A device and method for in-situ high-speed measurement of dynamic morphology during photoresist exposure

Abstract

The invention belongs to the field of optical measurement technology, and discloses an in-situ high-speed measurement device and method for dynamic morphology of photoresist exposure process, which is composed of a measurement optical path module and an exposure optical path module. In the measurement optical path, the detection light emitted by the measurement light source is modulated by a synchronous electronic shutter, a reflector, a polarizer, and a photoelastic phase modulator in sequence, and then irradiated to the sample surface and reflected. The reflected light beam is divided into three beams of roughly the same light intensity by two beam splitters, which are respectively subjected to demodulation of wave plates and polarization beam splitters of different specifications, and then the instantaneous light intensity is sensed by 6 photomultiplier tubes; according to the measured light intensity and combined with the optical model of the measurement system, the measurement Mueller matrix of the sample is extracted, and then the three-dimensional morphology of the sample is obtained according to the sample optical model, so as to realize the dynamic monitoring of the photoresist exposure process. The invention has the advantages of high time resolution, in-situ dynamic measurement, and rich measurement information.

Description

Technical Field

[0001] The present invention belongs to the technical field related to polarization optical measurement, and relates to an in-situ high-speed measurement device and method for dynamic morphology of a photoresist exposure process. More specifically, it relates to a dynamic measurement device and method for realizing online in-situ measurement of a photoresist exposure process in combination with a high-speed Mueller ellipsometric measurement technology. Background Art

[0002] Chip technology is the epitome of the world's most advanced productivity in the 21st century. The photolithography process can be simply divided into several links: spin coating, exposure, development, and etching. The exposure process of photoresist is undoubtedly an extremely important link, which significantly affects the yield of the entire chip production process. After being irradiated with ultraviolet light, the photosensitizer molecules inside the photoresist will absorb the energy of photons and convert into other substances, and on a macroscopic level, the overall optical properties and geometric morphology of the photoresist will change with the progress of the exposure reaction. However, since this reaction process is very rapid and the characterization experiment requires very high measurement accuracy, there is currently a lack of research in this area. The dynamic measurement and characterization of the property change process of photoresist during the exposure process not only provides a direct theoretical basis for improving the photolithography process, which helps to further improve the photolithography process, but also has a very important significance for further research and improvement of the performance of photoresist.

[0003] Ellipsometry is a non-destructive optical measurement technology that accurately characterizes thin film materials. After the photoresist is prepared into a thin film, this step is similar to the spin coating process in the actual production of chips. The geometric parameters and optical properties of the photoresist film can be measured by ellipsometric measurement technology. However, in the actual production process, the exposure process of the photoresist takes a very short time. The exposure in the ultraviolet band generally only takes 3 to 5 seconds, and the exposure time in the deep ultraviolet and extreme ultraviolet bands is even shorter. The time resolution of existing ellipsometers is usually in the order of seconds, which is difficult to meet the requirements of high time resolution for the measurement of the photoresist exposure process. Its structure cannot realize the online in-situ measurement of the photoresist exposure process. Summary of the invention

[0004] In view of the demand for high temporal resolution in dynamic measurement of photoresist exposure process and the shortcomings of existing measurement devices, the present invention provides an in-situ high-speed measurement device and method for dynamic morphology of photoresist exposure process, with the purpose of realizing high temporal resolution Mueller matrix measurement of photoresist samples to record and analyze the changes in their geometric morphology and optical properties during the exposure process.

[0005] In order to achieve the above-mentioned object, according to one aspect of the present invention, there is provided an in-situ high-speed measurement device for dynamic morphology of photoresist exposure process, which is used to measure photoresist samples and includes a measurement optical path unit and an exposure optical path unit;

[0006] The measuring optical path unit comprises an incident optical path, a reflected optical path and a data acquisition instrument; the incident light emitted by the incident optical path is reflected by the photoresist sample to form reflected light that enters the reflected optical path; the incident optical path comprises a measuring light source, a polarizer and two photoelastic phase modulators arranged in sequence; the reflected optical path comprises two non-polarizing beam splitters, three polarizing beam splitters and six photomultiplier tubes, the reflected light is divided into three beams by the two non-polarizing beam splitters, and one-to-one corresponds to the three polarizing beam splitters and then divided into two to obtain a total of six outgoing lights; the six outgoing lights are respectively converted into electrical signals by six photomultiplier tubes and then input into the data acquisition instrument;

[0007] The exposure optical path unit comprises an exposure light source, a lens group mask, a non-polarizing beam splitter and an objective lens arranged in sequence;

[0008] A synchronous electronic shutter is respectively provided between the measuring light source and the polarizer, and between the lens group and the mask, and the two synchronous electronic shutters are controlled synchronously; during measurement, the exposure spot range formed by the outgoing light of the objective lens on the surface of the photoresist sample completely covers the spot formed by the incident light path on the surface of the photoresist sample.

[0009] Furthermore, the lens group includes a front lens and a rear lens, the rear focal plane of the front lens coincides with the front focal plane of the rear lens to form a confocal plane, and a small aperture stop is arranged on the confocal plane.

[0010] Furthermore, the mask is used to control the shape and size of the light spot.

[0011] According to another aspect of the present invention, a method for in-situ high-speed measurement of dynamic morphology during photoresist exposure is provided, which is implemented based on the in-situ high-speed measurement device for dynamic morphology during photoresist exposure as described in any of the preceding items, and comprises the following steps:

[0012] S1: In reflection mode, the measuring light source is modulated to form measuring light with different polarization states;

[0013] S2: Turn on the measuring light source, adjust the height and angle of the standard sample, so that the measuring light is reflected from the center of the standard sample and enters the reflection light path, and the light intensity signal can be collected by six photomultiplier tubes;

[0014] Turn on the exposure light source and adjust the exposure spot size to ensure that the center of the exposure spot is in the same position as the center of the measurement spot and that the area where the exposure spot is located completely contains the area where the measurement spot is located.

[0015] S3: Replace the standard sample with the photoresist sample to be tested, and trigger two synchronous electronic shutters to make in-situ measurement and exposure reaction simultaneously, and record the surface morphology changes and UV reflection intensity of the sample in real time. ref (t), and the light intensity information collected by six photomultiplier tubes is used to obtain the measured light intensity matrix Bexp ;

[0016] S4: According to the specific working parameters of the two photoelastic phase modulators, the theoretical light intensity matrix B is calculated. mod , the measured light intensity matrix B is fitted by the least squares method exp With the theoretical light intensity matrix B mod , a complete dynamic Mueller matrix carrying information about changes in the photoresist during exposure is obtained, thereby extracting the dynamic morphology and optical properties information of the photoresist sample during exposure.

[0017] Furthermore, the method for modulating the measuring light source in step S1 includes: in the reflection mode, turning on two photoelastic phase modulators at the same time, so that the optical axes of the polarizer and the two photoelastic phase modulators are maintained at a relative angle, and setting different driving voltages on the two photoelastic phase modulators so that the two photoelastic phase modulators have different frequencies.

[0018] Furthermore, in step S4, the theoretical light intensity matrix B mod The calculation method is as follows:

[0019] t i The Stokes vector of the incident light at time has the following form:

[0020]

[0021] Among them, the azimuth angle of the polarizer and the Mueller matrix are represented by θ P and M P , the azimuth angle and Mueller matrix of the photoelastic phase modulator are represented by θ PEM and M PEM ; δ PEM represents the photoelastic phase delay, and for any time t, its expression is:

[0022]

[0023] Among them, δ peak is the peak phase delay of the photoelastic phase modulator, δ static is the static phase delay of the photoelastic phase modulator, f is the frequency, is the initial phase; in addition, R represents the coordinate rotation matrix, M represents the Mueller matrix of the element, and the matrix forms of R and M are:

[0024]

[0025] m 11 ~m 44 is the Mueller matrix element;

[0026] The modulation matrix W of the polarizing arm is composed of the Stokes vector S(ti ) are combined into the form of:

[0027] W=[S(t 1 ),S(t 2 ),...,S(t N )] (4)

[0028] Where N is a positive integer, indicating the length of the time series. The 4×N modulation matrix W of the polarizing arm and the 4×4 Mueller matrix M of the photoresist sample are s The 6×4 polarization matrix A of the polarization analysis system is cascaded in sequence to obtain the theoretical light intensity matrix B of the measurement system. mod as follows:

[0029] B mod =[b(t 1 ),b(t 2 ),...,b(t N )]=AM s W (5)

[0030] Among them, b(t i ) indicates t i The column vector of light intensities measured by six photomultiplier tubes at each moment;

[0031] Least squares fit B exp With B mod The formula is:

[0032]

[0033] Further, in step S4, for a photoresist sample having a one-dimensional periodic exposure pattern, the theoretical Mueller matrix M of the photoresist sample is mod and the measured Mueller matrix M exp Inversion fitting is performed to extract the dynamic morphology of the photoresist sample during exposure, specifically:

[0034] By rigorous coupled wave analysis, the incident light electric field vector E inc The complex amplitude coefficient R of the zero-order diffraction wave is obtained by calculating the angle between the incident plane and the incident plane when α = 90° and α = 0°. s and R p , and further calculate the Jones matrix J of the photoresist sample:

[0035]

[0036] Where i is the imaginary unit, α = 0°: r pp =R s , r ps =1i×R p ;

[0037] α=90°:r sp =R s , r ss =1i×R p ;

[0038] When the depolarization effect is not considered, the theoretical Mueller matrix M of the photoresist sample is mod The relationship with Jones matrix J is:

[0039]

[0040] in represents the Kronecker product, J * is the complex conjugate matrix of matrix J, matrix A t for:

[0041]

[0042] Among them, the matrix A t The i in is the imaginary unit;

[0043] When the azimuth angle ψ is not 0, the theoretical Mueller matrix M is obtained by formula (8): mod for:

[0044]

[0045] Where Re and Im represent the real and imaginary parts of the complex number, respectively. * represents the conjugate of the complex elements; the theoretical Mueller matrix M of the photoresist sample mod and the measured Mueller matrix M exp Perform inversion fitting, the fitting formula is:

[0046]

[0047] x 1 、x 2 、x 3 represent the top line width, side wall angle, and line height of the one-dimensional periodic exposure pattern on the photoresist sample, respectively;

[0048] At each measurement time t i Formula (10) is used to measure the Mueller matrix M of the sample exp and the theoretical Mueller matrix M mod Perform fitting to obtain the unknown parameter x 1 (t), x 2 (t), x 3 (t), the dynamic changes of the top line width, side wall angle and line height of the one-dimensional periodic structure formed by the photoresist sample during the exposure process are obtained.

[0049] In general, the above technical solution conceived by the present invention has the following technical advantages compared with the prior art:

[0050] (1) The measuring device described in the present invention can perform in-situ real-time measurement of the photoresist exposure process with a time resolution of up to microseconds, and can obtain a complete Mueller matrix containing sample geometric morphology and optical property information.

[0051] (2) The device proposed in the present invention has a simple structure, adjustable configuration, and rich scalability. The present invention extracts the measured Mueller matrix of the sample based on the measured light intensity and combined with the optical model of the measurement system. A variety of experimental conditions can be set to perform measurement experiments to meet different application scenarios and measurement requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 It is a structural schematic diagram of an in-situ high-speed Mueller matrix ellipsometric measurement device for dynamic morphology in a photoresist exposure process provided by an embodiment of the present invention.

[0053] Figure 2 It is an optical model in which a sample forms a one-dimensional periodic structure during the exposure process.

[0054] Among them: 1-measuring light source, 2-synchronous electronic shutter, 3-non-polarizing beam splitter, 4-polarizing beam splitter, 5-polarizer, 6-photoelastic phase modulator, 7-objective lens, 8-wave plate, 9-photomultiplier tube, 10-CCD camera, 11-mask, 12-data acquisition instrument, 13-lens group, 14-exposure light source, 15-reflector, 16-photoresist sample. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0056] As attached Figure 1 As shown, an embodiment of the present invention provides an in-situ high-speed Mueller matrix ellipsometric measurement device for dynamic morphology of a photoresist exposure process, and the device mainly includes a measurement optical path unit and an exposure optical path unit.

[0057] The measuring optical path unit mainly comprises a measuring light source 1, a synchronous electronic shutter 2, a reflector 15, a polarizer 5, a photoelastic phase modulator 6, a non-polarizing beam splitter 3, a polarizing beam splitter 4, an achromatic wave plate 8 and a photomultiplier tube 9 which are arranged in sequence.

[0058] Preferably, there are two photoelastic phase modulators, namely the first photoelastic phase modulator and the second photoelastic phase modulator. The light emitted by the laser light source is phase-modulated by a polarizer and controlled to have different frequencies, and becomes an elliptically polarized light that changes with time and is projected onto the sample surface. After being reflected at the sample, it enters the polarization analyzer system.

[0059] Preferably, there are two non-polarizing beam splitters 3, namely the first non-polarizing beam splitter and the second non-polarizing beam splitter; there are three polarizing beam splitters 4, namely the first polarizing beam splitter, the second polarizing beam splitter and the third polarizing beam splitter. The reflected light entering the polarization analyzer system is first divided into two beams by the first non-polarizing beam splitter with a splitting ratio of 7:3, of which the stronger beam is then divided into three beams with roughly the same light intensity by the second non-polarizing beam splitter with a splitting ratio of 5:5, so that the reflected light is converted into three beams with roughly the same light intensity. The first beam is directly divided into P light and S light through the first polarizing beam splitter, the second beam is first divided into P light and S light through a half wave plate, and then divided into P light and S light through the second polarizing beam splitter, and the third beam is first divided into P light and S light through a quarter wave plate, and then divided into P light and S light through the third polarizing beam splitter. These six beams of light must be converted into light intensity curves that change with time on the six channels of the oscilloscope.

[0060] Its working principle is as follows: the measuring light source generates the required linear polarized light through a polarizer, which is modulated by a pair of photoelastic phase modulators (PEM) to form polarized light of different polarization states, which is incident obliquely on the sample to be measured at a certain incident angle. In the polarization analyzer system, two non-polarization beam splitters are used to split the polarized light to be measured into three branch beams. In the first branch beam, the polarized light to be measured is analyzed by the first polarization beam splitter (PBS) and split into two linear polarized lights with mutually perpendicular vibration directions, namely p light and s light, which are then detected by the photomultiplier tube (PMT) for calculating the Stokes parameter S1; in the second branch beam, before being analyzed and split by the PBS, the polarized light to be measured is phase modulated by a 1 / 2 wave plate for calculating the Stokes parameter S2; the third branch beam is used to calculate the Stokes parameter S3, and the polarized light to be measured is first modulated by a 1 / 4 wave plate, then analyzed and split by the PBS, and finally the light intensity is detected by the PMT.

[0061] The exposure optical path unit mainly includes an exposure light source 14, a lens group 13, a synchronous electronic shutter 2, a reflector 15, a mask 11, a non-polarizing beam splitter 3, and an objective lens 7, wherein the rear focal plane of the front lens in the lens group coincides with the front focal plane of the rear lens, and the ultraviolet light emitted by the exposure light source is converged and collimated by the lens group, and the shape and size of the light spot are controlled by the mask.

[0062] Furthermore, a small aperture diaphragm is added on the confocal plane of the lens group of the exposure light path to filter out stray light from the light source, which can further improve the uniformity and parallelism of the exposure light beam.

[0063] Furthermore, a non-polarizing beam splitter and an objective lens are introduced between the sample and the mask of the exposure light path, which are used to project the mask layout pattern onto the photoresist surface. The sample then reflects a portion of the exposure light beam back to the exposure light path. This reflected light beam will pass through the objective lens, the non-polarizing beam splitter and be incident on a CCD camera, which can synchronously detect changes in the sample surface morphology during the exposure process.

[0064] Preferably, the measuring light source is a 532nm laser light source, which is used to generate a parallel light beam in the 532nm band. After being modulated by a polarizer and dual photoelasticity, the parallel light beam becomes a beam of polarized light whose polarization state changes rapidly with time.

[0065] Preferably, the exposure light source adopts a 365nm light source, which is mainly used to provide the energy required for the photoresist exposure process. The light source uses the Kohler illumination principle, and the parallel light generated by the light source passes through the mask, beam splitter, and objective lens, and then irradiates the sample and reflects. The reflected light then passes through the objective lens and beam splitter and is then captured by the CCD camera.

[0066] As a preferred embodiment, another aspect of the present invention provides an in-situ high-speed Mueller matrix ellipsometric measurement method for dynamic morphology of a photoresist exposure process, comprising the following steps:

[0067] S1: In the reflection mode, the incident angle of the incident light is adjusted to 65°, the two photoelastic phase modulators are turned on, the driving voltages thereof are set to 4.2V and 4.8V respectively, and the azimuth angle of the polarizer is adjusted to 45°;

[0068] S2: Standard SiO 2 The sample is placed on the sample stage, the measurement light source is turned on, and the position of the sample stage is adjusted so that the incident light enters the high-speed polarization analyzer module after being reflected by the sample, and the light intensity information can be collected by six photomultiplier tubes. The ultraviolet exposure light source is turned on to ensure that the exposure spot size is large enough to completely contain the measurement spot.

[0069] S3: Turn off the measurement and exposure light sources first, replace the sample with the photoresist sample to be tested, and set the UV light intensity to 50mW / cm 2 Then, the measurement light source and the exposure light source are opened simultaneously through the synchronized electronic shutter, and the surface morphology changes of the sample and the UV reflected light intensity I are recorded in real time through the non-polarizing beam splitter and CCD camera above the sample. ref (t), and record the light intensity information collected by six photomultiplier tubes through an oscilloscope to obtain the measured light intensity matrix B exp ;

[0070] S4: The theoretical light intensity matrix B of the sample is calculated using the optical model of the measurement system mod , the measured light intensity matrix B is fitted by the least squares method expWith the theoretical light intensity matrix B mod , and obtain the complete Mueller matrix M that carries the information of the dynamic change of the optical properties of the photoresist sample during exposure exp (t i ).

[0071] In this step, the theoretical light intensity matrix B mod The detailed calculation process is as follows:

[0072] t i The Stokes vector of the incident light at time has the following form:

[0073]

[0074] Among them, the azimuth angle of the polarizer and the Mueller matrix are represented by θ P and M P , the azimuth angle and Mueller matrix of the photoelastic phase modulator are represented by θ PEM and M PEM ; δ PEM represents the photoelastic phase delay, and for any time t, its expression is:

[0075]

[0076] where δ peak is the peak phase delay of the photoelastic phase modulator, δ static is the static phase delay of the photoelastic phase modulator, f is the frequency, is the initial phase. In addition, R represents the coordinate rotation matrix, M represents the Mueller matrix of the element, and m 11 ~m 44 is a Mueller matrix element. Each element can be individually calibrated by a commercial Mueller matrix ellipsometer to obtain its Mueller matrix. The matrix form of R and M is:

[0077]

[0078] The modulation matrix W of the polarizing arm is composed of the Stokes vector S(t i ) are combined into the form of:

[0079] W=[S(t 1 ),S(t 2 ),...,S(t N )] (4)

[0080] Where N is a positive integer, indicating the length of the time series. The 4×N modulation matrix W of the polarizing arm and the 4×4 Mueller matrix M of the sample are s The theoretical light intensity matrix B of the measurement system can be obtained by sequentially cascading the 6×4 polarization matrix A of the polarization analysis system.mod , which is of the form:

[0081] B mod =[b(t 1 ),b(t 2 ),...,b(t N )]=AM s W (5)

[0082] The polarization matrix A of the polarization system can be obtained by using the Mueller matrix SiO 2 The sample is used to calibrate the system in situ, b(t i ) corresponds to t i The column vector composed of the light intensity measured by six photomultiplier tubes at each moment, i=1~N.

[0083] In this step, the least squares method fits B exp With B mod The formula is:

[0084]

[0085] In addition, the measured data is analyzed. Taking the exposure pattern as a one-dimensional periodic grating as an example, the simplified optical model of the sample during the exposure process is shown in the attached figure. Figure 2 As shown, where N begin Represents the complex refractive index of the photoresist before exposure, N end represents the complex refractive index of the photoresist after exposure, x 1 、x 2 、x 3 are unknown coefficients, representing the top line width, side wall angle and line height respectively, T represents the grating period, and during the exposure process, x 1 、x 2 、x 3 will change gradually, and the fixed period T remains unchanged. After the complex refractive index of each region, the initial value of the unknown parameter, the period and the film thickness are given, the incident light electric field vector E is respectively inc The complex amplitude coefficient R of the zero-order diffraction wave is obtained by calculating the angle between the incident plane and the incident plane when α=90° (TE polarization) and α=0° (TM polarization). s and R p , and further calculate the Jones matrix J of the sample to be tested:

[0086]

[0087] where r pp =R s (α=0°), r ps =1i×R p (α=0°), r sp =R s(α=90°), r ss =1i×R p (α=90°).

[0088] When the depolarization effect is not considered, the sample corresponds to the theoretical Mueller matrix M mod The relationship with Jones matrix J is:

[0089]

[0090] in represents the Kronecker product, J * is the complex conjugate matrix of matrix J, matrix A t for:

[0091]

[0092] When the azimuth angle ψ is not 0, the corresponding Mueller matrix is ​​obtained from (8):

[0093]

[0094] Where Re and Im represent the real and imaginary parts of the complex number, respectively, and * represents the conjugation of the complex elements. The theoretical Mueller matrix M for the sample mod and the measured Mueller matrix M exp Perform inversion fitting, the fitting formula is:

[0095]

[0096] At each measurement time t i Formula (10) is used to measure the Mueller matrix M of the sample exp and the theoretical Mueller matrix M mod Perform fitting to obtain the unknown parameter x 1 (t), x 2 (t), x 3 (t), the dynamic changes of the top line width, side wall angle and line height of the one-dimensional periodic structure formed by the sample during the exposure process are obtained.

[0097] Through the above-mentioned device and method, the present invention can, on the one hand, perform the exposure process of the photoresist and the measurement of its surface state, and on the other hand, can realize the Mueller matrix measurement of the photoresist film with a time resolution of milliseconds to record and analyze the changes in its geometric morphology and optical properties during the exposure process.

[0098] It will be easily understood by those skilled in the art that the above description is only one embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-speed in-situ measurement device for dynamic morphology during photoresist exposure, used for measuring photoresist samples, characterized in that: It includes a measuring optical path unit and an exposure optical path unit; The measuring optical path unit comprises an incident optical path, a reflected optical path and a data acquisition instrument (12); incident light emitted by the incident optical path is reflected by the photoresist sample to form reflected light entering the reflected optical path; the incident optical path comprises a measuring light source (1), a polarizer (5) and two photoelastic phase modulators (6) arranged in sequence; the reflected optical path comprises two non-polarizing beam splitters (3), three polarizing beam splitters (4) and six photomultiplier tubes (9); the reflected light is divided into three branch light beams by the two non-polarizing beam splitters (3) and enters the three photomultiplier tubes (9) in a one-to-one correspondence. The polarized light to be measured is polarized by the first polarization beam splitter and split into two beams of linear polarized light with vibration directions perpendicular to each other; in the second branch light beam, before being polarized and split by the second polarization beam splitter, phase modulation is performed on the polarized light to be measured by a 1 / 2 wave plate; in the third branch light beam, the polarized light to be measured is first modulated by a 1 / 4 wave plate, and then polarized and split by the third polarization beam splitter; The exposure optical path unit comprises an exposure light source (14), a lens group (13), a mask (11), a non-polarizing beam splitter (3) and an objective lens (7) which are arranged in sequence; A synchronous electronic shutter (2) is respectively arranged between the measuring light source (1) and the polarizer (5), and between the lens group (13) and the mask (11), and the two synchronous electronic shutters (2) are synchronously controlled; during measurement, the exposure spot formed on the surface of the photoresist sample by the outgoing light of the objective lens (7) completely covers the spot formed on the surface of the photoresist sample by the incident light path.

2. The in-situ high-speed measurement device for dynamic morphology of photoresist exposure process according to claim 1, characterized in that: The lens group (13) comprises a front lens and a rear lens, the rear focal plane of the front lens and the front focal plane of the rear lens overlap to form a confocal plane, and a small aperture stop is arranged on the confocal plane.

3. The in-situ high-speed measurement device for dynamic morphology during photoresist exposure process according to claim 1, characterized in that: The mask (11) is used to control the shape and size of the light spot.

4. A method for in-situ high-speed measurement of dynamic morphology during photoresist exposure process, implemented based on the in-situ high-speed measurement device for dynamic morphology during photoresist exposure process according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1: In the reflection mode, the measuring light source (1) is modulated to form measuring lights of different polarization states; S2: Turn on the measuring light source (1), adjust the height and angle of the standard sample, so that the measuring light is reflected from the center of the standard sample and enters the reflection light path, and the light intensity signal can be collected by the six photomultiplier tubes (9); Turning on the exposure light source (14), adjusting the size of the exposure spot, ensuring that the center of the exposure spot and the center of the measurement spot are at the same position, and that the area where the exposure spot is located completely includes the area where the measurement spot is located; S3: Replace the standard sample with the photoresist sample to be tested, and trigger the two synchronous electronic shutters (2) synchronously to make the in-situ measurement and exposure reaction proceed simultaneously, and record the surface morphology change of the sample and the ultraviolet reflection light intensity I in real time. ref (t), and the light intensity information collected by six photomultiplier tubes is used to obtain the measured light intensity matrix B exp ; S4: According to the specific working parameters of the two photoelastic phase modulators, the theoretical light intensity matrix B is calculated. mod , the measured light intensity matrix B is fitted by the least squares method exp With the theoretical light intensity matrix B mod , a complete dynamic Mueller matrix carrying information about changes in the photoresist during exposure is obtained, thereby extracting the dynamic morphology and optical properties information of the photoresist sample during exposure.

5. A method for in-situ high-speed measurement of dynamic morphology during photoresist exposure process as claimed in claim 4, characterized in that: The method for modulating the measuring light source (1) in step S1 comprises: in a reflection mode, simultaneously turning on two photoelastic phase modulators (6), so that the optical axes of the polarizer (5) and the two photoelastic phase modulators (6) are maintained at a relative angle, and different driving voltages are set on the two photoelastic phase modulators (6), so that the two photoelastic phase modulators (6) have different frequencies.

6. A method for in-situ high-speed measurement of dynamic morphology during photoresist exposure process as claimed in claim 4, characterized in that: In step S4, the theoretical light intensity matrix B mod The calculation method is as follows: t i The Stokes vector of the incident light at time has the following form: Among them, the azimuth angle of the polarizer and the Mueller matrix are represented by θ P and M P , the azimuth angle and Mueller matrix of the photoelastic phase modulator are represented by θ PEM and M PEM ; δ PEM represents the photoelastic phase delay, and for any time t, its expression is: Among them, δ peak is the peak phase delay of the photoelastic phase modulator, δ static is the static phase delay of the photoelastic phase modulator, f is the frequency, is the initial phase; in addition, R represents the coordinate rotation matrix, M represents the Mueller matrix of the element, and the matrix forms of R and M are: m 11 ~m 44 is the Mueller matrix element; The modulation matrix W of the polarizing arm is composed of the Stokes vector S(t i ) are combined into the form of: W=[S(t1),S(t2),...,S(t N )] (4) Where N is a positive integer, indicating the length of the time series. The 4×N modulation matrix W of the polarizing arm and the 4×4 Mueller matrix M of the photoresist sample are s The 6×4 polarization matrix A of the polarization analysis system is cascaded in sequence to obtain the theoretical light intensity matrix B of the measurement system. mod as follows: B mod =[b(t1),b(t2),...,b(t N )]=AM s W (5) Among them, b(t i ) indicates t i The column vector of light intensities measured by six photomultiplier tubes at each moment; Least squares fitting B exp With B mod The formula is:

7. A method for in-situ high-speed measurement of dynamic morphology during photoresist exposure process as claimed in claim 6, characterized in that: In step S4, for a photoresist sample having a one-dimensional periodic exposure pattern, the theoretical Mueller matrix M of the photoresist sample is mod and the measured Mueller matrix M exp Inversion fitting is performed to extract the dynamic morphology of the photoresist sample during exposure, specifically: By rigorous coupled wave analysis, the incident light electric field vector E inc The complex amplitude coefficient R of the zero-order diffraction wave is obtained by calculating the angle between the incident plane and the incident plane when α = 90° and α = 0°. s and R p , and further calculate the Jones matrix J of the photoresist sample: Where i is the imaginary unit, α = 0°: r pp =R s , r ps =1i×R p ; α=90°:r sp =R s ,r ss =1i×R p ; When the depolarization effect is not considered, the theoretical Mueller matrix M of the photoresist sample is mod The relationship with Jones matrix J is: in represents the Kronecker product, J * is the complex conjugate matrix of matrix J, matrix A t for: Among them, the matrix A t The i in is the imaginary unit; When the azimuth angle ψ is not 0, the theoretical Mueller matrix M is obtained by formula (8): mod for: Where Re and Im represent the real and imaginary parts of the complex number, respectively. * represents the conjugate of the complex elements; the theoretical Mueller matrix M of the photoresist sample mod and the measured Mueller matrix M exp Perform inversion fitting, the fitting formula is: x1, x2, and x3 represent the top line width, sidewall angle, and line height of the one-dimensional periodic exposure pattern on the photoresist sample, respectively; At each measurement time t i Formula (10) is used to measure the Mueller matrix M of the sample exp and the theoretical Mueller matrix M mod Fitting is performed to obtain the unknown parameters x1(t), x2(t), and x3(t), and the dynamic changes of the top line width, side wall angle, and line height of the one-dimensional periodic structure formed by the photoresist sample during the exposure process are obtained.

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