A gas control method and device used in semiconductor manufacturing

Abstract

The present application provides a gas control method and device for use in semiconductor manufacturing. Different gases can produce a thermal effect on the corresponding gas after being irradiated with infrared light of corresponding frequency, and a slight increase in temperature will lead to a significant increase in radiation energy. The pixel value in the infrared image is based on the magnitude of the radiation energy. Based on this principle, infrared images before and after irradiation with infrared light are obtained successively, and then the infrared images are compared, so that the pixels that have changed or the pixels that have not changed significantly in the infrared image can be determined. The gas ratio of hydrogen gas and phosphine gas can be determined by the ratio of the pixels that have changed or the pixels that have not changed significantly, and then it can be determined whether to adjust the flow control valve based on the ratio. In the above manner, the mixing ratio of the mixed gas can be adjusted in time, which is beneficial to improving the yield rate.

Description

Technical Field

[0001] The present application relates to the field of semiconductor manufacturing technology, and in particular, to a gas control method and device used in semiconductor manufacturing. Background Art

[0002] In CVD (Chemical Vapor Deposition) equipment, the mixed gas commonly used is a mixed gas of phosphine and hydrogen, wherein hydrogen exists as a gas to dilute phosphine. When performing the chemical vapor deposition process, the proportion of phosphine in the mixed gas needs to meet certain requirements before normal operation can be carried out. Too high or too low a proportion of phosphine in the mixed gas will affect the yield.

[0003] In the prior art, a flow control valve is usually used to control the mixing ratio of phosphine and hydrogen. This mixing method cannot achieve precise control, and when the mixing ratio cannot meet the requirements, it cannot be adjusted in time, resulting in a decrease in the yield. Summary of the invention

[0004] In view of this, an embodiment of the present application provides a gas control method and device for use in semiconductor manufacturing to timely control the ratio of mixed gases and improve the yield rate in the semiconductor manufacturing process.

[0005] In a first aspect, an embodiment of the present application provides a gas control method for semiconductor manufacturing, wherein the gas control method is used to adjust the ratio of phosphine gas and hydrogen gas in a gas mixing tank for providing mixed gas for chemical vapor deposition equipment, wherein the gas mixing tank is provided with a filter that allows infrared wavelengths within a preset range of the absorption peak of the phosphine gas to infrared light to pass through and an infrared light source blocked by the filter, wherein a plurality of infrared cameras are provided at different positions outside the gas mixing tank, and an infrared detector for detecting wavelengths is provided at each infrared camera, and a concentration sensor for detecting air concentration, a first temperature sensor for detecting air temperature, and a humidity sensor for detecting air humidity are also provided at the space where the gas mixing tank is located, and the gas control method comprises:

[0006] Controlling the plurality of infrared cameras to photograph the area corresponding to the gas mixing tank according to a preset cycle to obtain a plurality of first infrared images, and controlling each of the infrared detectors to collect the current first wavelength, the concentration sensor to collect the current first air concentration, the first temperature sensor to collect the current first air temperature, and the humidity sensor to collect the current first air humidity;

[0007] Controlling the infrared light source to emit infrared light, and controlling the plurality of infrared cameras to shoot the area corresponding to the gas mixing tank to obtain a plurality of second infrared images, and controlling each of the infrared detectors to collect the current second wavelength, the concentration sensor to collect the current second air concentration, the first temperature sensor to collect the current second air temperature, and the humidity sensor to collect the current second air humidity;

[0008] For each target infrared image, the infrared propagation loss rate corresponding to the target infrared image is calculated using the following formula:

[0009] = 1-exp[−( (λ,C,T)+ (λ,T,RH)).x];

[0010] The target infrared image includes the first infrared image and the second infrared image. (λ,C,T) represents the absorption attenuation coefficient, (λ,T,RH) represents the scattering attenuation coefficient, λ is the wavelength collected by the infrared detector corresponding to the target infrared image when the target infrared image is acquired, C is the air concentration collected by the concentration sensor when the target infrared image is acquired, T is the air temperature collected by the first temperature sensor when the target infrared image is acquired, RH is the air humidity collected by the humidity sensor when the target infrared image is acquired, x is the distance of the infrared camera corresponding to the target infrared image relative to the shooting area, and exp represents the natural exponential function;

[0011] The target infrared image is corrected using the following formula to obtain the corrected infrared image corresponding to the target infrared image:

[0012] ;

[0013] in, is the pixel in the infrared image of the target The corresponding pixel brightness;

[0014] Compare pixels at the same position in a first corrected infrared image and a second corrected infrared image corresponding to the same infrared camera to determine the number of first pixels in the second corrected infrared image whose brightness changes exceed a preset threshold and the number of second pixels whose brightness changes do not exceed the preset threshold relative to the first corrected infrared image;

[0015] The flow control valve on the first delivery pipeline corresponding to the hydrogen supply cylinder is adjusted according to the average of the ratios of all the first pixel numbers to the second pixel numbers.

[0016] Optionally, adjusting the flow control valve on the first delivery pipeline corresponding to the hydrogen supply cylinder according to the average of the ratios of all the first pixel numbers to the second pixel numbers includes:

[0017] When the average of the ratios is greater than a first preset threshold, controlling the flow rate of the flow control valve to increase;

[0018] When the average of the ratios is less than a second preset threshold, controlling the flow rate of the flow control valve to decrease;

[0019] Wherein, the first preset threshold is greater than the second preset threshold.

[0020] Optionally, a second temperature sensor is further provided in the gas mixing tank, and the method further comprises:

[0021] When the first infrared image is obtained, controlling the second temperature sensor to collect the temperature inside the tank;

[0022] Taking the gray value corresponding to the temperature inside the tank as a threshold, binarizing the second corrected infrared image to obtain a binary image corresponding to the second corrected infrared image;

[0023] Calculating a first distance between any two pixels having a pixel value of 0 in the binary image, and calculating a second distance between any two pixels having a pixel value of 255 in the binary image;

[0024] Calculate the mean square error of a set of values ​​consisting of the first distance and the second distance;

[0025] After obtaining the mean square errors corresponding to all infrared cameras, determining whether each mean square error is less than or equal to a preset mean square error;

[0026] When each mean square error is less than or equal to the preset mean square error, it is determined that the gas in the gas mixing tank is uniformly mixed;

[0027] When at least one mean square error is greater than the preset mean square error, it is determined that the gas in the gas mixing tank is not mixed uniformly.

[0028] Optionally, the method further comprises:

[0029] When at least one mean square error is greater than the preset mean square error, the disturbance device in the gas mixing tank is controlled to perform disturbance.

[0030] Optionally, one end of the first delivery pipeline and the second delivery pipeline are respectively connected to the exhaust pipeline, and the other end is connected to the purge pipeline.

[0031] In a second aspect, an embodiment of the present application provides a gas control device used in semiconductor manufacturing, wherein the gas control device is used to adjust the ratio of phosphine gas and hydrogen gas in a gas mixing tank that provides a mixed gas for chemical vapor deposition equipment, and the gas mixing tank is provided with a filter that allows infrared wavelengths within a preset range of the absorption peak of the phosphine gas to infrared light to pass through and an infrared light source blocked by the filter, and multiple infrared cameras are arranged at different positions outside the gas mixing tank, and each infrared camera is provided with an infrared detector for detecting wavelengths, and a concentration sensor for detecting air concentration, a first temperature sensor for detecting air temperature, and a humidity sensor for detecting air humidity are also provided in the space where the gas mixing tank is located, and the gas control device includes:

[0032] A first control unit is used to control the plurality of infrared cameras to photograph the area corresponding to the gas mixing tank according to a preset cycle to obtain a plurality of first infrared images, and control each of the infrared detectors to collect a current first wavelength, the concentration sensor to collect a current first air concentration, the first temperature sensor to collect a current first air temperature, and the humidity sensor to collect a current first air humidity;

[0033] a second control unit, for controlling the infrared light source to emit infrared light, and controlling the plurality of infrared cameras to photograph the area corresponding to the gas mixing tank to obtain a plurality of second infrared images, and controlling each of the infrared detectors to collect the current second wavelength, the concentration sensor to collect the current second air concentration, the first temperature sensor to collect the current second air temperature, and the humidity sensor to collect the current second air humidity;

[0034] The first calculation unit is used to calculate the infrared propagation loss rate corresponding to each target infrared image using the following formula:

[0035] = 1-exp[−( (λ,C,T)+ (λ,T,RH)).x];

[0036] The target infrared image includes the first infrared image and the second infrared image. (λ,C,T) represents the absorption attenuation coefficient, (λ,T,RH) represents the scattering attenuation coefficient, λ is the wavelength collected by the infrared detector corresponding to the target infrared image when the target infrared image is acquired, C is the air concentration collected by the concentration sensor when the target infrared image is acquired, T is the air temperature collected by the first temperature sensor when the target infrared image is acquired, RH is the air humidity collected by the humidity sensor when the target infrared image is acquired, x is the distance of the infrared camera corresponding to the target infrared image relative to the shooting area, and exp represents the natural exponential function;

[0037] The correction unit is used to correct the target infrared image using the following formula to obtain a corrected infrared image corresponding to the target infrared image:

[0038] ;

[0039] in, is the pixel in the infrared image of the target The corresponding pixel brightness;

[0040] A comparison unit is used to compare pixels at the same position in a first corrected infrared image and a second corrected infrared image corresponding to the same infrared camera, and determine the number of first pixels in the second corrected infrared image whose brightness changes exceed a preset threshold and the number of second pixels whose brightness changes do not exceed the preset threshold relative to the first corrected infrared image;

[0041] The regulating unit is used to regulate the flow control valve on the first delivery pipeline corresponding to the hydrogen supply cylinder according to the average of the ratios of all the first pixel numbers to the second pixel numbers.

[0042] Optionally, the regulating unit is used to regulate the flow control valve on the first delivery pipeline corresponding to the hydrogen supply cylinder according to the average of the ratios of all the first pixel numbers to the second pixel numbers, including:

[0043] When the average of the ratios is greater than a first preset threshold, controlling the flow rate of the flow control valve to increase;

[0044] When the average of the ratios is less than a second preset threshold, controlling the flow rate of the flow control valve to decrease;

[0045] Wherein, the first preset threshold is greater than the second preset threshold.

[0046] Optionally, a second temperature sensor is further provided in the gas mixing tank, and the gas control device further comprises:

[0047] a third control unit, configured to control the second temperature sensor to collect the temperature inside the tank when the first infrared image is obtained;

[0048] A processing unit, configured to perform binarization processing on the second corrected infrared image by taking the gray value corresponding to the temperature inside the tank as a threshold value, so as to obtain a binary image corresponding to the second corrected infrared image;

[0049] A second calculation unit is used to calculate a first distance between any two pixels whose pixel values ​​are 0 in the binary image, and to calculate a second distance between any two pixels whose pixel values ​​are 255 in the binary image; and to calculate a mean square error of a numerical set consisting of the first distance and the second distance;

[0050] The judgment unit is used to judge whether each mean square deviation is less than or equal to a preset mean square deviation after obtaining the mean square deviations corresponding to all infrared cameras; when each mean square deviation is less than or equal to the preset mean square deviation, it is determined that the gas in the gas mixing tank is evenly mixed; when at least one mean square deviation is greater than the preset mean square deviation, it is determined that the gas in the gas mixing tank is unevenly mixed.

[0051] Optionally, the gas control device further comprises:

[0052] The fourth control unit is used to control the disturbance device in the gas mixing tank to perform disturbance when at least one mean square error is greater than the preset mean square error.

[0053] Optionally, one end of the first delivery pipeline and the second delivery pipeline are respectively connected to the exhaust pipeline, and the other end is connected to the purge pipeline.

[0054] The technical solution provided by the embodiments of the present application may have the following beneficial effects:

[0055] In the present application, a variety of gases can be mixed through a gas mixing tank. Different gases can produce a thermal effect on the corresponding gas after being irradiated with infrared light of corresponding frequency, and a slight increase in temperature will lead to a significant increase in radiation energy. The pixel value in the infrared image is based on the magnitude of the radiation energy. Based on this principle, infrared images before and after irradiation with infrared light are obtained successively, and then the infrared images are compared, so that the pixels that have changed or have not changed significantly in the infrared image can be determined. The gas ratio of hydrogen gas and phosphine gas can be determined by the ratio of the pixels that have changed or the pixels that have not changed significantly, and then the flow control valve can be determined based on the ratio. In this way, the mixing ratio of the mixed gas can be adjusted in time, which is beneficial to improving the yield.

[0056] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0058] Figure 1 A flow chart of a gas control method applied in semiconductor manufacturing provided in an embodiment of the present application;

[0059] Figure 2 A schematic diagram of the structure of a gas mixing system provided in an embodiment of the present application;

[0060] Figure 3 A schematic flow chart of another gas control method used in semiconductor manufacturing provided in an embodiment of the present application;

[0061] Figure 4 A schematic diagram of the structure of a gas control device used in semiconductor manufacturing provided in an embodiment of the present application. DETAILED DESCRIPTION

[0062] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0063] When infrared light irradiates a mixed gas, part of the infrared light will be absorbed by the gas molecules, and part will be reflected or scattered. This interaction between radiation and matter will cause changes in the intensity of the infrared light. In addition, when infrared light irradiates a mixed gas, it will also produce a certain thermal effect. Although this thermal effect is relatively small, it is enough to cause a slight change in the temperature of the gas molecules, thereby changing the intensity of the infrared radiation emitted outward. In addition, since a slight increase in temperature will lead to a significant increase in radiation energy, infrared imaging equipment captures these radiation changes caused by infrared light irradiation (including direct reflection, scattering, and radiation changes caused by thermal effects) and converts them into electrical signals for processing, ultimately forming a visible infrared image. Therefore, gases that absorb infrared light can undergo significant changes in infrared images.

[0064] Based on the above principle, infrared images are obtained before and after irradiation with infrared light that causes only one gas to produce a thermal effect, and then the infrared images are compared, so that the pixels that have changed or the pixels that have not changed significantly in the infrared image can be determined. The gas ratio of hydrogen gas and phosphine gas can be determined by the ratio of the pixels that have changed or the pixels that have not changed significantly, and then it is determined whether to adjust the flow control valve based on the ratio. In the above manner, the mixing ratio of the mixed gas can be adjusted in time, which is beneficial to improving the yield.

[0065] Figure 1 A flow chart of a gas control method used in semiconductor manufacturing provided in an embodiment of the present application, wherein the gas control method is used to adjust the ratio of phosphine gas and hydrogen gas in a gas mixing tank that provides a mixed gas for chemical vapor deposition equipment, wherein the gas mixing tank is provided with a filter that allows infrared wavelengths within a preset range from the absorption peak of the phosphine gas to infrared light to pass through and an infrared light source blocked by the filter, wherein a plurality of infrared cameras are provided at different positions outside the gas mixing tank, and each infrared camera is provided with an infrared detector for detecting wavelengths, and a concentration sensor for detecting air concentration, a first temperature sensor for detecting air temperature, and a humidity sensor for detecting air humidity are also provided in the space where the gas mixing tank is located, such as Figure 1 As shown, the gas control method comprises the following steps:

[0066] Step 101, controlling the plurality of infrared cameras to shoot the area corresponding to the gas mixing tank according to a preset cycle to obtain a plurality of first infrared images, and controlling each of the infrared detectors to collect the current first wavelength, the concentration sensor to collect the current first air concentration, the first temperature sensor to collect the current first air temperature, and the humidity sensor to collect the current first air humidity.

[0067] Step 102, control the infrared light source to emit infrared light, and control the multiple infrared cameras to shoot the area corresponding to the gas mixing tank to obtain multiple second infrared images, and control each of the infrared detectors to collect the current second wavelength, the concentration sensor to collect the current second air concentration, the first temperature sensor to collect the current second air temperature, and the humidity sensor to collect the current second air humidity.

[0068] Step 103: For each target infrared image, the infrared propagation loss rate corresponding to the target infrared image is calculated using the following formula 1:

[0069] = 1-exp[−( (λ,C,T)+ (λ,T,RH)).x];

[0070] The target infrared image includes the first infrared image and the second infrared image. (λ,C,T) represents the absorption attenuation coefficient, (λ,T,RH) represents the scattering attenuation coefficient, λ is the wavelength collected by the infrared detector corresponding to the target infrared image when the target infrared image is acquired, C is the air concentration collected by the concentration sensor when the target infrared image is acquired, T is the air temperature collected by the first temperature sensor when the target infrared image is acquired, RH is the air humidity collected by the humidity sensor when the target infrared image is acquired, x is the distance of the infrared camera corresponding to the target infrared image relative to the shooting area, and exp represents the natural exponential function.

[0071] Step 104: Correct the target infrared image using the following formula 2 to obtain a corrected infrared image corresponding to the target infrared image:

[0072] ; (Formula 2)

[0073] in, is the pixel in the infrared image of the target The corresponding pixel brightness.

[0074] Step 105: compare the pixels at the same position in the first corrected infrared image and the second corrected infrared image corresponding to the same infrared camera, and determine the number of first pixels in the second corrected infrared image whose pixel brightness changes exceed a preset threshold and the number of second pixels whose pixel brightness changes do not exceed the preset threshold relative to those in the first corrected infrared image.

[0075] Step 106: According to the average of the ratios of all the first pixel numbers to the second pixel numbers, the flow control valve on the first delivery pipeline corresponding to the hydrogen supply cylinder is adjusted.

[0076] Specifically, Figure 2 A schematic diagram of a gas mixing system provided in an embodiment of the present application is shown in FIG. Figure 2 As shown, the gas control method runs on the processor of the gas mixing system ( Figure 1 ), such as Figure 2 As shown, the gas mixing system further comprises a phosphine supply gas cylinder 1, a hydrogen supply gas cylinder 2, a gas mixing tank 3, a first delivery pipeline 4 and a second delivery pipeline 5, wherein the phosphine supply gas cylinder 1 and the hydrogen supply gas cylinder 2 are respectively connected to the gas mixing tank 3 through different first delivery pipelines 4, and an infrared light source ( Figure 1 Not shown) and filters ( Figure 1 ), wherein the filter allows infrared wavelengths within a preset range from the absorption peak of phosphine gas to infrared light to pass through, and the infrared light emitted by the infrared light source is irradiated to the inside of the gas mixing tank 3 through the filter, and multiple infrared cameras 6 are arranged at different positions outside the gas mixing tank 3, and each infrared camera 6 is provided with an infrared detector 7 for detecting wavelengths, and each infrared camera 6 is used to photograph different areas of the outer wall of the gas mixing tank 3, and the shooting parameters of the multiple infrared cameras 6 are the same, and each infrared camera 6 and the infrared detector 7 are communicatively connected with the processor, and the gas mixing tank 3 connects the mixed gas to the chemical vapor deposition equipment 8 through the second delivery pipeline 5, and the space where the gas mixing tank 3 is located is also provided with a concentration sensor for detecting the air concentration in the space ( Figure 1 ), a first temperature sensor (not shown) for detecting the air temperature in the space Figure 1 ), and a humidity sensor ( Figure 1 (not shown), the concentration sensor, the first temperature sensor and the humidity sensor are all communicatively connected to the processor.

[0077] The phosphine gas provided by the phosphine supply cylinder and the hydrogen gas provided by the hydrogen supply cylinder are mixed in a gas mixing tank after passing through their respective corresponding first delivery pipelines, wherein the hydrogen gas is used to dilute the phosphine gas, that is, the hydrogen gas is used to adjust the concentration of the phosphine gas. A plurality of infrared cameras are arranged at different positions outside the gas mixing tank, and an infrared light source for emitting infrared light and a filter for filtering the infrared light source are arranged in the gas mixing tank. The filter can filter out infrared light except for infrared light with an infrared wavelength within a preset range from an absorption peak of the phosphine gas to the infrared light. In this way, it can be ensured that when the mixed gas is irradiated with infrared light, only the phosphine gas can absorb the infrared light to generate a thermal effect, thereby causing a significant change in the pixel points representing the phosphine gas in the obtained infrared image.

[0078] In order to improve the clarity of infrared imaging, when taking the first infrared image and the second infrared image, it is also necessary to control the infrared detector, the concentration sensor, the first temperature sensor and the humidity sensor to collect current data so as to denoise the currently obtained infrared image according to the current data.

[0079] For example: four infrared cameras are set in the four directions of up, down, left and right outside the gas mixing tank, each infrared camera shoots a different area, and the shot areas do not overlap. In the process of the gas mixing system providing mixed gas for the chemical vapor deposition equipment, the infrared camera periodically shoots the corresponding area according to a preset cycle to obtain the first infrared image A, the first infrared image B, the first infrared image C and the first infrared image D, and controls the infrared detector, the concentration sensor, the first temperature sensor and the humidity sensor to collect the current first wavelength, the first air concentration, the first air temperature and the first air humidity, and in the same shooting cycle, after obtaining the first infrared image, controls the infrared light source to emit infrared light. At this time, the phosphine gas It can absorb the infrared light, while hydrogen gas cannot absorb the infrared light, and the second infrared image E, the second infrared image F, the second infrared image G and the second infrared image H at this time are photographed by the infrared camera, and the infrared detector, the concentration sensor, the first temperature sensor and the humidity sensor are controlled to collect the current second wavelength, the second air concentration, the second air temperature and the second air humidity, wherein the first infrared image A and the second infrared image E are photographed by the same infrared camera, the first infrared image B and the second infrared image F are photographed by the same infrared camera, the first infrared image C and the second infrared image G are photographed by the same infrared camera, and the first infrared image D and the second infrared image H are photographed by the same infrared camera.

[0080] Taking the first infrared image A as an example among the first infrared image A, the first infrared image B, the first infrared image C and the first infrared image D, the infrared propagation loss rate corresponding to the first infrared image A is calculated using the first wavelength, the first air concentration, the first air temperature, the first air humidity and the first formula, and then the first corrected infrared image I corresponding to the first infrared image A is obtained using formula 2 and the infrared propagation loss rate. Similarly, the first corrected infrared image J corresponding to the first infrared image B, the first corrected infrared image K corresponding to the first infrared image C, and the first corrected infrared image L corresponding to the first infrared image D can be obtained.

[0081] Among the second infrared image E, the second infrared image F, the second infrared image G and the second infrared image H, taking the second infrared image E as an example, the infrared propagation loss rate corresponding to the second infrared image E is calculated using the second wavelength, the second air concentration, the second air temperature, the second air humidity and the first formula, and then the second corrected infrared image M corresponding to the second infrared image E is obtained using formula 2 and the infrared propagation loss rate. Similarly, the second corrected infrared image N corresponding to the second infrared image F, the second corrected infrared image O corresponding to the second infrared image G, and the second corrected infrared image P corresponding to the second infrared image H can be obtained.

[0082] Taking the first infrared image A and the second infrared image E as an example, since the change of phosphine gas in the infrared image is obvious before and after the infrared light irradiation, the pixels at the same position in the first corrected infrared image I and the second corrected infrared image M can be compared to determine the number of first pixels in the second corrected infrared image M whose pixel brightness changes by more than a preset threshold and the number of second pixels whose pixel brightness changes by less than the preset threshold relative to the first corrected infrared image I, that is, in the second corrected infrared image M, the pixel points whose pixel brightness changes by more than the preset threshold are the pixels corresponding to the phosphine gas, and the pixel points whose pixel brightness changes by less than the preset threshold are the pixels corresponding to the hydrogen gas, and the ratio of the number of the two pixel points is approximately equal to the mixing ratio of the phosphine gas and the hydrogen gas. In order to avoid errors caused by uneven gas mixing, the infrared images taken by four infrared cameras can be compared to obtain four ratios, and then the four comparisons are averaged, and then the flow control valve of the hydrogen supply cylinder is controlled according to the obtained average value to adjust the proportion of hydrogen in the mixed gas, thereby controlling the ratio of the mixed gas. In this way, the mixing ratio of the mixed gas can be adjusted in time, which is conducive to improving the yield.

[0083] In a feasible implementation manner, when the flow control valve on the first delivery pipeline corresponding to the hydrogen supply cylinder is adjusted according to the average of the ratios of all the first pixel numbers and the second pixel numbers, when the average of the ratios is greater than a first preset threshold, the flow of the flow control valve is controlled to increase; when the average of the ratios is less than a second preset threshold, the flow of the flow control valve is controlled to decrease; wherein the first preset threshold is greater than the second preset threshold.

[0084] Specifically, when the mean value of the ratio is greater than the first preset threshold value, it indicates that the proportion of phosphine gas in the mixed gas is relatively high, and therefore it is necessary to control the flow rate of the flow control valve corresponding to the hydrogen gas to increase, thereby increasing the proportion of the hydrogen gas in the mixed gas so that the mixing ratio of the mixed gas meets the requirements. Similarly, when the mean value of the ratio is less than the first preset threshold value, it indicates that the proportion of phosphine gas in the mixed gas is relatively low, and therefore it is necessary to control the flow rate of the flow control valve corresponding to the hydrogen gas to decrease, thereby increasing the proportion of the phosphine gas in the mixed gas so that the mixing ratio of the mixed gas meets the requirements.

[0085] It should be noted that the first preset threshold value may be a fixed value or a preset numerical range, and may be set according to actual needs, and is not specifically limited here.

[0086] In a feasible embodiment, a second temperature sensor is further provided in the gas mixing tank. Figure 3 A flow chart of another gas control method for semiconductor manufacturing provided in an embodiment of the present application is shown as follows: Figure 3 As shown, the method comprises the following steps:

[0087] Step 301: When the first infrared image is obtained, control the second temperature sensor to collect the temperature inside the tank.

[0088] Step 302: Using the gray value corresponding to the temperature inside the tank as a threshold, binarize the second corrected infrared image to obtain a binary image corresponding to the second corrected infrared image.

[0089] Step 303: Calculate a first distance between any two pixels whose pixel values ​​are 0 in the binary image, and calculate a second distance between any two pixels whose pixel values ​​are 255 in the binary image.

[0090] Step 304: Calculate the mean square error of the numerical set consisting of the first distance and the second distance.

[0091] Step 305: After obtaining the mean square errors corresponding to all infrared cameras, determine whether each mean square error is less than or equal to a preset mean square error. When each mean square error is less than or equal to the preset mean square error, determine that the gas in the gas mixing tank is uniformly mixed. When at least one mean square error is greater than the preset mean square error, determine that the gas in the gas mixing tank is unevenly mixed.

[0092] Specifically, the brightness of the pixels in the infrared image is related to the temperature of the photographed object. In order to distinguish the pixels in the infrared image whose brightness has changed, a second temperature sensor can be set in the gas mixing tank. When shooting the first infrared image, the second temperature sensor is controlled to collect the temperature in the tank, and then the grayscale value corresponding to the temperature in the tank is used as the threshold to perform binarization on the second corrected infrared image. Since the temperature of the phosphine gas increases after absorbing infrared light, after the second corrected infrared image is grayed, the grayscale value corresponding to the phosphine gas will be higher than the threshold, and the grayscale value corresponding to the hydrogen gas will be less than or equal to the threshold. At this time, the grayscale value above the high threshold can be set as the threshold. The pixel value after binarization is determined to be 255, and the pixel value below or equal to the threshold is determined to be 0, so that the pixel points corresponding to the phosphine gas and the hydrogen gas are distinguished, and then the mean square error of the numerical set composed of the first distance and the second distance is determined through subsequent steps. The mean square error can show the distribution of different pixel points. After obtaining the mean square error of the binary image corresponding to each infrared camera, if there is a mean square error greater than the preset mean square error, it indicates that there is uneven mixing in the gas mixing tank. If all the mean square errors are greater than or equal to the preset mean square error, it indicates that the gas in the gas mixing tank is evenly mixed.

[0093] In a feasible embodiment, when at least one mean square error is greater than the preset mean square error, the disturbance device in the gas mixing tank is controlled to perform disturbance so that the mixed gas is evenly mixed while meeting the mixing ratio requirement.

[0094] In a feasible implementation manner, one end of the first delivery pipeline and the second delivery pipeline are respectively connected to the exhaust pipeline, and the other end is connected to the purge pipeline.

[0095] Specifically, one end of the first delivery pipeline and the second delivery pipeline are respectively connected to the exhaust pipeline, and the other end is connected to the purge pipeline. When the pipeline needs to be inspected, the gas delivery can be closed by the pneumatic diaphragm valve, and then the gas in the first delivery pipeline and the second delivery pipeline can be discharged through the purge pipeline and the exhaust pipeline.

[0096] Figure 4A schematic structural diagram of a gas control device used in semiconductor manufacturing is provided in an embodiment of the present application, wherein the gas control device is used to adjust the ratio of phosphine gas and hydrogen gas in a gas mixing tank that provides mixed gas for chemical vapor deposition equipment, the gas mixing tank is provided with a filter that allows infrared wavelengths within a preset range from the absorption peak of the phosphine gas to infrared light to pass through and an infrared light source blocked by the filter, a plurality of infrared cameras are provided at different positions outside the gas mixing tank, each infrared camera is provided with an infrared detector for detecting wavelengths, and a concentration sensor for detecting air concentration, a first temperature sensor for detecting air temperature, and a humidity sensor for detecting air humidity are also provided in the space where the gas mixing tank is located, such as Figure 4 As shown, the gas control device comprises:

[0097] A first control unit 41 is used to control the plurality of infrared cameras to photograph the area corresponding to the gas mixing tank according to a preset cycle to obtain a plurality of first infrared images, and control each of the infrared detectors to collect the current first wavelength, the concentration sensor to collect the current first air concentration, the first temperature sensor to collect the current first air temperature, and the humidity sensor to collect the current first air humidity;

[0098] The second control unit 42 is used to control the infrared light source to emit infrared light, and control the plurality of infrared cameras to shoot the area corresponding to the gas mixing tank to obtain a plurality of second infrared images, and control each of the infrared detectors to collect the current second wavelength, the concentration sensor to collect the current second air concentration, the first temperature sensor to collect the current second air temperature, and the humidity sensor to collect the current second air humidity;

[0099] The first calculation unit 43 is used to calculate the infrared propagation loss rate corresponding to each target infrared image using the following formula:

[0100] = 1-exp[−( (λ,C,T)+ (λ,T,RH)).x];

[0101] The target infrared image includes the first infrared image and the second infrared image. (λ,C,T) represents the absorption attenuation coefficient, (λ,T,RH) represents the scattering attenuation coefficient, λ is the wavelength collected by the infrared detector corresponding to the target infrared image when the target infrared image is acquired, C is the air concentration collected by the concentration sensor when the target infrared image is acquired, T is the air temperature collected by the first temperature sensor when the target infrared image is acquired, RH is the air humidity collected by the humidity sensor when the target infrared image is acquired, x is the distance of the infrared camera corresponding to the target infrared image relative to the shooting area, and exp represents the natural exponential function;

[0102] The correction unit 44 is used to correct the target infrared image using the following formula to obtain a corrected infrared image corresponding to the target infrared image:

[0103] ;

[0104] in, is the pixel in the infrared image of the target The corresponding pixel brightness;

[0105] A comparison unit 45 is used to compare pixels at the same position in the first corrected infrared image and the second corrected infrared image corresponding to the same infrared camera, and determine the number of first pixels in the second corrected infrared image whose brightness changes exceed a preset threshold and the number of second pixels whose brightness changes do not exceed the preset threshold relative to the first corrected infrared image;

[0106] The regulating unit 46 is used to regulate the flow control valve on the first delivery pipeline corresponding to the hydrogen supply cylinder according to the average of the ratios of all the first pixel numbers to the second pixel numbers.

[0107] In a feasible embodiment, the regulating unit, when used to regulate the flow control valve on the first delivery pipeline corresponding to the hydrogen supply cylinder according to the ratio of the first number of pixels to the second number of pixels, includes:

[0108] When the ratio is greater than a first preset threshold, controlling the flow rate of the flow control valve to increase;

[0109] When the ratio is less than a second preset threshold, controlling the flow rate of the flow control valve to decrease;

[0110] Wherein, the first preset threshold is greater than the second preset threshold.

[0111] In a feasible embodiment, a second temperature sensor is further provided in the gas mixing tank, and the gas control device further comprises:

[0112] a third control unit, configured to control the second temperature sensor to collect the temperature inside the tank when the first infrared image is obtained;

[0113] A processing unit, configured to perform binarization processing on the second corrected infrared image by taking the gray value corresponding to the temperature inside the tank as a threshold value, so as to obtain a binary image corresponding to the second corrected infrared image;

[0114] A second calculation unit is used to calculate a first distance between any two pixels whose pixel values ​​are 0 in the binary image, and to calculate a second distance between any two pixels whose pixel values ​​are 255 in the binary image; and to calculate a mean square error of a numerical set consisting of the first distance and the second distance;

[0115] The judgment unit is used to judge whether each mean square deviation is less than or equal to a preset mean square deviation after obtaining the mean square deviations corresponding to all infrared cameras; when each mean square deviation is less than or equal to the preset mean square deviation, it is determined that the gas in the gas mixing tank is evenly mixed; when at least one mean square deviation is greater than the preset mean square deviation, it is determined that the gas in the gas mixing tank is unevenly mixed.

[0116] In a feasible embodiment, the gas control device further comprises:

[0117] The fourth control unit is used to control the disturbance device in the gas mixing tank to perform disturbance when at least one mean square error is greater than the preset mean square error.

[0118] In a feasible embodiment, one end of the first delivery pipeline and the second delivery pipeline are respectively connected to the exhaust pipeline, and the other end is connected to the purge pipeline.

[0119] about Figure 4 The principles of related content can be found in Figure 1-Figure 3 The explanation of the relevant content will not be repeated in detail here.

[0120] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, and the indirect coupling or communication connection of the devices or units can be electrical, mechanical or other forms.

[0121] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0122] In addition, each functional unit in the embodiments provided in the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0123] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, and other media that can store program codes.

[0124] It should be noted that similar numbers and letters represent similar items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description and are not to be understood as indicating or implying relative importance.

[0125] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solutions of the present application, rather than to limit them. The protection scope of the present application is not limited thereto. Although the present application is described in detail with reference to the above-mentioned embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-mentioned embodiments within the technical scope disclosed in the present application, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application. They should all be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A gas control method used in semiconductor manufacturing, characterized in that: The gas control method is used to adjust the ratio of phosphine gas and hydrogen gas in a gas mixing tank for providing mixed gas for chemical vapor deposition equipment. The gas mixing tank is provided with a filter that allows infrared wavelengths within a preset range from the absorption peak of phosphine gas to infrared light to pass through and an infrared light source blocked by the filter. A plurality of infrared cameras are provided at different positions outside the gas mixing tank, and an infrared detector for detecting wavelengths is provided at each infrared camera. A concentration sensor for detecting air concentration, a first temperature sensor for detecting air temperature, and a humidity sensor for detecting air humidity are also provided at the space where the gas mixing tank is located. The gas control method comprises: Controlling the plurality of infrared cameras to photograph the area corresponding to the gas mixing tank according to a preset cycle to obtain a plurality of first infrared images, and controlling each of the infrared detectors to collect the current first wavelength, the concentration sensor to collect the current first air concentration, the first temperature sensor to collect the current first air temperature, and the humidity sensor to collect the current first air humidity; Controlling the infrared light source to emit infrared light, and controlling the plurality of infrared cameras to shoot the area corresponding to the gas mixing tank to obtain a plurality of second infrared images, and controlling each of the infrared detectors to collect the current second wavelength, the concentration sensor to collect the current second air concentration, the first temperature sensor to collect the current second air temperature, and the humidity sensor to collect the current second air humidity; For each target infrared image, the infrared propagation loss rate corresponding to the target infrared image is calculated using the following formula: =1-exp[−( (λ,C,T)+ (λ,T,RH)) x]; The target infrared image includes the first infrared image and the second infrared image. (λ,C,T) represents the absorption attenuation coefficient, (λ,T,RH) represents the scattering attenuation coefficient, λ is the wavelength collected by the infrared detector corresponding to the target infrared image when the target infrared image is acquired, C is the air concentration collected by the concentration sensor when the target infrared image is acquired, T is the air temperature collected by the first temperature sensor when the target infrared image is acquired, RH is the air humidity collected by the humidity sensor when the target infrared image is acquired, x is the distance of the infrared camera corresponding to the target infrared image relative to the shooting area, and exp represents the natural exponential function; The target infrared image is corrected using the following formula to obtain the corrected infrared image corresponding to the target infrared image: ； in, is the pixel in the infrared image of the target The corresponding pixel brightness; Compare pixels at the same position in a first corrected infrared image and a second corrected infrared image corresponding to the same infrared camera to determine the number of first pixels in the second corrected infrared image whose brightness changes exceed a preset threshold and the number of second pixels whose brightness changes do not exceed the preset threshold relative to the first corrected infrared image; According to the average of the ratios of all the first pixel numbers to the second pixel numbers, the flow control valve on the first delivery pipeline corresponding to the hydrogen supply cylinder is adjusted.

2. The gas control method according to claim 1, characterized in that: The step of adjusting the flow control valve on the first delivery pipeline corresponding to the hydrogen supply cylinder according to the average of the ratios of all the first pixel numbers to the second pixel numbers includes: When the average of the ratios is greater than a first preset threshold, controlling the flow rate of the flow control valve to increase; When the average of the ratios is less than a second preset threshold, controlling the flow rate of the flow control valve to decrease; Wherein, the first preset threshold is greater than the second preset threshold.

3. The gas control method according to claim 1, characterized in that: A second temperature sensor is also provided in the gas mixing tank, and the method further comprises: When the first infrared image is obtained, controlling the second temperature sensor to collect the temperature inside the tank; Taking the gray value corresponding to the temperature inside the tank as a threshold, binarizing the second corrected infrared image to obtain a binary image corresponding to the second corrected infrared image; Calculating a first distance between any two pixels having a pixel value of 0 in the binary image, and calculating a second distance between any two pixels having a pixel value of 255 in the binary image; Calculate the mean square error of a set of values ​​consisting of the first distance and the second distance; After obtaining the mean square errors corresponding to all infrared cameras, determining whether each mean square error is less than or equal to a preset mean square error; When each mean square error is less than or equal to the preset mean square error, it is determined that the gas in the gas mixing tank is uniformly mixed; When at least one mean square error is greater than the preset mean square error, it is determined that the gas in the gas mixing tank is not mixed uniformly.

4. The gas control method according to claim 3, characterized in that: The method further comprises: When at least one mean square error is greater than the preset mean square error, the disturbance device in the gas mixing tank is controlled to perform disturbance.

5. The gas control method according to claim 1, characterized in that: One end of the first delivery pipeline and the second delivery pipeline are respectively connected to the exhaust pipeline, and the other end is connected to the purge pipeline.

6. A gas control device used in semiconductor manufacturing, characterized in that: The gas control device is used to adjust the ratio of phosphine gas and hydrogen gas in a gas mixing tank that provides mixed gas for chemical vapor deposition equipment. The gas mixing tank is provided with a filter that allows infrared wavelengths within a preset range of the absorption peak of phosphine gas to infrared light to pass through and an infrared light source blocked by the filter. A plurality of infrared cameras are provided at different positions outside the gas mixing tank, and each infrared camera is provided with an infrared detector for detecting wavelengths. A concentration sensor for detecting air concentration, a first temperature sensor for detecting air temperature, and a humidity sensor for detecting air humidity are also provided in the space where the gas mixing tank is located. The gas control device includes: A first control unit is used to control the plurality of infrared cameras to photograph the area corresponding to the gas mixing tank according to a preset cycle to obtain a plurality of first infrared images, and control each of the infrared detectors to collect a current first wavelength, the concentration sensor to collect a current first air concentration, the first temperature sensor to collect a current first air temperature, and the humidity sensor to collect a current first air humidity; a second control unit, for controlling the infrared light source to emit infrared light, and controlling the plurality of infrared cameras to photograph the area corresponding to the gas mixing tank to obtain a plurality of second infrared images, and controlling each of the infrared detectors to collect the current second wavelength, the concentration sensor to collect the current second air concentration, the first temperature sensor to collect the current second air temperature, and the humidity sensor to collect the current second air humidity; The first calculation unit is used to calculate the infrared propagation loss rate corresponding to each target infrared image using the following formula: =1-exp[−( (λ,C,T)+ (λ,T,RH)) x]; The target infrared image includes the first infrared image and the second infrared image. (λ,C,T) represents the absorption attenuation coefficient, (λ,T,RH) represents the scattering attenuation coefficient, λ is the wavelength collected by the infrared detector corresponding to the target infrared image when the target infrared image is acquired, C is the air concentration collected by the concentration sensor when the target infrared image is acquired, T is the air temperature collected by the first temperature sensor when the target infrared image is acquired, RH is the air humidity collected by the humidity sensor when the target infrared image is acquired, x is the distance of the infrared camera corresponding to the target infrared image relative to the shooting area, and exp represents the natural exponential function; The correction unit is used to correct the target infrared image using the following formula to obtain a corrected infrared image corresponding to the target infrared image: ； in, is the pixel in the infrared image of the target The corresponding pixel brightness; A comparison unit is used to compare pixels at the same position in a first corrected infrared image and a second corrected infrared image corresponding to the same infrared camera, and determine the number of first pixels in the second corrected infrared image whose brightness changes exceed a preset threshold and the number of second pixels whose brightness changes do not exceed the preset threshold relative to the first corrected infrared image; The regulating unit is used to regulate the flow control valve on the first delivery pipeline corresponding to the hydrogen supply cylinder according to the average of the ratios of all the first pixel numbers to the second pixel numbers.

7. The gas control device according to claim 6, characterized in that: The regulating unit is used to regulate the flow control valve on the first delivery pipeline corresponding to the hydrogen supply cylinder according to the average of the ratios of all the first pixel numbers to the second pixel numbers, including: When the average of the ratios is greater than a first preset threshold, controlling the flow rate of the flow control valve to increase; When the average of the ratios is less than a second preset threshold, controlling the flow rate of the flow control valve to decrease; Wherein, the first preset threshold is greater than the second preset threshold.

8. The gas control device according to claim 6, characterized in that: A second temperature sensor is also provided in the gas mixing tank, and the gas control device further comprises: a third control unit, configured to control the second temperature sensor to collect the temperature inside the tank when the first infrared image is obtained; A processing unit, configured to perform binarization processing on the second corrected infrared image by taking the gray value corresponding to the temperature inside the tank as a threshold value, so as to obtain a binary image corresponding to the second corrected infrared image; A second calculation unit is used to calculate a first distance between any two pixels whose pixel values ​​are 0 in the binary image, and to calculate a second distance between any two pixels whose pixel values ​​are 255 in the binary image; and to calculate a mean square error of a numerical set consisting of the first distance and the second distance; The judgment unit is used to judge whether each mean square deviation is less than or equal to a preset mean square deviation after obtaining the mean square deviations corresponding to all infrared cameras; when each mean square deviation is less than or equal to the preset mean square deviation, it is determined that the gas in the gas mixing tank is evenly mixed; when at least one mean square deviation is greater than the preset mean square deviation, it is determined that the gas in the gas mixing tank is unevenly mixed.

9. The gas control device according to claim 8, characterized in that: The gas control device also includes: The fourth control unit is used to control the disturbance device in the gas mixing tank to perform disturbance when at least one mean square error is greater than the preset mean square error.

10. The gas control device according to claim 6, characterized in that: One end of the first delivery pipeline and the second delivery pipeline are respectively connected to the exhaust pipeline, and the other end is connected to the purge pipeline.

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