to shift the wavelength used to irradiate the sample. The latter effect can be used, for example, to extend the range of IR and THZ systems into the visible range.

Even in view of the known prior art, there remains a need for the advantages provided by the use of wavelength modifiers in ellipsometer, polarimeter, reflectometer, and spectrophotometer sample investigation systems, either on the detector side or the source side of the system stage.

First, as in co-pending application Ser. No. 16/602,088, the sample interrogation system and method of use of the present invention consists of and derives from various combinations of at least three different sub-inventive areas, which are:

Application of detector systems in combinations that can be optimized for use in a wide range of electromagnetic radiation wavelengths;

the use of a supercontinuum laser to provide a beam of coherent electromagnetic radiation over a wavelength range of at least 400 to 4400 nm in combination with other sources of electromagnetic radiation over an extended wavelength range; and

The application of a speckle reducer with a supercontinuum laser source to effectively provide more consistent intensity versus position in the electromagnetic radiation beam derived from the supercontinuity laser output in ellipsometers, reflectometers, spectrophotometers, and similar systems.

However, the presently disclosed invention further consists of further sub-inventive areas, said sub-inventive areas namely:

Most importantly, the application of wavelength modifiers to receive relatively longer wavelengths of electromagnetic radiation (e.g. in the infrared (IR) and terahertz (THZ) range) that solid-state detector elements cannot detect, and e.g. , a solid-state (or other type) detector element is further configured to provide relatively shorter wavelength electromagnetic radiation that can be detected.

Golay cells, bolometers, micro-bolometers, thermocouples, photoconductive materials; photoconductive material; deuterated triglycine sulfate (DTGS); HgCdTe(MCT); LiTaO3; PbSe; PbS; and InSb detectors that receive relatively short wavelength electromagnetic radiation have problems detecting and providing relatively longer wavelength electromagnetic radiation that can be detected.

Additional sub-inventive areas include:

Application of supercontinuum laser sources providing wavelengths up to approximately 18000 nm;

Application of additional types of electromagnetic radiation sources in combination with or replacing supercontinuum lasers to extend the wavelength range over which the sample irradiation system of the present invention can be used (e.g. Nernst Glower and Globar, respectively) Provides wavelengths up to between 14000 nm and 50000 nm or other possible sources including DTHS, laser stabilized arc lamps, Hg arc lamps, fixed or tunable quantum cascade lasers, QTH and other sources that can),

Application of a supercontinuum laser to a Fourier transform infrared source in combination with a Michelson interferometer, believed not previously disclosed in the context of applications in ellipsometers, reflectometers, spectrophotometers, and similar systems;

It is believed that subcategories of the present invention provide novel, non-obvious sample interrogation systems in various combinations and enable new, non-obvious and useful methods of use.

The invention claimed in this application is for use in irradiating samples with electromagnetic radiation:

ellipsometer;

polarimeter;

reflectometer; and

spectrophotometer;

It focuses on a sample survey system selected from a group consisting of;

The system:

electromagnetic source (LS);

Stage supporting the sample (STG); and

a detector (PA) comprising detector elements (DE's);

In one important embodiment, the system source (LS) provides long-wavelength electromagnetic radiation in the IR and THZ range, and the detector comprises solid state elements (DE's) that are unable to detect the IR and THZ wavelengths. However, the system allows the detector elements (DE's) to detect by the presence of at least one wavelength modifier (WM) in front of the detector (PA) for receiving electromagnetic radiation of wavelengths outside the range of the detector (PA). and characterized in that the detector elements (DE's) provide output electromagnetic radiation above a detectable wavelength.

The system may further include polarization state generator (PSG) and polarization state analyzer (PSA) components respectively before and after the stage (STG), where the system is an ellipsometer.

The system may provide that at least one wavelength modifier (WM) receives electromagnetic radiation comprising wavelengths in the IR and THZ ranges and outputs electromagnetic radiation having wavelengths in the visible wavelength range.

The system can provide that at least one wavelength modifier (WM) receives electromagnetic radiation comprising a wavelength in the far-infrared (far-IR) range and outputs electromagnetic radiation having a wavelength in the visible wavelength range.

The system may provide that at least one wavelength modifier (WM) receives electromagnetic radiation comprising a wavelength in the mid-IR range and outputs electromagnetic radiation having a wavelength in the visible wavelength range.

The system can provide that at least one wavelength modifier (WM) receives electromagnetic radiation comprising a wavelength in the near-IR range and outputs electromagnetic radiation having a wavelength in the visible wavelength range.

The system may further include dispersive optics (DO) between the stage and the detector to spatially separate different wavelengths for presentation to multiple element (DE's) detectors (PA).

The wavelength modifiers are:

between the source (LS) and the stage (STG);

Between the stage (STG) and the distributed optical system (DO);

It may be arranged between the distributed optical system (DO) and the detector (PA) selected from the group consisting of.

The invention also provides for use in irradiating samples with electromagnetic radiation:

ellipsometer;

polarimeter;

reflectometer; and

spectrophotometer;

It is a sample survey system selected from a group consisting of;

The system:

electromagnetic source (LS);

Stage supporting the sample (STG); and

Includes a detector (PA).

The system source (LS) provides electromagnetic radiation in a wavelength range longer or shorter than what the detector elements (DE's) can detect; The system allows the state elements (DE's) to be detected by the presence of at least one wavelength modifier (WM) in front of the detector (PA) for receiving electromagnetic radiation of wavelengths outside the range of the detector (PA). and the solid state element (DE'S) provides output electromagnetic radiation based on a detectable wavelength.

The system has a source (LS):

UV-rays;

line of sight;

Far infrared rays;

mid-infrared;

terahertz;

providing electromagnetic radiation having a wavelength range selected from

The detector,

UV-rays;

line of sight;

Far infrared rays;

mid-infrared;

terahertz;

To detect a wavelength in a selected range from

Here, the selected detection wavelength range is different from the wavelength range provided by the source LS.

The system has sources:

Far infrared rays;

mid-infrared;

near infrared; and

terahertz;

providing a range of wavelengths selected from;

The wavelength modifiers are:

UV-rays; and

line of sight;

Provides a wavelength in a range selected from the group consisting of.

The present invention is also a sample investigation method comprising the following steps:

a) For use in irradiating samples with electromagnetic radiation,

ellipsometer,

polarimeter;

reflectometer; and

spectrophotometer;

It includes the step of providing,

The system:

electromagnetic source (LS);

Stage supporting the sample (STG); and

Detector (PA) comprising detector elements (DE's);

The system source (LS) provides electromagnetic radiation in a wavelength range longer or shorter than what the detector elements (DE's) can detect; The system is such that the state elements (DE's) can be detected by the presence of at least one wavelength modifier (WM) before the detector (PA) to accommodate electromagnetic radiation of wavelengths outside the range of the detector (PA). and wherein the solid state elements (DE's) provide output electromagnetic radiation based on a detectable wavelength.

The method is followed by the following steps:

b) placing the sample to be examined on the stage (STG);

c) the source (LS) providing electromagnetic radiation comprising a wavelength that the detector elements (DE's) cannot detect and directing a beam of electromagnetic radiation at the sample;

d) causing the wavelength modifier to receive electromagnetic radiation wavelengths from the sample provided by the source LS and modify them into a wavelength detectable by the detector element DE;

e) causing the detector element to detect modified electromagnetic radiation and provide output data;

f) analyzing the output data to determine sample characteristics.

The method may provide that the system further includes distributed optics (DO) that spatially separates different electromagnetic wavelengths.

The wavelength modifier (WM) may be located between the source (LS) and the stage, or between the stage (STG) and the distributed optics (DO), or between the distributed optics (DO) and the detector (PA). You can.

Another method of irradiating a sample with different wavelengths of electromagnetic radiation provided by a source includes the following steps:

a) For use in irradiating samples with electromagnetic radiation,

ellipsometer,

polarimeter;

reflectometer; and

spectrophotometer;

It includes the step of providing,

The system:

electromagnetic source (LS);

Stage supporting the sample (STG); and

Detector (PA) comprising detector elements (DE's);

The system source LS provides electromagnetic radiation in a wavelength range longer or shorter than what the detector elements DE's can detect.

The system is characterized by the presence of a wavelength modifier (WM) before the step (STG).

The method is followed by the following steps:

b) placing the sample to be examined on the stage (STG);

c) the source LS providing electromagnetic radiation and directing a beam of electromagnetic radiation toward the sample;

d) said wavelength modifier (WM) receiving a first range of electromagnetic radiation wavelengths provided by said source (LS) and emitting a modified range of wavelengths;

e) detecting modified electromagnetic radiation wavelengths after the detector elements (DE's) interact with the sample (MS);

f) analyzing the output data to determine sample characteristics.

The method provides an arrangement between the stage (STG) and the detector (PA) to place a detector element in the range of the detector (PA) capable of detecting the wavelength from the sample (MS) between steps c) and d). A step (c') of placing a two-wavelength modifier (WM) may be further included.

In view of the main invention claimed herein (the use of a wavelength modifier (WM) to change the wavelength of an electromagnetic wave at a point within a sample irradiation system), any electromagnetic radiation source in the present invention can be used to provide electromagnetic radiation of a desired wavelength. You must understand that you can use . For example, continuous sources such as Ar, Line sources such as Hg and Na lamps in the UV and visible ranges and lasers in the visible and IR ranges are also applicable, but the advantage can be derived from the fact that the intensity of the electromagnetic radiation beam from supercontinuum lasers is: It is generally much higher over a wider range of wavelengths than is the case for other electromagnetic radiation sources commonly used in ellipsometric and similar applications. The detector system of the present invention is capable of providing electromagnetic radiation at a certain range of wavelengths (including modified wavelengths produced by wavelength modifiers - typically longer to shorter wavelengths, but can be from shorter to longer wavelengths). By being able to provide optimized detection of do. However, since other known sources provide longer wavelengths than can currently be produced by supercontinuum lasers, but will certainly be produced by improved supercontinuum lasers in the future, the present invention also provides for the use of improved supercontinuity lasers. This includes its use when necessary to enable sample irradiation at longer//shorter wavelengths until possible. An increase in wavelength range from about 400 to 2500 nm about 5 years ago, currently available supercontinuum lasers provide wavelengths up to at least 4400 nm. For example, the NP Photonics SpectraChrome 1000 Mid-IR supercontinuum laser. Note that supercontinuum lasers can be used that provide wavelengths up to about 18000 nm, although the intensity of the wavelengths drops off at the longest wavelengths. The source from IPG Photonics (CLPF-2500-SC IDFG series) shows plots down to 18 microns, for example. However, many such sources only extend up to about 5000 nm. The present invention should be considered to cover any such possible supercontinuum laser wavelength range.

SAMPLE INVESTIGATION SYSTEMS

With the foregoing in mind, the present invention first:

reflectometer;

spectrophotometer;

ellipsometer; and

polarimeter;

It can be described as a sample survey system selected from the group consisting of,

The sample investigation system includes;

a) a source of a spectral beam of electromagnetic radiation;

b) supporting the sample; and

c) a detector system for monitoring electromagnetic radiation provided by a single sample.

The above systems are distinguished in the following respects:

The source of the spectral beam of electromagnetic radiation is a supercontinuum laser that provides a high intensity, highly directional coherent spectrum of electromagnetic radiation wavelengths in the range covering 400 to at least 4400 nm, which results in a wide spectral broadening. Resulting from the interaction of pulsed lasers and nonlinear processes;

The sampling system is characterized by at least one selection from a primary selection group, the primary selection group being:

PRIMARY SELECTION GROUP

In use, a source of a spectroscopic beam of electromagnetic radiation directs the beam provided by it at an angle to a sample placed on the stage to support the sample, but does not include the beam passing through a combination of a beam splitter and an objective lens, in that order. and

In use, the fluorescence caused by the illumination beam of electromagnetic radiation is not detected by the illumination beam path between the object to be inspected and the detector and illumination means that spatially resolve the radiation emitted by the object to be inspected, and between the object to be inspected and the detector. The detection beam path of does not include illumination optics designed to produce a light sheet of illumination radiation extending across the illumination beam path, the axis of the detection beam path being oriented substantially perpendicular to the light sheet and the cross-sectional plane of the object to be inspected. wherein the illumination beam path between the illumination means and the object to be inspected and the detection beam path between the object to be inspected and the detector do not include illumination optics, wherein the illumination optics comprises illumination radiation extending across the axis of the illumination beam path. designed to create a light sheet and the detection beam path is oriented at an angle diverging at 9 degrees with respect to the object to be inspected and the cross-sectional plane of the light sheet; and

In use, the system is configured to fire from a pumped CO2 laser configured to fire into a photonic crystal fiber made of chalgenide glass as a substantial element or partially formed from at least one selection from the group of AlClxBr(1-x), NaCl and ZnSe. does not use a supercontinuum source comprised of a pulsed laser configured to do so; A system comprising a titanium:sapphire laser is configured to fire femtosecond pulses through a nonlinear optical element disposed in an inert gas in a gas containment cell such that second harmonic pulses are generated and produce supercontinuum terahertz radiation.

You can choose two or all three.

The sample irradiation system may further include a spot reducer; The speckle reducer serves to reduce wild swings in the intensity of electromagnetic radiation as a function of time and position of the beam due to interference effects between different coherent wavelengths in the widely extended spectrum.

The sample irradiation system may further include a polarization state generator between the source of the electromagnetic radiation beam and the stage for supporting the sample, and may include a polarization state analyzer between the detector and the stage for supporting the sample. The system may be an ellipsometer or a polarimeter, and optionally further comprises a polarization state generator and/or a compensator to the polarization state detector.

The sample irradiation system may include a speckle reducer in the form of a multimode fiber.

The sample irradiation system may include a speckle reducer in the form of a beam diffuser.

The sample irradiation system may include a speckle reducer in the form of a fly's-eye beam homogenizer.

The sample irradiation system may include a speckle reducer in the form of a rotating beam diffuser.

The sample irradiation system may include a speckle reducer in the form of an electrocrystal driven beam diffuser.

The sample irradiation system may include a speckle reducer in the form of electronic means to shorten the temporal coherence length.

The sample interrogation system may further include at least one selection from the group consisting of:

The system further includes a Michelson interferometer and the supercontinuum laser source of electromagnetic radiation is functionally coupled thereto, wherein the source is a FTIR source;

The system further includes a wavelength modifier to receive relatively long (short) wavelength electromagnetism and provide an output of shorter (longer) wavelengths that can be detected by the detector element(s);

The detector system includes a single element;

The detector system includes a plurality of detector elements capable of detecting a wavelength coming from the wavelength modifier when a relatively long (short) wavelength is input, the detectable wavelength being:

at least one beam splitter;

at least one combined dichroic mirror and prism; and

at least one grid;

are guided into the detector element through at least one selection from the group consisting of; and

The system further includes a second source providing wavelengths within a longer or shorter range than that provided by the supercontinuum laser.

Sample interrogation methods of the present invention may include:

a) Provision of a sample survey system selected from the group consisting of:

reflectometer;

spectrophotometer;

ellipsometer, and

polarimeter;

The system:

a') a beam source of a spectral beam of electromagnetic radiation;

b') a stage supporting the sample; and

c') a detector system for monitoring electromagnetic radiation provided from a single sample.

The system is such that a source of a high-intensity, highly directional spectral beam of electromagnetic radiation provides a coherent spectrum of electromagnetic radiation wavelengths in the range covering from 400 to at least 4400 nm, and pulsed lasers and nonlinear processes result in a broad spectral broadening. Distinguished in that it is a continuous laser, the system further comprising a second source providing a wavelength within a range longer or shorter than that provided by the supercontinuum laser, wherein both sources are substantially the same as the supercontinuum source. It is configured to provide electromagnetic radiation to the same location on the sample.

The system further comprises a spot reducer of a type selected from the group consisting of:

multimode fiber;

beam spreader;

fly's-eye beam homogenizer;

rotating beam spreader;

Piezoelectric crystal driven beam diffuser;

Electronic means to shorten the temporal coherence length;

The speckle reducer serves to reduce the harsh swings in the intensity of electromagnetic radiation as a function of the position of the beam resulting from interference effects between different coherent wavelengths in the widely extended spectrum.

The sampling system is characterized by at least one selection from the group consisting of:

THE PRIMARY SELECTION GROUP

The method continues as follows:

b) causing a spectral beam of speckle-reduced electromagnetic radiation provided by the supercontinuum laser and a speckle reducer to interact with the sample of the stage and then enter the detector system and/or electromagnetic radiation provided by the second source. causing it to interact with a sample on the stage and enter the detector;

c) analyzing the data provided by the detector to characterize the sample.

The detector may comprise a system of at least two detectors and means for distributing a portion of the spectral beam to each based on wavelength.

Other examples of sample survey systems are selected from the group consisting of:

reflectometer;

spectrophotometer;

ellipsometer, and

polarimeter;

Includes:

a) a source of a spectral beam of electromagnetic radiation;

b) a stage supporting the sample; and

c) Detector system for monitoring electromagnetic radiation.

The above systems are distinguished in the following respects:

The source of the spectral beam of electromagnetic radiation provides a high-intensity, highly directional coherent spectrum of electromagnetic radiation wavelengths in the range comprising 400 to at least 4400 nm due to the interaction of a pulsed laser with a nonlinear process and causes a wide spectral broadening. A supercontinuum laser resulting from the interaction of a pulsed laser and a non-linear process, the system further comprising a second source providing a wavelength within a longer or shorter range than that provided by the supercontinuum laser, The system is configured such that both sources provide electromagnetic radiation to substantially the same location on the sample as the supercontinuum source;

And the sample investigation system is characterized by:

THE PRIMARY SELECTION GROUP

The system further comprises a spot reducer of a type selected from the group consisting of:

multimode fiber;

beam spreader;

Plyss-Eye Beam Homogenizer;

rotating beam spreader;

Piezoelectric crystal driven beam diffuser;

Electronic means to shorten the temporal coherence length;

The speckle reducer serves to reduce wild swings in the intensity of electromagnetic radiation as a function of time and position of the beam due to interference effects between different coherent wavelengths in the widely extended spectrum.

The system may further include a polarization state generator between the source of the electromagnetic radiation beam and the stage for supporting the sample, and a polarization state analyzer between the stage for supporting the sample and the detector, is an ellipsometer or polarimeter, the system optionally further comprising a polarization state generator and/or a compensator of the polarization storage detector.

The sample irradiation system may include a speckle reducer in the form of a multimode fiber, a beam spreader, a fly-eye beam homogenizer, a rotating beam spreader, a piezoelectric crystal driven beam spreader, or electronic means for shortening the temporal coherence length.

Where applicable, the detector system of any embodiment may include a selection from the group consisting of:

Golay cell;

Bolometer;

thermocouple;

Contains a photoconductive material;

comprising photovoltaic materials;

Contains deuterated triglycine sulfate (DTGS);

Includes HgCdTe (MCT);

Contains LiTaO ₃ ;

Contains PbSe;

Contains PbS; and

Contains InSb;

The group further includes:

The detector system comprises a plurality of detector elements capable of detecting the internally guided wavelength via those selected from the group consisting of:

at least one beam splitter;

at least one combined dichroic mirror and prism; and

At least one grid.

In another example of a sample irradiation system for use in sample irradiation over a wavelength range comprising from 400 nm to at least 50000 nm, the sample irradiation system is selected from the group consisting of:

reflectometer;

spectrophotometer;

ellipsometer, and

polarimeter;

Includes:

a) a source of a spectral beam of electromagnetic radiation;

b) a stage supporting the sample; and

c) At least one detector system for monitoring electromagnetic radiation.

The source of the spectral beam of electromagnetic radiation is

Supercontinuous laser;

Nernst Glower;

Globar;

Laser stabilized arc lamp;

HG arc lamp; and

Fixed or tunable quantum cascade lasers;

is selected from the group consisting of; and,

This provides wavelengths in the infrared and/or terahertz range.

The at least one detector system may include detector element(s) that are unable to detect long electromagnetic radiation wavelengths spanning at least part of the infrared and terahertz ranges. In this case, the sample irradiation system, in use, receives electromagnetic radiation of relatively long (short) wavelengths that the element(s) of the at least one detector system cannot detect, and which the detector element(s) cannot detect. providing an output of a shorter (longer) wavelength capable of detecting electromagnetic radiation of the shorter (longer) wavelength, and inputting the detectable wavelength to the at least one detector system comprised of element(s) capable of detecting electromagnetic radiation of the shorter (longer) wavelength. further comprising at least one wavelength modifier.

Another example of a sample investigation method includes the following steps:

a) providing a sample irradiation system for use in irradiating a sample over a wavelength range comprising 400 nm to at least 50000 nm, wherein the sample irradiation system is selected from the group consisting of:

reflectometer;

spectrophotometer;

ellipsometer, and

polarimeter;

Includes:

a') a source of a spectral beam of electromagnetic radiation;

b') a stage supporting the sample; and

c') at least one detector system for monitoring electromagnetic radiation;

The source of the spectral beam of electromagnetic radiation is:

Supercontinuous laser;

Nernst Glor;

Globa;

Laser stabilized arc lamp;

HG arc lamp; and

Fixed or tunable quantum cascade lasers;

is selected from the group consisting of;

This provides wavelengths in the infrared and/or terahertz range.

The at least one detector system may include detector element(s) capable of detecting long electromagnetic radiation wavelengths spanning at least part of the infrared and terahertz ranges, and the sample irradiation system may, in use, detect the at least one receive electromagnetic radiation of relatively long (short) wavelengths that the detector element(s) of the detector system cannot detect, and provide an output of shorter (longer) wavelengths that the detector element(s) can detect, and and at least one wavelength modifier that inputs the detectable wavelength to the at least one detector system comprised of element(s) capable of detecting electromagnetic radiation of the shorter (longer) wavelength.

The method is followed by the following steps:

b) selecting a supercontinuum laser source and further providing a speckle reduction system selected from the group consisting of:

multimode fiber;

beam spreader;

Fly's Eye Beam Homogenizer;

rotating beam spreader;

Piezoelectric crystal driven beam diffuser; and

Electronic means to shorten the temporal coherence length;

c) placing the sample to be examined on the stage to support the sample;

d) causing a beam of electromagnetic radiation to be generated by the supercontinuum laser source and interact with the sample and then enter the at least one detector system to monitor the electromagnetic radiation;

at least one supercontinuum laser source, wherein the electromagnetic radiation beam comprises the supercontinuum laser source and element(s) that are incapable of detecting long (short) electromagnetic radiation wavelengths over at least part of the infrared and terahertz ranges; to also interact with the wavelength modifier and the speckle reduction system between the detector systems of

causing electromagnetic radiation of a wavelength(s) detectable by element(s) in the at least one detector to enter the at least one detector system, and

e) analyzing the output from the at least one detector to provide insight into the characteristics of the sample.

Another method of examining a sample includes the following steps:

a) providing a sample irradiation system for use in irradiating a sample over a wavelength range comprising 400 nm to at least 50000 nm, wherein the sample irradiation system is selected from the group consisting of:

reflectometer;

spectrophotometer;

ellipsometer, and

polarimeter;

Includes:

a') a source of a spectral beam of electromagnetic radiation;

b') a stage supporting the sample; and

c') At least one detector system for monitoring electromagnetic radiation.

The source of the spectral beam of electromagnetic radiation is:

Supercontinuous laser;

Nernst Glor;

Globa;

Laser stabilized arc lamp;

HG arc lamp; and

Fixed or tunable quantum cascade lasers;

is selected from the group consisting of;

This provides wavelengths in the infrared and/or terahertz range.

The at least one detector system may include detector element(s) capable of detecting electromagnetic radiation wavelengths over at least a portion of the infrared and terahertz ranges;

The sample irradiation system, in use, receives electromagnetic radiation of relatively long (short) wavelengths that the detector element(s) of the at least one detector system cannot detect and that the detector element(s) of the at least one detector system can detect. At least one wavelength, providing an output of a shorter (longer) wavelength, and inputting the detectable wavelength to the at least one detector system consisting of element(s) capable of detecting electromagnetic radiation of the shorter wavelength. Includes more modifiers.

The method is followed by the following steps:

b) selecting other than a supercontinuum laser source of electromagnetic radiation;

c) placing the sample to be examined on the stage to support the sample;

d) causing a beam of electromagnetic radiation to be generated by the source and interact with the sample and then enter the at least one detector system to monitor the electromagnetic radiation;

wherein the electromagnetic radiation beam is between the source and at least one detector system comprising detector element(s) capable of detecting long (short) electromagnetic radiation wavelengths over at least part of the infrared and terahertz ranges. to also interact with the wavelength modifier,

causing electromagnetic radiation of a wavelength(s) detectable by detector element(s) in the at least one detector to enter the at least one detector system, and

e) analyzing the output from the at least one detector to provide insight into the characteristics of the sample.

In any of the foregoing examples, where applicable, the sample irradiation system may be provided such that a supercontinuum laser source of electromagnetic radiation is functionally combined with a Michaelson interferometer, wherein the detector is selected from the group consisting of:

golay cell;

bolometer;

thermocouple;

The detector is characterized in that it contains a substance selected from the group consisting of:

deuterated triglycine sulfate (DTGS);

HgCdTe(MCT);

LiTaO ₃ ;

PbSe;

PbS;

InSb; and

InGaAs.

Another sample irradiation system for use in sample irradiation over a wavelength range of the present invention is wherein the sample irradiation system is selected from the group consisting of:

reflectometer;

spectrophotometer;

ellipsometer; and

polarimeter;

The sample investigation system includes;

a) as a beam source of a spectral beam of electromagnetic radiation:

Supercontinuous laser; and

A source selected from the group consisting of: a source providing a longer or shorter wavelength than that provided by the supercontinuum laser;

b) a stage supporting the sample; and

c) a detector system for monitoring electromagnetic radiation provided by a single sample.

The at least one detector system may include detector element(s) that are unable to detect long (short) electromagnetic radiation wavelengths over at least a portion of the source range of the wavelengths.

The system may further require at least one selection from the group consisting of:

In use, the element(s) of the at least one detector system receive electromagnetic radiation of relatively long (shorter) wavelengths that the detector element(s) cannot detect, and the element(s) of the at least one detector system receive electromagnetic radiation of relatively long (shorter) wavelengths that the detector element(s) can detect. at least one wavelength modifier providing an output, the file modifier being input as a detector element(s) of a detector system as a detectable wavelength being the output of said wavelength modifier; and

A speckle reducer that serves to reduce wild swings in the intensity of electromagnetic radiation as a function of time and position of the beam due to interference effects between different coherent wavelengths in the broadly extended spectrum.

The invention can be used in the following combinations:

Application of detector systems;

Use of supercontinuous lasers;

Application of spot reducer;

Application of additional sources of electromagnetic radiation;

Application of supercontinuum lasers from Fourier transform infrared sources;

Application of wavelength modifier.

DETECTOR SYSTEMS

The present invention includes the use of both single element and multi-element detectors. When you need to analyze the beam as a whole, either monochromatic or spectral:

golay cell;

bolometer;

Single element detectors, such as thermocouples;

or

photoconductive material;

photovoltaic materials; As a phosphorus detector,

Contains deuterated triglycine sulfate (DTGS);

Includes HgCdTe (MCT);

Contains LiTaO ₃ ;

Contains PbSe;

Contains PbS; or

Containing InSb; detector

It can be utilized. For example, electromagnetic radiation sources are often functionally combined with Michelson interferometers.

The detector system of the invention may alternatively include means for generating a plurality of distinct wavelength ranges from an incident spectral beam, said system comprising a sequence of at least two elements, each element consisting of: It is selected from the group:

a grating which, when presented with an incident spectral beam of electromagnetic radiation, produces a spectrum of diffracted dispersed wavelengths and at the same time produces a reflected beam of altered spectral content of electromagnetic radiation;

A combined dichroic beam splitter-prism that produces a spectrum of wavelengths transmitted and emitted through said prism when provided with a spectral beam of electromagnetic radiation, and at the same time produces a beam of altered spectral content of electromagnetic radiation.

In use, a spectroscopic beam of electromagnetic radiation from the source is directed to interact with a sample disposed on the stage and then impinge on a second selected element that likewise produces a spectrum of scattered wavelengths directed toward a second detector. Simultaneously with the creation of the reflected changed spectral content of the radiation, a spectrum of scattered wavelengths is generated and simultaneously impinges on the first selected element such that it is directed towards the first detector.

while the reflected altered spectral content of the electromagnetic radiation may be directed to impinge on a beam splitter that directs at least a portion of the beam onto a third selected element producing a spectrum of scattered wavelengths directed to a third detector. , directing at least a portion of the altered spectral content beam toward the second selected element that continues to direct a limited range spectrum of dispersed wavelengths produced toward the second detector.

The detector system may include at least one selection from the group consisting of:

at least one of the first and second selected elements is designed to optimally configure the wavelength range emanating therefrom;

at least one of the first and second detectors is designed to optimally detect the wavelength range input by each of the first and second selected elements;

Functionally activated.

The detector system may further include more than two selected elements, wherein the reflected electromagnetic beam produced by the second selected element is:

impinging on a dichroic beam splitter and a third selected element therefrom;

collides directly with a third selected element;

impinging on at least one reflector and a dichroic beam splitter and a third selected element therefrom; and

It is directed towards at least one selection from the group consisting of at least one reflector and a third selected element.

The detector system may provide for a third selected element to generate a spectrum of scattered wavelengths that are directed toward the third detector when receiving the reflected beam of electromagnetic radiation.

The detector system may provide at least one selection from the group consisting of:

the third selected element is designed to optimally configure the wavelength range emerging therefrom;

It becomes possible for the third detector to be designed to optimally detect the wavelength ranges respectively input by the first and second selected elements.

The detector system includes four elements selected, wherein there is either a reflected electromagnetic beam produced by a third selected element or a current dichroic beam splitter associated with the second selected element:

impinging on a dichroic beam splitter and a fourth selected element therefrom;

collides directly with a fourth selected element;

impacting at least one reflector and a dichroic beam splitter and a fourth selected element therefrom; and

It is directed towards at least one selection from the group consisting of at least one reflector and a fourth selected element.

The detector system may provide for a fourth selected element to produce a spectrum of scattered wavelengths directed toward the fourth detector when receiving the reflected beam of electromagnetic radiation.

The detector system may provide at least one selection from the group consisting of:

said fourth selected element is designed to optimally configure the wavelength range emerging therefrom;

It becomes possible for the fourth detector to be designed to optimally detect the wavelength ranges respectively input by the first and second selected elements.

The detector system may include a beam of spectroscopic electromagnetic radiation from the sample that is caused to impinge on a grating or combination dichroic beam splitter prism that produces a spectrum of diffracted dispersed wavelengths, which is directed to the detector and of the electromagnetic radiation. simultaneously producing a reflected beam of altered spectral content of electromagnetic radiation that is directed to interact with a dichroic beam splitter causing the altered spectral content reflected beam to split into two beams, both oriented in a separate selection from the group consisting of: :

a grating which, when presented with an incident spectral beam of electromagnetic radiation, produces a spectrum of diffracted dispersed wavelengths and at the same time produces a reflected beam of altered spectral content of electromagnetic radiation;

a combined dichroic beam splitter-prism, which produces a spectrum of wavelengths transmitted and emitted through the prism when provided with a spectral beam of electromagnetic radiation, and at the same time produces a beam of altered spectral content of electromagnetic radiation;

Currently, the spectrum of scattered wavelengths from a grating or combination dichroic beam splitter-prism is directed to each separate detector.

The detector system is configured to produce a spectrum of scattered wavelengths with the production of a reflected beam of altered spectral content of electromagnetic radiation directed to impinge on a second selected element producing a spectrum of scattered wavelengths that is likewise directed towards the second detector. It may be provided that the spectroscopic beam of electromagnetic radiation from the sample is the output beam of an ellipsometer or polarimeter exiting its analyzer, causing it to impinge on a first selected element to be directed towards a first detector.

The detector system may specifically include a beam of spectroscopic electromagnetic radiation from the sample caused to interact with a set of elements, the set of elements being:

The reflected beam exiting the first grating is a zero-order beam and is directed to a second grating and a second detector, including a first grating and a first detector.

The detector system may specifically include a beam of spectroscopic electromagnetic radiation from the sample caused to interact with a set of elements, the set of elements being:

The reflected beam exiting the first grating is a zero-order beam and is directed to a first dichroic beam splitter-prism combination and a second detector, comprising a first grating and a first detector.

The detector system may specifically include a beam of spectroscopic electromagnetic radiation from the sample caused to interact with a set of elements, the set of elements being:

a dichroic beam splitter transmitting first and second ranges of scattered wavelengths, each substantially above and below a particular wavelength, each selected from the group consisting of:

a first grating and a first detector, wherein the reflected beam exiting the first grating is a zero-order beam and is directed to a second grating and a second detector; and

A first grating and a first detector, wherein the reflected beam exiting the first grating is a zero-order beam and is directed to a first dichroic beam splitter-prism combination and a second detector.

The detector system may specifically include a beam of spectroscopic electromagnetic radiation from the sample caused to interact with a series of elements, the series of elements being:

A first combined dichroic beam splitter-prism and a second detector, wherein the reflected beam reflected from the first combined dichroic beam splitter-prism is directed to the first grating and the second detector.

The detector system may specifically include a beam of spectroscopic electromagnetic radiation from the sample caused to interact with a series of elements, the series of elements being:

A first grating and a first detector, wherein the reflected beam generated by the first grating is a zero-order beam and is directed to a second grating and a second detector, and wherein the reflected beam generated by the second grating is: It is a zero-order beam and is directed to a third grating and a third detector.

The detector system may specifically include a beam of spectroscopic electromagnetic radiation from the sample caused to interact with a series of elements, the series of elements being:

a first grating and a first detector, wherein the reflected beam produced by the first grating is a zero-order beam and is directed to a first combined dichroic beam splitter-prism and a second detector, wherein the first combined dichroic beam splitter-prism The beam reflected from the beam splitter-prism is directed through a dichroic beam splitter to a third grating and a third detector.

The detector system may specifically include a beam of spectroscopic electromagnetic radiation from the sample caused to interact with a series of elements, the series of elements being:

A first grating and a first detector, wherein the reflected beam generated by the first grating is a zero-order beam and is directed to a second grating and a second detector, and wherein the reflected beam generated by the second grating is: It is a zero-order beam and is directed to a first combination dichroic beam splitter-prism and a third detector.

The detector system may specifically include a beam of spectroscopic electromagnetic radiation from the sample caused to interact with a series of elements, the series of elements being:

a first grating and a first detector, wherein the reflected beam produced by the first grating is a zero-order beam and is directed to a first combined dichroic beam splitter-prism and a second detector, wherein the first combined dichroic beam splitter-prism The beam reflected from the beam splitter-prism is directed through the beam splitter to a second dichroic beam splitter-prism combination and a third detector.

The detector system may specifically include a beam of spectroscopic electromagnetic radiation from the sample caused to interact with a series of elements, the series of elements being:

comprising a first combined dichroic beam splitter-prism and a first detector, wherein a reflected beam produced by the first combined dichroic beam splitter-prism is directed to a second grating and a second detector, wherein the second grating The reflected beam produced by is a zero-order beam and is directed to the third grating and the third detector.

The detector system may specifically include a beam of spectroscopic electromagnetic radiation from the sample caused to interact with a series of elements, the series of elements being:

A first combined dichroic beam splitter-prism and a first detector, wherein the reflected beam reflected by the first combined dichroic beam splitter-prism is directed to a second combined dichroic beam splitter-prism and a second detector. and the beam reflected from the second combination dichroic beam splitter-prism is directed through the dichroic beam splitter to the third grating and the third dichroic beam splitter-prism combination.

The detector system may specifically include a beam of spectroscopic electromagnetic radiation from the sample caused to interact with a series of elements, the series of elements being:

comprising a first combined dichroic beam splitter-prism and a first detector, wherein a reflected beam produced by the first combined dichroic beam splitter-prism is directed to a first grating and a second detector, and wherein the second grating The reflected beam produced by is a zero-order beam and is directed to a second combined dichroic beam splitter-prism and a third detector.

The detector system may specifically include a beam of spectroscopic electromagnetic radiation from the sample caused to interact with a series of elements, the series of elements being:

a first combined dichroic beam splitter-prism and a first detector, wherein the reflected beam reflected from the first combined dichroic beam splitter-prism is directed to a second combined dichroic beam splitter-prism and a second detector; , the reflected beam reflected from the combined second dichroic beam splitter-prism is directed through the beam splitter to a third combined dichroic beam splitter-prism and a third detector.

The detector system may include a spectrum of dispersed diffracted waves produced by the grating that is a + or - order spectrum.

Additionally, where relatively shorter wavelengths can be modified to longer wavelengths, the longer wavelengths should be monitored, for example by a Golay Cell, Bolometer or Micro-Bolometer. You must understand. However, the present invention is functionally coupled with a solid-state detector element that, for example, cannot monitor longer wavelengths, but can monitor shorter, higher energy wavelengths, thereby converting electromagnetic radiation of relatively longer wavelengths into shorter wavelengths. It is more likely to contain a wavelength modifier to change the wavelength into electromagnetic radiation.

A typical configuration in the context of the present invention is that the source provides wavelengths in the infrared and/or terahertz range and the detector element is in a solid state capable of detecting only the higher energy, shorter wavelengths. However, this does not exclude situations where the wavelength modulator inputs relatively shorter wavelengths and outputs longer wavelengths, and the detector element is a Golay cell, bolometer, micro-bolometer, etc. Where solid state detector elements are used, the present invention provides utility in the form of reduced initial and operating costs (e.g. cooling when longer wavelengths are detected).

In the claims in which the element(s) are recited, the distinction between detector types is indicated. That is, the claims should be interpreted as applying when the detector includes a single element and monitors a single color or all wavelengths of the spectroscopic beam together, or when the wavelengths are monitored separately separately.

Hereinafter, the present invention will be described in more detail with reference to the attached drawings.

Figure 1 shows the different wavelength ranges that various multi-channel detectors (DET1) (DET2) (DET3) are designed to optimally process.
2 shows a relatively higher energy reflected beam (e.g. order O (ZO) for a grating), electromagnetic radiation directed to the subsequent grating (G), as well as at least one + or - order spectrum of this wavelength. Some inventive combinations of multiple gratings (G) and/or dichroic beam splitter-prism combinations (generally denoted (G/P)) are shown as examples for generating beams.
Figure 3a shows a grating G which reflects the incident beam IB of electromagnetism and provides a spectrum of the wavelength λ of all its orders (e.g. 1+ order) along with the zero order ZO. .
Figure 3aa shows a situation where a reflected (RB) beam is reflected from a dichroic beam splitter-prism (DBS-PR) combination at a surface where a coating is present, imparting dichroic properties. Note that at least the + or - order spectrum exits the prism (P).
Figure 4 represents an ellipsometer system for which the invention finds very suitable application.
Figure 5 illustrates the use of sequential subsequent gratings with electromagnetic radiation encountered sequentially.
Figure 6 shows using a beam splitter to direct a portion of the beam to different detectors that can be optimized to respond to different wavelength ranges.
Figures 7a and 7b respectively show typical intensity versus position of the beam for an electromagnetic radiation beam provided by a supercontinuum laser source over a range of approximately 400 to 2500 nm, showing identical results when a speckle reducer is applied to the plot in Figure 7a.
Figures 8A, 8AA-8AC illustrate the Fly's Eye approach for reducing speckles.
Figures 8B-8F depict various speckle reducers.
Figures 9A and 9B are included to show the basic ellipsometer of a basic reflectometer or spectrophotometer system and a polarimeter system, respectively, including one or more wavelength modifiers (WM).
Figure 9c shows a basic FTIR system including an electromagnetic radiation source therein.
Figures 9d and 9e show Figures 9 and 9e with dispersive optics and a wavelength modifier (WM).
Figure 9f shows a basic reflectometer or spectrophotometer system with two wave modifiers (WM).
Figures 9g-9i show further examples of ellipsometer systems with a wavelength modifier (WM) present therein.
Figure 10A is included to show typical Inventor generated intensity vs. wavelength results from a supercontinuum laser compared to a typical conventional source of electromagnetic radiation intensity vs. wavelength.
Figure 10b is included to show that recent developments have expanded the range of supercontinuum lasers to sizes of at least 4400 nm and even 18000 nm.

To begin, it should be understood that the invention claimed herein is best illustrated in FIGS. 9F and 9J with respect to the wavelength modifier (WM) applied in the context of reflectometer, spectrophotometer, ellipsometer and polarimeter sample examination systems. do. The wavelength modifier (WM) changes the wavelength of the incoming electromagnetic radiation, which may be present before or after the sample (SAM) supporting stage (STG). However, the presently claimed invention also inseparably includes a source (LS) and a detector (PA) of electromagnetic radiation. The drawings herein are adapted from co-pending application Ser. No. 17/300, 091 (relating to source (LS) and detector (DET)) and are explained in the order presented here.

Turning now to Figure 1, several wavelength ranges are shown that various multi-channel detectors (DET1) (DET2) (DETS) are designed to optimally process. Many additional wavelength ranges can be represented similarly, such as (4) shown in Figure 2.

Figure 2 shows a source (EM) of electromagnetic wavelengths in the infrared or terahertz range, which accepts said infrared or terahertz wavelengths and generally has a wavelength within the range of a solid state detector (DET) element (DE) (see Figure 4). One may perceive the exemplary use of commonly existing through holes and wavelength modifiers (WM) to provide the output wavelength. Figure 2 also shows the combination of multiple gratings (G) (see Figure 3a) and/or the dichroic beam splitter-prism combination (DBS-RP) of Figure 2 (see Figure 3aa), which each has one + or - the order spectrum (△λ) and the altered spectral content of the electromagnetic radiation reflected (RB/OR) beam, e.g. a zero-order (OR) beam as in the case of a grating (G) or a dichroic beam splitter-prism combination (DBS- In the case of PR), it generates a functionally similar reflected beam (RB) (both possibilities are denoted as G/P- in Figure 2), the combined dichroic beam splitter-prism (DBS-PR) and zero order (OR) in Figure 3a. ) See reflected beam (RB) in Figure 3aa for the beam (the term zero-order (ZO) refers to the threshold at which the dichroic beam splitter-prism combination (DBSP) is applied rather than the grating (G), although the results presented are functionally similar. 2 is a relevant example of a system detector system of the present invention, wherein a source (EM) of an electromagnetic radiation beam (IB) provides electromagnetic radiation through an aperture (AP). Exiting (G/Pl) is the primary range, typically + or -, which proceeds through reflection at the mirror (M) as indicated by the detector (DET1). This is the first-order spectrum of the wavelength λ. Also shown is the reflected beam RB, which is reflected from another mirror M and meets the dichroic beam splitter DBS, which is the first positive beam splitter DBS. Directs the incoming beam to (G/P3), which (G/PS) disperses the beam within a range of wavelengths λ towards detector DET3. A second amount of beam entering (DBS) is directed to detector DET2. and directs the reflected beam RB"//OORR" to (G/P4) which provides a distributed range of wavelengths λ to the detector DET4. Figure 2 The present invention includes a plurality of detectors (DET's), each of the plurality of detectors comprising a plurality of solid state detector elements (DE's) (see Figure 44), wherein the plurality of solid state detector elements have a relatively long wavelength (e.g. e.g., in the IR or THZ range) may detect a wavelength emanating from a wavelength modifier (WM) when entering therein, within the plurality of solid state detector elements, a solid state detector element from the wavelength modifier (WM). The wavelength detectable by (DE's) is transmitted through a beam splitter (DBS) and/or a combination prism/dichroic beam splitter (DBS-PR) (see Figure 3) and/or a grating (G) (see Figure 3A). It is guided into solid state detector elements (DE's).

Figure 3a shows a grating (G) on which an input beam (IB) of electromagnetic radiation impinges, resulting in at least one +/- order spectrum of wavelengths together with the zero-order (ZO) beam.

Figure 3aa shows a situation where a reflected (RB) beam is reflected from a dichroic beam splitter-prism (DBS-PR) combination on a surface with a coating, imparting dichroic properties. Note that at least the + or - order spectrum exits the prism (P). The coating (C) is shown to be present on the surface upon which the input beam impinges and serves to form a dichroic beam splitter (DBS). For insight, dichroism refers to different properties based on wavelength, e.g. reflection/transmission of electromagnetic radiation.

It should be understood that the designation of (G/P_) in Figure 2 should be interpreted as possibly being one of the systems of Figures 3A and 3AA.

Figure 4 (which is taken from Patent No. 7,345,762 to Liphardt et al., Figure 2) is included to illustrate an ellipsometer system, for which ellipsometers, polarimeters, and similar systems of the present invention have very suitable applications. look for When so applied, the beam exiting the ellipsometer polarization state analyzer (i.e. (EPCLB) in Figure 4 above) is advantageously considered to be beam IB as shown in Figure 2 attached. Figure 2 roughly corresponds to the dispersive element (i.e. grating), (DO) of Figure 4 above. Note that Figure 4 shows an ellipsometer source LS providing a polarized ellipsometer beam PPCLB by interaction with the polarizer P shown. The beam (PPCLB) then interacts with the sample (MS) shown, indicating that it may be a focused beam at that point. The beam reflected from the sample (MS) can be re-collimated and passes through the analyzer (A), appearing as a beam (EPCLB), before being focused by (FE) onto a dispersive element (e.g. grating) (DO), (DO ) serves to disperse the wavelength with a multi-element detector (PA). One or two correctors (C) may be present as indicated in the system connected to a polarization state generator or analyzer or to a polarizer and analyzer respectively. Again, for relevance, the dispersion element (DO) is almost identical to the grating (G1) in Figure 2. Also shown is an indication that the focusing (SSC) and re-collimating (SSC') lenses can be positioned to optimize the intended effect.

Figure 5 (from Figure 9 of Patent No. 7,345,762) is included to demonstrate the use of sequential subsequent gratings (e.g., G1 and G1') to reach the desired wavelength in the spectrometer system.

Figure 6 (taken from Figure 1A of Patent No. 8,169,611) to illustrate the use of beam splitters (B1 and B2) to direct a portion of the beam to different detectors (D1 and D2) that can be optimized to respond to different wavelength ranges. included. For further explanation, see Patent Nos. 7,345,762 and 8,169,611. However, the patent does not propose the invention to direct the reflected altered spectral content beam to a subsequent beam diverging element. Figure 6 also shows using a beam splitter to direct portions of the beam to different detectors that can be optimized to respond to different wavelength ranges.

The +/- orders shown in the diagram are typically generated when an incident spectral beam of electromagnetic radiation is presented to a grating and responds to produce a spectrum of diffracted scattered wavelengths and simultaneously a reflected beam with a changed spectral content of the electromagnetic typically of the zero-order beam. It can be described in terms of wavelength range.

7A shows a typical intensity versus position within the beam cross section for an electromagnetic radiation beam provided by a supercontinuum laser source over a range from about 400 to at least 4400 nm. In particular, note that interaction effects between coherent components result in very inconsistent intensity plots. Speckles may result in wavelength instability, and supercontinuum lasers may be applied to the presently claimed invention to change the wavelength provided thereby to a wavelength that a solid state detector can detect, possibly with a wavelength filter.

Figure 7b shows that applying a “spot reducer” to the beam intensity profile of Figure 6 can result in a much more stable beam intensity compared to the position Ln of the beam profile. This much more stable intensity profile is well suited for applications in metrology systems such as ellipsometers, polarimeters, and reflectometers. It is believed that the use of the supercontinuity laser source and speckle reducer described herein is novel and novel, especially in combination with the detector system also described. As previously mentioned, coherent sources result in interference effects, and the system further comprises a speckle reducer of a type selected from the group consisting of:

multimode fiber;

beam spreader;

Fly's Eye Beam Homogenizer;

rotating beam spreader;

Piezoelectric crystal driven beam diffuser;

Electronic means to shorten the temporal coherence length;

This is to effectively reduce wide variations in intensity over a very small wavelength range (i.e. speckles).

Figures 8A, 8AA-8AC show a beam homogenization approach to reduce speckles. Figure 8a shows that input electromagnetic radiation, denoted (EMI), can be converted into output electromagnetic radiation, denoted (EMO), which is very uneven in intensity but very uniform in intensity.

The system consists of a beam expander (BE), a beam collimator (BC1), two Fly's Eye lenses (MFI) (MF2), and a second beam applied to focus the collimated beam exiting (MF2). The collimator BC2 and the second beam collimator BC2, which re-collimates the provided beam, consist of the provided beam. The energy content of (EMI) was uniformly distributed by the action of the fly's eye lens (MFI) and (MF2), as indicated by (EMO). Figures 8aa and 8ab show a typical fly's eye lens structure. Figure 8ac is included to illustrate how the system of Figure 8a (BH) can be applied to an ellipsometer system. At "A" the beam coming from the source (LS) is denoted as (EMI) and at "B" the beam energy is distributed as denoted by (EMO) and the polarization element (DE) is distributed as indicated by (EMO) on the sample at a position (D) above it. It can be applied in front of the beam interacting with the sample (and location D) by a detector arranged to monitor the beam reflected from.

Figures 8B-8F show various other speckle reducers. Figure 8b shows a beam spreader plate with the input beam (BI) entering and exiting the diffuse beam (DBO) component. Figure 8c shows a simple fly's eye lens (FE) that produces a similar effect as the beam spreader of Figure 8b when a beam passes through it. Figure 8d shows the beam spreader (BD) of Figure 8b attached to a motor (M) causing it to rotate during use. The input beam (B) is passed back as shown and appears as a diffuse beam (DBO). Figure 8e shows the beam spreader (BD) plate as in Figure 8b attached to a piezoelectric driver (PZ) adapted to cause the beam spreader (BD) to oscillate vertically and/or horizontally during use. A fly's eye lens (FE) can also be used in configurations such as FIGS. 8D and 8E. Figure 8f shows an end-on view of a multimode fiber. Note core region 1 and outer region 2. In multimode optical fiber, zone 1 is an important part of zone 2. Zone 1 cores are much less prominent in single-mode fiber.

Figure 9A is included to show a basic reflectometer or spectrophotometer system comprising:

a) source (S) of the electromagnetic radiation beam;

b) stage (STG) supporting the sample (SAM);

c) Electromagnetic detector system (DET);

In the present invention, the system is distinguished in that the source S of the spectral beam of electromagnetic radiation is a supercontinuum laser providing an output spectrum as shown in Figure 7a and preferably in Figure 7b. That is, the main distinguishing aspect of the present invention is the use of a high intensity, highly directive supercontinuum laser to provide electromagnetic radiation. As previously described in connection with Figure 2, another aspect of the invention involves the use of a detector system that provides a wide range of wavelengths to a detector well suited for detecting those wavelengths.

Figure 9b shows the element of Figure 9a with a polarization state generator (PSG) and polarization state analyzer (PSA) to effect an ellipsometer or polarimeter system.

(Please note that when more than one source (S) is mentioned in this specification and claims, the designation of (S) in the relevant drawings should be construed as indicating the source in use.)

It is understood that the detector systems described above may have multiple multi-element arrays as in Figure 2, a single array as in Figure 4, or a single detector as shown by Figures 9A and 9B. Figures 9D and 9E show the detector side of the system shown in Figures 9A and 9B modified to include detector (DET) array elements (DE's). In Figure 9e, the Wave Modifier (WM) is moved from before to after the Dispersive Optics (DO). In all configurations, the functional element(s) that provide the measurable electrical signal may be solid-state (e.g., a CCD array) or a single element (e.g., a Golay cell or bolometer). Modern detectors can be applied to monitor infrared and terahertz frequency electromagnetic radiation. Golay cells convert temperature changes caused by electromagnetic radiation into electrically monitorable signals. For example, there may be a distortable diaphragm/film that reflects electromagnetic radiation to one or another photo cell. Distortions in the shape of the diaphragm/film in the Golay cell's chamber affect the electromagnetic radiation directed to the monitoring photo cell. Bolometers work by impinging electromagnetic radiation on a black material and converting it into a change in electrical resistance. Additionally, the detector may include a wavelength modifier, if applicable, which changes far-infrared to near-infrared frequencies/wavelengths, allowing for the use of less expensive and easier to use silicon-based elements. 9A, 9B, 9D, and 9E identify the wavelength modifier (WM). An example of a wavelength modifier that converts longer wavelengths to shorter wavelengths is the NLIR nonlinear infrared sensor, which converts mid-infrared (Mid-IR) wavelengths to near-infrared wavelengths. FIG. 9C is included to illustrate that the source S of electromagnetic radiation may be part of a Fourier Transform Interferometry (FTIR) system. The source (S), beam splitter (BS), and two mirrors (M1) and (M2) are shown. The mirror M1 in use moves up and down as shown. This increases or decreases the path length of the beam from the beam splitter (BS) to the mirror. In the beam splitter, various transmissions and interceptions occur at different positions of the mirror M1 due to interference between the beam splitter BS and the mirror M1 and between the beam splitter BS and the mirror M2.

Figure 9f shows a basic reflectometer or spectrophotometer system with two wavelength modifiers (WM). Showing two is not to be construed as restrictive, as usually there can only be one of them, but if there is only one it can be on either side of the stage (STG). When a wavelength modifier is placed in front of the stage (STG), the sample irradiation system is transformed into a system that irradiates samples (MS) of different wavelength ranges provided by a source (LS) of electromagnetic radiation. This can be useful when one wants to irradiate samples over a very wide range of wavelengths using the same sample irradiation system without changing the source (LS) of electromagnetic radiation.

9G-9I show further examples of ellipsometer systems with wavelength modifiers (WM) present at various locations after the stage (STG). The system consists of a source of spectral electromagnetic radiation (LS), a polarizer (P), a compensator (C) ((P) and (C) combined make up (PSG)), a sample (MS) on the stage (STG), 2 Compensator (C') comprising analyzer (A) ((C') and (A) include (PSA)), focusing element (FE), dispersing optics (DO) and a plurality of detector elements (DE's) It is shown as including a detector (PA). In Figure 9g a wave modifier (WM) is present between the stage (STG) and the dispersive optics (DO). FIG. 9H presents a two detector arrangement further comprising a beam splitter (BS) and a mirror (M), both of which have a wave modifier (WM) between the stage (STG) and the dispersive optics (DO). has do. 9i is shown in Fig. 9i in that the wave modifier (WM) exists between the dispersive optics (DO) and the detector (PA). It is different from 9g. Such arrangements should be considered within the scope of the present invention.

9G-9I show the location of the wave modifier (WM) in an exemplary system of the present invention. Additionally, note that the configuration of Figure 9g may exist in Figures 9h and 9i. That is, there can be a wave modifier (WM) between the source (LS) and the stage (STG) regardless of whether the system is a reflectometer, spectrophotometer, ellipsometer, or polarimeter.

Polarizer (P), analyzer (A) or corrector(s) (C) (integrated into a polarization state generator (PSG) or polarization state analyzer (PSA) as in FIG. 6 or as in FIG. 9B) is in use or stationary. Note that some or all of the images may be rotated.

FIG. 10A shows a typical inventor of the present invention showing intensity versus wavelength results generated from a supercontinuum laser when a 0.0325% neutral density filter is present in the path of the supercontinuum laser beam, compared to the electromagnetic radiation intensity versus wavelength of a conventional source. Includes. The supercontinuum laser intensity is much larger than the conventional source spectrum (approximately 30 times larger) and requires significant attenuation with a 0.0325 neutral density filter to compare the wavelength spectral characteristics.

Figure 10b is included to demonstrate the progress made in supercontinuum laser sources since the patent application was submitted. Note the greatly expanded wavelength range in Figure 10b compared to Figure 10a. Further wavelength range expansion is expected to continue and the present invention should be considered in this light. This is the supercontinuum laser source wavelength range shown in FIGS. 10A and 10B, which is illustrative and not limiting. For example, supercontinuum lasers are available that provide wavelengths up to 18000 nm, but the intensity decreases at longer wavelengths.

Having thus disclosed the subject matter of the invention, it should be apparent that various modifications, substitutions, and variations of the invention are possible in light of the teachings. Accordingly, it should be understood that the invention may be practiced otherwise than as specifically described, and that its breadth and scope should be limited only by the claims.

Claims (22)

1. A sample irradiation system for use in irradiating a sample with electromagnetic radiation, comprising:
ellipsometer;
polarimeter;
reflectometer; and
Spectrophotometer; is selected from the group consisting of,
The system:
electromagnetic source (LS);
Stage for supporting the sample (STG); and
Detector (PA) comprising detector elements (DE's);
wherein the system source (LS) provides long-wavelength electromagnetic radiation in the IR and THZ ranges, and the detector comprises solid state elements (DE's) that are unable to detect the IR and THZ wavelengths;
The system receives, before the detector PA, electromagnetic radiation of wavelengths outside the range of the detector elements (DE's) that the detector elements (DE's) can detect and based on the wavelengths that the detector elements (DE's) can detect. A sample irradiation system, characterized in that at least one wavelength modifier (WM) is present for providing output electromagnetic radiation. According to paragraph 1,
A sample irradiation system further comprising a polarization state generator (PSG) and a polarization state analyzer (PSA) components before and after the stage (STG), respectively, wherein the system is an ellipsometer. According to paragraph 1,
A sample irradiation system, wherein at least one wavelength modifier (WM) receives electromagnetic radiation comprising wavelengths in the IR and THZ ranges and outputs electromagnetic radiation having wavelengths in the visible wavelength range. According to paragraph 1,
A sample irradiation system, wherein at least one wavelength modifier (WM) receives electromagnetic radiation comprising a wavelength in the far-infrared (far-IR) range and outputs electromagnetic radiation having a wavelength in the visible wavelength range. According to paragraph 1,
A sample irradiation system, wherein at least one wavelength modifier (WM) receives electromagnetic radiation comprising a wavelength in the mid-IR range and outputs electromagnetic radiation having a wavelength in the visible wavelength range. According to paragraph 1,
A sample irradiation system, wherein at least one wavelength modifier (WM) receives electromagnetic radiation comprising a wavelength in the near-infrared (near-IR) range and outputs electromagnetic radiation having a wavelength in the visible wavelength range. According to paragraph 1,
It further comprises dispersive optics (DO) for spatially separating different wavelengths present after the stage (STG), wherein the wavelength modifier is:
between the source (LS) and the stage (STG);
Between the stage (STG) and the distributed optical system (DO);
Between the distributed optical system (DO) and the detector (PA);
A sample survey system deployed at a location selected from the group consisting of: 1. A sample irradiation system for use in irradiating a sample with electromagnetic radiation, comprising:
ellipsometer;
polarimeter;
reflectometer; and
Spectrophotometer; is selected from the group consisting of,
The system:
electromagnetic source (LS);
Stage supporting the sample (STG); and
Includes a detector (PA);
The system source (LS) provides electromagnetic radiation in a wavelength range longer or shorter than what the detector elements (DE's) can detect;
The system receives electromagnetic radiation at wavelengths outside the range of the detectors (PA) that the solid state elements (DE's) can detect before the detector (PA) and at wavelengths that the solid state elements (DE's) can detect. A sample irradiation system, characterized in that at least one wavelength modifier (WM) is present for providing output electromagnetic radiation based on the WM. According to clause 8,
The source (LS) is:
UV-rays;
line of sight;
Far infrared rays;
mid-infrared;
terahertz;
A sample irradiation system providing electromagnetic radiation having a wavelength range selected from According to clause 9,
The detector:
UV-rays;
line of sight;
Far infrared rays;
mid-infrared;
terahertz;
Detects a wavelength in a selected range from
The sample irradiation system of claim 1, wherein the selected range is different from the wavelength range provided by the source (LS). According to clause 10,
The above sources are:
Far infrared rays;
mid-infrared;
near infrared; and
terahertz;
providing a range of wavelengths selected from;
The wavelength modifiers are:
UV-rays; and
line of sight;
A sample irradiation system that provides a range of wavelengths selected from the group consisting of. According to clause 8,
Sources of electromagnetic radiation are:
Ar, Xe and He discharge lamps in the UV region;
Tungsten filament lamp in the visible area;
Blackbody radiators, Nernst and Globa in the infrared range;
Lamps producing Hg and Na lines in UV and visible range;
Lasers in the visible and IR range; and
Supercontinuum laser with a wavelength range from 400 nm to 18000 nm;
is selected from the group consisting of,
The detector:
golay cell;
bolometer;
micro-bolometer;
thermocouple;
photoconductive material;
deuterated triglycine sulfate (DTGS);
HgCdTe(MCT);
LiTaO3;
PbSe;
PbS;
InSb; and
silicon, germanium, and gallium arsenide solid-state devices;
A sample survey system, characterized in that selected from the group consisting of. As a sample survey method,
a) For use in irradiating samples with electromagnetic radiation,
ellipsometer,
polarimeter;
reflectometer; and
A step of providing a spectrophotometer,
The system:
electromagnetic source (LS);
Stage supporting the sample (STG); and
Detector (PA) comprising detector elements (DE's);
wherein the system source (LS) provides electromagnetic radiation in a wavelength range longer or shorter than what the detector elements (DE's) can detect,
The system receives, before the detector (PA), electromagnetic radiation of wavelengths outside the range of the detector (PA) that the solid state elements (DE's) can detect and based on the wavelengths that the solid state elements (DE's) can detect. Characterized in that at least one wavelength modifier (WM) is present for providing the output electromagnetic radiation,
The providing step;
b) placing the sample to be examined on the stage (STG);
c) the source (LS) providing electromagnetic radiation comprising a wavelength that the detector elements (DE's) cannot detect and directing a beam of electromagnetic radiation at the sample;
d) causing the wavelength modifier to receive electromagnetic radiation wavelengths from the sample provided by the source LS and modify them into a wavelength detectable by the detector element DE;
e) causing the detector element to detect modified electromagnetic radiation and provide output data;
f) analyzing the output data to determine sample characteristics. According to clause 13,
The system further comprises dispersive optics (DO) that spatially separates different electromagnetic wavelengths, and the wavelength modifier (WM) is located between the source (LS) and the detector (PA). According to clause 14,
The at least one wavelength modifier is positioned between the source (LS) and the stage (STG). According to clause 14,
The method of claim 1, wherein the at least one wavelength modifier is positioned between the stage (STG) and the dispersive optics (DO). According to clause 14,
The at least one wavelength modifier (WM) is positioned between the dispersive optics (DO) and the detector (PA). According to paragraph 1,
A sample irradiation system comprising at least two wavelength modifiers between the source (LS) or electromagnetic radiation and the detector (PA). According to clause 8,
A sample irradiation system comprising at least two wavelength modifiers between the source (LS) or electromagnetic radiation and the detector (PA). According to clause 13,
The system further comprises dispersive optics (DO) that spatially separates different electromagnetic wavelengths, and the wavelength modifier (WM) is located between the source (LS) and the detector (PA). As another method of irradiating a sample with electromagnetic radiation of between wavelengths provided by a source:
a) For use in irradiating samples with electromagnetic radiation,
ellipsometer,
polarimeter;
reflectometer; and
spectrophotometer;
As a step to provide,
The system:
electromagnetic source (LS);
Stage supporting the sample (STG); and
Detector (PA) comprising detector elements (DE's);
wherein the system source (LS) provides electromagnetic radiation in a wavelength range longer or shorter than what the detector elements (DE's) can detect,
The system is characterized in that a wavelength modifier (WM) is present before the step (STG),
The providing step;
b) placing the sample to be examined on the stage (STG);
c) the source LS providing electromagnetic radiation and directing a beam of electromagnetic radiation toward the sample;
d) said wavelength modifier (WM) receiving a first range of electromagnetic radiation wavelengths provided by said source (LS) and emitting a modified range of wavelengths;
e) detecting modified electromagnetic radiation wavelengths after the detector elements (DE's) interact with the sample (MS);
f) analyzing the output data to determine sample characteristics. According to clause 21,
Between steps c) and d), the stage (STG) and the detector ( Method for irradiating a sample, further comprising the step (c') of placing a second wavelength modifier (WM) between PA).