Patent Application
20220082476
The disclosure relates to the field of semiconductors, and in particular, to a system for monitoring an environment and a monitoring method based on a system for monitoring an environment.
With the increase in the complexity of the semiconductor industry process and the miniaturization of feature sizes of products, the impact of the stability of gas environment in process areas on the products has become a key concern for environmental control of a clean room.
To resolve the problem above, embodiments of the disclosure provide a monitoring method based on a system for monitoring an environment, used for monitoring concentrations of airborne contaminants in a plurality of process areas in a clean room. The method is characterized by the following. The system for monitoring an environment includes: a sampling device, configured to collect environmental samples of the process areas and including a system sampling pipeline, the environmental sample including air; an analysis device, connected to an output end of the system sampling pipeline and configured to analyze the collected environmental samples; and an air supply device, connected to the system sampling pipeline and configured to provide a purge gas and purge the system sampling pipeline using the purge gas. In a period for a single sampling, a ratio between the time period for purging the system sampling pipeline by using the air supply device and the time period for sampling by using the sampling device is controlled to be 1:5.
The embodiments of the disclosure further provide a system for monitoring an environment, used for monitoring concentrations of airborne contaminants in a plurality of process areas in a clean room. The system includes an air supply device, a sampling device, an analysis device, and a control device.
The air supply device is connected to a system sampling pipeline and configured to provide a purge gas and purge the system sampling pipeline by using the purge gas.
The sampling device includes the system sampling pipeline and is configured to collect environmental samples of the process areas. The environmental samples include air.
The analysis device is connected to an output end of the system sampling pipeline and configured to analyze the collected environmental samples.
The control device is configured to control, in a period for a single sampling, a ratio between the time period for purging the system sampling pipeline by using the air supply device and the time period for sampling by using the sampling device to be 1:5.
One or more embodiments are exemplified by figures in the corresponding drawings. These exemplified descriptions do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings do not constitute a scale limitation.
To make the objectives, technical solutions, and advantages of embodiments of the disclosure clearer, the embodiments of the disclosure are described below in detail with reference to the accompanying drawings. However, it should be understood for persons of ordinary skill in the art that, in each embodiment of the disclosure, many technical details are proposed for a reader to better understand the disclosure. However, the technical solutions claimed by the disclosure can be realized, even without these technical details and various changes and modifications based on the following embodiments.
In related technologies, the ratio between the time period for cleaning the sampling pipeline and the time period for sampling by using the sampling device in system for monitoring an environment is not fixed. The time period of sampling cycle is different each time. The composition of the gas in the process areas is different, after each sampling cycle, causing the problem of unstable gas environment in the process areas, which in turn affects the product yield. To resolve the problem, the embodiments of the disclosure provide a system for monitoring an environment and a monitoring method based on a system for monitoring an environment.
Referring to
In this embodiment, the sampling device includes a sampling pump 111, located between the system sampling pipeline 114 and the analysis device 12. During sampling, the sampling pump 111 is operated to collect the environmental samples from the process areas 10 and transmit the collected environmental samples to the analysis device 12.
In some examples, the environment monitoring system further includes a control device, configured to control the ratio between the time period for purging the system sampling pipeline by using the air supply device and the time period for sampling by the using sampling device to be 1:5. The control system is further configured to control the operation of the sampling pump during the sampling.
In another example, the sampling device further includes a buffer box (not shown). The buffer box is used for pre-mixing and stabling the environmental samples collected by the sampling pump 111, to ensure that the air pressure of the environmental samples for analysis is within a preset range, avoiding a pressure fluctuation caused by intermittent sampling of the sampling pump 111, preventing data analysis of the analysis device 12 from being affected by the pressure fluctuation, and ensuring the accuracy of concentration data of airborne contaminants obtained by the analysis device 12.
Data analysis can be performed by the analysis device 12 when the pressure in the buffer box is within the preset range. The buffer box may perform a pressure calculation function. In addition, the buffer box may have a pressure relief port, which is used to relieve part of the pressure when there is no time for data analysis due to sudden increase in the internal pressure of the buffer box, to ensure that the concentration data obtained by the analysis has higher accuracy.
In this embodiment, the sampling pump 111 may be in type of a diaphragm pump. A gas transport pipeline is separated from a plunger through a diaphragm, so as to prevent contaminants on a surface of the plunger from contaminating the transported gas, thereby ensuring the accuracy of the data about the concentration obtained by the analysis device 12.
In one example, the analysis device 12 is further configured to analyze the gas purged from the system sampling pipeline 114 to the analysis device 12. The analysis device 12 includes a plurality of analysis modules. Each of the analysis modules is configured to analyze the concentration of the corresponding airborne contaminant. The plurality of analysis modules can simultaneously analyze the environmental samples collected by the sampling device. In this way, concentrations of different types of airborne contaminants can be obtained at the same time without sequential analysis, which facilitates shortening the overall analysis time for the concentrations of airborne contaminants In addition, the sampling frequency of the environmental samples can be reduced, and thus the monitoring time for the concentrations of airborne contaminants, can be further shortened, thereby facilitating the rapid monitoring and rapid treatment for the concentrations of the airborne contaminants.
In another example, the analysis device 12 includes an acid analysis module, an ammonia analysis module, a sulfur analysis module, and an organic substance analysis module, which are respectively configured to monitor the concentration of an acidic gas, the concentration of ammonia, the concentration of a sulfur dioxide, and the concentration of an organic substance in the process areas 10, to prevent acidic gas and ammonia from affecting the formation of metal wires, prevent salts produced by the reaction of acid gas and ammonia from affecting the product yield, and prevent sulfur dioxide from combining with ammonia to cause atomization on a surface of a photomask, thereby avoiding the reduction in the product yield and the increase in rework rate caused by the atomization.
In other embodiments, the analysis device may further include an analysis module for other airborne contaminants. It should be noted that any gas that may affect the process or product yield may be regarded as an airborne contaminant, and the types of airborne contaminants may be different in different process areas.
In this embodiment, referring to
A positional relationship among the single sampling pipelines 113, the system sampling pipeline 114, and the sampling valve 115 is shown, referring to
The monitoring method of this embodiment further includes the following operations. When sampling, the sampling valve 115 is controlled to connect one of the single sampling pipelines 113 corresponding to one of the target process areas to the system sampling pipeline 114, and disconnect the other single sampling pipelines 113 from the system sampling pipeline 114. The environmental sample collected from the target process area is analyzed by the analysis device 12.
It should be noted that at a same moment, a plurality of sampling valves 115 may be in a state of connecting the single sampling pipelines 113 and the system sampling pipeline 114. That is, the analysis device 12 can be configured to analyze the concentration of the airborne contaminant in one process area 10, and can also be configured to analyze an average concentration of the airborne contaminants in the plurality of process areas 10.
Referring to
Since the system sampling pipeline 114 is shared, in order to avoid residual airborne contaminants in the previous sampling process from affecting a next sampling, it is necessary to clean the system sampling pipeline 114 between two collections. The sampling valve 115 can be disposed at one end of the single sampling pipeline 113 towards the system sampling pipeline 114, in order to being unable to be effectively removed due to the accumulation of airborne contaminants in the single sampling pipeline 113 during the cleaning process. In this way, it is ensured that the single sampling pipeline 113 has a higher cleanliness, and the sampling valve 115 can be cleaned to a certain extent.
In this embodiment, the air supply device 13 is connected to the system sampling pipeline 114. The air supply device 13 is configured to provide a purge gas, purge the system sampling pipeline 114 using the purge gas, and send the purged gas to the analysis device 12. In this way, when the environment of the system sampling pipeline 114 is confirmed to satisfy the sampling requirements by using the analysis device 12, the air supply device 13 is controlled by using the control device to stop purging, and thus the next sampling is performed. In this way, it is ensured that the environment of the system sampling pipeline 114 during the next sampling satisfies the preset requirements, so as to prevent the environment of the system sampling pipeline 114 from interfering the analysis of the airborne contaminant concentration in the process areas 10, and to ensure the accuracy of detection results.
It should be noted that the purging of the system sampling pipeline 114 by using the air supply device 13 may also affect the adsorption of an inner wall of the system sampling pipeline 114. Specifically, the longer the purging time is, the cleaner the inner wall of the system sampling pipeline 114 is, the greater the adsorption capacity of the inner wall to the airborne contaminants is, and the lower the detection value of airborne contaminants is. Accordingly, the shorter the purging time is, the dirtier the inner wall of the system sampling pipeline 114 is. The airborne contaminants on the inner wall of the system sampling pipeline 114 may affect the detection results, resulting in the higher detection value of airborne contaminants. That is, when cleaning the system sampling pipeline 114, the cleaning time needs to be controlled, so that the inner wall of the system sampling pipeline 114 is at a preset clean level.
In this embodiment, the environment monitoring system further includes a control device (not shown), configured to control the sampling device to collect environmental samples from preset process areas 10. The control device is further configured to control a valve state of the sampling valve 115. That is, the switching of objects collected from the process areas 10 is realized, by controlling the valve state of the sampling valve 115 through the control device, so as to obtain the data about the concentrations of airborne contaminants of the specific process areas 10.
In this embodiment, the control device is further configured to set a concentration threshold for at least one process area 10. The system for monitoring an environment further includes a warning device (not shown), configured to send, responsive to a concentration threshold of any process area 10 exceeding a preset concentration threshold of the process area 10, warning information. In this way, it is beneficial to quickly clean the specific process areas where airborne contaminants exceed the standard.
Referring to
It should be noted that, in this embodiment, in order to save a time-cost of the entire sampling cycle process and to ensure that the inner wall of the system sampling pipeline 114 is at a preset clean level, in the period for a single sampling, the time period for purging the system sampling pipeline 114 by using the air supply device 13 may be controlled in a range from 10 minutes to 15 minutes, specifically, 12 minutes, 13 minutes, or 14 minutes, and the time period for sampling by using the sampling device may be controlled in a range from 50 minutes to 75 minutes, specifically 55 minutes, 60 minutes, or 65 minutes.
Referring to
In one example, referring to
Referring to
Referring to
In the sampling process of a process area 10, because the system sampling pipeline 114 is in contact with each sampling valve 115, airborne contaminants may be deposited on a surface of each sampling valve 115 exposed by the system sampling pipeline 114. At the same time, since molecules of the airborne contaminants are small and prone to drift, a small amount of airborne contaminants may be transferred to other positions of the sampling valve. Before performing the sampling in this process area 10 again, it is necessary to purge the system sampling pipeline 114 using the air supply device 13, to remove the airborne contaminants left in the system sampling pipeline 114 when the previous process area 10 is sampled, avoiding the airborne contaminants in the system sampling pipeline 114 from affecting the analysis result of the analysis device 12. In addition, since a small amount of airborne contaminants cannot be purged and removed by the air supply device 13, the CDA can be introduced for back-blowing, so as to perform further cleaning on the single sampling valve 115 corresponding to the process area 10 sampled for the second time. Since there are fewer residual airborne contaminants, the back-blowing has less influence on the analysis results.
It should be noted that, since the gas used by the air supply device 13 for purging is finally introduced to the buffer box, inert gas or nitrogen may be used for purging. In addition, since the gas during the back-blowing is finally introduced to the process area 10 of the clean room, and there may be a staff in the clean room, breathable dry air may be used, to ensure the life safety of the staff.
In this embodiment, the system for monitoring an environment further includes a humidification device 14, configured to provide a water mist. The humidification device 14 is connected between the air supply device 13 and the system sampling pipeline 114. The water mist is generated by the humidification device 14, so that the purge gas and the water mist are mixed and then enter the system sampling pipeline 114. In this way, after the purge gas provided by the air supply device 13 is humidified by the water mist provided by the humidification device 14, the purge gas contains the water mist. Because some residual contaminants in the system sampling pipeline 114 are soluble in water, the residual contaminants in the system sampling pipeline 114 can be removed quickly. Therefore, the cleaning time is shortened, increasing the sampling frequency. Moreover, after one sampling and prior to next sampling, the residual contaminants in the system sampling pipeline 114 can be more thoroughly removed by the humidification device 14, to ensure that each sampling would not be interfered by the airborne contaminants in the process area from the sampling prior to it, which facilitates ensuring that the data about the airborne contaminants in the process area obtained from each sampling analysis have higher accuracy.
In the embodiments of the present disclosure, the humidification device 14 is also connected between the air inlet pipeline 17 and the cleaning pipeline 16, so that the CDA and the water mist are mixed to clean the sampling valve 115 and the single sampling pipeline 113. In this way, the air inlet pipeline 17 contains the water mist humidified CDA, which can clean the single sampling pipeline 113 through the cleaning pipeline 16. Because some residual contaminants in the single sampling pipeline 113 are soluble in water, the residual contaminants in the single sampling pipeline 113 can be removed quickly. Therefore, the cleaning time is shortened, and the sampling frequency is increased.
The residual contaminants in the pipelines may be ammonia.
Referring to
In some examples, the control device is further configured to control the purge gas and the water mist to be mixed and then transmitted to the system sampling pipeline via the humidification pipeline.
In one example, referring to
The switch valve 14c may be a solenoid valve.
In another example, referring to
Referring to
In summary, the humidification device 14 being connected to the system sampling pipeline 114 using the humidification pipeline 14a or the drying pipeline 14b can be switched by the timing module 14d or the first processing module 15.
Referring to
In this embodiment, the humidification device 14 further includes a circulating pump 14j connected to the water storage tank 14e and configured to maintain the continuous flow of water in the water storage tank 14e and prevent bacteria breeding.
In this embodiment, the system for monitoring an environment further includes a humidity sensor and a second processing module. The humidity sensor is disposed at a port of the system sampling pipeline 114 facing the humidification device 14 and configured to detect a humidity of the purge gas in the system sampling humidification 114. The second processing module is used for displaying, according to a humidity displayed by the humidity sensor, an amount of the water mist provided by the humidification device 14.
Referring to
Referring to
When a process area 10 is sampled, single sampling pipelines 113 corresponding to other process areas 10 can be connected to the cleaning pipeline 16, and one end of the cleaning pipeline 16 is connected to the air outlet pipeline 172. A gas in the single sampling pipeline 113 is the same as an ambient gas in the corresponding process area 10 through pumping by the cleaning pump 173, facilitating the next sampling. The gas in the single sampling pipeline 113 is kept in a flow state through pumping by the cleaning pump 173, avoiding the airborne contaminants in the single sampling pipeline 113 from being adsorbed on the inner wall of the single sampling pipeline 113 due to the gas in a static state, and ensuring that the single sampling pipeline 113 has a higher degree of cleanliness, which is beneficial to improve the accuracy of the detection results.
Compared with back-blowing cleaning, different airborne contaminants in the process areas 10 may be removed proportionally or non-proportionally by air-pumping cleaning, which causes an inaccurate detection results. Specifically, when the ratio of the removed airborne contaminants to the total airborne contaminants is different from the ratio of the removed carrier gas (gases other than the airborne contaminants) to the total carrier gas, the concentration of airborne contaminants in the process area 10 may be increased or reduced. When the ratio of different types of removed airborne contaminants to the total amount of airborne contaminants is different, the contrast relationship of the concentration of different types of airborne contaminants in the process area 10 may change.
Since the total amount of CDA introduced during back-blowing can be calculated, the back-blowing cleaning solution can eliminate the influence of CDA on the analysis of airborne contaminant concentration through calculation, thereby accurately obtaining the analysis results of airborne contaminants. The analysis results include the types of airborne contaminants, the concentrations of airborne contaminants, and the concentration ratio of different airborne contaminants.
In this embodiment, in the period for a single sampling, the ratio between the time period for purging the system sampling pipeline by using the air supply device and the time period for sampling by using the sampling device is controlled to be 1:5. In addition, the cleaning of the system sampling pipeline 114 by the air supply device 13 and the cleaning of the single sampling pipelines by the CDA are started at the same time, and last for the same period. Therefore, the ratio between the time period for cleaning the system and the time period for sampling by using the sampling device is the same. In this way, in each sampling cycle, the single sampling pipelines have the same cleanliness, and the degree of sampling gases of the process areas is also the same. Thus, there would be no analysis error caused by the different sampling cycles in the analysis on the components of ambient gas in the process areas, which ensures that there is only a small change in the composition of ambient gas in process areas after each sampling cycle, improving the stability of the ambient gas in the process areas.
Persons of ordinary skill in the art can understand that the foregoing embodiments are exemplary embodiments for realizing the disclosure. In practical applications, various changes can be made in form and details, without departing from the spirit and the scope of the embodiments of the disclosure. Any person skilled in the art can make various changes and modifications without departing from the spirit and the scope of the embodiments of the disclosure. Therefore, the protection scope of the embodiments of the disclosure should be subject to the scope defined by the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202010973476.9 | Sep 2020 | CN | national |
This application is a U.S. continuation application of International Application No. PCT/CN2021/105332, filed on Jul. 8, 2021, which claims priority to Chinese Patent Application No. 202010973476.9, filed on Sep. 16, 2020. International Application No. PCT/CN2021/105332 and Chinese Patent Application No. 202010973476.9 are incorporated herein by reference in their entireties.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/CN2021/105332 | Jul 2021 | US |
| Child | 17504586 | US |
