CVD online in situ observation system and method based on absorption spectroscopy

Abstract

The present invention discloses a CVD online in-situ observation system and method based on absorption spectroscopy, which belongs to the semiconductor manufacturing equipment technical field. This CVD in-situ observation system includes an absorption spectrum detector, a spectral shift and optical path calibration device, and a tubular CVD apparatus. By improving a conventional tubular CVD apparatus and incorporating the proposed environmental compensation method, it achieves accurate detection of the chemical vapor deposition process in a high-temperature, low-pressure environment. Furthermore, the present invention enables real-time detection, thereby obtaining the law of change in the sample or reaction system over time. In response to changes in the system's temperature and pressure, the law of change in the sample or reaction system due to environmental changes such as temperature and pressure can be further obtained. This allows for the determination of optimal deposition conditions. Furthermore, the system's automatic optical path calibration enables online detection of the deposition status of the sample at any position within the quartz tube during the chemical vapor deposition process, allowing for the rapid determination of the exact growth region of the sample.

Description

[Technical Field]

[0001] The present invention relates to a CVD online in-situ observation system and method based on absorption spectroscopy, and particularly to the technical field of semiconductor manufacturing equipment. [Background technology]

[0002] Deposition is a key technology in semiconductor processing and manufacturing, and the equipment used in this technology is collectively referred to as thin-film deposition equipment. Common thin-film deposition processes are divided into physical vapor deposition (PVD) and chemical vapor deposition (CVD). Chemical vapor deposition (CVD) refers to the interaction of reactants or reactants with a substrate under specific temperature and pressure conditions to produce the desired product on the substrate. Typically, the reactants in chemical vapor deposition are gaseous substances, and the product is a solid substance. For example, the process of growing carbon nanotubes on a quartz substrate requires the introduction of CH4 gas as a reactant, and the product is solid carbon nanotubes. Chemical vapor deposition (CVD) has gradually become an important method for atomic-scale manufacturing due to its advantages, such as a simple manufacturing process, large growth area, and easy transport. Furthermore, this technology has led to the development of atomic layer deposition (ALD), which has been widely used to produce various materials such as graphene, carbon nanotubes, and disulfides. CVD equipment, such as a tubular furnace, is one of the core tools in atomic-scale manufacturing.

[0003] Because chemical vapor deposition (CVD) and atomic layer deposition (ALD) processes are typically performed under constant temperature and vacuum conditions, conventional chemical vapor deposition (CVD) systems are unable to monitor the progress of thin film deposition in real time. Instead, the deposited sample is typically removed from the CVD system after deposition and then monitored using various methods. These methods of transporting the sample and monitoring are collectively referred to as non-in situ (ex situ) observation techniques. In atomic layer deposition (ALD) processes, such as those for depositing materials like graphene and carbon nanotubes, in situ monitoring is required to understand the structural changes and reaction mechanisms of the reaction and to study the microstructures of intermediates and products during the reaction. However, conventional CVD systems, such as tubular furnaces, are unable to perform in situ monitoring. Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional in-situ observation techniques are primarily used in electrochemical research, but most of these reactors have small reaction chambers and therefore cannot be directly applied to CVD equipment, which requires a large experimental setup. Furthermore, the high-temperature, low-pressure environment associated with chemical vapor deposition can lead to errors in the in-situ observation results.

[0005] To solve the problem of in-situ detection not being possible with conventional CVD equipment, the present invention provides a CVD online in-situ observation system and method based on absorption spectroscopy. A system is designed to perform real-time in-situ detection of film-forming samples during vapor phase growth processes, and by taking into account the influence of film-forming parameters on the detection results and performing corresponding corrections, in-situ detection is realized for the vapor phase growth process, enabling research into the microstructures of intermediates and products in the reaction process and the determination of optimal film-forming conditions. [Means for solving the problem]

[0006] A first object of the present invention is to provide a CVD online in-situ observation system based on absorption spectroscopy, which includes an absorption spectrum detector, a spectrum shift and optical path calibration device, and a tubular CVD apparatus, and performs online in-situ observation of a deposition sample using the absorption spectrum detector.

[0007] The absorption spectrum detection device includes a light source, a light source-emitting device, a light source-receiving device, and a spectrometer connected to the light source-receiving device. The spectral shift and optical path calibration device includes two moving rails. The light source-emitting device and the light source-receiving device are attached to the two moving rails, respectively. The light source-emitting device and the light source-receiving device are moved by the moving rails. This allows online in-situ observation of a sample at any position inside the quartz tube.

[0008] The tubular CVD apparatus includes a furnace body, a quartz tube, and a quartz board for placing a deposition sample in the quartz tube. The furnace body of the present invention has two light-transmitting grooves that are parallel to and symmetrical with the quartz tube, allowing the light emitted from the light source-emitting device to pass through the furnace body and for online in-situ observation of a sample at any position within the quartz tube. The two light-transmitting grooves share the axial center of the quartz tube as their axis of symmetry. Two moving rails in the spectral shift and optical path calibration device are located on the outside of the furnace body at positions corresponding to the two light-transmitting grooves, allowing the light source-emitting device and light source-receiving device to move linearly along the axial direction of the quartz tube for in-situ detection of a sample at any position within the quartz tube. The light emitted from the light source-emitting device reaches the light source-receiving device through the light-transmitting grooves, the quartz tube, and the deposition sample therein. Furthermore, a spectrometer performs spectral analysis based on the received light source to perform in-situ detection of the deposition sample. The width of the light transmitting groove is set so that the light emitted from the light source emitting device and the light received by the light source light receiving device can pass completely through.

[0009] Optionally, the spectral shift and optical path calibration device further includes four step motors, and a four-axis optical path automatic calibration system is arranged. The four step motors are a first horizontal step motor, a first vertical step motor, a second horizontal step motor, and a second vertical step motor, respectively. The first horizontal step motor and the first vertical step motor move the ball screw and the movable rail to position the light source emitting device in the horizontal plane. The second horizontal step motor and the second vertical step motor control the rotation of the light source emitting device in the horizontal plane and the vertical plane.

[0010] Optionally, the 4-axis optical path automatic calibration system uses a microcontroller or PLC controller to control the stepper motors. The rotation speed of each motor is controlled by setting the PWM waveform of each motor. By comparing the feedback light intensity, the optical path can be fine-tuned to maximize the received light intensity and facilitate subsequent spectral analysis.

[0011] Optionally, the light source is a white light source, has a continuous spectrum, and covers wavelengths of at least 200 to 1050 nm. The luminous flux of the ultraviolet band in the wavelength range of 250 nm to 400 nm is 10 mW / mm 2 The light source has high collimation performance and can focus a spot light into a circle with a diameter of 1 mm within a distance of 0.5 m.

[0012] A second object of the present invention is to provide a CVD online in-situ observation method based on absorption spectra, which is realized by the above-mentioned system and includes an optical path calibration step 1 in which the optical paths of the light source-emitting device and the light source-receiving device in the absorption spectrum detection device are calibrated using a spectral shift and optical path calibration device, a step 2 in which the absorption spectrum of the film-formed sample is acquired during the film formation process using the absorption spectrum detection device, and a step 3 in which the film-formed sample is observed in-situ based on the acquired absorption spectrum of the film-formed sample.

[0013] Optionally, step 2 comprises: Step 2.1: Obtain red-light-corrected spectra at different interval temperatures without placing the sample in the tubular CVD apparatus by an absorption spectrum detector. Step 2.2: Acquire real-time absorption spectra during the film deposition process Step 2.3 is included in this step. From the real-time absorption spectrum, subtract the red-light corrected spectrum at the corresponding temperature to obtain the final spectrum of the deposited sample.

[0014] Optionally, step 2.1 comprises: a step of acquiring one spectrum as an initial spectrum by transmitting light through a quartz tube and a quartz board to a light source / light receiver under room temperature conditions without placing a sample; The temperature is gradually increased, and a spectrum is acquired once for each ΔT from 100° C. to determine the difference from the initial spectrum, thereby obtaining red-light corrected spectra at different temperature gradients.

[0015] Optionally, step 1 includes a step of searching for the position of the light source / light receiving device in a scanning manner using a first horizontal step motor and a first vertical step motor, and then maximizing the intensity of the incident light by fine-tuning the angle using a second horizontal step motor and a second vertical step motor.

[0016] A third object of the present invention is to provide a method for determining a growth region of a deposition sample, said method being implemented by the system described above, comprising: an optical path calibration step S1 of calibrating an optical path for a light source emitting device and a light source receiving device in the absorption spectrum detection device using a spectral shift and optical path calibration device; Step S2: moving the light source emitting device and the light source receiving device along a moving rail, and acquiring an absorption spectrum corresponding to the film-forming sample at each position during the film-forming process in real time; and step S3 of determining a growth region of the deposited sample based on an absorption spectrum corresponding to the deposited sample at each position during the deposition process.

[0017] Optionally, step 3 comprises: analyzing the material growth status at different positions based on the absorption spectrum corresponding to the deposition sample at each position during the deposition process; and selecting a position where the material growth condition is best as the growth region of the film-formed sample. [Effects of the Invention]

[0018] The beneficial effects of the present invention are as follows: By improving a conventional tubular CVD apparatus and incorporating the proposed environmental compensation method, the present invention achieves accurate detection of the chemical vapor deposition process in a high-temperature, low-pressure environment. Furthermore, because real-time detection is possible, the present invention can obtain the law of change over time of the sample or reaction system. In response to changes in the system's temperature and pressure, the law of change in the sample or reaction system due to environmental changes such as temperature and pressure can be further obtained. This allows optimal deposition conditions to be determined. Furthermore, this system uses automatic optical path calibration to detect the deposition status of the sample at any position within the quartz tube during the chemical vapor deposition process, allowing the accurate growth area of ​​the sample to be quickly determined. [Brief explanation of the drawings]

[0019] In order to more clearly explain the technical solutions in the embodiments of the present invention, the drawings necessary for use in the description of the embodiments will be briefly described below. However, the drawings described below are only some embodiments of the present invention, and it is obvious that a person skilled in the art can obtain other drawings based on these drawings without making any creative efforts. [Figure 1] FIG. 1 is a diagram showing the configuration of a CVD online in-situ observation system based on absorption spectra according to the present invention. [Figure 2]FIG. 1 is a top view showing a furnace body in a CVD online in-situ observation system based on absorption spectroscopy according to the present invention, in which 1 denotes the furnace body, 2 denotes a quartz tube, 3 denotes a quartz board, 4 denotes a deposition sample, 5 denotes a light-transmitting groove, 6 denotes a light source, 7 denotes a light-source emitting device, 8 denotes a light-source receiving device, 9 denotes a spectrometer, 10 denotes a rail, and 11 denotes a step motor. [Figure 3] FIG. 1 is a perspective view showing a four-axis optical path calibration system. [Figure 4] 11 is a plan view showing a four-axis optical path calibration system, in which 1101 denotes a first horizontal step motor, 1102 denotes a first vertical step motor, 1103 denotes a second vertical step motor, and 1104 denotes a second horizontal step motor. [Figure 5] FIG. 1 is a spectrum diagram of a xenon light source. [Figure 6] FIG. 2 is a spectral diagram of an improved white light source according to the present invention. [Figure 7] FIG. 1 is a diagram showing the positions of light-transmitting grooves in a furnace body in a CVD tubular furnace based on absorption spectra according to the present invention. [Figure 8] 1 is an online absorption spectrum diagram obtained during a low growth rate experiment using the CVD online in-situ observation system based on the absorption spectrum according to the present invention. FIG. [Figure 9] This is an actual sample image of a low growth rate experiment. [Figure 10] 1 is an online absorption spectrum diagram obtained during a high growth rate experiment using the CVD online in-situ observation system based on the absorption spectrum according to the present invention. FIG. [Figure 11] This is an actual sample image from a high growth rate experiment. [Figure 12] FIG. 10 is a Raman spectrum of a high growth rate experiment. [Figure 13] This is an SEM image of a high growth rate experiment. DETAILED DESCRIPTION OF THE INVENTION

[0020] In order to make the objectives, technical solutions and advantages of the present invention clearer, the following detailed description of the embodiments of the present invention will be given in conjunction with the accompanying drawings.

[0021] First Example This embodiment provides a CVD online in-situ observation system based on absorption spectroscopy. As shown in Figure 1, the CVD online in-situ observation system based on absorption spectroscopy includes an absorption spectrum detection device, a spectral shift and optical path calibration device, and a tubular CVD apparatus. The absorption spectrum detection device includes a light source 6, a light source emitting device 7, a light source receiving device 8, and a spectrometer 9 connected to the light source receiving device 8. The spectral shift and optical path calibration device includes two moving rails 10 and corresponding step motors 11. The light source emitting device 7 and the light source receiving device 8 are mounted on the two moving rails 10, respectively. The tubular CVD apparatus includes a furnace body 1, a quartz tube 2, and a quartz board 3 for placing a deposition sample on the quartz tube 2. The furnace body 1 has two light-transmitting grooves 5 symmetrically arranged parallel to the quartz tube. As shown in Figure 2, the two light-transmitting grooves 5 share the axial center of the quartz tube as their axis of symmetry. The two moving rails 10 in the spectral shift device are respectively positioned at locations corresponding to the two light-transmitting grooves 5 on the outside of the furnace body 1, thereby allowing the light source-emitting device 7 and the light source-receiving device 8 to move linearly along the axial direction of the quartz tube 2. The light emitted from the light source-emitting device 7 reaches the light source-receiving device 8 through the light-transmitting groove 5, the quartz tube 2, and the film-forming sample 4 therein. Furthermore, the spectrometer 9 performs spectral analysis based on the received light source, thereby performing in situ detection on the film-forming sample 4.

[0022] The length of the light-transmitting groove 5 is determined according to the actual situation. The width of the light-transmitting groove 5 is set so that the light emitted from the light-emitting device 7 and the light received by the light-receiving device 8 can pass completely through.

[0023] The tubular CVD apparatus further includes other conventional components in addition to the furnace body, the quartz tube, and the quartz board for placing the film-forming sample in the quartz tube. Since the present invention does not improve these other components, the other conventional components will not be described.

[0024] To ensure that the light emitted from the light-emitting device 7 is accurately received by the light-receiving device 8, the present invention designs a four-axis optical path calibration system, which uses four step motors 11 to calibrate the optical path between the light-emitting device 7 and the light-receiving device 8. Specifically, as shown in FIGS. 3 and 4, the first horizontal step motor 1101 and the first vertical step motor 1102 are used for coarse adjustment, and the second horizontal step motor 1104 and the second vertical step motor 1103 are used for fine adjustment. The first horizontal step motor 1101 and the first vertical step motor 1102 move the ball screw and slide rail to position the light-emitting device 7 in the horizontal plane. The second horizontal step motor 1104 and the second vertical step motor 1103 control the rotation of the light-emitting device 7 in the horizontal and vertical planes. The combination of the four motors allows for calibration of the light source. Furthermore, the four step motors are controlled by a microcontroller or a PLC controller. The rotational speed of each motor is controlled by setting the PWM wave of each motor. By comparing the intensity of the feedback light, the light path can be fine-tuned to maximize the intensity of the received light, facilitating subsequent spectral analysis.

[0025] Considering the high-temperature, low-pressure environment inside the quartz tube during the chemical vapor deposition process (for example, the furnace body becomes red under high temperatures, which can have a certain effect on the light source signal), the light source selection process for the CVD online in-situ observation system based on the above absorption spectrum is as follows. The first type of white light source selected is a xenon lamp light source. Its advantages include high brightness and a wide spectral range, with a wavelength range of 200 to 2500 nm, covering the ultraviolet, visible, and infrared spectrums. When powered on, a 150 W high-voltage short-arc spherical xenon lamp installed in the xenon lamp light source chamber generates an arc discharge through high-frequency and high-voltage excitation. The light source's emission point is a small point light source, and when lit, it emits a strong, stable, continuous spectrum, with a visible light color similar to sunlight. The white light can be transmitted to the outside via an optical fiber at the tail. Actual testing showed that the signal from this white light source was weak in the ultraviolet range, especially in the 200 to 300 nm range. The specific spectral signal is shown in Figure 5. Figure 5 shows the number of collected photons corresponding to different wavelengths. The more photons collected, the greater the light intensity.

[0026] However, because the ultraviolet band plays an important role in the detection process, in this invention, we replace it with a laser-induced white light source, which has a stronger signal in the ultraviolet band, to meet experimental requirements. Compared to a xenon lamp light source, the signal of the laser-induced white light source is particularly stronger in the ultraviolet band. Furthermore, to further reduce losses in the ultraviolet band, a purge gas must be introduced into this light source to prevent atmospheric oxygen from turning into ozone, which would attenuate the light output in the 220-289 nm band. Nitrogen gas is selected as the purge gas and is supplied using a steel cylinder. A pressure reducing valve and a ball valve are sequentially attached to the intake line, and finally, nitrogen gas is introduced into the lamphouse through a 4 mm quick-insert tube for purging. The specific spectral signal of the improved light source is shown in Figure 6. Compared to Figure 5, the improved spectral signal shows an enhanced signal in the 200-300 nm range.

[0027] The spectrometer 9 must have a measurable wavelength range of 200 nm to 1050 nm and may be a StellarNet Blue-Wave UVNb spectrometer. This spectrometer not only has a measurable wavelength range of 200 nm to 1050 nm, but also has the advantages of being compact and fast-responding, allowing for fast real-time spectrum readings in conjunction with the SpectraWiz spectral analysis software. The light source receiver 8 receives the incident white light and transmits the light to the spectrometer via optical fiber. After analyzing and processing the data, spectral information can be obtained. The spectrometer 9 may be a spectrometer such as the HORIBA iHR320, PG2000-pro, or FLEX+ UV-Vis-NIR Spectrometer.

[0028] The light source in the CVD online in-situ observation system based on absorption spectra according to the present invention may be the improved laser-induced white light source described above, or may be any other light source that satisfies the following conditions. 1) The spectrum is continuous, covering wavelengths from 200 to 2000 nm. 2) The light is strong enough overall, especially in the ultraviolet range (200 nm to 400 nm), with a luminous flux of 10 mW / mm 2 ·sr·exceeds nm. 3) It has high collimation performance, and can focus spot light into a circle with a diameter of 1 mm within a distance of 0.5 m.

[0029] For example, the EQ-99-FC-S LDLS, EQ-77X-QZ-S LDLS, HPX-2000 xenon lamp light source, and HGILX300 xenon lamp light source.

[0030] Second Example This embodiment provides a CVD online in-situ observation method based on absorption spectroscopy. This method is realized by the CVD online in-situ observation system based on absorption spectroscopy according to the first embodiment, which includes a tubular furnace with an optical transmission groove 5, as shown in Figure 7. The CVD online in-situ observation method based on absorption spectroscopy includes the following steps: Step 1: Optical path calibration During the optical path calibration process, the two motors at the bottom, namely, the first horizontal step motor 1101 and the first vertical step motor 1102, are used to locate the position of the spectrometer detector, which is the light source receiving device 8, in a scanning manner, and then the two motors at the top, namely, the second horizontal step motor 1104 and the second vertical step motor 1103, are used to fine-tune the angle to maximize the intensity of the incident light and facilitate subsequent measurements.

[0031] The optical path calibration is realized by an STM32 microcontroller. The rotation speed of each motor is controlled by setting the PWM wave of each motor. By comparing the light intensity received by the spectrometer detector, the optical path is fine-tuned to maximize the received light intensity. Step 2: Acquire a temperature gradient corrected spectrum. Step 2 specifically includes the following steps: Step 2.1: Without placing a sample, the light path is passed through a quartz tube and a quartz board to the spectrometer detector, which is the light source / light receiving device 8, and one spectrum is acquired as an initial spectrum. Step 2.2: Gradually increase the temperature to 900°C, acquiring a spectrum every ΔT from 100°C, and then calculating the difference from the initial spectrum to obtain red-corrected spectra at different temperature gradients. ΔT can be set to an appropriate value depending on the actual situation, such as 5°C, 10°C, 25°C, or 50°C. Then, subtract the corresponding red-corrected spectrum from the spectrum acquired in real time at a given temperature during the deposition process to obtain a more accurate absorption spectrum as the final spectrum.

[0032] When analyzing a substance by absorption spectroscopy, the formula for calculating the substance absorbance is as follows: Absorbance = log(incident light intensity / transmitted light intensity) Here, the intensity of the incident light is the intensity of the light emitted from the light source light-emitting device 7, and the intensity of the transmitted light is the intensity of the light received by the light source light-receiving device 8.

[0033] For example, before placing a sample, a light beam passes through a quartz board and a quartz tube, and the intensity of the transmitted light in the absence of red light under room temperature conditions (25°C) is recorded as L1. After the sample is placed, under the experimental environment, light passes through the quartz tube, quartz board, and sample, and the temperature is 800°C. If the intensity of the transmitted light when red light is present is recorded as L2, and the light intensity of the red light corrected spectrum corresponding to 800°C is recorded as L3, the absorbance (measured value) without correction is A = lg(L1 / L2), and the actual value (true value) is A' = lg(L1 / (L2-L3)), so the corrected value Δ of the red light corrected spectrum corresponding to 800°C is 800 =A'-A=lg(L2 / (L2-L3)).

[0034] According to the above method, the correction value Δ of the red light correction spectrum corresponding to every 25°C from 100°C is 125 , Δ 150 , Δ 175 , , Δ 1000 get.

[0035] In the subsequent film formation process, if the film formation temperature is set to 800°C, the correction value Δ 800 The final spectrum is obtained by subtracting the above. Further analysis is performed based on the final spectrum.

[0036] Step 3: Analyze the film formation status during the film formation process based on the final spectrum.

[0037] The spectrometer 9 uses conventional spectral analysis techniques to analyze the deposition status based on the final spectrum.

[0038] The light source emitter 7 and light source receiver 8 of the present invention are respectively attached to two movable rails 10, and the light source can be made to reach any position within the quartz tube 2 by the axial length of the light transmission groove opened in the furnace body.Therefore, by moving the light source emitter 7 and light source receiver 8 during the film formation process, the sample at any position within the quartz tube 2 can be detected in real time and the film formation status of the sample can be obtained.

[0039] Conventional in-situ techniques are limited to in-situ observation at a single position. In the present invention, the synchronized movement of the white light source emitting device 7 and the light source receiving device 8 enables mobile in-situ observation within the quartz tube. This innovation plays an important role in exploring the growth areas of new materials.

[0040] In many CVD processes, after determining conditions such as temperature, pressure, and carrier gas flow rate, material grows at a specific location. This location is usually called the growth region. A typical experimental process requires repeated experiments at different locations and offline observations after the experiments. The growth region may be roughly determined after several or even dozens of experiments. This process is tedious and time-consuming. The system and method of the present invention can be moved arbitrarily during an experiment, observing the growth of material at different locations to determine the growth region, thereby enabling excellent film formation results to be achieved quickly.

[0041] Third Example This embodiment provides a CVD online in-situ observation method based on absorption spectroscopy. This method is realized by the CVD online in-situ observation system based on absorption spectroscopy according to the first embodiment, and is explained using an experiment on the growth of vertically aligned single-walled carbon nanotubes as an example.

[0042] In conventional experiments on the growth of vertically aligned single-walled carbon nanotubes, if one wishes to judge the results of the experiment, the carbon nanotube sample must be removed after the test and observed using a scanning electron microscope (SEM), transmission electron microscope (TEM), atomic force microscope (AFM), etc. However, the CVD online in situ observation system based on the absorption spectrum of the present invention enables real-time observation.

[0043] During the experimental process, online absorption spectra are acquired in real time throughout the entire experimental process.

[0044] Figure 8 shows an online absorption spectrum obtained during a low-growth-rate experiment (referred to as Experiment 1) using the CVD online in-situ observation system based on absorption spectra according to the present invention. The maximum absorbance was observed to be approximately 0.135, suggesting that the number of growths was small. Figure 9 shows the results of the low-growth-rate experiment, revealing the presence of a light gray substance on the substrate surface, proving that only a small number of single-walled carbon nanotubes had grown on the substrate.

[0045] Figure 10 shows an online absorption spectrum obtained during a high-growth-rate experiment (referred to as Experiment 2) using the CVD online in-situ observation system based on absorption spectra according to the present invention. The maximum absorbance was observed to be around 1.5, suggesting a large number of single-walled carbon nanotubes growing. Figure 11 shows the results of the high-growth-rate experiment, revealing the clear appearance of black material on the substrate surface. This, combined with the Raman spectrum (shown in Figure 12) and SEM image (shown in Figure 13), confirms the growth of a large number of single-walled carbon nanotubes on the substrate.

[0046] If the position of the in situ observation needs to be changed, the top motor that controls the spectrometer detector and the bottom motor that corresponds to the direction are simultaneously moved a specific distance, and then the optical path is automatically recalibrated before measurement.

[0047] 8 and 10, the CVD online in-situ observation system based on absorption spectroscopy according to the present invention can measure the law of change of a sample or reaction system over time, and by combining the changes in the temperature and pressure of the system over time, the law of change of the sample or reaction system with environmental changes such as temperature and pressure can be further obtained.

[0048] Some steps in the embodiments of the present invention can be realized by software, and the corresponding software program may be stored in a readable storage medium such as an optical disk or a hard disk.

[0049] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. 1. A CVD online in-situ observation system based on absorption spectroscopy, comprising: The apparatus includes an absorption spectrum detector, a spectrum shift and optical path calibration device, and a tubular CVD apparatus; The absorption spectrum detection device includes a light source, a light source emitting device, a light source receiving device, and a spectrometer connected to the light source receiving device; The spectral shift and optical path calibration device includes two moving rails; The light source emitting device and the light source receiving device are respectively mounted on two moving rails; The tubular CVD apparatus includes a furnace body, a quartz tube, and a quartz board for placing a film-forming sample in the quartz tube; The furnace body has two light-transmitting grooves that are parallel to and symmetrical with the quartz tube. The two light transmitting grooves are symmetrical about the center of the axial direction of the quartz tube, The two moving rails of the spectral shift and optical path calibration device are respectively located at positions on the outside of the furnace body corresponding to the two light transmission grooves, so that the light source emitting device and the light source receiving device can move linearly along the axial direction of the quartz tube to perform in situ detection on a sample at any position inside the quartz tube; The light emitted from the light source emitter passes through the light transmission groove, the quartz tube, and the film-formed sample therein to reach the light source receiver, and the spectrometer performs spectral analysis based on the received light source to perform in-situ detection on the film-formed sample; The light source is a white light source, has a continuous spectrum, and covers at least a wavelength range of 200 to 1050 nm. The luminous flux of the ultraviolet band signal having a wavelength in the range of 250 nm to 400 nm is 10 mW / mm ２ ・Beyond sr / nm, When the spectrometer performs spectral analysis based on the light source received, the method for acquiring the absorption spectrum of the film-formed sample is as follows: Using an absorption spectrum detector, obtain red light corrected spectra at different interval temperatures when no sample is placed in the tubular CVD apparatus; Obtaining a real-time absorption spectrum during the film formation process; and subtracting the red light correction spectrum at the corresponding temperature from the real-time absorption spectrum to obtain a final spectrum of the deposited sample.

2. The spectral shift and optical path calibration device further includes four step motors, and a four-axis optical path automatic calibration system is arranged; the four step motors are a first horizontal step motor, a first vertical step motor, a second horizontal step motor, and a second vertical step motor, respectively; the first horizontal step motor and the first vertical step motor move the ball screw and the movable rail to position the light source emitting device in a horizontal plane; 10. The system of claim 1, wherein a second lateral stepper motor and a second longitudinal stepper motor control rotation of the light source emitting device in the horizontal and vertical planes.

3. 3. The system of claim 2, wherein the four-axis optical path automatic calibration system controls a step motor by a microcontroller or a PLC controller.

4. A CVD online in-situ observation method based on absorption spectroscopy, which is realized by the system according to any one of claims 1 to 3, comprising: an optical path calibration step 1 in which an optical path is calibrated for a light source emitting device and a light source receiving device in the absorption spectrum detection device using a spectral shift and optical path calibration device; Step 2: acquiring an absorption spectrum of the film-forming sample during the film-forming process using an absorption spectrum detector; and step 3 of performing in situ observation of the deposited sample based on the acquired absorption spectrum of the deposited sample; Step 2 is Step 2.1: Obtaining red light corrected spectra at different interval temperatures without placing a sample in the tubular CVD apparatus by an absorption spectrum detector; Step 2.2: acquiring a real-time absorption spectrum during the film formation process; and step 2.3, subtracting the red-light corrected spectrum at the corresponding temperature from the real-time absorption spectrum to obtain the final spectrum of the as-deposited sample.

5. Step 2.1 a step of acquiring one spectrum as an initial spectrum by transmitting light through a quartz tube and a quartz board to a light source / light receiving device under room temperature conditions without placing a sample; 5. The method of claim 4, further comprising the step of gradually increasing the temperature, acquiring a spectrum once every ΔT from 100° C., and calculating the difference from the initial spectrum to obtain red-light corrected spectra at different temperature gradients.

6. Step 1 5. The method according to claim 4, further comprising the steps of: searching for the position of the light source / light receiver in a scanning manner using a first horizontal step motor and a first vertical step motor; and then maximizing the intensity of the incident light by fine-tuning the angle using a second horizontal step motor and a second vertical step motor.

7. A method for determining a growth area of ​​a deposition sample, implemented by the system of any one of claims 1 to 3, comprising: an optical path calibration step S1 of calibrating an optical path for a light source emitting device and a light source receiving device in the absorption spectrum detection device using a spectral shift and optical path calibration device; a step S2 of moving the light source emitting device and the light source receiving device along a moving rail and acquiring an absorption spectrum corresponding to the film-formed sample at each position during the film-formation process in real time; and step S3 of determining a growth region of the deposited sample based on an absorption spectrum corresponding to the deposited sample at each position during the deposition process.

8. Step S3 analyzing the material growth status at different positions based on the absorption spectrum corresponding to the deposition sample at each position during the deposition process; 8. The method of claim 7, further comprising the step of: selecting a position where material growth conditions are best as the growth region of the film-deposited sample.

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