Clean room environment detection method, device and equipment and storage medium

Abstract

The invention provides a clean room environment detection method, device and equipment and a storage medium. The method comprises the steps that air in a clean room is collected; component analysis is conducted on the air in the clean room, and the concentration of positive ions and the concentration of negative ions in the clean room are obtained; the positive ions are basic ions, and the negative ions are acidic ions; and determining the environmental pollution state of the clean room according to the concentration of the cations and / or the concentration of the anions. According to the clean room environment detection method provided by the embodiment of the invention, the component analysis result of the air in the clean room can be obtained by collecting the air in the clean room, so that the concentration of positive ions and the concentration of negative ions in the clean room are determined, and finally the environment pollution state in the clean room is determined according to the concentration of the positive ions and the concentration of the negative ions in the clean room. The problem that no specific evaluation method for judging the environment pollution state in the clean room exists in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor processing technology, and in particular to a clean room environment detection method, device, equipment and storage medium. Background Art

[0002] The semiconductor silicon wafer manufacturing process requires a highly clean environment to ensure the quality of the silicon wafer products. Cleanrooms primarily provide a clean environment through physical isolation to prevent contamination of silicon wafer products by pollutants such as dust, microorganisms, and airborne molecular contaminants (AMC). Under certain time and temperature conditions, the anions and cations in AMC can easily form time-dependent haze defects (TDH) on the silicon wafer surface, affecting the quality of the silicon wafer. Disposal of these contaminated wafers is costly. However, it is currently impossible to quantify the impact of different concentrations of anions and cations on the severity of TDH formed on the silicon wafer surface, and there is no specific evaluation method to determine the environmental contamination status within the cleanroom. Summary of the Invention

[0003] The embodiments of the present invention provide a clean room environment detection method, device, equipment and storage medium, which are used to solve the problem that there is no specific evaluation method to judge the environmental pollution status in the clean room in the prior art.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0005] In a first aspect, an embodiment of the present invention provides a clean room environment detection method, comprising:

[0006] Collecting air from clean rooms;

[0007] Performing a component analysis on the air in the clean room to obtain the concentration of cations and anions in the clean room; the cations are alkaline ions and the anions are acidic ions;

[0008] The environmental pollution state of the clean room is determined according to the concentration of the cations and / or the concentration of the anions.

[0009] Optionally, before determining the environmental pollution state of the clean room according to the concentration of the cations and / or the concentration of the anions, the method further comprises:

[0010] Placing a plurality of sample silicon wafers in environments with different contamination states for degradation testing to obtain test results; the sample silicon wafers are cleaned and have a surface particle count less than a preset count; the concentrations of the cations and / or anions in the different state environments are different; and the test results include a time-dependent number of fog defects on the surfaces of the sample silicon wafers;

[0011] According to the test result, a first correspondence between the concentration of the cations and / or the concentration of the anions and the number of defects in the time-dependent fog is determined.

[0012] Optionally, determining the environmental pollution state of the clean room according to the concentration of the cations and / or the concentration of the anions includes:

[0013] Determining a first preset threshold and / or a second preset threshold according to the first corresponding relationship; the first preset threshold is the concentration of the cation corresponding to when the number of defects in the time-dependent fog is a first number; the second preset threshold is the concentration of the anion corresponding to when the number of defects in the time-dependent fog is a first number;

[0014] When the concentration of the cations is greater than the first preset threshold, and / or the concentration of the anions is greater than the second preset threshold, it is determined that the environment of the clean room is contaminated.

[0015] Optionally, the first preset threshold is 5000 ng / m 3 The second preset threshold is 200000ng / m 3 .

[0016] Optionally, performing a composition analysis on the air in the clean room to obtain the concentration of cations and anions in the clean room includes:

[0017] dissolving the air in the clean room in ultrapure water to obtain a mixed solution;

[0018] The mixed solution is quantitatively analyzed to obtain the concentration of cations and anions in the clean room.

[0019] Optionally, multiple sample silicon wafers are placed in environments with different pollution states to perform degradation tests, and test results are obtained, including:

[0020] The morphology of the sample silicon wafer that has undergone the degradation test is detected to obtain the test result including the number of time-dependent fog defects on the surface of the sample silicon wafer.

[0021] Optionally, the method further includes one of the following:

[0022] When the concentration of the cations is greater than the first preset threshold and the concentration of the anions is greater than the second preset threshold, cleaning the target silicon wafer and replacing the air in the clean room; the target silicon wafer is a silicon wafer being processed in the clean room;

[0023] When the concentration of the cations is greater than the first preset threshold and the concentration of the anions is less than or equal to the second preset threshold, cleaning the target silicon wafer and replacing the air in the clean room;

[0024] When the concentration of the cations is less than or equal to the first preset threshold, there is no need to clean the target silicon wafer and replace the air in the clean room.

[0025] In a second aspect, an embodiment of the present invention provides a clean room environment detection device, comprising:

[0026] Collection module, used to collect air in the clean room;

[0027] An analysis module, configured to analyze the composition of the air in the clean room to obtain the concentration of cations and anions in the clean room; the cations are alkaline ions and the anions are acidic ions;

[0028] The determination module is used to determine the environmental pollution state of the clean room according to the concentration of the cations and / or the concentration of the anions.

[0029] In a third aspect, an embodiment of the present invention provides a clean room environment detection device, comprising: a transceiver, a memory, a processor, and a computer program stored in the memory and runnable on the processor. When the processor executes the computer program, the steps of the clean room environment detection method as described above are implemented.

[0030] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon, which implements the steps of the clean room environment detection method as described above when executed by a processor.

[0031] The beneficial effects of the present invention are:

[0032] The cleanroom environment monitoring method of the present application, by collecting air from the cleanroom, can obtain compositional analysis results of the cleanroom air, thereby determining the concentrations of cations and anions in the cleanroom. Ultimately, based on the concentrations of cations and anions in the cleanroom, the environmental pollution status within the cleanroom is determined. This solves the problem of the lack of a specific evaluation method for determining the environmental pollution status within a cleanroom in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A schematic diagram showing the steps of a clean room environment detection method according to an embodiment of the present invention;

[0034] Figure 2 A schematic diagram showing the surface of a sample silicon wafer in a clean room environment according to an embodiment of the present invention;

[0035] Figure 3 A schematic diagram showing the surface of a sample silicon wafer in a clean room environment according to another embodiment of the present invention;

[0036] Figure 4 A schematic diagram showing the surface of a sample silicon wafer in a clean room environment according to another embodiment of the present invention;

[0037] Figure 5 A schematic diagram of a module of a clean room environment detection device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0038] To make the technical problems, technical solutions, and advantages to be solved by the present invention more apparent, a detailed description will be given below with reference to the accompanying drawings and specific embodiments. In the following description, specific details such as specific configurations and components are provided solely to facilitate a comprehensive understanding of the embodiments of the present invention. Therefore, it should be clear to those skilled in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present invention. In addition, for the sake of clarity and brevity, descriptions of known functions and configurations have been omitted.

[0039] It should be understood that references throughout this specification to "one embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic associated with the embodiment is included in at least one embodiment of the present invention. Therefore, the appearances of "in one embodiment" or "in an embodiment" throughout this specification do not necessarily refer to the same embodiment. Furthermore, these particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0040] Aiming at the problem that there is no specific evaluation method for judging the environmental pollution state in a clean room in the prior art, the present invention provides a clean room environment detection method, device, equipment and storage medium.

[0041] like Figure 1 As shown, the embodiment of the present application provides a clean room environment detection method, comprising the following steps:

[0042] Step 101, collecting air in the clean room;

[0043] Step 102: Analyze the composition of the air in the clean room to obtain the concentration of cations and anions in the clean room; the cations are alkaline ions and the anions are acidic ions;

[0044] Step 103: Determine the environmental pollution state of the clean room according to the concentration of the cations and / or the concentration of the anions.

[0045] Exemplarily, collecting the air in the clean room includes:

[0046] An air sampling pump is used to collect air in the clean room;

[0047] The sampling flow rate of the sampling pump is 0.2L / min-2L / min, and the sampling time of the sampling pump is 10min-60min.

[0048] In one embodiment of the present invention, the sampling flow rate of the sampling pump is 0.2 L / min, and the sampling time of the sampling pump is 60 min.

[0049] In another embodiment of the present invention, the sampling flow rate of the sampling pump is 1 L / min, and the sampling time of the sampling pump is 30 minutes.

[0050] In yet another embodiment of the present invention, the sampling flow rate of the sampling pump is 2 L / min, and the sampling time of the sampling pump is 10 min.

[0051] It should be noted that when the flow rate of the sampling pump is small, the sampling period of the air in the clean room is too long, which affects the efficiency of environmental detection on the one hand, and on the other hand, the long sampling period may cause the air in the clean room to circulate with the outside world, resulting in inaccurate samples.

[0052] When the flow rate of the sampling pump is large, although the air collection in the clean room can be completed quickly, it is easy to cause the indoor air to be greatly disturbed and circulated with the outside world, resulting in inaccurate collected samples, and a high-power sampling pump is required, resulting in high air collection costs.

[0053] Exemplarily, the cations include: NH4 + ;

[0054] The anion includes at least one of the following: Cl - 、NO3 - and SO4 2- .

[0055] It should be noted that HCl, HNO3 or HSO4 may exist or be produced during the processing of silicon wafers in a clean room; therefore, for the anions in the clean room, consider Cl - 、NO3 - and SO4 2- At least one of the .

[0056] In one embodiment of the present invention, the cation is NH4 + ;

[0057] The anion is Cl - and NO3 - .

[0058] In another embodiment of the present invention, the cation is NH4 + ;

[0059] The anion is Cl - 、NO3 - and SO4 2- .

[0060] It should be noted that a certain concentration of the cations and a certain concentration of the anions will lead to the formation of time-dependent haze (TDH) defects on the surface of the silicon wafer, which affects the quality of the silicon wafer. It costs a lot to deal with this type of pollution.

[0061] The cleanroom environment monitoring method of the present application, by collecting air from the cleanroom, can obtain compositional analysis results of the cleanroom air, thereby determining the concentrations of cations and anions in the cleanroom. Ultimately, based on the concentrations of cations and anions in the cleanroom, the environmental pollution status within the cleanroom is determined. This solves the problem of the lack of a specific evaluation method for determining the environmental pollution status within a cleanroom in the prior art.

[0062] Optionally, before determining the environmental pollution state of the clean room according to the concentration of the cations and / or the concentration of the anions, the method further comprises:

[0063] Placing a plurality of sample silicon wafers in environments with different contamination states for degradation testing to obtain test results; the sample silicon wafers are cleaned and have a surface particle count less than a preset count; the concentrations of the cations and / or anions in the different state environments are different; and the test results include a time-dependent number of fog defects on the surfaces of the sample silicon wafers;

[0064] According to the test result, a first correspondence between the concentration of the cations and / or the concentration of the anions and the number of defects in the time-dependent fog is determined.

[0065] In the embodiment of the present application, the sample silicon wafer is a silicon wafer that has been cleaned with a cleaning agent and has a number of particles on its surface that is less than or equal to 10.

[0066] For example, the different environmental pollution states are simulated and constructed by an experiment. In a clean room, a mixed acid solution and ammonia water are used and volatilized to simulate the environmental pollution state.

[0067] The mixed acid solution is HCl and HNO3 in a concentration ratio of 1:1-1:2, and the ammonia solution is 10%-90% of the HCl concentration. In the embodiment of the present application, an experiment is used to simulate and construct the different environmental pollution states, such as the following:

[0068] First environmental contamination state: In a 200L cleanroom, a mixed acid solution and ammonia water were volatilized for 30 minutes. The mixed acid solution was a mixture of HCl and HNO3, with a concentration ratio of HCl to HNO3 of 1:2 (e.g., 0.7% HCl and 0.7% HNO3). The concentration of the ammonia water was 10% of the HCl concentration, i.e., 0.07%. During the volatilization process, the cleanroom temperature was maintained at 25°C and the pressure at 1 atmosphere.

[0069] Second environmental contamination state: In a 200L cleanroom, a mixed acid solution and ammonia water were volatilized for 30 minutes. The mixed acid solution was a mixture of HCl and HNO3, with a concentration ratio of HCl to HNO3 of 1:1 (e.g., 0.5% HCl and 0.5% HNO3). The concentration of the ammonia water was 50% of the HCl concentration, i.e., 0.25%. During the volatilization process, the cleanroom temperature was maintained at 25°C and the pressure at 1 atmosphere.

[0070] Third environmental contamination state: In a 200L cleanroom, a mixed acid solution and ammonia water were volatilized for 30 minutes. The mixed acid solution was a mixture of HCl and HNO3, with a concentration ratio of HCl to HNO3 of 1:1 (e.g., 0.5% HCl and 1% HNO3). The concentration of the ammonia water was 90% of the concentration of the HCl, i.e., 0.45%. During the volatilization process, the cleanroom temperature was maintained at 25°C and the pressure at 1 atmosphere.

[0071] For example, in a clean room, a mixed acid solution is used and allowed to volatilize;

[0072] Wherein, the mixed acid solution is HCl and HNO3 with a concentration ratio ranging from 1:1 to 1:2.

[0073] In another embodiment of the present application, different environmental pollution states are simulated and constructed by experiments, for example:

[0074] Fourth environmental pollution state: In a 200L clean room, a mixed acid solution is used and volatilized for 30 minutes; wherein the mixed acid solution is a mixture of HCl and HNO3, and the concentration ratio of HCl to HNO3 in the mixed acid solution is 1:1 (for example, the concentration of HCl is 1% and the concentration of HNO3 is 1%); during the volatilization process, the clean room temperature is controlled at 25°C and the pressure is 1 atmosphere; or,

[0075] Fifth environmental contamination state: In a 200 L clean room, a mixed acid solution is volatilized for 30 minutes. The mixed acid solution comprises a mixture of HCl and HNO3, with a concentration ratio of HCl to HNO3 of 1:2 (e.g., 1% HCl and 2% HNO3). During the volatilization process, the clean room temperature is maintained at 25°C and the pressure is maintained at 1 atmosphere.

[0076] For example, in a clean room, ammonia is used and allowed to volatilize;

[0077] The concentration of the ammonia water is 1%-5%.

[0078] In another embodiment of the present application, different environmental pollution states are simulated and constructed by an experimental method, for example:

[0079] Sixth environmental pollution state: In a 200L clean room, ammonia water is used and allowed to evaporate for 30 minutes; wherein the concentration of the ammonia water is 1%; during the evaporation process, the clean room temperature is controlled at 25°C and the pressure is controlled at 1 atmosphere; or,

[0080] The seventh environmental pollution state: In a 200L clean room, ammonia water is used and allowed to evaporate for 30 minutes; the concentration of the ammonia water is 5%; during the volatilization process, the temperature of the clean room is controlled at 25°C and the pressure is 1 atmosphere.

[0081] It should be noted that, for the different environmental pollution states constructed, the specific ratio of the mixed acid solution and the concentration of the ammonia solution are not limited to the above embodiment. It is necessary to construct a large number of experimental environments with different environmental pollution states, and then determine the concentrations of anions and cations in different environmental pollution states;

[0082] The first corresponding relationship is determined by placing the silicon wafer in different environmental pollution states.

[0083] It should be noted that the temperature, humidity and pressure in the clean room are generally at a relatively stable level; therefore, the simulated environment adopts a temperature of 25°C and a constant pressure to eliminate the influence of temperature and pressure on the formation of time-dependent fog defects on the surface of the sample silicon wafer.

[0084] It should be noted that the purpose of conducting deterioration tests on silicon wafers under different environmental pollution conditions is to accelerate the generation of time-dependent fog defects on the silicon wafer surface and simulate the impact of cations and anions in the air on silicon wafers during the silicon wafer production process.

[0085] Exemplarily, the test object of the degradation test is a silicon wafer, the test variables are time and temperature, and the test result is the number of time-dependent fog defects on the surface of the silicon wafer;

[0086] Wherein, the duration includes exposure duration and heating duration;

[0087] The exposure time is 20 min to 60 min;

[0088] The heating time is 16h-32h;

[0089] The heating time is divided into multiple stages (for example, 16 stages to 64 stages), the heating temperature of each stage is different, and the stage heating time of each stage is the same (for example, the stage heating time is 0.5h-1h).

[0090] In the examples of the present application, the Kazumi test was performed in an oven.

[0091] In one embodiment of the present application, the deterioration test is:

[0092] An equal number of the sample silicon wafers were exposed to each environmental state, and the sample silicon wafers were placed in a front opening wafer shipping box (FOSB) for 20 minutes.

[0093] The exposed sample silicon wafer is introduced into a new FOSB and allowed to stand for a period of time;

[0094] The sample silicon wafer is heated in an oven after being left to stand;

[0095] The heating of the sample silicon wafer is divided into 16 stages, and the heating temperature of each stage is gradually increased, heating the sample silicon wafer from 25°C to 60°C; the stage heating time is 1 hour; and the total heating time is 16 hours.

[0096] In another embodiment of the present application, the deterioration test is:

[0097] An equal number of the sample silicon wafers were exposed to each environmental state, and the sample silicon wafers were placed in a front opening wafer shipping box (FOSB) for 30 minutes;

[0098] The exposed sample silicon wafer is introduced into a new FOSB and allowed to stand for a period of time;

[0099] The sample silicon wafer is heated in an oven after being left to stand;

[0100] The heating of the sample silicon wafer is divided into 24 stages, and the heating temperature of each stage gradually increases, heating the sample silicon wafer from 25°C to 60°C; the stage heating time is 0.6h; and the total heating time is 14.4h.

[0101] In another embodiment of the present application, the deterioration test is:

[0102] An equal number of the sample silicon wafers were exposed to each environmental state, and the sample silicon wafers were placed in a front opening wafer shipping box (FOSB) for 40 minutes.

[0103] The exposed sample silicon wafer is introduced into a new FOSB and allowed to stand for a period of time;

[0104] The sample silicon wafer is heated in an oven after being left to stand;

[0105] The heating of the sample silicon wafer is divided into 64 stages, and the heating temperature of each stage gradually increases, heating the sample silicon wafer from 25°C to 80°C; the stage heating time is 0.5h; and the total heating time is 32h.

[0106] The clean room environment detection method of the embodiment of the present application constructs a plurality of different environmental pollution states and detects the number of time-dependent fog defects on silicon wafers in these different environmental pollution states. It is possible to obtain a first correspondence between the concentration of the cations and / or the concentration of the anions and the number of time-dependent fog defects, thereby quickly determining the environmental pollution state of the clean room corresponding to the different concentrations of cations and / or anions in the clean room.

[0107] Optionally, performing a composition analysis on the air in the clean room to obtain the concentration of cations and anions in the clean room includes:

[0108] dissolving the air in the clean room in ultrapure water to obtain a mixed solution;

[0109] The mixed solution is quantitatively analyzed to obtain the concentration of cations and anions in the clean room.

[0110] The clean room environment detection method of the embodiment of the present application can determine the concentration of cations and anions in the clean room by quantitatively analyzing the mixed solution, thereby accurately determining the environmental status in the clean room.

[0111] In the embodiment of the present application, the concentration of anions and cations in the simulated environment is measured using an ion chromatography device, which can accurately measure the concentration of cations and anions in the environment;

[0112] Specifically:

[0113] Dissolving the collected gases from the different simulated environments in ultrapure water (UPW) to obtain the mixed solution; the volume of the ultrapure water is determined according to the volume of the collected gases, ensuring that the volume of the ultrapure water is less than or equal to the volume of the collected gases;

[0114] The mixed solution is quantitatively analyzed using an ion chromatography device to obtain the concentration of cations and anions in the mixed solution.

[0115] In one embodiment of the present application, the first correspondence is in the form of a model;

[0116] Determining the first corresponding relationship according to the test result includes:

[0117] Obtain the concentration of cations and anions in each environmental state;

[0118] determining the number of defects in the time-dependent fog on the surface of a sample silicon wafer placed in each environmental contamination state;

[0119] Performing model training according to the concentration of the cations, the concentration of the anions, and the number of defects in the time-dependent fog to obtain a target model;

[0120] The input of the model is the concentration of the cations and the concentration of the anions, and the output of the model is the number of defects in the time-dependent fog;

[0121] The target model is determined to be the first corresponding relationship.

[0122] In another embodiment of the present application, the first corresponding relationship is in the form of a curve;

[0123] Determining the first corresponding relationship according to the test result includes:

[0124] Obtain the concentration of cations and anions in each environmental state;

[0125] determining the number of defects in the time-dependent fog on the surface of a sample silicon wafer placed in each environmental contamination state;

[0126] Performing curve fitting according to the concentration of the cations, the concentration of the anions, and the number of defects in the time-dependent fog to obtain a target curve;

[0127] The fitting curve is used to characterize the corresponding relationship between the concentration of the cations, the concentration of the anions, and the number of defects in the time-dependent fog;

[0128] The target curve is determined to be the first corresponding relationship.

[0129] In another embodiment of the present application, the first corresponding relationship is in the form of a mathematical formula;

[0130] Determining the first corresponding relationship according to the test result includes:

[0131] Obtain the concentration of cations and anions in each environmental state;

[0132] determining the number of defects in the time-dependent fog on the surface of a sample silicon wafer placed in each environmental contamination state;

[0133] Fitting a mathematical formula according to the concentration of the cations, the concentration of the anions, and the number of defects in the time-dependent fog to obtain a target mathematical formula;

[0134] Wherein, one end of the mathematical formula includes the concentration of the cations and the concentration of the anions, and the other end of the mathematical formula is the number of defects in the time-dependent fog;

[0135] The target mathematical formula is determined to be the first corresponding relationship.

[0136] Optionally, multiple sample silicon wafers are placed in environments with different pollution states to perform degradation tests, and test results are obtained, including:

[0137] The sample silicon wafer that has undergone the degradation test is subjected to a morphology test to obtain the test result including the number of time-dependent fog defects on the surface of the sample silicon wafer.

[0138] In the embodiment of the present application, after the degradation test is completed, the surface of the sample silicon wafer is scanned using a scanning probe X-ray (SPX) and an electron microscope (SEM) to obtain test results of the number and morphology of time-dependent fog defects on the surface of the sample silicon wafer;

[0139] Matching the test results with the cation concentration and anion concentration corresponding to each test result, and compiling a database;

[0140] Model training, curve fitting or mathematical formula fitting is performed according to the database to obtain the first corresponding relationship.

[0141] The clean room environment detection method of the embodiment of the present application can simulate the extreme environmental conditions that the sample silicon wafer will face through the deterioration test, thereby determining the conservative number of time-dependent fog defects on the surface of the sample silicon wafer; through the determination of the first corresponding relationship, the environmental pollution state can be quickly judged based on the anion concentration and / or cation concentration in the environment.

[0142] Optionally, determining the environmental pollution state of the clean room according to the concentration of the cations and / or the concentration of the anions includes:

[0143] Determining a first preset threshold and a second preset threshold according to the first corresponding relationship; the first preset threshold is the concentration of the cation corresponding to when the defects of the time-dependent fog are a first number; the second preset threshold is the concentration of the anion corresponding to when the defects of the time-dependent fog are the first number;

[0144] When the concentration of the cations is greater than the first preset threshold and / or the concentration of the anions is greater than the second preset threshold, it is determined that the environment of the clean room is contaminated.

[0145] Optionally, the first quantity is determined according to requirements for the sample silicon wafer;

[0146] If the quality requirement of the sample silicon wafer is that the number of time-dependent surface fog defects is smaller than a target number, the first number is the target number.

[0147] In the embodiment of the present application, if the quality requirement of the sample silicon wafer is that the number of time-dependent fog defects on the surface must be less than 6, then the first number is 6.

[0148] Optionally, the first preset threshold is 5000 ng / m 3 The second preset threshold is 200000ng / m 3 .

[0149] The cleanroom environment detection method of the embodiment of the present application determines the first preset threshold value and the second preset threshold value based on the first corresponding relationship, thereby determining whether the concentrations of anions and cations in the cleanroom environment will cause the surface of a sample silicon wafer in the cleanroom to produce more than the first number of surface-dependent fog defects. If the concentrations of anions and cations cause the surface of the sample silicon wafer in the cleanroom to produce more than the first number of surface-dependent fog defects, timely measures are taken to improve the environment in the cleanroom. This solves the problem in the prior art of lacking a specific evaluation method for determining the environmental pollution status in a cleanroom.

[0150] Optionally, the method further includes one of the following:

[0151] When the concentration of the cations is greater than the first preset threshold and the concentration of the anions is greater than the second preset threshold, cleaning the target silicon wafer and replacing the air in the clean room; the target silicon wafer is a silicon wafer being processed in the clean room;

[0152] When the concentration of the cations is greater than the first preset threshold and the concentration of the anions is less than or equal to the second preset threshold, cleaning the target silicon wafer and replacing the air in the clean room;

[0153] When the concentration of the cations is less than or equal to the first preset threshold, there is no need to clean the target silicon wafer and replace the air in the clean room.

[0154] In one embodiment of the present application, the air in the clean room contains NH4 + The concentration of the cation is 2.71 million (ng / m 3 ), All acid(Cl - 、NO3 - and SO4 2- The anion concentration is 1.32 million (ng / m 3 ); that is, the concentration of the cations is greater than the first preset threshold, and the concentration of the anions is greater than the second preset threshold; the surface of the sample silicon wafer is as Figure 2 As shown;

[0155] Therefore, the environmental conditions in the clean room are contaminated by cations and anions. The silicon wafer production line in the clean room needs to be stopped immediately, and the source of acid and alkali leakage pollution needs to be identified. The silicon wafers processed in the clean room are cleaned using a cleaning machine and transported to a clean room where the anion and cation standards meet.

[0156] In another embodiment of the present application, the air in the clean room contains NH4 +The concentration of (the cation) is 10000 (ng / m 3 ), All acid (Cl-, NO3- and SO42-) (the anions) ion concentration is 3000 (ng / m 3 ); that is, the concentration of the cations is greater than the first preset threshold, but the concentration of the anions is less than the second preset threshold; the surface of the sample silicon wafer is as Figure 3 As shown;

[0157] Therefore, the environmental conditions in the clean room are contaminated by cations, and it is necessary to control the air intake of the makeup air unit (MAU) in the clean room to increase and replace the air in the clean room; and after the air replacement is completed, the silicon wafers processed in the clean room are cleaned.

[0158] In another embodiment of the present application, the air in the clean room contains NH4 + The concentration of (the cation) is 100 (ng / m 3 ), All acid (Cl-, NO3- and SO42-) (the anions) ion concentration is 65000 (ng / m 3 ); that is, the concentration of the cations is less than the first preset threshold and can be ignored, and the concentration of the anions is less than the second preset threshold; the surface of the sample silicon wafer is as Figure 4 As shown;

[0159] Therefore, the environmental conditions in the clean room are not polluted, and there is no need to clean the target silicon wafer or replace the air in the clean room.

[0160] It should be noted that if only cations exist in the clean room, the possibility of time-dependent fog defects occurring in the sample silicon wafer is low; if only all acid (Cl-, NO3-, and SO42-) anions exist in the clean room, time-dependent fog defects will not occur in the sample silicon wafer, but acid etching will form on the surface of the sample silicon wafer; therefore, for the generation of time-dependent fog defects, while focusing on the influence of cations, it is also necessary to consider both cations and anions.

[0161] Optionally, the method further includes:

[0162] The components of the time-dependent fog defects on the surface of the sample silicon wafer are analyzed.

[0163] In the embodiment of the present application, component analysis of the time-dependent fog defects on the surface of the sample silicon wafer is performed, including:

[0164] Cleaning the sample silicon wafer on which time-dependent fog defects have formed with ultrapure water to obtain a cleaning solution;

[0165] An ion chromatography device is used to perform component analysis on the cleaning liquid to determine the components of the time-dependent mist defect.

[0166] The clean room environment detection method of the embodiment of the present application can quickly determine the environmental pollution status based on the cation concentration and / or anion concentration in the clean room, thereby making corresponding treatments to the clean room environment and the silicon wafers in the clean room, avoiding the generation of time-dependent fog defects on the silicon wafer surface and resulting in a decrease in silicon wafer yield.

[0167] like Figure 5 As shown, the embodiment of the present application further provides a clean room environment detection device 500, comprising:

[0168] The collection module 501 is used to collect air in the clean room;

[0169] An analysis module 502 is configured to analyze the composition of the air in the clean room to obtain the concentration of cations and anions in the clean room; the cations are alkaline ions and the anions are acidic ions;

[0170] The determination module 503 is configured to determine the environmental pollution state of the clean room according to the concentration of the cations and / or the concentration of the anions.

[0171] The cleanroom environment monitoring device of the present application collects air from the cleanroom to analyze its composition, thereby determining the concentrations of cations and anions within the cleanroom. Ultimately, the environmental pollution status within the cleanroom is determined based on these concentrations. This solves the problem of the prior art lacking a specific evaluation method for determining the environmental pollution status within a cleanroom.

[0172] Optionally, the determining module includes:

[0173] A testing unit is configured to place a plurality of sample silicon wafers in environments with different pollution states to perform degradation testing and obtain test results; the sample silicon wafers are cleaned and have a surface particle count less than a preset count; the concentrations of the cations and / or anions in the different state environments are different; and the test results include a time-dependent number of fog defects on the surfaces of the sample silicon wafers;

[0174] A determining unit is configured to determine, based on the test result, a first corresponding relationship between the concentration of the cations and / or the concentration of the anions and the number of defects in the time-dependent fog.

[0175] Optionally, the determining unit is further configured to:

[0176] Determining a first preset threshold and / or a second preset threshold according to the first corresponding relationship; the first preset threshold is the concentration of the cation corresponding to when the number of defects in the time-dependent fog is a first number; the second preset threshold is the concentration of the anion corresponding to when the number of defects in the time-dependent fog is a first number;

[0177] When the concentration of the cations is greater than the first preset threshold, and / or the concentration of the anions is greater than the second preset threshold, it is determined that the environment of the clean room is contaminated.

[0178] Optionally, the analysis module is further configured to:

[0179] dissolving the air in the clean room in ultrapure water to obtain a mixed solution;

[0180] The mixed solution is quantitatively analyzed to obtain the concentration of cations and anions in the clean room.

[0181] Optionally, the testing unit is further used to:

[0182] The sample silicon wafer that has undergone the degradation test is subjected to a morphology test to obtain the test result including the number of time-dependent fog defects on the surface of the sample silicon wafer.

[0183] An embodiment of the present application also provides a clean room environment detection device, including: a transceiver, a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the clean room environment detection method described above are implemented.

[0184] In addition, a specific embodiment of the present invention further provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the above-described cleanroom environment detection method. The program also achieves the same technical effects and is not further described here to avoid repetition.

[0185] An embodiment of the present application also provides a computer program product, including computer instructions. When the computer instructions are executed by a processor, the various processes of the above-mentioned clean room environment detection method embodiment are implemented and can achieve the same technical effect. To avoid repetition, they will not be repeated here.

[0186] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary personnel in this technical field, several improvements and modifications can be made without departing from the principles described in the present invention. These improvements and modifications are also within the scope of protection of the present invention.

Claims

1. A clean room environment detection method, characterized in that: include: Collecting air from clean rooms; Performing a component analysis on the air in the clean room to obtain the concentration of cations and anions in the clean room; the cations are alkaline ions and the anions are acidic ions; The environmental pollution state of the clean room is determined according to the concentration of the cations and / or the concentration of the anions.

2. The clean room environment detection method according to claim 1, characterized in that: Before determining the environmental pollution state of the clean room according to the concentration of the cations and / or the concentration of the anions, the method includes: Placing a plurality of sample silicon wafers in environments with different contamination states for degradation testing to obtain test results; the sample silicon wafers are cleaned and have a surface particle count less than a preset count; the concentrations of the cations and / or anions in the different state environments are different; and the test results include a time-dependent number of fog defects on the surfaces of the sample silicon wafers; According to the test result, a first correspondence between the concentration of the cations and / or the concentration of the anions and the number of defects in the time-dependent fog is determined.

3. The clean room environment detection method according to claim 2, characterized in that: Determining the environmental pollution state of the clean room according to the concentration of the cations and / or the concentration of the anions includes: Determining a first preset threshold and / or a second preset threshold according to the first corresponding relationship; the first preset threshold is the concentration of the cation corresponding to when the number of defects in the time-dependent fog is a first number; the second preset threshold is the concentration of the anion corresponding to when the number of defects in the time-dependent fog is a first number; When the concentration of the cations is greater than the first preset threshold, and / or the concentration of the anions is greater than the second preset threshold, it is determined that the environment of the clean room is contaminated.

4. The clean room environment detection method according to claim 3, characterized in that: The first preset threshold is 5000ng / m 3 The second preset threshold is 200000ng / m 3 .

5. The clean room environment detection method according to claim 1, characterized in that: Performing a component analysis on the air in the clean room to obtain the concentration of cations and anions in the clean room, including: dissolving the air in the clean room in ultrapure water to obtain a mixed solution; The mixed solution is quantitatively analyzed to obtain the concentration of cations and anions in the clean room.

6. The clean room environment detection method according to claim 2, characterized in that: Multiple sample silicon wafers were placed in environments with different pollution conditions for degradation testing, and the test results included: The sample silicon wafer that has undergone the degradation test is subjected to a morphology test to obtain the test result including the number of time-dependent fog defects on the surface of the sample silicon wafer.

7. The clean room environment detection method according to claim 3, characterized in that: The method further comprises one of the following: When the concentration of the cations is greater than the first preset threshold and the concentration of the anions is greater than the second preset threshold, cleaning the target silicon wafer and replacing the air in the clean room; the target silicon wafer is a silicon wafer being processed in the clean room; When the concentration of the cations is greater than the first preset threshold and the concentration of the anions is less than or equal to the second preset threshold, cleaning the target silicon wafer and replacing the air in the clean room; When the concentration of the cations is less than or equal to the first preset threshold, there is no need to clean the target silicon wafer and replace the air in the clean room.

8. A clean room environment detection device, characterized in that: include: Collection module, used to collect air in the clean room; An analysis module, configured to analyze the composition of the air in the clean room to obtain the concentration of cations and anions in the clean room; the cations are alkaline ions and the anions are acidic ions; The determination module is used to determine the environmental pollution state of the clean room according to the concentration of the cations and / or the concentration of the anions.

9. A clean room environment detection device comprising: A transceiver, a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the clean room environment detection method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the clean room environment detection method according to any one of claims 1 to 7 are implemented.

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