CN117368114A - Snapshot type ellipsometry method and device - Google Patents

Snapshot type ellipsometry method and device Download PDF

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CN117368114A
CN117368114A CN202311188558.2A CN202311188558A CN117368114A CN 117368114 A CN117368114 A CN 117368114A CN 202311188558 A CN202311188558 A CN 202311188558A CN 117368114 A CN117368114 A CN 117368114A
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polarization
phase
arm
ellipsometry
azimuth angle
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陈修国
陈文龙
胡静
杨世龙
王逸夫
刘世元
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Huazhong University of Science and Technology
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    • G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/21—Polarisation-affecting properties
    • G01N21/211—Ellipsometry
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    • G01N21/21—Polarisation-affecting properties
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Abstract

The invention belongs to the technical field of optical measurement and discloses a snapshot type ellipsometry method and equipment, wherein the equipment comprises a light source, a polarizing arm, a polarization detection arm, a detector and a data processor; the light source is connected to the polarization arm through an optical fiber, the polarization detection arm is arranged on the optical path of the polarization detection arm, and the detector is arranged on the optical path of the polarization detection arm; the data processor is connected with the detector; the polarizing arm comprises a first lens, a polarizer and a first phase retarder which are sequentially arranged along the light path; the polarization-maintaining arm comprises a second phase retarder, a polarization analyzer and a second lens which are sequentially arranged along the light path. The polarizing device of the invention only has two phase retarders and two polarizing plates, can measure most isotropic samples, such as isotropic films, and has no moving parts, so that the installation error is easier to control, and the measuring speed is high and stable.

Description

Snapshot type ellipsometry method and device
Technical Field
The invention belongs to the technical field of optical measurement, and particularly relates to a snapshot type ellipsometry method and equipment.
Background
With the continuous progress of manufacturing processes, the nodes of semiconductor manufacturing technology are continuously reduced, and IC devices are facing serious challenges brought by the trend of miniaturization, portability, high speed and low power consumption. More and more nano devices are beginning to be deeply integrated into daily life. In the manufacturing process of the nano devices, parameters such as three-dimensional morphology size and relative position size of the nano structures, film thickness, physical optical performance of materials and the like directly influence the final performance of the devices, so that the rapid and accurate online monitoring and real-time feedback correction of the parameters in the production process are key steps for improving the performance of the devices.
The current optical measurement technology has the advantages of high measurement speed, no contact, no damage, low cost, easy on-line integration and the like, and is widely applied to the measurement of the critical dimension of integrated circuit devices. However, the conventional optical microscopic imaging method is difficult to apply to three-dimensional morphology detection of the nanostructure due to the limitation of diffraction limit, and polarization optical measurement containing more information is receiving more and more attention. The spectroscopic ellipsometry technology is a typical polarized optical measurement, and is used for inverting the thickness and optical constants of devices such as thin films by measuring the polarization state change of reflected light, and the measurement speed and stability of the traditional measuring instrument are limited due to the fact that the traditional measuring instrument comprises a rotary moving part or a phase modulation device. The snapshot ellipsometer adopts the principle of wavelength modulation, and does not contain moving parts, so that the measurement speed and stability of the ellipsometer can be obviously improved, but the existing snapshot ellipsometer has more problems, such as narrower measurement wave band, sensitivity to installation errors, certain requirements on wave plates and the like, so that the parameter extraction precision is limited, and in the measurement field, a snapshot ellipsometry method with high measurement precision and high measurement speed is needed.
Disclosure of Invention
Aiming at the defects or improvement demands of the prior art, the invention provides a snapshot type ellipsometry method and equipment, which aim to reduce the installation error of the equipment and improve the accuracy and stability of the snapshot type ellipsometry at the same time so as to realize the snapshot type ellipsometry with high measurement accuracy and stable measurement.
In order to achieve the above object, according to one aspect of the present invention, there is provided a snapshot type ellipsometry apparatus including a light source, a polarizing arm, a polarization detecting arm, a detector, and a data processor; the light source is connected to the polarization arm through an optical fiber, the polarization detection arm is arranged on the optical path of the polarization detection arm, and the detector is arranged on the optical path of the polarization detection arm; the data processor is connected with the detector;
the polarizing arm comprises a first lens, a polarizer and a first phase retarder which are sequentially arranged along the light path; the polarization-maintaining arm comprises a second phase retarder, a polarization analyzer and a second lens which are sequentially arranged along the light path.
Further, the detector is a spectrometer with light splitting capability, and the data processor is used for converting the light intensity of the light beam into a Mueller matrix element or an ellipsometry parameter of the sample to be detected.
Further, the first lens is used for beam collimation, and the polarizing arm is used for realizing first polarization; the first phase delay device is used for realizing first phase delay, the second phase delay device is used for realizing second phase delay, and the polarization detection arm is used for realizing second polarization; the second lens is used for converging light beams.
Further, the fast axis azimuth errors of the polarizer, the first phase retarder and the second phase retarder are measured by measuring the measured spectra of air and linear polarizers in real time, and fourier transforming the measured spectra, using peak cancellation control of a specific channel.
Further, the light transmission axis azimuth angle of the polarizer is 45 degrees, the fast axis azimuth angle of the first phase retarder is 90 degrees, the fast axis azimuth angle of the second phase retarder is 45 degrees, and the light transmission axis azimuth angle of the analyzer is 90 degrees.
Further, the light transmission axis azimuth angle of the polarizer is + -45 degrees, the fast axis azimuth angle of the first phase retarder is 0 degrees, the fast axis azimuth angle of the second phase retarder is + -45 degrees, and the light transmission axis azimuth angle of the analyzer is 0 degrees.
Further, the first phase retarder and the second phase retarder are multi-stage wave plates made of birefringent crystals, and the phase retardation ratio of the first phase retarder to the second phase retarder is 3:1 or 1:3.
The invention also provides a snapshot type ellipsometry method, which comprises the following steps:
(1) And (3) calibrating equipment and calibrating feedback: after the snapshot type ellipsometry equipment is adjusted to be of a straight-through type, measuring air and a linear polaroid, performing real-time feedback calibration on azimuth errors of a polarizing arm and an analyzer arm in the equipment through an extinction method and a peak elimination method, and calibrating phase delay amounts of the first phase delay device and the second phase delay device through a reference light calibration mode;
(2) Sample measurement: measuring the sample to be measured by adopting the equipment to obtain polarized modulated light of the sample to be measured;
(3) Parameter extraction: and extracting parameters of the obtained spectrum to obtain the Mueller matrix elements or ellipsometry parameters of the sample to be detected.
Further, the mathematical expression of the system model adopted in the calibration and feedback of the equipment is as follows:
wherein S is out For the beam after passing the sample to correspond to the Stokes vector, M P 、M A Corresponding Mueller matrix respectively for first polarization and second polarization, M sample A Mueller matrix corresponding to the sample; r (x) represents a mueller rotation matrix when the rotation angle is x, α 1 、α 2 Azimuth angle epsilon of light transmission axis in first polarization and second polarization respectively 1 Is the azimuth angle error of the light transmission axis when polarized for the first time, beta 1 、β 2 The fast axis azimuth angles epsilon of the first phase delay and the second phase delay are respectively 2 、ε 3 The fast axis azimuth angle errors epsilon during the first phase delay and the second phase delay are respectively 4 To measure the azimuth angle error of the light transmission axis corresponding to the linear polaroid of the sample, M R The [ delta ] is the Mueller matrix corresponding to the phase retarder 1 、δ 2 The phase delay amounts at the first phase delay and the second phase delay are respectively S in Is the stokes vector corresponding to the beam incident on the measurement system.
Further, extracting a multichannel coefficient by a Fourier method, and further linearly combining the multichannel coefficients to extract a Mueller matrix element or an ellipsometry parameter of a sample to be detected; or extracting parameters by a compressed sensing and neural network method based on a physical model.
In general, compared with the prior art, the snapshot ellipsometry method and the snapshot ellipsometry equipment provided by the invention have the following advantages:
1. the invention is based on the snapshot ellipsometry principle of wavelength modulation, only one measurement is needed, the polarizer only has two phase retarders and two polaroids, and although the obtained effective data is less, the parameter extraction under the underdetermined condition of a wave number (the reciprocal of wavelength) domain is carried out, a plurality of isotropic samples, such as isotropic films, can be measured by adding some physical characteristic constraints known by the sample to be measured for parameter extraction, and no moving part exists, so that the installation error is easier to control, and the measurement speed is fast and stable.
2. The physical model and the measurement configuration provided by the invention are sensitive enough to azimuth angle errors, and the change can be obviously observed in the Fourier domain of the measured spectrum, the azimuth angle errors are basically reduced by the principle of amplifying the influence of the azimuth angle errors, the installation errors of all the polarizing elements in the measurement equipment can be effectively reduced by observing the peak value change of the Fourier domain of the measured spectrum in real time, the influence of the azimuth angle errors can be theoretically and even completely eliminated, meanwhile, the expansibility is better, and the measurement precision of the snapshot type ellipsometry instrument is effectively improved.
3. According to the parameter extraction method, the channel parameters extracted by the Fourier method are linearly combined, so that the ellipsometry parameters of the sample are obtained, and the influence of azimuth angle errors can be eliminated theoretically.
4. The compressed sensing or neural network parameter extraction method based on the physical model can ignore the problems of channel crosstalk and truncation errors in the traditional Fourier method under the condition of ensuring that the phase delay amount can be accurately calibrated.
Drawings
FIG. 1 is a schematic flow chart of a snapshot ellipsometry method provided by the invention;
FIG. 2 is a schematic diagram of an optical path of a snapshot-type ellipsometry apparatus according to an embodiment of the present invention, (a) is a conventional oblique incidence type, (b) is an angular resolution type;
fig. 3 (a) and (b) are schematic diagrams of a polarizing arm and a polarization analyzer of the snapshot-type ellipsometry apparatus according to the embodiment of the present invention;
fig. 4 (a), (b), and (c) are fourier diagrams of measured spectra provided by embodiments of the present invention, respectively;
FIGS. 5 (a), (b) and (c) are respectively provided for a 100nm thin film (Si substrate, siO) according to an embodiment of the present invention 2 Thin film) mueller matrix element measurements.
The same reference numbers are used throughout the drawings to reference like elements or structures, wherein: 1-light source, 2-optical fiber, 3-polarizing arm, 4-sample to be measured, 5-polarization analyzer, 6-detector, 7-data processor, 8-beam splitter, 9-converging lens, 10-high-value objective lens, 301-first lens, 302-polarizer, 303-first phase retarder, 501-second phase retarder, 502-polarization analyzer and 503-second lens.
Detailed Description
The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention. In addition, the technical features of the embodiments of the present invention described below may be combined with each other as long as they do not collide with each other.
Referring to fig. 1,2 and 3, the present invention provides a snapshot type ellipsometry apparatus, which includes a light source 1, a polarizing arm 3, a polarization detecting arm 5, a detector 6 and a data processor 7, wherein the light source 1 is connected to the polarizing arm 3 through an optical fiber 2. The polarization-detecting arm 5 is arranged on the light path of the polarization-detecting arm 3, and the detector 6 is arranged on the light path of the polarization-detecting arm 5. The data processor 7 is connected to the detector 6.
The light source 1 is configured to generate a spectrum with a relatively broad wavelength band, and the polarizer arm 3 includes a first lens 301, a polarizer 302, and a first phase retarder 303 sequentially disposed along an optical path. The polarization analyzer arm 5 includes a second phase retarder 501, an analyzer 502, and a second lens 503 sequentially disposed along the optical path. The detector 6 is a spectrometer with light splitting capability, and the data processor 7 is used for converting the light intensity of the light beam into a mueller matrix element or an ellipsometry parameter of the sample to be detected. Wherein the first lens 301 is used for beam collimation and the polarizing arm 3 is used for realizing a first polarization. The first phase retarder 303 is used for realizing a first phase retardation, the second phase retarder 501 is used for realizing a second phase retardation, and the polarization analyzer arm 5 is used for realizing a second polarization. The second lens 503 is used for beam focusing.
The light path of the snapshot type ellipsometry equipment has no clear requirement, and the snapshot type ellipsometry equipment can adopt a traditional oblique incidence type ellipsometry equipment, and comprises a light source 1, an optical fiber 2, a polarization arm 3, a sample to be detected, a polarization detection arm 5, a detector 6 and a data processor 7; the optical fiber can also adopt angular resolution type, and comprises a light source 1, an optical fiber 2, a polarizing arm 3, a sample to be detected, a polarization detecting arm 5, a detector 6, a data processor 7, a beam splitter, a converging lens 9 and a high-value objective lens 10.
The azimuth angles of the polarizer 302, the analyzer 502, the first phase retarder 303 and the second phase retarder 501 should be arranged according to the designed azimuth angles, and the system calibration is performed by the azimuth angle feedback calibration method, so that the more accurate measurement of the mueller matrix elements or ellipsometry parameters of the film sample can be completed.
Taking the azimuth angle of the transmission axis of the analyzer 502 as a reference, the error of the azimuth angle of the transmission axis of the linear polarizer of the reference sample and the analyzer 502 can control the light path to be completely extinction within a smaller range, and the fast axis azimuth errors of the polarizer 302, the first phase retarder 303 and the second phase retarder 501 can control the peak elimination of a specific channel within a smaller range by measuring the measured spectrum of air and the linear polarizer in real time and performing Fourier transform on the measured spectrum.
In this embodiment, the light transmission axis azimuth angle of the polarizer 302 is 45 °, the fast axis azimuth angle of the first phase retarder 303 is 90 °, the fast axis azimuth angle of the second phase retarder 501 is 45 °, and the light transmission axis azimuth angle of the analyzer 502 is 90 °. In another embodiment, polarizer 302 has a light transmission axis azimuth angle of ±45°, first phase retarder 303 has a fast axis azimuth angle of 0 °, second phase retarder 501 has a fast axis azimuth angle of ±45°, and analyzer 502 has a light transmission axis azimuth angle of 0 °.
The polarizer 302, the analyzer 502, and the linear polarizer should have a sufficient extinction ratio, the first phase retarder 303 and the second phase retarder 501 are all multi-stage wave plates made of birefringent crystals, the ratio of the phase retardation of the first phase retarder 303 to the phase retardation of the second phase retarder 501 is 3:1 or 1:3, the phase retardation should be as linear as possible in the corresponding wave bands along with the wave numbers, such as quartz materials and magnesium fluoride crystals, and meanwhile, because of the characteristic of ellipsometric parameters of the sample to be measured and the limitation of the optical resolution of the detector 6, in order to avoid channel crosstalk, the basic thickness of the wave plates should be designed, and in this embodiment, the magnesium fluoride crystals with the basic thickness of 1.5mm should be selected.
The type of the detector 6 needs to be matched with the type of the light source 1, and the device measures the mueller matrix elements with the wide spectrum of the film, so that the light source 1 needs to generate light with the wide spectrum, such as the wide spectrum white light source 1 or the sweep laser source 1, the wide spectrum white light source 1 needs to be matched with the spectrometer detector 6 with the light splitting capability, and the sweep laser source 1 only needs to be matched with a photodiode to acquire the light intensity. The measurement speed is different, the measurement time of the broad spectrum light source 1 and the spectrometer is dependent on the integration time of the spectrometer, and the measurement time of the sweep laser light source 1 and the photodiode is dependent on the scanning frequency of the sweep laser light source 1.
When the device performs system calibration and feedback calibration, the device is arranged to be in a straight-through type for measuring transmission type samples such as air, linear polaroid and the like, and the Mueller matrix of the air and the linear polaroid is known, and when the device performs sample measurement, the device is arranged to be in a sample measurement mode, and reflection type measurement is generally adopted.
Referring to fig. 4 and 5, the present invention further provides a snapshot type ellipsometry method, which mainly includes the following steps:
step one, equipment calibration and feedback calibration: after the snapshot type ellipsometry equipment is adjusted to be in a straight-through type, air and a linear polaroid are measured, azimuth angle errors of a polarizing arm 3 and an analyzer arm 5 in the equipment are subjected to real-time feedback calibration through an extinction method and a peak elimination method, and phase delay amounts of the first phase delay device 303 and the second phase delay device 501 are calibrated through a reference light calibration mode.
The mathematical expression of the system model adopted in the equipment calibration and feedback calibration is as follows:
wherein S is out For the beam after passing the sample to correspond to the Stokes vector, M P 、M A Corresponding Mueller matrix respectively for first polarization and second polarization, M sample For the corresponding mueller matrix of the sample, including a reference sample (air and linear polarizer) and a sample to be measured, such as a film, R (x) represents the mueller rotation matrix with rotation angle as x, α 1 、α 2 Azimuth angle epsilon of light transmission axis in first polarization and second polarization respectively 1 Is the azimuth angle error of the light transmission axis when polarized for the first time, beta 1 、β 2 The fast axis azimuth angles epsilon of the first phase delay and the second phase delay are respectively 2 、ε 3 The fast axis azimuth angle errors epsilon during the first phase delay and the second phase delay are respectively 4 To measure the azimuth angle error of the light transmission axis corresponding to the linear polaroid of the sample, M R The [ delta ] is the Mueller matrix corresponding to the phase retarder 1 、δ 2 The phase delay amounts at the first phase delay and the second phase delay are respectively S in Is the stokes vector corresponding to the beam incident on the measurement system.
The light transmission axis azimuth angle at the first polarization is 45 degrees, the fast axis azimuth angle at the first phase delay is +/-90 degrees, the light transmission axis azimuth angle at the second polarization is +/-90 degrees, and the fast axis azimuth angle at the first phase delay is 45 degrees; or the light transmission axis azimuth angle at the first polarization is + -45 DEG, the fast axis azimuth angle at the first phase delay is 0 DEG, the light transmission axis azimuth angle at the second polarization is 0 DEG, and the fast axis azimuth angle at the first phase delay is + -45 deg.
In this embodiment, the sample to be measured is exemplified by an isotropic film, in which air, linear polarizer and the Mueller matrix of the film, i.e., M air 、M LP And M film The specific form of (2) is as follows:
where n=cos (2 ψ), c=sin (2 ψ) cos (Δ), s=sin (2 ψ) sin (Δ), ψ and Δ being the ellipsometric parameters of the film, respectively.
Taking the light transmission axis azimuth angle of the primary polarization as 45 degrees, the fast axis azimuth angle of the primary phase delay as 90 degrees, the fast axis azimuth angle of the secondary phase delay as 45 degrees, and the light transmission axis azimuth angle of the secondary polarization as 90 degrees as an example, namely: alpha 1 ＝45°，α 2 ＝90°，β 1 ＝90°，β 1 =45°. At the same time treating the azimuth error as a smaller value, i.e. sin ε i ＝ε i ，cosε i ＝1，ε i ε j =0, i, j=1, 2,3,4; i is not equal to j, and the devices used for the first phase retardation and the second phase retardation are multi-stage wave plates made of the same birefringent crystal material, and the thickness ratio is 3:1, the phase delay delta 1 ＝3δ 2 The intensity of the outgoing beam (i.e., the first element of the stokes vector corresponding to the outgoing beam) can be obtained:
as can be seen from equations (5) and (6), some channels have only azimuth errors, or the channel disappears when the azimuth error is 0. According to the principle, the calibration azimuth error can be fed back by reading the spectrum of the air or the linear polarizer in real time and performing Fourier transform to eliminate the peak of a specific channel, so that the calibration azimuth error is maintained at a value as small as possible.
Meanwhile, as shown in the formula (7), when parameter extraction is performed through Fourier transformation, the influence of azimuth angle errors can be eliminated through linear combination of different channel coefficients. Parameter extraction can be performed by a compressed sensing or neural network method based on the physical model, so that the influence of channel crosstalk and truncation errors of a Fourier method is avoided.
Step two, sample measurement: and after the equipment is adjusted to a measurement mode, measuring the sample to be measured to obtain the polarization modulation light of the sample to be measured.
Step three, parameter extraction: and extracting parameters of the obtained spectrum to obtain the Mueller matrix elements or ellipsometry parameters of the sample to be detected.
Parameter extraction is performed through a Fourier method or a compressed sensing or neural network method based on a physical model, and Mueller matrix elements or ellipsometry parameters of a sample to be detected are obtained. Extracting a multichannel coefficient by a Fourier method, and linearly combining the multichannel coefficient to extract a Mueller matrix element or an ellipsometry parameter of a sample to be detected; or extracting parameters by a compressed sensing and neural network method based on a physical model.
It will be readily appreciated by those skilled in the art that the foregoing description is merely a preferred embodiment of the invention and is not intended to limit the invention, but any modifications, equivalents, improvements or alternatives falling within the spirit and principles of the invention are intended to be included within the scope of the invention.

Claims (10)

1. A snapshot ellipsometry apparatus, characterized by:
the device comprises a light source, a polarizing arm, a polarization detecting arm, a detector and a data processor; the light source is connected to the polarization arm through an optical fiber, the polarization detection arm is arranged on the optical path of the polarization detection arm, and the detector is arranged on the optical path of the polarization detection arm; the data processor is connected with the detector;
the polarizing arm comprises a first lens, a polarizer and a first phase retarder which are sequentially arranged along the light path; the polarization-maintaining arm comprises a second phase retarder, a polarization analyzer and a second lens which are sequentially arranged along the light path.
2. A snapshot ellipsometry apparatus of claim 1, wherein: the detector is a spectrometer with light splitting capability, and the data processor is used for converting the light beam intensity into a Mueller matrix element or an ellipsometry parameter of a sample to be detected.
3. A snapshot ellipsometry apparatus of claim 1, wherein: the first lens is used for collimating light beams, and the polarizing arm is used for realizing first polarization; the first phase delay device is used for realizing first phase delay, the second phase delay device is used for realizing second phase delay, and the polarization detection arm is used for realizing second polarization; the second lens is used for converging light beams.
4. A snapshot ellipsometry apparatus of claim 1, wherein: the fast axis azimuth errors of the polarizer, the first phase retarder and the second phase retarder are obtained by measuring the measured spectra of air and a linear polarizer in real time, performing fourier transformation on the measured spectra, and using peak elimination control of a specific channel.
5. A snapshot ellipsometry apparatus of claim 1, wherein: the light transmission axis azimuth angle of the polarizer is 45 degrees, the fast axis azimuth angle of the first phase retarder is 90 degrees, the fast axis azimuth angle of the second phase retarder is 45 degrees, and the light transmission axis azimuth angle of the analyzer is 90 degrees.
6. A snapshot ellipsometry apparatus of claim 1, wherein: the light transmission axis azimuth angle of the polarizer is +/-45 degrees, the fast axis azimuth angle of the first phase retarder is 0 degrees, the fast axis azimuth angle of the second phase retarder is +/-45 degrees, and the light transmission axis azimuth angle of the analyzer is 0 degrees.
7. A snapshot ellipsometry apparatus of claim 1, wherein: the first phase retarder and the second phase retarder are multi-stage wave plates made of birefringent crystals, and the phase retardation ratio of the first phase retarder to the second phase retarder is 3:1 or 1:3.
8. A snapshot ellipsometry method, comprising the steps of:
(1) And (3) calibrating equipment and calibrating feedback: after the snapshot ellipsometry equipment of any one of claims 1-7 is adjusted to be in a straight-through type, measuring air and a linear polaroid, performing real-time feedback calibration on azimuth errors of a polarizing arm and an analyzer arm in the equipment through an extinction method and a peak elimination method, and calibrating phase delay amounts of the first phase delay device and the second phase delay device through a reference light calibration mode;
(2) Sample measurement: measuring the sample to be measured by adopting the equipment to obtain polarized modulated light of the sample to be measured;
(3) Parameter extraction: and extracting parameters of the obtained spectrum to obtain the Mueller matrix elements or ellipsometry parameters of the sample to be detected.
9. A snapshot ellipsometry method of claim 8, wherein: the mathematical expression of the system model adopted in the equipment calibration and feedback calibration is as follows:
wherein S is out For the beam after passing the sample to correspond to the Stokes vector, M P 、M A Corresponding Mueller matrix respectively for first polarization and second polarization, M sample A Mueller matrix corresponding to the sample; r (x) represents a mueller rotation matrix when the rotation angle is x, α 1 、α 2 Azimuth angle epsilon of light transmission axis in first polarization and second polarization respectively 1 Is the azimuth angle error of the light transmission axis when polarized for the first time, beta 1 、β 2 The fast axis azimuth angles epsilon of the first phase delay and the second phase delay are respectively 2 、ε 3 Respectively at the first phase delay and the second phase delayFast axis azimuth error, ε 4 To measure the azimuth angle error of the light transmission axis corresponding to the linear polaroid of the sample, M R The [ delta ] is the Mueller matrix corresponding to the phase retarder 1 、δ 2 The phase delay amounts at the first phase delay and the second phase delay are respectively S in Is the stokes vector corresponding to the beam incident on the measurement system.
10. A snapshot ellipsometry method of claim 8, wherein: extracting a multichannel coefficient by a Fourier method, and further linearly combining the multichannel coefficient to extract a Mueller matrix element or an ellipsometry parameter of a sample to be detected; or extracting parameters by a compressed sensing and neural network method based on a physical model.
CN202311188558.2A 2023-09-13 2023-09-13 Snapshot type ellipsometry method and device Pending CN117368114A (en)

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