A method for measuring a crystallization state of a film layer, and related devices and storage medium

Abstract

The application discloses a kind of film layer crystallization state measurement method and related device, storage medium, the method includes: by pumping light to the material to be measured excitation ultrasound, again emit probe light to the same point position and carry out ultrasound detection, obtain current detection signal;If the signal-to-noise ratio of current detection signal is greater than decibel threshold value, from the acoustic impedance based on detection signal analysis abnormal crystallization region, indicate the degree of abnormal crystallization of the material to be measured;If the signal-to-noise ratio of current detection signal is not greater than decibel threshold value, based on current detection signal analysis the acoustic velocity and acoustic impedance of the material to be measured;The Young's modulus of the material to be measured is calculated using the acoustic velocity and acoustic impedance of the material to be measured, and is output as the quantitative index of the crystallization state of the material to be measured;If the acoustic velocity of the material to be measured cannot be analyzed, the amplitude of two echo signals is obtained based on current detection signal, and the attenuation parameter of echo is calculated using the ratio of the amplitude of two echo signals, and is output as the quantitative index of the crystallization state of the material to be measured.

Description

Technical Field

[0001] This application relates to a method for measuring the crystallization state of a film deposited on a wafer surface, and particularly to a method for measuring the crystallization state of a film layer, as well as related apparatus and storage medium. Background Technology

[0002] The crystallization state of the film layer on the wafer surface affects the etching rate and other aspects of IC manufacturing. Therefore, accurate measurement of the crystallization state of the material can determine the quality of the surface film layer, which is particularly important for wafer production and use.

[0003] Currently, the measurement of the crystallinity of materials mainly involves ultrasonic testing to determine the crystallinity. Specifically, traditional ultrasonic technology is used to directly excite megahertz-level ultrasonic waves into the material under test to measure the overall crystallinity of the material.

[0004] However, these detection methods generate ultrasonic frequencies in the megahertz range, resulting in wavelengths of approximately 0.1 millimeters. The thickness of the surface film on a wafer typically ranges from tens of nanometers to tens of micrometers, therefore the emitted ultrasonic waves are much longer than the film thickness, making them unsuitable for directly measuring the crystallinity of the wafer's surface film. Furthermore, they primarily measure crystallinity, not the specific crystalline state. Summary of the Invention

[0005] In view of the shortcomings of the prior art, this application provides a method, related device and storage medium for measuring the crystallization state of a film layer, so as to solve the problem that the prior art cannot accurately measure the crystallization state of the film layer.

[0006] To achieve the above objectives, this application provides the following technical solution:

[0007] The first aspect of this application provides a method for measuring the crystallization state of a film, comprising:

[0008] By exciting ultrasound at any scanning point of the material under test with pump light, and then emitting probe light at the same scanning point to perform ultrasonic detection, the current detection signal is obtained.

[0009] If the signal-to-noise ratio of the current detected signal is greater than a decibel threshold, the acoustic impedance of the abnormal crystallization region is analyzed based on the current detected signal; wherein, the decibel threshold is the decibel threshold of the signal-to-noise ratio of the echo signal detected in the abnormal crystallization region;

[0010] The acoustic impedance of the abnormal crystallization region is used to indicate the degree of abnormal crystallization in the test material.

[0011] If the signal-to-noise ratio of the current detection signal is not greater than the decibel threshold, then the sound velocity and acoustic impedance of the material under test are analyzed based on the current detection signal.

[0012] The Young's modulus of the material under test is calculated using the sound velocity and acoustic impedance of the material under test, and the Young's modulus of the material under test is output as a quantitative index of the crystallization state of the material under test.

[0013] If the sound velocity of the material under test cannot be analyzed, the amplitude of the two echo signals is obtained based on the current detection signal, and the attenuation parameter of the echo is calculated using the ratio of the amplitude of the two echo signals. The attenuation parameter is then output as a quantitative index of the crystallization state of the material under test.

[0014] Optionally, in the above-described method for measuring the crystallization state of the film, the step of analyzing the acoustic impedance of the abnormal crystallization region based on the current detection signal includes:

[0015] Obtain the signal amplitude of the abnormal crystallization region from the current detection signal;

[0016] The acoustic impedance of the normal crystalline region of the test material and the signal amplitude of the normal crystalline region are obtained; wherein, the acoustic impedance of the normal crystalline region of the test material is obtained by multiplying the density of the normal crystalline region of the test material by the sound velocity;

[0017] The acoustic impedance of the abnormal crystallization region is calculated based on the signal amplitude of the normal crystallization region, the signal amplitude of the abnormal crystallization region, and the acoustic impedance of the normal crystallization region.

[0018] The formula for calculating the acoustic impedance of the abnormal crystallization region is as follows: ; A represents the signal amplitude in the abnormal crystallization region; A represents the signal amplitude in the normal crystallization region. Indicates the acoustic impedance of the normal crystallization region; This indicates the acoustic impedance of the abnormal crystallization region.

[0019] Optionally, in the above method for measuring the crystallization state of the film, if the signal-to-noise ratio of the current detection signal is greater than a decibel threshold, the method further includes:

[0020] Based on the current detection signal, the arrival time of the reflected signal of the abnormal crystallization region is analyzed, and the location data of the abnormal crystallization region is calculated using the arrival time of the reflected signal of the abnormal crystallization region, and the location of the abnormal crystallization region is output.

[0021] Optionally, in the above-described method for measuring the crystallization state of the film, calculating the location data of the abnormal crystallization region using the arrival time of the reflected signal from the abnormal crystallization region includes:

[0022] Obtain the sound velocity in the normal crystallization region of the material under test;

[0023] The distance between the upper surface of the abnormal crystallization region and the surface of the material under test is calculated based on the sound velocity in the normal crystallization region and the arrival time of the reflected signal in the abnormal crystallization region.

[0024] The formula for calculating the distance between the upper surface of the abnormal crystallization region and the surface of the material to be tested is as follows: ; This represents the sound velocity in the normal crystallization region of the material under test. This indicates the arrival time of the reflected signal from the abnormal crystallization region.

[0025] Optionally, in the above-described method for measuring the crystallization state of the film, the step of analyzing the sound velocity and acoustic impedance of the material under test based on the current detection signal includes:

[0026] If the material to be tested is a transparent material, then obtain the oscillation frequency of the Brillouin oscillation signal in the current detection signal;

[0027] The velocity of sound in the material under test is calculated using the oscillation frequency of the Brillouin oscillation signal.

[0028] If the material to be tested is a non-transparent material, the echo time is determined based on the current detection signal;

[0029] The sound velocity of the material under test is obtained by dividing twice the thickness of the material under test by the echo time.

[0030] The amplitude of the interface echo signal is obtained from the current detection signal, and the acoustic impedance of the material under test is calculated based on the amplitude of the interface echo signal and the acoustic impedance of the substrate material.

[0031] Optionally, in the above-described method for measuring the crystallization state of a film, the step of calculating the Young's modulus of the material under test using the sound velocity and acoustic impedance of the material under test includes:

[0032] The Young's modulus of the material under test is calculated based on the Poisson's ratio, the sound velocity of the material under test, and the acoustic impedance of the material under test.

[0033] The formula for calculating the Young's modulus of the material to be tested is as follows: ; The Poisson's ratio of the material to be tested. The acoustic impedance of the material under test is given. The velocity of sound in the material being tested is denoted as .

[0034] Optionally, in the above-described method for measuring the crystallization state of the film, the step of acquiring the amplitudes of two echo signals based on the current detection signal and calculating the attenuation parameter of the echo using the ratio of the amplitudes of the two echo signals includes:

[0035] If the current detection signal contains two echo signals, then the amplitudes of the two adjacent echo signals are extracted from the current detection signal as the first echo amplitude and the second echo amplitude.

[0036] The attenuation coefficient of the echo is calculated using the ratio of the first echo amplitude to the second echo amplitude, the thickness of the film to be measured, and the ultrasonic reflectivity.

[0037] If the current detection signal contains only one echo signal, then the amplitude of the first echo signal is extracted from the current detection signal and used as the third echo amplitude.

[0038] Pump light is emitted towards a standard sample to excite ultrasound, and probe light is emitted towards the standard sample for ultrasonic detection to obtain the amplitude of the echo signal of the standard sample, which is used as the fourth echo amplitude.

[0039] The change in the attenuation coefficient of the echo is calculated using the ratio of the third echo amplitude value to the fourth echo amplitude value and the thickness of the film layer to be measured.

[0040] Optionally, in the above-described method for measuring the crystallization state of a film, the step of exciting ultrasound at any scanning point of the material under test with pump light and then emitting probe light to the same scanning point for ultrasonic detection includes:

[0041] For each scanning point of the material under test, an ultrasonic wave is excited at the scanning point on the surface of the material under test by a pump light beam, and the probe light is focused on the scanning point by a delay line to perform ultrasonic detection and obtain the current detection signal.

[0042] A second aspect of this application provides a measuring device for the crystallization state of a film, comprising:

[0043] The ultrasonic testing unit is used to excite ultrasound at any scanning point of the material under test by pumping light, and then emit probe light to the same scanning point to perform ultrasonic testing and obtain the current detection signal.

[0044] The first information acquisition unit is used to analyze the acoustic impedance of the abnormal crystallization region based on the current detection signal when the signal-to-noise ratio of the current detection signal is greater than a decibel threshold; wherein, the decibel threshold is a decibel threshold for the signal-to-noise ratio of the echo signal of the detected abnormal crystallization region;

[0045] An abnormal crystallization indicator unit is used to indicate the degree of abnormal crystallization of the material under test by utilizing the acoustic impedance of the abnormal crystallization region.

[0046] The information analysis and acquisition unit is used to analyze the sound velocity and acoustic impedance of the material under test based on the current detection signal when the signal-to-noise ratio of the current detection signal is not greater than a decibel threshold.

[0047] The Young's modulus calculation unit is used to calculate the Young's modulus of the material under test using the sound velocity and acoustic impedance of the material under test, and output the Young's modulus of the material under test as a quantitative index of the crystallization state of the material under test.

[0048] The attenuation parameter calculation unit is used to obtain the amplitude of two echo signals based on the current detection signal when the sound velocity of the material under test cannot be analyzed, and to calculate the attenuation parameter of the echo using the ratio of the amplitude of the two echo signals, and output the attenuation parameter as a quantitative index of the crystallization state of the material under test.

[0049] Optionally, the above-mentioned measuring device for the crystallization state of the film layer further includes:

[0050] The location calculation unit is used to calculate the location data of the abnormal crystallization region by using the arrival time of the reflected signal of the abnormal crystallization region, and output the location of the abnormal crystallization region.

[0051] Optionally, in the above-described measuring device for the crystallization state of the film, the acoustic impedance calculation unit includes:

[0052] A basic information acquisition unit is used to acquire the signal amplitude of the abnormal crystallization region from the current detection signal;

[0053] The second information acquisition unit is used to acquire the acoustic impedance of the normal crystalline region of the material under test; wherein, the acoustic impedance of the normal crystalline region of the material under test is obtained by multiplying the density of the normal crystalline region of the material under test by the sound velocity;

[0054] The first calculation unit is used to calculate the acoustic impedance of the abnormal crystallization region based on the signal amplitude of the normal crystallization region, the signal amplitude of the abnormal crystallization region, and the acoustic impedance of the normal crystallization region.

[0055] The formula for calculating the acoustic impedance of the abnormal crystallization region is as follows: ; A represents the signal amplitude in the abnormal crystallization region; A represents the signal amplitude in the normal crystallization region. Indicates the acoustic impedance of the normal crystallization region; This indicates the acoustic impedance of the abnormal crystallization region.

[0056] Optionally, in the above-described measuring device for the crystallization state of the film, the position calculation unit includes:

[0057] The third information acquisition unit is used to acquire the sound velocity in the normal crystallization region of the material under test;

[0058] The second calculation unit is used to calculate the distance between the upper surface of the abnormal crystallization region and the surface of the material to be tested based on the sound velocity of the normal crystallization region and the arrival time of the reflected signal of the abnormal crystallization region.

[0059] The formula for calculating the distance between the upper surface of the abnormal crystallization region and the surface of the material to be tested is as follows: ; This represents the sound velocity in the normal crystallization region of the material under test. This indicates the arrival time of the reflected signal from the abnormal crystallization region.

[0060] Optionally, in the above-described measuring device for the crystallization state of the film, the information analysis and acquisition unit includes:

[0061] The fourth information acquisition unit is used to acquire the oscillation frequency of the Brillouin oscillation signal in the current detection signal when the material to be tested is a transparent material;

[0062] The third calculation unit is used to calculate the sound velocity of the material under test using the oscillation frequency of the Brillouin oscillation signal;

[0063] A time determination unit is used to determine the echo time based on the current detection signal when the material to be tested is a non-transparent material;

[0064] The third calculation unit is used to divide twice the thickness of the material under test by the echo time to obtain the sound velocity of the material under test;

[0065] The fourth calculation unit is used to obtain the amplitude of the interface echo signal from the current detection signal, and calculate the acoustic impedance of the material under test based on the amplitude of the interface echo signal and the acoustic impedance of the substrate material.

[0066] Optionally, in the above-mentioned measuring device for the crystallization state of the film, the Young's modulus calculation unit includes:

[0067] The fifth calculation unit is used to calculate the Young's modulus of the material under test based on the Poisson's ratio, the sound velocity of the material under test, and the acoustic impedance of the material under test.

[0068] The formula for calculating the Young's modulus of the material to be tested is as follows: ; The Poisson's ratio of the material to be tested. The acoustic impedance of the material under test is given. is the sound velocity of the material to be tested.

[0069] Optionally, in the above-described measuring device for the crystallization state of the film, the attenuation parameter calculation unit includes:

[0070] The first advance unit is used to extract the amplitudes of two adjacent echo signals from the current detection signal as the first echo amplitude and the second echo amplitude when the current detection signal contains two echo signals.

[0071] The sixth calculation unit is used to calculate the attenuation coefficient of the echo using the ratio of the first echo amplitude to the second echo amplitude, the thickness of the film layer to be measured, and the ultrasonic reflectivity.

[0072] The second extraction unit is used to extract the amplitude of the first echo signal from the current detection signal when the current detection signal contains only one echo signal, and use it as the third echo amplitude.

[0073] The sample detection unit is used to emit pump light to a standard sample to excite ultrasound through the pump light, and to emit probe light to the standard sample for ultrasonic detection to obtain the amplitude of the echo signal of the standard sample as the fourth echo amplitude.

[0074] The seventh calculation unit is used to calculate the change in the attenuation coefficient of the echo using the ratio of the third echo amplitude value to the fourth echo amplitude value and the thickness of the film layer to be measured.

[0075] Optionally, in the above-described measuring device for the crystallization state of the film, the ultrasonic detection unit includes:

[0076] The ultrasonic testing subunit is used to sequentially excite ultrasound at each scanning point on the surface of the material under test using a beam of pump light, and to control the probe light to focus on the scanning point for ultrasonic testing using a delay line to obtain the current detection signal.

[0077] A third aspect of this application provides an electronic device, comprising:

[0078] Memory and processor;

[0079] The memory is used to store programs;

[0080] The processor is used to execute the program, which, when executed, is specifically used to implement the method for measuring the crystallization state of the film layer as described in any of the above.

[0081] A fourth aspect of this application provides a computer storage medium for storing a computer program, which, when executed by a processor, is used to implement the method for measuring the crystallization state of a film layer as described in any of the preceding claims.

[0082] This application provides a method for measuring the crystallization state of a film layer. It involves exciting ultrasound at any scanning point of the material under test using a pump light, and then emitting a probe light at the same scanning point for ultrasonic detection. This method achieves effective measurement of the film layer by exciting ultrasound with the pump light and performing ultrasonic detection with the probe wave. When the signal-to-noise ratio (SNR) of the current detection signal is greater than a decibel threshold, the acoustic impedance of the abnormal crystallization region is analyzed based on the current detection signal. The decibel threshold is the SNR threshold of the echo signal from the detected abnormal crystallization region. When a significant change in crystallization state occurs, the acoustic impedance of the abnormal region with the significant crystallization change is output, accurately reflecting its crystallization state. When the SNR of the current detection signal is not greater than the decibel threshold, the sound velocity and acoustic impedance of the material under test are analyzed based on the current detection signal. The Young's modulus of the material under test is calculated using the sound velocity and acoustic impedance, and this Young's modulus is output as a quantitative indicator of the crystallization state of the material under test. Therefore, when a significant change in the crystallization state occurs, the Young's modulus of the test material is calculated to characterize the property changes in the abnormal crystallization region. This means that the property changes in the abnormal crystallization region can be attributed to changes in the Young's modulus of the material, thus quantifying the crystallization state. When the sound velocity of the test material cannot be analyzed, the amplitudes of two echo signals are obtained based on the current detection signal, and the attenuation parameter of the echo is calculated using the ratio of the amplitudes of the two echo signals. This attenuation parameter is then output as a quantitative indicator of the crystallization state of the test material. Thus, even when the sound velocity of the test material cannot be obtained, the attenuation of multiple echoes based on the crystallization state allows for the analysis of the echo attenuation parameter to characterize the crystallization state, thereby realizing a method for accurately measuring various crystallization states of a film layer. Attached Figure Description

[0083] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0084] Figure 1 A flowchart illustrating a method for measuring the crystallization state of a film layer, provided as an embodiment of this application;

[0085] Figure 2 A schematic diagram of the architecture of a femtosecond laser ultrasound system provided in this application embodiment;

[0086] Figure 3A schematic diagram illustrating an example of detecting a significantly abnormal crystallization region provided in an embodiment of this application;

[0087] Figure 4 A flowchart illustrating a method for analyzing the acoustic impedance of abnormal crystallization regions provided in this application embodiment;

[0088] Figure 5 A flowchart illustrating a method for calculating the location data of an abnormal crystallization region provided in an embodiment of this application;

[0089] Figure 6 A flowchart illustrating a method for analyzing the sound velocity and acoustic impedance of a material under test based on a current detection signal, provided in this application embodiment;

[0090] Figure 7 A schematic diagram illustrating an example of detecting a Brillouin oscillation signal, provided as an embodiment of this application;

[0091] Figure 8 A schematic diagram illustrating an example of detecting two reflected echo signals, provided as an embodiment of this application;

[0092] Figure 9 A flowchart illustrating a method for calculating an attenuation parameter provided in an embodiment of this application;

[0093] Figure 10 A schematic diagram illustrating an example of a one-dimensional linear scan provided in an embodiment of this application;

[0094] Figure 11 A schematic diagram illustrating an example of measuring wafers in different crystal states based on Brillouin oscillation signals, provided as an embodiment of this application.

[0095] Figure 12 A data graph illustrating an example of attenuation coefficient measurements for wafers in different crystal states, provided as an embodiment of this application;

[0096] Figure 13 A schematic diagram of the architecture of a measuring device for measuring the crystallization state of a film layer provided in an embodiment of this application;

[0097] Figure 14 This is a schematic diagram of the architecture of an electronic device provided in an embodiment of this application. Detailed Implementation

[0098] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0099] In this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0100] This application provides a method for measuring the crystallization state of a film, such as... Figure 1 As shown, it includes:

[0101] S101. Excite ultrasound at any scanning point of the material under test by pumping light, and then emit probe light to the same scanning point to perform ultrasonic detection to obtain the current detection signal.

[0102] Because current technologies can only excite wavelengths much larger than the film thickness, making them unsuitable for wafer surface films, this embodiment employs a pump light incident on any scanning point of the material under test (TUT) to excite ultrasound waves with frequencies around 100 gigahertz (GHz) and wavelengths of approximately tens of nanometers within the TUT. A probe light is then incident on the same scanning point, and the reflected light (the current detection signal) is received to detect the ultrasonic signal and thus the crystallization state of the wafer surface film. Both the pump light and the probe light are on the femtosecond scale.

[0103] Optionally, in another embodiment of this application, one specific implementation of step S101 includes:

[0104] For each scanning point on the material under test, a pump light is used to excite ultrasound at the scanning point on the surface of the material under test, and the probe light is focused on the scanning point by the delay line to perform ultrasonic detection and obtain the current detection signal.

[0105] And, as Figure 2As shown, to accurately emit excitation light to a designated scanning point on the test material, pump light is incident on the upper surface of the thin film of the test material to excite ultrasonic waves. For example, the pump light can be reflected by one or more mirrors and then focused onto the upper surface of the thin film of the test material by a lens to generate ultrasonic waves. After generation, the ultrasonic waves propagate within the test material at a certain speed. When the ultrasonic waves propagate to the interface between the thin film and the substrate, they are transmitted and reflected at the interface. The reflected ultrasonic waves propagate back to the upper surface of the test material, causing a small displacement of the surface or a change in reflectivity. Subsequently, another femtosecond laser beam, i.e., the probe light, is controlled by a delay line and incident on the same scanning point on the upper surface of the thin film of the test material. For example, the probe light can be reflected by multiple mirrors and then focused onto the same scanning point on the upper surface of the thin film of the test material by a lens for acoustic wave detection. When the reflected ultrasonic waves reach the sample surface, the intensity of the probe light will be affected by the surface displacement or change in reflectivity. The change in the intensity of the probe light can be collected by a photodetector to determine the echo signal. Furthermore, by controlling the time delay between the pump light and the probe light using a delay line, the time-varying photoacoustic echo signal, i.e., the current detection signal, can be detected. The delay line can be a mechanical delay line or other delay methods; no specific method is specified here.

[0106] It should be noted that when the material under test has a light penetration depth greater than the ultrasonic wavelength, the ultrasound excited by the pump light will produce Brillouin scattering, thereby generating a Brillouin oscillation signal, which can also be simply referred to as a Brillouin signal. For example, ... Figure 3 The initial signal shown is the Brillouin oscillation signal excited within the silicon dioxide thin film. The method provided in this application relies on the Brillouin oscillation signal; therefore, the wavelength of the excited ultrasonic wave needs to be smaller than the light penetration depth of the material under test.

[0107] S102. Determine whether the signal-to-noise ratio of the current detected signal is greater than the decibel threshold.

[0108] The decibel threshold is the decibel threshold for the signal-to-noise ratio of the echo signal from the detected abnormal crystallization region.

[0109] It should be noted that analysis of the crystallization state reveals that significant changes in the crystallization state can lead to the formation of distinct interfaces within the material, causing premature reflection of the excited ultrasonic waves. Therefore, changes in the internal crystallization of the material can be directly determined through the echo. Analysis shows that the signal-to-noise ratio of the ultrasonic echo at this point exceeds a certain decibel threshold. This decibel threshold is set accordingly for different test materials. Specifically, it can be determined and set by conducting pre-test measurements on the test material.

[0110] Therefore, the analysis method for the specific crystallization state can be determined by judging whether the signal-to-noise ratio (SNR) of the received current detection signal, i.e., the current echo signal, is greater than the decibel threshold. Specifically, if the SNR of the echo signal in the current detection signal is greater than the decibel threshold, step S103 is executed. If the SNR of the echo signal in the current detection signal is not greater than the decibel threshold, step S105 is executed.

[0111] S103. Based on the current detection signal, analyze the acoustic impedance of the abnormal crystallization region to indicate the degree of abnormal crystallization in the material under test.

[0112] It should be noted that, as Figure 3 As shown in the left figure, when a significant change in the crystallization state occurs, i.e., when an abnormal crystallization region exists, some sound waves will be reflected upon reaching the abnormal crystallization region, thus receiving the reflected echo signal. Only when some sound waves pass through the abnormal crystallization region and reach the lower interface of the abnormal crystallization region, or even the next film layer or substrate, will they be reflected. Therefore, the detected echo signal is as follows: Figure 3 As shown in the right figure, before receiving signal fluctuations at the material interface, fluctuations from the abnormal crystallization region are received, i.e., echoes from the abnormal crystallization region. Therefore, the echo signal from the abnormal crystallization region can be determined from the current detection signal.

[0113] Since the internal properties of a material determine its acoustic impedance, and the magnitude of the acoustic impedance affects the amplitude of the echo signal, this embodiment analyzes the correlation between the acoustic impedance of the abnormal crystallization region and the degree of crystallization abnormality based on the current detection signal. This quantitatively analyzes the crystallization state of the abnormal crystallization region in the material under test, using the output acoustic impedance as a quantitative indicator to characterize the degree of crystallization abnormality in the abnormal crystallization region. Thus, by analyzing the magnitude of the acoustic impedance based on the current detection signal, the degree of crystallization abnormality in the abnormal crystallization region can be characterized.

[0114] Optionally, step S103 is provided in another embodiment of this application, such as... Figure 4 As shown, it includes:

[0115] S401. Obtain the signal amplitude of the abnormal crystallization region from the current detection signal.

[0116] It should be noted that since acoustic impedance needs to be calculated based on the signal amplitude of the anomalous crystallization region, the signal amplitude of the anomalous crystallization region needs to be directly extracted from the current detection signal. Since the current detection signal contains information about signal changes over time, the arrival time of the reflected signal can also be directly obtained from it.

[0117] S402. Obtain the acoustic impedance of the normal crystalline region of the material under test and the signal amplitude of the normal crystalline region.

[0118] The acoustic impedance of the normal crystalline region of the test material is obtained by multiplying the density of the normal crystalline region by the sound velocity. Since the test material is fixed, its sound velocity and density are constant values, meaning the sound velocity and density of the correct region of the test material are constant values, which can be obtained through other methods. Thus, the acoustic impedance of the normal crystalline region of the test material can be obtained.

[0119] Furthermore, the ultrasonic excitation signal is also fixed. The signal amplitude in the normal crystallization region is consistent with the amplitude of the initial ultrasonic excitation signal, and it is related to the test material and excitation conditions. Since the test material and excitation conditions are fixed, they can be obtained through the ultrasonic excitation principle formula.

[0120] Since there is a correlation between the acoustic impedance of a material and its signal amplitude, that is, the magnitude of the signal amplitude is determined by the acoustic impedance, by obtaining the acoustic impedance of the normal crystalline region of the material under test and the signal amplitude of the normal crystalline region, the relationship between the acoustic impedance and the signal amplitude can be analyzed, and then the acoustic impedance of the abnormal crystalline region can be analyzed based on this relationship.

[0121] Optionally, the acoustic impedance and signal amplitude of the normal crystalline region of the material under test can be pre-analyzed and stored, and read directly when needed. Of course, the analysis can also be performed on the spot.

[0122] S403. Based on the signal amplitude of the normal crystallization region, the signal amplitude of the abnormal crystallization region, and the acoustic impedance of the normal crystallization region, calculate the acoustic impedance of the abnormal crystallization region to indicate the degree of abnormal crystallization of the material under test.

[0123] Specifically, the relationship between the amplitude of the ultrasonic signal reflected from the abnormal crystallization region, i.e., the amplitude of the echo signal, and its acoustic impedance can be expressed as follows:

[0124]

[0125] in, A represents the signal amplitude in the abnormal crystallization region; A represents the signal amplitude in the normal crystallization region. Indicates the acoustic impedance of the normal crystallization region; This indicates the acoustic impedance of the abnormal crystallization region.

[0126] Therefore, the corresponding formula for calculating the acoustic impedance of the abnormal crystallization region can be expressed as:

[0127]

[0128] Optionally, in order to provide feedback on the location of the abnormal crystallization region, another embodiment of this application further includes: analyzing the arrival time of the reflected signal of the abnormal crystallization region based on the current detection signal, calculating the location data of the abnormal crystallization region using the arrival time of the reflected signal of the abnormal crystallization region, and outputting the location of the abnormal crystallization region.

[0129] Since the propagation speed of sound waves in the normal crystalline state of the material under test is known, by further analyzing the arrival time of the reflected signal from the abnormal crystalline region from the current detection signal, that is, the time when the signal reflected back from the abnormal crystalline region is detected, the location data of the abnormal crystalline region can be calculated, that is, the distance from the interface of the abnormal crystalline region to the interface of the material under test, thereby indicating the location of the abnormal crystalline region in the material under test.

[0130] Optionally, in another embodiment of this application, a method for calculating the location data of abnormal crystallization regions is provided, such as... Figure 5 As shown, it includes:

[0131] S501. Obtain the sound velocity in the normal crystallization region of the material to be tested.

[0132] The sound velocity in the normal crystalline region of the test material refers to the speed at which sound waves propagate within this region. Since the test material is known, the sound velocity in its normal crystalline region is also known.

[0133] S502. Calculate the distance between the upper surface of the abnormal crystallization region and the surface of the material to be tested based on the sound velocity in the normal crystallization region and the arrival time of the reflected signal in the abnormal crystallization region.

[0134] Since the distance obtained by multiplying the sound velocity in the normal crystallization region by the arrival time of the reflected signal in the abnormal crystallization region is the total distance from the surface of the material through the normal crystallization region to the abnormal crystallization region, and then reflected back to the surface of the material through the normal crystallization region, which is twice the distance between the upper surface of the abnormal crystallization region and the surface of the material to be tested, the distance between the upper surface of the abnormal crystallization region and the surface of the material to be tested can be obtained by multiplying the sound velocity in the normal crystallization region by the arrival time of the reflected signal in the abnormal crystallization region and dividing by 2.

[0135] Specifically, the arrival time of the reflected signal from the abnormal crystallization region can be expressed as:

[0136]

[0137] in, This indicates the distance between the upper surface of the crystalline region and the surface of the material; This represents the sound velocity in the normal crystallization region of the material being tested.

[0138] Therefore, the formula for calculating the distance between the upper surface of the crystalline region and the surface of the material being tested is:

[0139]

[0140] S104. Determine whether the sound velocity of the material under test can be analyzed.

[0141] It should be noted that when the signal-to-noise ratio of the ultrasonic echo signal caused by the change in crystallization state is <20dB, it will not form an interface premature reflection of the sound wave, but will directly pass through the entire material under test. Therefore, it is impossible to analyze the crystallization state through the premature emission feedback, nor is it possible to analyze the abnormal crystallization region formed. In this case, the embodiments of this application characterize the crystallization state of the material under test by analyzing the Young's modulus.

[0142] Since Young's modulus calculations require the measurement of the material's sound velocity, and the accuracy of the sound velocity of the material being tested cannot be guaranteed, it is necessary to determine whether the sound velocity of the material can be analyzed. Specifically, this involves determining whether the parameters for calculating the sound velocity of the material have been obtained, or whether they can be obtained, thereby determining whether the sound velocity of the material can be analyzed.

[0143] If it is determined that the sound velocity of the material under test can be analyzed, then step S105 is executed. If the sound velocity of the material under test cannot be analyzed, then step S107 is executed.

[0144] Currently, the signal-to-noise ratio (SNR) of the ultrasonic echo signal caused by changes in the crystallization state can be directly analyzed using the decibel threshold, i.e., step S107 can be executed directly. That is, after executing step S102, if it is determined that the SNR of the current detected signal is not greater than the decibel threshold, step S107 is executed, instead of step S104.

[0145] S105. Analyze the sound velocity and acoustic impedance of the material under test based on the current detection signal.

[0146] The speed of sound in the test material refers to the speed at which sound waves propagate in the test material.

[0147] Since the sound velocity and acoustic impedance of the material under test affect the propagation of sound waves—that is, parameters characterizing the sound wave propagation of the material under test—they influence the received echo signal, thus determining the current detection signal. Therefore, there is a correlation between the sound velocity and acoustic impedance of the material under test and the current detection signal; thus, the sound velocity and acoustic impedance of the material under test can be analyzed based on the current detection signal.

[0148] Optionally, in another embodiment of this application, one specific implementation of step S105 is as follows: Figure 6 As shown, it includes:

[0149] S601. Determine whether the material to be tested is a transparent material.

[0150] It should be noted that for transparent materials where the light penetration depth is greater than the ultrasonic wavelength, the transmitted femtosecond laser ultrasound will generate a Brillouin oscillation signal within the transparent film. The sound velocity of the material under test can be obtained by the oscillation frequency of the Brillouin oscillation signal. Therefore, for transparent materials, the sound velocity of the material under test can be analyzed based on the Brillouin oscillation signal. So if the material under test is transparent, proceed to step S602. If the material under test is not transparent, since it will not generate a Brillouin oscillation signal, another method needs to be used for analysis, so proceed to step S603.

[0151] S602. Obtain the oscillation frequency of the Brillouin oscillation signal in the current detection signal.

[0152] It should be noted that the current detection signal obtained for transparent materials will include a Brillouin oscillation signal, i.e., a Brillouin oscillation signal, for example, such as... Figure 7 The acoustic signal detected for activated carbon showed Brillouin oscillations, so the Brillouin oscillation signal can be determined from the detected signal. Then, a Fourier transform is performed on the Brillouin oscillation signal to obtain its oscillation frequency.

[0153] S603. Calculate the sound velocity of the material under test using the oscillation frequency of the Brillouin oscillation signal.

[0154] It should be noted that the relationship between the oscillation frequency of the Brillouin oscillation signal and the sound velocity of the material under test is as follows:

[0155]

[0156] in, The velocity of sound in the material being tested. To detect the wavelength of light, where n is the refractive index of the material. This represents the angle between the incident light and the direction of ultrasound propagation in free space. Because... and Since it is related to the femtosecond laser ultrasound system, it is a known quantity. The refractive index n is also a known quantity. Therefore, the Brillouin oscillation signal is processed by FFT to obtain its oscillation frequency, and then substituted into the above formula to calculate the sound velocity of the material under test.

[0157] S604. Determine the echo time based on the current detection signal.

[0158] For non-transparent materials, femtosecond laser ultrasound cannot excite Brillouin oscillations within the material, thus making it impossible to directly obtain sound velocity information from the Brillouin oscillations. Therefore, in this embodiment, the sound velocity of a non-transparent material is characterized by the arrival time of the echo. The arrival time is determined by the material thickness (L) and the sound velocity (v). The material thickness (L) can be measured using other methods, such as X-ray. The echo time can be obtained from the current detection signal, i.e., the echo signal is determined and its time is obtained. Subsequently, the acquired echo time (v) is used to characterize the sound velocity of the material. The velocity of sound is calculated from the material thickness (L).

[0159] S605. Divide twice the thickness of the material under test by the echo time to obtain the sound velocity of the material under test.

[0160] It should be noted that the sound velocity of the material under test is related to its thickness and echo time by the following relationship: Therefore, the sound velocity of the material under test can be calculated using this relationship.

[0161]

[0162] S606. Obtain the amplitude of the interface echo signal from the current detection signal, and calculate the acoustic impedance of the material under test based on the amplitude of the interface echo signal and the acoustic impedance of the substrate material.

[0163] It should be noted that the calculation principle of the acoustic impedance of the material under test is the same as... Figure 4 The principle behind calculating the acoustic impedance of the anomalous crystallization region is the same. The only difference is that the acoustic impedance of the normally crystallized region becomes that of the material under test, which needs to be addressed, while the reflected echo signal changes from the anomalous crystallization region to the next layer of material. Therefore, the acoustic impedance of the anomalous crystallization region becomes the known acoustic impedance of the substrate material. Thus, the acoustic impedance of the material under test can be calculated using this known information. In other words, the relationship between the amplitude of the interface echo signal and the acoustic impedance of the material under test is expressed as:

[0164]

[0165] in, This represents the amplitude of the interface echo signal. Since the signal amplitude A in the normal crystallization region can be obtained through calculation, or by using the same standard to obtain the standard ultrasonic amplitude A, ... This represents the acoustic impedance of the substrate material, which is a constant. Therefore, the acoustic impedance of the material under test can be calculated using the above method. .

[0166] S106. Calculate the Young's modulus of the material under test using the sound velocity and acoustic impedance, and output the Young's modulus of the material under test as a quantitative index of the crystallization state of the material under test.

[0167] Since the changes in the properties of the abnormal crystalline regions within the test material can be attributed to changes in the Young's modulus, the Young's modulus of the test material can be calculated using the sound velocity and acoustic impedance. This Young's modulus can then be used as a quantitative indicator of the crystallinity of the test material, thus quantitatively characterizing its specific crystallinity. A higher Young's modulus indicates higher crystallinity.

[0168] Optionally, in another embodiment of this application, one specific implementation of step S107 includes:

[0169] The Young's modulus of the material under test is calculated based on the Poisson's ratio, the sound velocity of the material under test, and the acoustic impedance of the material under test.

[0170] Therefore, the specific formula for calculating the Young's modulus of the material to be tested is as follows:

[0171]

[0172] in, The Poisson's ratio of the material to be tested can be obtained in advance through appropriate methods; The acoustic impedance of the material under test is... denoted as , where is the sound velocity of the material being tested.

[0173] S107. Based on the current detection signal, obtain the amplitude of the two echo signals, and use the ratio of the amplitude of the two echo signals to calculate the attenuation parameter of the echo, and output the attenuation parameter as a quantitative index of the crystallization state of the material under test.

[0174] It should be noted that when the sound velocity of the material under test cannot be accurately obtained, the relative ultrasonic attenuation coefficient is used to characterize the crystallization state in this embodiment. Because the increase in grain size or crystallization inhomogeneity within the internal crystals leads to greater ultrasonic attenuation, the attenuation parameter of the ultrasonic echo can be measured to characterize the internal crystallization properties. Therefore, the signals of two adjacent echoes of the material are detected, and the attenuation parameter of the second echo signal relative to the first echo signal is analyzed based on the ratio of their amplitudes. That is, the attenuation parameter is analyzed based on the attenuation of the echo signal amplitude, and then output as a quantitative index of the crystallization state of the material under test. This quantitative characterization of the crystallization state of the material under test serves as an indicator of the degree of crystallinity. A larger attenuation parameter indicates a higher degree of crystallinity in the material under test.

[0175] Specifically, by using a femtosecond laser ultrasonic system to excite ultrasound on a material surface, multiple reflected echoes from the interface can be obtained simultaneously when the excitation energy is sufficient. For example, ... Figure 8 As shown in the left figure, the excited ultrasound can acquire two reflected echoes from the interface. Therefore, the signals of these two reflected echoes can be obtained from the detected signal, such as... Figure 8 As shown in the right figure, the detected signal curve contains two echo signals. Therefore, the amplitudes of the two echo signals can be obtained from the current detected signal, and the attenuation parameter of the echo can be calculated using the ratio of the amplitudes of the two echo signals.

[0176] Optionally, in another embodiment of this application, one specific implementation of step S108 is as follows: Figure 9 As shown, it includes:

[0177] S901. Determine whether the current detection signal contains two echo signals.

[0178] It should be noted that, considering that multiple reflected echoes cannot be obtained in some cases, such as when the excitation capability is insufficient, it is necessary to determine whether the current detection signal contains at least two echo signals, and then take the appropriate steps to analyze them.

[0179] If the current detected signal contains two echo signals, then step S902 can be executed. If the current detected signal contains only one echo signal, then step S904 can be executed.

[0180] S902. Extract the amplitudes of two adjacent echo signals from the current detection signal as the first echo amplitude and the second echo amplitude.

[0181] Specifically, the amplitudes of two adjacent echo signals are extracted from the current detection signal and used as the first echo amplitude and the second echo amplitude. For example, the amplitudes of the first and second echo signals can be used as the first echo amplitude and the second echo amplitude, respectively. Similarly, the amplitudes of the second and third interface echo signals can be used as the first echo amplitude and the second echo amplitude, respectively.

[0182] S903. Calculate the attenuation coefficient of the echo using the ratio of the first echo amplitude to the second echo amplitude, the thickness of the film to be measured, and the ultrasonic reflectivity.

[0183] The relationship between the ratio of the amplitudes of the two echo signals and the attenuation coefficient of the echo is shown below:

[0184]

[0185] Where R is the ultrasonic reflectivity, which is related to the material structure and is therefore a constant; L is the thickness of the material to be measured, which can also be obtained using methods such as X-ray. Therefore, L is a measurable known quantity, R is a constant, and by combining the ratio of the amplitudes of the two echo signals, the attenuation coefficient α of the echo can be obtained.

[0186] S904. Extract the amplitude of the first echo signal from the current detection signal and use it as the amplitude of the third echo.

[0187] Since there is only one transmitted echo at this time, the amplitude of the only echo signal is extracted from the current detection signal and used as the amplitude of the third echo.

[0188] S905. A pump light is emitted to the standard sample to excite ultrasound, and a probe light is emitted to the standard sample for ultrasonic detection to obtain the amplitude of the echo signal of the standard sample, which is used as the fourth echo amplitude.

[0189] Since there is only one echo signal at this time, it is impossible to obtain the amplitude attenuation from the two echo signals. Therefore, in this embodiment, a standard sample with uniform crystallization is prepared. Similar to the detection of the material to be tested, pump light is emitted towards this sample to excite an ultrasonic signal on the sample, and probe light is emitted towards the sample for ultrasonic detection, thereby obtaining the amplitude of the standard ultrasonic echo signal. This is used as the fourth echo amplitude. Because the crystals of the standard sheet are uniform, by comparing the amplitude of the standard ultrasonic echo signal with the amplitude of the echo signal of the material under test, the change in amplitude caused by abnormal crystallization in the material under test can be obtained, and thus the attenuation coefficient caused by abnormal crystallization in the material under test can be obtained.

[0190] S906. Using the ratio of the third echo amplitude to the fourth echo amplitude and the thickness of the film to be measured, the change in the attenuation coefficient of the echo is calculated.

[0191] It should be noted that the same system parameters are required to excite ultrasonic signals on the material under test to obtain the amplitude of the ultrasonic echo. That is, the amplitude of the third echo is obtained, and the change in the attenuation coefficient can be expressed as:

[0192]

[0193] Therefore, this application provides three schemes for measuring the crystallization state of materials. These three schemes can be selected according to the execution process as described in the above embodiments to analyze the parameters characterizing the crystallization state. Alternatively, one scheme can be selected and executed individually based on the actual situation and needs.

[0194] Furthermore, all three methods can perform one-dimensional and two-dimensional scanning on the same material, that is, scanning along a one-dimensional line or in a two-dimensional plane, thereby obtaining changes in the crystallization state of the entire sample. For example, Figure 10As shown in the left figure, a one-dimensional scan of the material under test is performed along the x-axis, and the signals of each scanned point are sorted according to their position. This yields the following results: Figure 10 The signal diagram shown is a one-dimensional scan of the material. When the properties of the crystalline region change significantly, a smaller echo will be generated in the abnormal crystalline region. Therefore, the one-dimensional scan of the material can reveal the signal within the abnormal crystalline region, and the location of the abnormal crystalline region can be determined by the position coordinates corresponding to the signal. If the properties of the crystalline region do not change significantly, the location of the abnormal crystalline region can be determined by the amplitude and arrival time of the interface echo signal.

[0195] To verify the method provided in the embodiments of this application, a femtosecond laser ultrasonic system was used to measure amorphous carbon (a-Carbon) wafers of the same thickness (L) under different crystal states, thereby obtaining the following results: Figure 11 The detection signal is shown in Figure (a). Among them, the amorphous carbon wafers in different crystal states are controlled by different temperatures. The higher the temperature, the greater the crystallinity, the greater the density, the lower the sound velocity, and the greater the attenuation.

[0196] Because of the existence of Brillouin oscillations, the speed of sound can be calculated using these signals. Specifically, for amorphous carbon wafers at different temperatures, such as the baseline temperature, and amorphous carbon wafers at the baseline temperature plus or minus 5° and 10°, the calculated relationship between the speed of sound and temperature / crystallinity is as follows: Figure 11 As shown in Figure (b), a negative linear relationship exists, which is consistent with reality: the higher the temperature and density, the lower the sound velocity. Then, using the echo amplitude, the acoustic impedance can be calculated, and thus the Young's modulus can be calculated based on the acoustic impedance and sound velocity, as detailed below. Figure 11 As shown in Figure (c), the calculated Young's modulus also exhibits a negative linear relationship with crystallinity.

[0197] The crystallinity can also be characterized using the attenuation coefficient in this experiment. Specifically, parameters such as... Figure 11 The detected signal is shown in Figure (a). Furthermore, the signal amplitude measured under the same system parameters at a standard base temperature needs to be used as the standard amplitude. The attenuation coefficient was then obtained by comparing the signal amplitude to the standard amplitude at other temperatures. Since the material thickness (L) was consistently 2.82 μm, the attenuation coefficient was calculated using the method described above. The specific relationship between the obtained attenuation coefficient and crystallinity is as follows... Figure 12 As shown, there is a positive linear relationship between the attenuation coefficient and the degree of crystallinity, which is consistent with the actual results. That is, the higher the temperature, the greater the degree of crystallinity, the greater the density, and the greater the attenuation.

[0198] This application provides a method for measuring the crystallization state of a film layer. It involves exciting ultrasound at any scanning point of the material under test using a pump light, and then emitting a probe light at the same scanning point for ultrasonic detection. This method effectively measures the film layer by exciting ultrasound waves with the pump light and performing ultrasonic detection with the probe wave. When the signal-to-noise ratio (SNR) of the current detection signal is greater than a decibel threshold, the acoustic impedance of the abnormal crystallization region is analyzed based on the current detection signal. The decibel threshold is the SNR of the echo signal from the detected abnormal crystallization region in decibels. When a significant change in crystallization state occurs, the acoustic impedance of the abnormal region with the significant crystallization change is output, accurately reflecting its crystallization state. When the SNR of the current detection signal is not greater than the decibel threshold, the sound velocity and acoustic impedance of the material under test are analyzed based on the current detection signal. The Young's modulus of the material under test is calculated using the sound velocity and acoustic impedance, and this Young's modulus is output as a quantitative indicator of the crystallization state of the material under test. Therefore, when there is no significant change in the crystallization state, the Young's modulus of the test material can be calculated to quantify the property changes in abnormal crystallization regions, meaning that the property changes in abnormal crystallization regions can be attributed to changes in the material's Young's modulus. When the sound velocity of the test material cannot be analyzed, the amplitudes of two echo signals are obtained based on the current detection signal, and the attenuation parameter of the echo is calculated using the ratio of the amplitudes of the two echo signals. This attenuation parameter is then output as a quantitative indicator of the crystallization state of the test material. Thus, even when the sound velocity of the test material cannot be obtained, the attenuation of multiple echoes based on the crystallization state allows for the analysis of the echo attenuation parameter to quantify the crystallization state, thereby realizing a method for accurately measuring various crystallization states of a film layer.

[0199] Another embodiment of this application provides a device for measuring the crystallization state of a film layer, such as... Figure 13 As shown, it includes:

[0200] The ultrasonic testing unit 1301 is used to excite ultrasound at any scanning point of the material under test by pumping light, and then emit probe light to the same scanning point to perform ultrasonic testing and obtain the current detection signal.

[0201] The first information acquisition unit 1302 is used to analyze the acoustic impedance of the abnormal crystallization region based on the current detection signal when the signal-to-noise ratio of the current detection signal is greater than a decibel threshold. The decibel threshold is the decibel threshold representing the signal-to-noise ratio of the echo signal from the detected abnormal crystallization region.

[0202] The abnormal crystallization indicator unit 1303 is used to indicate the degree of abnormal crystallization of the material under test by utilizing the acoustic impedance of the abnormal crystallization region.

[0203] The information analysis and acquisition unit 1304 is used to analyze the sound velocity and acoustic impedance of the material under test based on the current detection signal when the signal-to-noise ratio of the current detection signal is not greater than the decibel threshold.

[0204] The Young's modulus calculation unit 1305 is used to calculate the Young's modulus of the material under test using the sound velocity and acoustic impedance of the material under test, and outputs the Young's modulus of the material under test as a quantitative index of the crystallization state of the material under test.

[0205] The attenuation parameter calculation unit 1306 is used to obtain the amplitude of two echo signals based on the current detection signal when the sound velocity of the material under test cannot be analyzed, and to calculate the attenuation parameter of the echo using the ratio of the amplitude of the two echo signals. The attenuation parameter is then output as a quantitative index of the crystallization state of the material under test.

[0206] Optionally, in another embodiment of the measuring device for the crystallization state of a film provided in this application, the acoustic impedance calculation unit includes:

[0207] The basic information acquisition unit is used to obtain the signal amplitude of the abnormal crystallization region from the current detection signal.

[0208] The second information acquisition unit is used to acquire the acoustic impedance of the normal crystalline region of the material under test. The acoustic impedance of the normal crystalline region of the material under test is obtained by multiplying the density of the normal crystalline region of the material under test by the sound velocity.

[0209] The first calculation unit is used to calculate the acoustic impedance of the abnormal crystallization region based on the signal amplitude of the normal crystallization region, the signal amplitude of the abnormal crystallization region, and the acoustic impedance of the normal crystallization region.

[0210] The formula for calculating the acoustic impedance of the abnormal crystallization region is as follows: A represents the signal amplitude in the abnormal crystallization region. A represents the signal amplitude in the normal crystallization region. This represents the acoustic impedance of the normal crystallization region. This indicates the acoustic impedance of the abnormal crystallization region.

[0211] Optionally, in another embodiment of the measuring device for the crystallization state of a film provided in this application, the device further includes:

[0212] The location calculation unit is used to calculate the location data of the abnormal crystallization region by using the arrival time of the reflected signal of the abnormal crystallization region, and output the location of the abnormal crystallization region.

[0213] Optionally, in another embodiment of the measuring device for the crystallization state of a film provided in this application, the position calculation unit includes:

[0214] The third information acquisition unit is used to acquire the sound velocity in the normal crystallization region of the material under test.

[0215] The second calculation unit is used to calculate the distance between the upper surface of the abnormal crystallization region and the surface of the material to be tested based on the sound velocity in the normal crystallization region and the arrival time of the reflected signal in the abnormal crystallization region.

[0216] The formula for calculating the distance between the upper surface of the abnormal crystallization region and the surface of the material under test is as follows: This represents the sound velocity in the normal crystallization region of the material being tested. This indicates the arrival time of the reflected signal from the abnormal crystallization region.

[0217] Optionally, in another embodiment of the measuring device for the crystallization state of a film provided in this application, the information analysis and acquisition unit includes:

[0218] The fourth information acquisition unit is used to acquire the oscillation frequency of the Brillouin oscillation signal in the current detection signal when the material to be tested is a transparent material.

[0219] The third calculation unit is used to calculate the sound velocity of the material under test using the oscillation frequency of the Brillouin oscillation signal.

[0220] The time determination unit is used to determine the echo time based on the current detection signal when the material under test is a non-transparent material.

[0221] The third calculation unit is used to divide twice the thickness of the material under test by the echo time to obtain the sound velocity of the material under test.

[0222] The fourth calculation unit is used to obtain the amplitude of the interface echo signal from the current detection signal, and calculate the acoustic impedance of the material under test based on the amplitude of the interface echo signal and the acoustic impedance of the substrate material.

[0223] Optionally, in another embodiment of the measuring device for the crystallization state of a film provided in this application, the Young's modulus calculation unit includes:

[0224] The fifth calculation unit is used to calculate the Young's modulus of the material under test based on the Poisson's ratio, the sound velocity of the material under test, and the acoustic impedance of the material under test.

[0225] The formula for calculating the Young's modulus of the material to be tested is as follows: The Poisson's ratio of the material being tested. The acoustic impedance of the material under test is... denoted as , where is the sound velocity of the material being tested.

[0226] Optionally, in another embodiment of the measuring device for the crystallization state of a film layer provided in this application, the attenuation parameter calculation unit includes:

[0227] The first advance unit is used to extract the amplitudes of two adjacent echo signals from the current detection signal as the first echo amplitude and the second echo amplitude when the current detection signal contains two echo signals.

[0228] The sixth calculation unit is used to calculate the attenuation coefficient of the echo using the ratio of the first echo amplitude to the second echo amplitude, the thickness of the film to be measured, and the ultrasonic reflectivity.

[0229] The second extraction unit is used to extract the amplitude of a single echo signal from the current detection signal when the current detection signal contains only one echo signal, and use it as the amplitude of the third echo signal.

[0230] The sample detection unit is used to emit pump light to the standard sample to excite ultrasound, and to emit probe light to the standard sample for ultrasonic detection, so as to obtain the amplitude of the echo signal of the standard sample as the fourth echo amplitude.

[0231] The seventh calculation unit is used to calculate the change in the attenuation coefficient of the echo using the ratio of the third echo amplitude value to the fourth echo amplitude value and the thickness of the film layer to be measured.

[0232] Optionally, in another embodiment of the measuring device for the crystallization state of a film provided in this application, the ultrasonic detection unit includes:

[0233] The ultrasonic testing subunit is used to sequentially generate ultrasound at each scanning point on the surface of the material under test by using a pump light beam, and to perform ultrasonic testing by controlling the probe light to focus on the scanning point through a delay line, thereby obtaining the current detection signal.

[0234] It should be noted that the specific working process of each unit provided in the above embodiments of this application can be referred to the implementation process of the corresponding steps in the above method embodiments, and will not be repeated here.

[0235] Another embodiment of this application provides an electronic device, such as... Figure 14 As shown, it includes:

[0236] Memory 1401 and processor 1402.

[0237] The memory 1401 is used to store the program.

[0238] The processor 1402 is used to execute a program stored in the memory 1401, which, when executed, is specifically used to implement the method for measuring the crystallization state of the film layer as provided in any of the above embodiments.

[0239] Another embodiment of this application provides a computer storage medium for storing a computer program, which, when executed by a processor, is used to implement the method for measuring the crystallization state of a film layer as provided in any of the above embodiments.

[0240] Computer storage media, including both permanent and non-permanent, removable and non-removable media, can store information using any method or technology. Information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random-access memory (SRAM), dynamic random-access memory (DRAM), other types of random-access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other storage technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0241] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0242] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for measuring the crystallization state of a film, characterized in that, include: By exciting ultrasound at any scanning point of the material under test with pump light, and then emitting probe light at the same scanning point to perform ultrasonic detection, the current detection signal is obtained. If the signal-to-noise ratio of the current detected signal is greater than a decibel threshold, the acoustic impedance of the abnormal crystallization region is analyzed based on the current detected signal; wherein, the decibel threshold is the decibel threshold of the signal-to-noise ratio of the echo signal detected in the abnormal crystallization region; The acoustic impedance of the abnormal crystallization region is used to indicate the degree of abnormal crystallization in the test material. If the signal-to-noise ratio of the current detection signal is not greater than the decibel threshold, then the sound velocity and acoustic impedance of the material under test are analyzed based on the current detection signal. The Young's modulus of the material under test is calculated using the sound velocity and acoustic impedance of the material under test, and the Young's modulus of the material under test is output as a quantitative index of the crystallization state of the material under test. If the sound velocity of the material under test cannot be analyzed, the amplitude of the two echo signals is obtained based on the current detection signal, and the attenuation parameter of the echo is calculated using the ratio of the amplitude of the two echo signals. The attenuation parameter is then output as a quantitative index of the crystallization state of the material under test.

2. The method according to claim 1, characterized in that, The analysis of the acoustic impedance of the abnormal crystallization region based on the current detection signal includes: Obtain the signal amplitude of the abnormal crystallization region from the current detection signal; The acoustic impedance of the normal crystalline region of the test material and the signal amplitude of the normal crystalline region are obtained; wherein, the acoustic impedance of the normal crystalline region of the test material is obtained by multiplying the density of the normal crystalline region of the test material by the sound velocity; The acoustic impedance of the abnormal crystallization region is calculated based on the signal amplitude of the normal crystallization region, the signal amplitude of the abnormal crystallization region, and the acoustic impedance of the normal crystallization region. The formula for calculating the acoustic impedance of the abnormal crystallization region is as follows: ; A represents the signal amplitude in the abnormal crystallization region; A represents the signal amplitude in the normal crystallization region. Indicates the acoustic impedance of the normal crystallization region; This indicates the acoustic impedance of the abnormal crystallization region.

3. The method according to claim 1, characterized in that, If the signal-to-noise ratio of the currently detected signal is greater than a decibel threshold, the method further includes: Based on the current detection signal, the arrival time of the reflected signal of the abnormal crystallization region is analyzed, and the location data of the abnormal crystallization region is calculated using the arrival time of the reflected signal of the abnormal crystallization region, and the location of the abnormal crystallization region is output.

4. The method according to claim 3, characterized in that, The step of calculating the location data of the abnormal crystallization region using the arrival time of the reflected signal from the abnormal crystallization region includes: Obtain the sound velocity in the normal crystallization region of the material under test; The distance between the upper surface of the abnormal crystallization region and the surface of the material under test is calculated based on the sound velocity in the normal crystallization region and the arrival time of the reflected signal in the abnormal crystallization region. The formula for calculating the distance between the upper surface of the abnormal crystallization region and the surface of the material to be tested is as follows: ; This represents the sound velocity in the normal crystallization region of the material under test. This indicates the arrival time of the reflected signal from the abnormal crystallization region.

5. The method according to claim 1, characterized in that, The analysis of the sound velocity and acoustic impedance of the material under test based on the current detection signal includes: If the material to be tested is a transparent material, then obtain the oscillation frequency of the Brillouin oscillation signal in the current detection signal; The velocity of sound in the material under test is calculated using the oscillation frequency of the Brillouin oscillation signal. If the material to be tested is a non-transparent material, the echo time is determined based on the current detection signal; The sound velocity of the material under test is obtained by dividing twice the thickness of the material under test by the echo time. The amplitude of the interface echo signal is obtained from the current detection signal, and the acoustic impedance of the material under test is calculated based on the amplitude of the interface echo signal and the acoustic impedance of the substrate material.

6. The method according to claim 1, characterized in that, The calculation of the Young's modulus of the material under test using the sound velocity and acoustic impedance of the material under test includes: The Young's modulus of the material under test is calculated based on the Poisson's ratio, the sound velocity of the material under test, and the acoustic impedance of the material under test. The formula for calculating the Young's modulus of the material to be tested is as follows: ; The Poisson's ratio of the material to be tested. The acoustic impedance of the material under test is given. is the sound velocity of the material to be tested.

7. The method according to claim 1, characterized in that, The step of acquiring the amplitudes of two echo signals based on the current detection signal and calculating the echo attenuation parameter using the ratio of the amplitudes of the two echo signals includes: If the current detection signal contains two echo signals, then the amplitudes of the two adjacent echo signals are extracted from the current detection signal as the first echo amplitude and the second echo amplitude. The attenuation coefficient of the echo is calculated using the ratio of the first echo amplitude to the second echo amplitude, the thickness of the film to be measured, and the ultrasonic reflectivity. If the current detection signal contains only one echo signal, then the amplitude of the first echo signal is extracted from the current detection signal and used as the third echo amplitude. Pump light is emitted towards a standard sample to excite ultrasound, and probe light is emitted towards the standard sample for ultrasonic detection to obtain the amplitude of the echo signal of the standard sample, which is used as the fourth echo amplitude. The change in the attenuation coefficient of the echo is calculated using the ratio of the third echo amplitude value to the fourth echo amplitude value and the thickness of the film layer to be measured.

8. The method according to claim 1, characterized in that, The process of exciting ultrasound at any scanning point of the material under test with pump light and then emitting probe light at the same scanning point for ultrasonic detection includes: For each scanning point of the material under test, an ultrasonic wave is excited at the scanning point on the surface of the material under test by a pump light beam, and the probe light is focused on the scanning point by a delay line to perform ultrasonic detection and obtain the current detection signal.

9. A measuring device for the crystallization state of a film layer, characterized in that, include: The ultrasonic testing unit is used to excite ultrasound at any scanning point of the material under test by pumping light, and then emit probe light to the same scanning point to perform ultrasonic testing and obtain the current detection signal. The first information acquisition unit is used to analyze the acoustic impedance of the abnormal crystallization region based on the current detection signal when the signal-to-noise ratio of the current detection signal is greater than a decibel threshold; wherein, the decibel threshold is a decibel threshold for the signal-to-noise ratio of the echo signal of the detected abnormal crystallization region; An abnormal crystallization indicator unit is used to indicate the degree of abnormal crystallization of the material under test by utilizing the acoustic impedance of the abnormal crystallization region. The information analysis and acquisition unit is used to analyze the sound velocity and acoustic impedance of the material under test based on the current detection signal when the signal-to-noise ratio of the current detection signal is not greater than a decibel threshold. The Young's modulus calculation unit is used to calculate the Young's modulus of the material under test using the sound velocity and acoustic impedance of the material under test, and output the Young's modulus of the material under test as a quantitative index of the crystallization state of the material under test. The attenuation parameter calculation unit is used to obtain the amplitude of two echo signals based on the current detection signal when the sound velocity of the material under test cannot be analyzed, and to calculate the attenuation parameter of the echo using the ratio of the amplitude of the two echo signals, and output the attenuation parameter as a quantitative index of the crystallization state of the material under test.

10. The measuring device according to claim 9, characterized in that, Also includes: The location calculation unit is used to calculate the location data of the abnormal crystallization region using the arrival time of the reflected signal of the abnormal crystallization region, and output the location of the abnormal crystallization region.

11. An electronic device, characterized in that, include: Memory and processor; The memory is used to store programs; The processor is used to execute the program, which, when executed, is specifically used to implement the method for measuring the crystallization state of the film as described in any one of claims 1 to 8.

12. A computer storage medium, characterized in that, Used to store a computer program, which, when executed by a processor, is used to implement the method for measuring the crystallization state of a film as described in any one of claims 1 to 8.

Images