Device and method for detecting trace moisture in high-purity hydrogen bromide
By employing cavity ring-down spectroscopy and a corrosion-resistant pretreatment device, the accuracy and stability issues of trace moisture detection in high-purity hydrogen bromide have been resolved, achieving efficient and accurate trace moisture detection suitable for semiconductor manufacturing and fine chemical industries.
Patent Information
- Application Number
- CN202511560033.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-29
- Publication Date
- 2026-02-17
AI Technical Summary
Existing technologies are insufficient for the efficient, accurate, and stable detection of trace moisture in high-purity hydrogen bromide. Traditional methods suffer from poor accuracy, high cost, and poor long-term stability.
By employing cavity ring-down spectroscopy technology combined with a corrosion-resistant pretreatment device and detection unit, trace amounts of moisture are detected using an optical resonant cavity and a high-reflectivity lens, while impurities are removed using a highly efficient pretreatment agent, thus achieving automated detection.
It achieves ppb-level detection accuracy, can operate stably for a long time in harsh environments, and improves analysis efficiency and real-time detection.
Smart Images
Figure CN121540639A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of gas detection technology, specifically to a device and method for detecting trace moisture in high-purity hydrogen bromide. Background Technology
[0002] High-purity hydrogen bromide indeed has indispensable and critical applications in semiconductor manufacturing, fine chemicals, and other fields. In semiconductor chip manufacturing, high-purity hydrogen bromide is primarily used for polysilicon etching in 8-inch and 12-inch chip manufacturing processes. It is one of the core gases in advanced processes and is even considered a candidate etching gas for handling large trench structures in future, more advanced processes below 7 nanometers. Even minute fluctuations in its moisture content can lead to serious consequences. In the etching process, moisture inhibits wafer chemical reactions and exacerbates the corrosion of gas delivery systems and equipment components by hydrogen bromide. The molecular and particulate impurities generated by corrosion contaminate the wafer, greatly increasing the probability of chip defects, resulting in unstable etching effects, rough lines, or deviations in critical dimensions (CD), thus severely affecting chip performance, reliability, and final yield. In fine chemical fields such as pharmaceutical synthesis, hydrogen bromide acts as a catalyst or reactant. The presence of moisture can easily trigger unnecessary side reactions, not only reducing the purity and yield of the target product but also potentially generating impurities that are difficult to separate, seriously affecting the quality and safety of the final product.
[0003] Currently, common methods for detecting moisture in gases face numerous insurmountable problems when applied to the detection of highly corrosive high-purity hydrogen bromide. While the traditional cold mirror dew point method is used as a reference method for calibration and verification, its measurement accuracy is severely affected by factors such as ambient temperature, pressure, and mirror contamination, making it difficult to reliably meet the stringent requirements of high-purity hydrogen bromide for ppb-level moisture detection. The Karl Fischer method (coulometric method), although theoretically possessing high absolute measurement accuracy, suffers from the rapid poisoning of the electrolytic cell, damage to detection reagents and electrode components due to the strong corrosiveness of hydrogen bromide, leading to frequent failures. Furthermore, this method has a complex operation process and high maintenance and consumable costs. Capacitive methods (such as alumina sensors) suffer from extremely short sensor lifespans (typically only a few days or weeks) due to the rapid chemical reaction or physical aging of the sensor probe in the highly corrosive environment of hydrogen bromide, resulting in severe measurement signal drift and extremely poor reliability and long-term stability of the results.
[0004] Therefore, developing a dedicated trace moisture detection device and method that can resist strong corrosion, is highly efficient, accurate, and stable is still urgent for ensuring product quality and production safety in high-end semiconductor manufacturing and fine chemical industries. Summary of the Invention
[0005] To address the problems of poor accuracy, high cost, and poor long-term stability in existing methods for measuring trace moisture in high-purity hydrogen bromide, this application proposes a device and method for detecting trace moisture in high-purity hydrogen bromide.
[0006] The specific details of this application are as follows:
[0007] On the one hand, this application proposes a device for detecting trace moisture in high-purity hydrogen bromide, comprising:
[0008] A pretreatment tank is used to receive high-purity hydrogen bromide gas to be tested and remove impurities therein. The pretreatment tank is filled with a pretreatment agent. One end of the pretreatment tank is provided with an inlet and the other end with an outlet.
[0009] The detection unit is connected to the gas outlet of the pretreatment tank and is used to detect the moisture content of the pretreated gas. The detection unit is based on the optical cavity ring-down spectroscopy principle.
[0010] A data processing and display system, electrically connected to the detection unit, is used to calculate and display the moisture content.
[0011] Preferably, the detection unit includes a laser source whose emission wavelength matches the absorption peak of water molecules in the near-infrared band, connected along the detection path; an optical coupling system formed by an aspherical lens and a polarization-maintaining fiber; an optical resonant cavity composed of a high-reflectivity lens; a high-speed detector for capturing the attenuated light signal within the cavity; and a time measurement system for measuring the light intensity attenuation time.
[0012] Preferably, the lens substrate of the optical resonant cavity is fused silica, on which a transition layer and a functional layer are provided.
[0013] Preferably, the transition layer is aluminum oxide with a thickness of 75 nm, the functional layer is magnesium fluoride with a thickness of 180 nm, and the reflectivity of the lens is greater than 99.99%.
[0014] On the other hand, this application provides a method for detecting trace moisture in high-purity hydrogen bromide, comprising the following steps:
[0015] Step S1. Gas pretreatment: The high-purity hydrogen bromide gas to be tested is introduced into the pretreatment tank, and impurities are removed by the pretreatment agent in the pretreatment tank. The pretreatment temperature is controlled at 15℃~25℃, the pressure is 0.2MPa~0.4MPa, and the time is 4~6min.
[0016] Step S2. Moisture detection: The pretreated gas is introduced into the detection unit to obtain the trace moisture content in the high-purity hydrogen bromide.
[0017] Preferably, the pretreatment agent is composed of a fluorinated polymer carrier and an inorganic bromide active component; the pretreatment agent has an adsorption removal rate of more than 99.9% for elemental bromine and an adsorption capacity of less than 0.1 ppb for water.
[0018] Preferably, the fluorinated polymer carrier has a particle size of 50–100 μm and a specific surface area greater than 50 m². 2 / g of polytetrafluoroethylene microspheres.
[0019] Preferably, the inorganic bromide active component is a mixture of potassium bromide and calcium bromide, with a mass ratio of potassium bromide to calcium bromide of 3:1; the loading amount of the inorganic bromide active component on the surface of the polytetrafluoroethylene microspheres is 10-15%.
[0020] The beneficial effects of this application are:
[0021] This application discloses a device and method for detecting trace moisture in high-purity hydrogen bromide. It employs cavity ring-down spectroscopy combined with high-precision optical and electronic components, achieving a detection accuracy down to the ppb level, enabling precise detection of extremely low moisture content in high-purity hydrogen bromide. Furthermore, key components of the pretreatment device and detection unit utilize corrosion-resistant alloy materials and special pretreatment agents, effectively resisting the strong corrosiveness of hydrogen bromide and ensuring long-term stable operation of the device in harsh environments. The entire detection process is highly automated; from gas entry into the device to obtaining the detection result, only a few minutes are required, meeting the needs of real-time online detection and effectively improving analytical efficiency. Attached Figure Description
[0022] Figure 1 This is a diagram of a device for detecting trace moisture in high-purity hydrogen bromide, as described in this application.
[0023] Figure labels: 1. Pretreatment tank; 2. Laser source; 3. Optical coupling system; 4. Lens; 5. Optical resonant cavity; 6. High-speed detector; 7. Time measurement system; 8. Data processing and display system; 101. Air inlet; 102. Air outlet; 103. Pretreatment agent. Detailed Implementation
[0024] To further illustrate the technical means and effects adopted by this application in order to achieve the intended purpose of the invention, the following detailed description of the specific implementation methods, structures, features and effects of this application is provided in conjunction with the accompanying drawings and preferred embodiments.
[0025] Device Examples
[0026] This embodiment provides a device for detecting trace moisture in high-purity hydrogen bromide. See [link to relevant documentation]. Figure 1 ,include:
[0027] The pretreatment tank 1 is used to receive the high-purity hydrogen bromide gas to be tested and remove impurities therein. The pretreatment tank 1 is filled with pretreatment agent 103. One end of the pretreatment tank 1 is provided with an air inlet 101 and the other end is provided with an air outlet 102.
[0028] The detection unit is connected to the air outlet 102 of the pretreatment tank 1 and is used to detect the moisture content of the pretreated gas. The detection unit is based on the optical cavity ring-down spectroscopy principle.
[0029] The data processing and display system 8 is electrically connected to the detection unit and is used to calculate and display the moisture content.
[0030] The detection unit includes a laser source 2 that emits wavelengths matching the absorption peak of water molecules in the near-infrared band, an optical coupling system 3 formed by an aspherical lens and a polarization-maintaining fiber, an optical resonant cavity 5 composed of a high-reflectivity lens 4, a high-speed detector 6 for capturing the attenuated light signal within the cavity, and a time measurement system 7 for measuring the light intensity attenuation time.
[0031] The lens 4 of the optical resonant cavity 5 is made of fused silica, and a transition layer and a functional layer are provided on it.
[0032] The transition layer is aluminum oxide with a thickness of 75 nm, the functional layer is magnesium fluoride with a thickness of 180 nm, and the reflectivity of the lens 4 is greater than 99.99%.
[0033] Implementation principle of the device:
[0034] First, check the pretreatment agent 103 inside the pretreatment tank 1 and ensure it is filled evenly. Connect the inlet 101 of the pretreatment tank 1 to a high-purity hydrogen bromide gas source, and connect the outlet 102 to the inlet of the optical resonant cavity 5 of the detection unit via a pipeline. After ensuring all interfaces are secure, pressure test the entire gas system to confirm there are no leaks. This ensures that the gas sample will not leak during subsequent detection processes, preventing environmental moisture intrusion or sample loss, and guaranteeing the accuracy and reliability of the measurement results.
[0035] The high-purity hydrogen bromide gas to be tested is introduced into the pretreatment tank 1 at a controlled pressure of 0.2 MPa to 0.4 MPa. The gas is brought into full contact with the pretreatment agent 103 within the tank, with the pretreatment temperature controlled at 15℃ to 25℃ and the contact time maintained at 4 to 6 minutes. After treatment, the gas flows out from the outlet 102 of the pretreatment tank 1. The pretreatment agent 103 can efficiently remove interfering impurities such as elemental bromine (adsorption removal rate >99.9%), while its adsorption capacity for moisture is extremely low (<0.1 ppb). Therefore, during the gas purification process, the original trace moisture information in the sample is preserved to the maximum extent, avoiding errors or moisture loss introduced by the pretreatment steps.
[0036] Pretreated clean hydrogen bromide gas flows into the optical resonant cavity 5 of the detection unit. The laser source 2 emits a laser beam (around 1390 nm) with a wavelength matching the near-infrared absorption peak of water molecules. This beam is injected into the optical resonant cavity 5, which is composed of a high-reflectivity lens 4 (reflectivity > 99.99%), through an optical coupling system 3 consisting of an aspherical lens and a polarization-maintaining fiber (achieving efficient laser coupling and transmission, reducing energy loss). The laser undergoes multiple reflections within the cavity, forming a long optical path. After laser injection is stopped, a high-speed detector 6 captures the exponential decay curve of the optical signal within the cavity, and a time measurement system 7 accurately measures the ring-down time. Optical cavity ring-down spectroscopy has extremely high sensitivity, capable of detecting water content down to the ppb level. The high-reflectivity lens 4 of the optical resonant cavity 5 (using an alumina transition layer and a magnesium fluoride functional layer) ensures an extremely long effective optical path, enhancing the interaction with water molecules, thereby achieving ultra-high precision measurement.
[0037] The data processing and display system 8 displays the moisture content in the gas.
[0038] Examples 1-4 describe a device for detecting trace moisture in high-purity hydrogen bromide, based on the device examples provided. The specific determination method is as follows:
[0039] Example 1
[0040] Step S1. Take high-purity hydrogen bromide gas with a purity of 99.999% and a known moisture content of 8 ppb as the test sample. Pass the gas into a pretreatment device, controlling the pretreatment temperature at 20℃, the pressure at 0.3 MPa, and the gas residence time at 5 minutes. The pretreatment agent in the pretreatment device consists of a fluorinated polymer carrier and an inorganic bromide active component. The fluorinated polymer carrier has a particle size of 50–100 μm and a specific surface area of 70 m². 2 / g of polytetrafluoroethylene microspheres. The inorganic bromide active component is a mixture of potassium bromide and calcium bromide, with a mass ratio of potassium bromide to calcium bromide of 3:1; the loading of the inorganic bromide active component on the surface of the polytetrafluoroethylene microspheres is 13%.
[0041] Step S2. The pretreated gas is then introduced into the detection unit and detected using a cavity ring-down spectroscopy system. Before detection, the detection system is calibrated using high-purity hydrogen bromide standard gases with known moisture contents of 5 ppb and 10 ppb. After detection, the data processing system processes the collected data, and the final displayed moisture content is 7.8 ppb. The error between this and the actual value is within the allowable range, verifying the accuracy of the detection method and apparatus of this application.
[0042] Example 2
[0043] Step S1. Take high-purity hydrogen bromide gas with a purity of 99.998% and a known moisture content of 15 ppb as the test sample. Pass the gas into a pretreatment device, controlling the pretreatment temperature at 22℃, the pressure at 0.35 MPa, and the gas residence time at 5 minutes. The pretreatment agent in the pretreatment device consists of a fluorinated polymer carrier and an inorganic bromide active component. The fluorinated polymer carrier has a particle size of 50–100 μm and a specific surface area of 70 m². 2 / g of polytetrafluoroethylene microspheres. The inorganic bromide active component is a mixture of potassium bromide and calcium bromide, with a mass ratio of potassium bromide to calcium bromide of 3:1; the loading of the inorganic bromide active component on the surface of the polytetrafluoroethylene microspheres is 15%.
[0044] Step S2. The pretreated gas is then introduced into the detection unit and detected using a cavity ring-down spectroscopy system. The detection results show that the moisture content is 15.2 ppb, which also indicates that the detection method and device of this application can accurately detect trace moisture content in high-purity hydrogen bromide and has good repeatability and stability.
[0045] Example 3
[0046] Step S1. Take high-purity hydrogen bromide gas with a purity of 99.998% and a known moisture content of 15 ppb as the test sample. Pass the gas into a pretreatment device, controlling the pretreatment temperature at 15℃, the pressure at 0.4 MPa, and the gas residence time at 4 minutes. The pretreatment agent in the pretreatment device consists of a fluorinated polymer carrier and an inorganic bromide active component. The fluorinated polymer carrier has a particle size of 50–100 μm and a specific surface area of 70 m². 2 / g of polytetrafluoroethylene microspheres. The inorganic bromide active component is a mixture of potassium bromide and calcium bromide, with a mass ratio of potassium bromide to calcium bromide of 3:1; the loading of the inorganic bromide active component on the surface of the polytetrafluoroethylene microspheres is 10%.
[0047] Step S2. The pretreated gas is then introduced into the detection unit and detected using a cavity ring-down spectroscopy system. The detection results show that the moisture content is 14.9 ppb, which also indicates that the detection method and device of this application can accurately detect trace moisture content in high-purity hydrogen bromide and has good repeatability and stability.
[0048] Example 4
[0049] Step S1. Take high-purity hydrogen bromide gas with a purity of 99.998% and a known moisture content of 15 ppb as the test sample. Pass the gas into a pretreatment device, controlling the pretreatment temperature at 25℃, the pressure at 0.2 MPa, and the gas residence time at 6 minutes. The pretreatment agent in the pretreatment device consists of a fluorinated polymer carrier and an inorganic bromide active component. The fluorinated polymer carrier has a particle size of 50–100 μm and a specific surface area of 70 m². 2 / g of polytetrafluoroethylene microspheres. The inorganic bromide active component is a mixture of potassium bromide and calcium bromide, with a mass ratio of potassium bromide to calcium bromide of 3:1; the loading of the inorganic bromide active component on the surface of the polytetrafluoroethylene microspheres is 13%.
[0050] Step S2. The pretreated gas is then introduced into the detection unit and detected using a cavity ring-down spectroscopy system. The detection results show that the moisture content is 15.1 ppb, which also indicates that the detection method and device of this application can accurately detect trace moisture content in high-purity hydrogen bromide and has good repeatability and stability.
[0051] The above description is merely a preferred embodiment of this application and is not intended to limit this application in any way. Although this application has been disclosed above with reference to preferred embodiments, it is not intended to limit this application. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the technical solution of this application. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.
Claims
1. A device for detecting trace amounts of moisture in high purity hydrogen bromide, characterized by, The application relates to a high-purity hydrogen bromide gas moisture content detection device. The device comprises a pretreatment tank (1) for receiving high-purity hydrogen bromide gas to be detected and removing impurities in the high-purity hydrogen bromide gas, wherein the pretreatment tank (1) is internally filled with a pretreatment agent (103), one end of the pretreatment tank (1) is provided with a gas inlet (101), and the other end is provided with a gas outlet (102); a detection unit in communication with the gas outlet (102) of the pretreatment tank (1) and used for detecting the moisture content of the pretreated gas; and a data processing and display system (8) electrically connected with the detection unit and used for calculating and displaying the moisture content. The detection unit comprises a laser light source (2) emitting a wavelength matched with the absorption peak of moisture molecules in a near-infrared waveband, an optical coupling system (3) formed by an aspheric lens and a polarization maintaining optical fiber, an optical resonant cavity (5) composed of a high-reflectivity mirror (4), a high-speed detector (6) used for capturing the decay light signal in the cavity, and a time measurement system (7) used for measuring the light intensity decay time. The mirror (4) of the optical resonant cavity (5) is based on fused quartz, and a transition layer and a functional layer are arranged on the mirror (4).
2. The device for detecting trace moisture in high-purity hydrogen bromide according to claim 1, characterized by The transition layer is aluminum oxide with a thickness of 75 nm, the functional layer is magnesium fluoride with a thickness of 180 nm, and the reflectivity of the mirror (4) is greater than 99.99%.
3. The device for detecting trace moisture in high-purity hydrogen bromide according to claim 2, characterized by The device comprises the following steps:
4. The device for detecting trace moisture in high-purity hydrogen bromide according to claim 3, characterized by Step S1. Gas pretreatment: introducing high-purity hydrogen bromide gas to be detected into the pretreatment tank, removing impurities by the pretreatment agent in the pretreatment tank, controlling the pretreatment temperature to be 15-25 DEG C, the pressure to be 0.2-0.4 MPa, and the time to be 4-6 min; 5. A method for detecting trace moisture in high purity hydrogen bromide, based on the detection device for trace moisture in high purity hydrogen bromide according to any one of claims 1 to 4, characterized in that, Step S2. Moisture detection: introducing the pretreated gas into the detection unit to obtain the trace moisture content in the high-purity hydrogen bromide. The pretreatment agent is composed of a fluorine-containing high-molecular polymer carrier and an inorganic bromide active component; the adsorption removal rate of the pretreatment agent to elemental bromine is greater than 99.9%, and the adsorption amount of the pretreatment agent to moisture is less than 0.1 ppb. The inorganic bromide active component is a mixture of potassium bromide and calcium bromide, the mass ratio of the potassium bromide to the calcium bromide is 3:1, and the loading amount of the inorganic bromide active component on the surface of the polytetrafluoroethylene microsphere is 10-15%.
6. The method for detecting trace moisture in high-purity hydrogen bromide according to claim 5, characterized by, 7. The method for detecting trace moisture in high-purity hydrogen bromide according to claim 6, characterized by, The fluorine-containing high molecular polymer carrier is polytetrafluoroethylene microspheres with a particle size of 50-100 μm and a specific surface area of more than 50 m 2 / g.
8. The method for detecting trace moisture in high-purity hydrogen bromide according to claim 7, characterized by,