CN-121595476-B - Film crystallization state measuring method, related device and storage medium

CN121595476BCN 121595476 BCN121595476 BCN 121595476BCN-121595476-B

Abstract

The application discloses a method for measuring a crystallization state of a film layer, a related device and a storage medium, wherein the method comprises the steps of exciting ultrasonic waves to a material to be measured through pumping light, and then emitting detection light to the same point for ultrasonic detection to obtain a current detection signal; if the signal to noise ratio of the current detection signal is larger than a decibel threshold value, the abnormal crystallization degree of the material to be detected is indicated from the acoustic impedance of the abnormal crystallization area based on the detection signal, if the signal to noise ratio of the current detection signal is not larger than the decibel threshold value, the sound velocity and the acoustic impedance of the material to be detected are analyzed based on the current detection signal, the Young modulus of the material to be detected is calculated by using the sound velocity and the acoustic impedance of the material to be detected and is output as a quantization index of the crystallization state of the material to be detected, if the sound velocity of the material to be detected cannot be analyzed, the amplitude of the echo signal is obtained twice based on the current detection signal, the attenuation parameter of the echo is calculated by using the ratio of the amplitude of the echo signal twice, and the attenuation parameter is output as the quantization index of the crystallization state of the material to be detected.

Inventors

BAI YUANYUAN
MA YANZHONG
SUN TAO
DAI LUNAN
CUI SHUHAN
CHEN LU

Assignees

广州中科飞测科技有限公司

Dates

Publication Date: 20260508
Application Date: 20260129

Claims (12)

1. The method for measuring the crystallization state of the film layer is characterized by comprising the following steps of: Exciting ultrasound by pumping light to any scanning point position of the material to be detected, and then emitting detection light to the same scanning point position for ultrasonic detection to obtain a current detection signal; if the signal-to-noise ratio of the current detection signal is larger than a decibel threshold, analyzing the acoustic impedance of an abnormal crystallization area based on the current detection signal, wherein the decibel threshold is the decibel threshold of the signal-to-noise ratio of an echo signal of the abnormal crystallization area; indicating the degree of abnormal crystallization of the material to be detected by utilizing the acoustic impedance of the abnormal crystallization area; if the signal-to-noise ratio of the current detection signal is not greater than the decibel threshold, analyzing the sound velocity and the acoustic impedance of the material to be detected based on the current detection signal; Calculating the Young modulus of the material to be measured by utilizing the sound velocity and the acoustic impedance of the material to be measured, and outputting the Young modulus of the material to be measured as a quantization index of the crystallization state of the material to be measured; If the sound velocity of the material to be tested cannot be analyzed, acquiring the amplitude values of the two echo signals based on the current detection signal, calculating the attenuation parameter of the echo by using the ratio of the amplitude values of the two echo signals, and outputting the attenuation parameter as a quantization index of the crystallization state of the material to be tested.
2. The method of claim 1, wherein analyzing the acoustic impedance of the abnormal crystalline region based on the current detection signal comprises: acquiring a signal amplitude of the abnormal crystallization area from the current detection signal; obtaining the acoustic impedance of a normal crystallization area of the material to be detected and the signal amplitude of the normal crystallization area, wherein the acoustic impedance of the normal crystallization area of the material to be detected is obtained by multiplying the density of the normal crystallization area of the material to be detected by the sound velocity; Calculating the acoustic impedance of the abnormal crystallization area according to the signal amplitude of the normal crystallization area, the signal amplitude of the abnormal crystallization area and the acoustic impedance of the normal crystallization area; the calculation formula of the acoustic impedance of the abnormal crystallization area is as follows: ; a is the signal amplitude of the normal crystallization area; An acoustic impedance representing a normal crystalline region; Representing the acoustic impedance of the abnormal crystalline region.
3. The method of claim 1, wherein if the signal-to-noise ratio of the current detected signal is greater than a decibel threshold, the method further comprises: Analyzing the arrival time of the reflected signal of the abnormal crystallization area based on the current detection signal, calculating the position data of the abnormal crystallization area by using the arrival time of the reflected signal of the abnormal crystallization area, and outputting the position of the abnormal crystallization area.
4. The method of claim 3, wherein calculating the positional data of the abnormal crystal region using the arrival time of the reflected signal of the abnormal crystal region comprises: acquiring sound velocity of a normal crystallization area of the material to be detected; Calculating the distance between the upper surface of the abnormal crystallization area and the surface of the material to be measured according to the sound velocity of the normal crystallization area and the arrival time of the reflected signal of the abnormal crystallization area; Wherein, the calculation formula of the distance between the upper surface of the abnormal crystallization area and the surface of the material to be measured is as follows: ; representing the sound velocity of the normal crystalline region of the material under test, And the arrival time of the reflected signal of the abnormal crystallization area is represented.
5. The method of claim 1, wherein analyzing the sound speed and acoustic impedance of the material under test based on the current detection signal comprises: If the material to be detected is a transparent material, acquiring the oscillation frequency of a Brillouin oscillation signal in the current detection signal; Calculating the sound velocity of the material to be measured by using the oscillation frequency of the Brillouin oscillation signal; If the material to be detected is a non-transparent material, determining echo time based on the current detection signal; dividing the thickness of the material to be measured by the echo time to obtain the sound velocity of the material to be measured; and acquiring the amplitude of an interface echo signal from the current detection signal, and calculating the acoustic impedance of the material to be detected based on the amplitude of the interface echo signal and the acoustic impedance of the base material.
6. The method of claim 1, wherein calculating the young's modulus of the material to be measured using the sound speed and acoustic impedance of the material to be measured comprises: calculating to obtain Young modulus of the material to be measured according to the Poisson's ratio of the material to be measured, the sound velocity of the material to be measured and the acoustic impedance of the material to be measured; the calculation formula of Young modulus of the material to be measured is as follows: ; for the poisson's ratio of the material to be tested, For the acoustic impedance of the material to be measured, Is the sound velocity of the material to be measured.
7. The method of claim 1, wherein the acquiring the amplitudes of the 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 comprises: If the current detection signal contains two echo signals, extracting the amplitude values of two adjacent echo signals from the current detection signal as a first echo amplitude value and a second echo amplitude value; calculating an attenuation coefficient of the echo by using the ratio of the first echo amplitude to the second echo amplitude, the thickness of the film to be detected and the ultrasonic reflectivity; if the current detection signal only contains one echo signal, extracting the amplitude of the one echo signal from the current detection signal to be used as a third echo amplitude; Transmitting pumping light to a standard sample to excite ultrasound by the pumping light, and transmitting detection light to the standard sample to carry out ultrasonic detection to obtain the amplitude of an echo signal of the standard sample as a fourth echo amplitude; And calculating the variation of the attenuation coefficient of the echo by using the ratio of the third echo amplitude value to the fourth echo amplitude value and the thickness of the film layer to be detected.
8. The method according to claim 1, wherein the exciting the ultrasonic wave by the pumping light to any one scanning point location of the material to be tested and then emitting the probe light to the same scanning point location for ultrasonic detection comprises: And aiming at each scanning point position of the material to be detected, exciting ultrasonic waves at the scanning point position on the surface of the material to be detected through a beam of pumping light, and controlling the probe light to focus to the scanning point position through a delay line to carry out ultrasonic detection so as to obtain a current detection signal.
9. A device for measuring the crystalline state of a film, comprising: The ultrasonic detection unit is used for exciting ultrasonic waves to any scanning point position of the material to be detected through pumping light, and then emitting detection light to the same scanning point position for ultrasonic detection to obtain a current detection signal; The first information acquisition unit is used for analyzing the acoustic impedance of the abnormal crystallization area based on the current detection signal when the signal-to-noise ratio of the current detection signal is larger than a decibel threshold, wherein the decibel threshold is the decibel threshold of the signal-to-noise ratio of the echo signal of the abnormal crystallization area; An abnormal crystallization indication unit for indicating the degree of abnormal crystallization of the material to be measured by using the acoustic impedance of the abnormal crystallization region; The information analysis acquisition unit is used for analyzing the sound velocity and the acoustic impedance of the material to be detected 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 modulus calculation unit is used for calculating the Young modulus of the material to be measured by utilizing the sound velocity and the acoustic impedance of the material to be measured, and outputting the Young modulus of the material to be measured as a quantization index of the crystallization state of the material to be measured; And the attenuation parameter calculation unit is used for acquiring the amplitude of the echo signals twice based on the current detection signal when the sound velocity of the material to be detected cannot be analyzed, calculating the attenuation parameter of the echo by utilizing the ratio of the amplitude of the echo signals twice, and outputting the attenuation parameter as a quantization index of the crystallization state of the material to be detected.
10. The measurement device of claim 9, further comprising: And a position calculation unit for calculating position data of the abnormal crystallization region by using the arrival time of the reflected signal of the abnormal crystallization region and outputting the position of the abnormal crystallization region.
11. An electronic device, comprising: A memory and a processor; wherein the memory is used for storing programs; The processor is configured to execute the program, and when the program is executed, the program is specifically configured to implement the method for measuring a crystallization state of a film layer according to any one of claims 1 to 8.
12. A computer storage medium for storing a computer program which, when executed by a processor, is adapted to carry out a method of measuring the crystalline state of a film according to any one of claims 1 to 8.

Description

Film crystallization state measuring method, related device and storage medium Technical Field The present application relates to a method for measuring a crystallization state of a film coated on a wafer surface, and more particularly, to a method for measuring a crystallization state of a film layer, a related apparatus, and a storage medium. Background The crystallization state of the surface film layer of the wafer affects the etching rate and the like in the IC manufacturing process, so that the crystallization condition of the material can be accurately measured to determine the quality condition of the surface film layer, and the method is particularly important for the production and the use of the wafer. Current measurements of the crystalline state of a material are mainly made by ultrasound to detect the crystallinity of the material. Specifically, the method mainly adopts the traditional ultrasonic technology to directly excite megahertz-level ultrasonic waves to the material to be measured, and measures the overall crystallinity of the material to be measured. However, these detection methods excite ultrasonic frequencies in the megahertz range, so that the wavelength of the generated ultrasonic waves is about 0.1 mm. The thickness of the surface film layer in the wafer is generally from tens of nanometers to tens of micrometers, so that the emitted ultrasonic wave is far greater than the thickness of the film layer, and therefore, the method cannot be directly applied to the measurement of the crystallinity of the surface film layer of the wafer. In addition, it mainly measures crystallinity, but cannot measure a specific crystalline state. Disclosure of Invention Based on the defects in the prior art, the application provides a method for measuring the crystallization state of a film layer, a related device and a storage medium, so as to solve the problem that the crystallization state of the film layer cannot be accurately measured in the prior art. In order to achieve the above object, the present application provides the following technical solutions: The first aspect of the present application provides a method for measuring a crystallization state of a film layer, including: Exciting ultrasound by pumping light to any scanning point position of the material to be detected, and then emitting detection light to the same scanning point position for ultrasonic detection to obtain a current detection signal; if the signal-to-noise ratio of the current detection signal is larger than a decibel threshold, analyzing the acoustic impedance of an abnormal crystallization area based on the current detection signal, wherein the decibel threshold is the decibel threshold of the signal-to-noise ratio of an echo signal of the abnormal crystallization area; indicating the degree of abnormal crystallization of the material to be detected by utilizing the acoustic impedance of the abnormal crystallization area; if the signal-to-noise ratio of the current detection signal is not greater than the decibel threshold, analyzing the sound velocity and the acoustic impedance of the material to be detected based on the current detection signal; Calculating the Young modulus of the material to be measured by utilizing the sound velocity and the acoustic impedance of the material to be measured, and outputting the Young modulus of the material to be measured as a quantization index of the crystallization state of the material to be measured; If the sound velocity of the material to be tested cannot be analyzed, acquiring the amplitude values of the two echo signals based on the current detection signal, calculating the attenuation parameter of the echo by using the ratio of the amplitude values of the two echo signals, and outputting the attenuation parameter as a quantization index of the crystallization state of the material to be tested. Optionally, in the method for measuring a crystallization state of a film layer, analyzing an acoustic impedance of an abnormal crystallization region based on the current detection signal includes: acquiring a signal amplitude of the abnormal crystallization area from the current detection signal; obtaining the acoustic impedance of a normal crystallization area of the material to be detected and the signal amplitude of the normal crystallization area, wherein the acoustic impedance of the normal crystallization area of the material to be detected is obtained by multiplying the density of the normal crystallization area of the material to be detected by the sound velocity; Calculating the acoustic impedance of the abnormal crystallization area according to the signal amplitude of the normal crystallization area, the signal amplitude of the abnormal crystallization area and the acoustic impedance of the normal crystallization area; the calculation formula of the acoustic impedance of the abnormal crystallization area is as follows: ; a is the signal amplitude of the normal cryst