Regulation and control method and device for stably outputting ultrapure water for semiconductor process

Abstract

The invention discloses a regulation and control method and device for stably outputting ultrapure water for a semiconductor process. The regulation and control method comprises the following steps: S1, deep treatment: treating primary pure water to obtain secondary pure water; s2, first-order circulation: carrying out reflux circulation on part of secondary pure water to carry out the step S1, storing non-reflux secondary pure water into a pure water storage tank, distributing reflux water quantity in proportion according to a simulation output result of a liquid level of the pure water storage tank to form a first-order circulation ratio, and regulating and controlling a target decomposition dosage of first-order decomposition treatment according to the first-order circulation ratio and a detection result of the secondary pure water; s3, fine treatment: treating the secondary pure water to obtain ultrapure water; and S4, second-order circulation: stably outputting ultrapure water according to the water consumption of the downstream semiconductor process, refluxing the residual ultrapure water to carry out the step S3, and regulating and controlling the target decomposition dosage of the second-order decomposition treatment according to the ultrapure water consumption of the process and the detection result of the ultrapure water. According to the invention, ultrapure water with stable quality and flow can be output with high efficiency and low energy consumption according to the water demand of a downstream semiconductor process.

Description

Technical Field

[0001] The present invention relates to the technical field of ultrapure water for semiconductor processes, and in particular to a control method and device for stably outputting ultrapure water for semiconductor processes. Background Art

[0002] With the development of the electronics industry, the requirements for water quality in the production and processing of chips are becoming higher and higher. In order to meet the production needs of ultra-large-scale integrated circuits, in addition to high-purity raw materials, high-purity gases, and high-purity chemicals, ultrapure water is also one of the key factors. Ultrapure water is mainly used for product cleaning, liquid dilution and other links in the semiconductor production process. The ultrapure water manufacturing process is mainly divided into three links: pretreatment, primary pure water treatment, and ultrapure water treatment. In recent years, with the reduction of semiconductor device process nodes, its production process water has put forward extremely high requirements for indicators such as trace metals, total organic carbon (TOC), total silicon, microparticles and dissolved oxygen (DO). At present, a large number of technical researches are concentrated on the design and engineering guarantee of each water quality treatment link, in order to develop advanced ultrapure water preparation technology to meet the water quality requirements of semiconductor cutting-edge process water, realize the joint reduction of multiple pollutants, and achieve comprehensive control of trace metals, TOC, boron (B), DO, H2O2 and other indicators. However, little attention is paid to the stable output of ultrapure water in the ultrapure water preparation process and its coordination with downstream semiconductor process water. Even less attention is paid to reasonably adjusting the processing time, intensity and circulation method of each processing link according to the quality requirements of downstream semiconductor process water and the detection data of each processing link, resulting in energy waste in some processing links and high production costs.

[0003] Invention CN114751539A discloses a process for preparing ultrapure water with improved process stability and water quality, including that the electric proportional valve and pump in the first-stage reverse osmosis system are controlled by the PLC system; the PLC system monitors the SDI value of the ultrafiltration effluent and the water production pressure difference of the UF ultrafiltration system, and when the SDI rises to a certain value, backwashing is performed, and when the water production pressure difference reaches a certain value, chemical cleaning is performed; the pH value of the raw water entering the MB regeneration mixed bed is monitored, and the pH value of the inlet water is adjusted; the inlet and outlet resistance values ​​of TOC are monitored, and the number of polishing resin tanks is dynamically adjusted; the water temperature difference of the monitoring system changes less than 5°C. This ultrapure water process can improve the water production stability of the ultrapure water system, reduce the discharge of process wastewater, and increase the water production rate of the system, meeting the semiconductor industry's requirements for a more stable, more reliable, and more stringent water quality ultrapure water system. However, although the invention can use a monitoring system and a backwash system to improve the stability of water quality and water output, it does not pay attention to changes in water consumption and water quality requirements of downstream semiconductor processes. It is difficult to quickly adjust the output of high-quality and stable ultrapure water, which can easily lead to insufficient water use downstream, water waste, or water quality mismatch.

[0004] Invention CN118545861A discloses an ultrapure water quality intelligent control system and a control method thereof, the system includes a multi-stage filtration unit, a reverse osmosis treatment unit, an electrodeionization purification unit and an ultrapure water tank, the water outlet of the ultrapure water tank is connected to at least one water supply pipeline; it also includes a control unit, a rating unit and at least one monitoring unit, each monitoring unit corresponds to a water supply pipeline, and is used to monitor the water quality data of pure water in the water supply pipeline in real time and send it to the rating unit; the rating unit is used to receive water quality data, perform integrated calculation management, perform rating according to a preset water quality grade, and send it to the control unit; the control unit is used to execute a return water program or a water supply program corresponding to the rating result according to the rating result. The invention monitors the water quality of pure water stored in the ultrapure water tank in real time, and rates the water quality thereof, so as to perform targeted reflux purification according to different rating results, thereby improving the purification efficiency, the stability of ultrapure water quality, and reducing the loss of each purification unit. However, the pollution degree of ultrapure water stored in the ultrapure water tank for a long time increases, and the return water purification will also significantly increase the energy consumption.

[0005] Therefore, how to design and improve the existing ultrapure water preparation process, combine modern monitoring, detection and automated control methods, achieve scientific prediction and comprehensive control of water quality indicators, provide a continuous and stable supply of ultrapure water, improve water resource utilization, and reduce energy consumption and operating costs has become an urgent problem to be solved by technical personnel in this field. Summary of the invention

[0006] In view of the defects existing in the above-mentioned prior art, the present invention provides a control method and device for stably outputting ultrapure water for semiconductor processes, which can realize the estimation, prediction and comprehensive control of indicators such as trace metals, TOC, boron (B), DO, H2O2, etc., continuously provide high-quality ultrapure water, and output it in a controllable and stable manner to meet the water demand of downstream semiconductor processes, improve the utilization rate of water resources, and effectively reduce energy consumption and operating costs.

[0007] In a first aspect, the present invention provides a method for controlling the stable output of ultrapure water for semiconductor process, comprising the following steps: S1 deep treatment: deep desalination treatment, first-order decomposition treatment, first-order absorption exchange treatment and degassing treatment are carried out on the primary pure water to obtain secondary pure water; S2 first-order cycle: reflow part of the secondary pure water obtained in step S1 for further treatment in step S1, and store the secondary pure water not reflowed in the pure water storage tank; S3 fine treatment: hydrogenation treatment of the secondary pure water output from the pure water storage tank to make the dissolved hydrogen concentration above 0.05mg / l, followed by second-order decomposition treatment, second-order absorption exchange treatment, degassing and ultrafiltration treatment to obtain ultrapure water; S4 second-stage cycle: According to the water consumption of the downstream semiconductor process, ultrapure water is output stably, and the remaining ultrapure water is refluxed for step S3 fine treatment.

[0008] The present invention combines multi-stage purification and circulation control to stably and reliably provide ultrapure water that meets the requirements of semiconductor processes. Multi-stage purification ensures that impurities are removed to the greatest extent, and circulation control ensures the continuous stability of water quality and water output. And by controlling the degree of purification and the circulation ratio, a better balance can be achieved between water purity and output efficiency.

[0009] Specifically, the raw water is pretreated to obtain primary pure water (conductivity < 2μS / cm, TOC < 50μg / L). The raw water can be subjected to a series of treatments according to the method provided in the previous invention patent CN115636557B, or other methods capable of obtaining primary pure water can be used.

[0010] Preferably, the first-order decomposition process and the second-order decomposition process respectively use a plurality of independently controlled ultraviolet radiation light sources to perform ultraviolet decomposition processes; The target decomposition dose for the first-order decomposition treatment is 100-800 mJ / cm 2 Continuously adjustable; The target decomposition dose for the second-order decomposition treatment is 200-1000 mJ / cm 2 Continuously adjustable.

[0011] Preferably, the radiation light source for the first-order decomposition treatment and the second-order decomposition treatment includes a VUV / UV low-pressure high-intensity mercury vapor or a low-pressure high-intensity amalgam arc discharge light source.

[0012] The specific number is determined according to the amount of water to be treated and the water quality requirements. When the water production demand is low, 1-5 radiation light sources can be set. For example, 5-50 radiation light sources can be set to meet the needs of most application scenarios. The working current and irradiation time of each radiation light source are independently adjustable, so as to regulate the overall ultraviolet target decomposition dose. More preferably, a plurality of the radiation light sources are grouped, connected and controlled, for example, divided into 2-10 groups, each group of about 1-8 radiation light sources, so that the radiation light source is easier to regulate. Through the optimized design of the radiation light source of the present invention, the current, output power and energy consumption can be reduced according to the actual water volume and water quality requirements. On the other hand, the water use of downstream semiconductor processes is usually relatively stable, and it is not recommended to frequently regulate the opening and closing of the radiation light source, which is easy to reduce the life of the light source. Therefore, it is further preferred to regulate the variable current output of the ballast, reduce the current intensity, reduce the power output, and extend the life of the radiation light source while saving energy, thereby reducing the production cost as a whole.

[0013] Preferably, the first-order absorption exchange treatment includes positive adsorption treatment, complex reaction treatment and ion polishing treatment in sequence, and the ratio of the treatment time of the positive adsorption treatment, the complex reaction treatment and the ion polishing treatment is (1-4): (1-12): (1-6); The second-order absorption exchange treatment includes catalytic decomposition treatment and ion polishing treatment in sequence, and the treatment time ratio of the catalytic decomposition treatment and the ion polishing treatment is 1: (1-50).

[0014] According to the characteristics of water flow, the duration of each of the above-mentioned treatment links is related to the thickness and amount of the treatment material passed by the water flow. The present invention sets the above-mentioned treatment time ratio according to the absorption and exchange materials in each treatment area configured according to multiple tests, which can better meet the treatment effect.

[0015] The primary pure water passes through a continuous electric desalination system or an ion exchange system to deeply remove anions and cations in the water and remove a small amount of TOC. After that, the aforementioned first-order decomposition treatment and the first-order absorption and exchange treatment (positive adsorption treatment, complex reaction treatment and ion polishing treatment) downstream of the decomposition treatment can decompose low molecular organic matter (LMWOM) and remove weakly ionized impurities, and the resistivity is not reduced by pollution. Specifically, the positively charged adsorbent used in the positive adsorption treatment can efficiently adsorb the low molecular acidic organic matter (LMW CAs) produced by 185nmUV oxidation of LMWOM; the boron absorbent is used in the complex reaction treatment to undergo a complex reaction to achieve the effect of deep boron removal; the ion exchanger is used in the ion polishing treatment to remove the micro-contaminated electrolyte released by the NMDG-based absorbent, inhibit the decrease in resistivity, and control the increased TOC concentration to 1μg / L or even lower, which comprehensively improves the water quality of the first-order absorption and exchange treatment. Subsequently, the dissolved oxygen (including dissolved gases, volatile substances, etc.) in the water and the resin is removed by degassing treatment to form secondary pure water.

[0016] The water quality of the secondary pure water in the pure water storage tank reaches: resistivity>18.1 MΩ·cm, TOC<5μg / l, B<5ng / l, DO<5μg / l; preferably, resistivity>18.2 MΩ·cm, TOC<3μg / l, B<3ng / l, DO<2μg / l.

[0017] The secondary pure water is first treated by dissolving high-purity H2 in a membrane gas absorber (MGA) to make the dissolved hydrogen concentration above 0.05 mg / l. Then, it undergoes the aforementioned second-order decomposition treatment, as well as the second-order absorption and exchange treatment (catalytic decomposition treatment, ion polishing treatment) downstream of the decomposition treatment to further deeply remove, absorb and decompose trace metal ions, dissolved oxygen, weakly ionized impurities and low-molecular organic matter to extremely low limit values ​​of ppq, ppt and ppb levels respectively. At the same time, under the action of nano-complex catalysis, the H2O2 produced by the photo-oxidation TOC process can be controlled at the sub-ppb level (as low as below 1 μg / L). Specifically, metal catalysts are used in the catalytic decomposition treatment, preferably supported metal catalysts. The supported metal catalyst matrix can be a positively charged adsorbent that can efficiently adsorb low molecular weight acidic organic matter (LMW CAs) produced by 185nm UV oxidation of organic matter, and can decompose the byproduct H2O2 of photooxidation to make H2O2 <1μg / L. It can also catalytically reduce the byproduct O2 of the decomposition reaction to H2O at the active sites on the catalyst surface under the action of an appropriate amount of H2. Afterwards, the ion exchanger used in the ion polishing treatment can further remove trace metals and increase resistivity. Finally, degassing and ultrafiltration treatments are performed to achieve deep removal of dissolved gases and microparticles.

[0018] After the above series of treatments, the output ultrapure water quality can stably reach: Trace metals <0.1ng / l, TOC <0.5μg / l, DO <1μg / l, B <1ng / l, H2O2 <1μg / l, particle number concentration larger than 0.05μm <0.1pcs / mL.

[0019] Preferably, the positive adsorption treatment uses a positively charged adsorbent, which is a positively charged adsorption resin with amine polyhydroxyl functional groups or a mixed resin mixed with a positively charged adsorption resin with amine polyhydroxyl functional groups. One method for preparing this absorbent is to react with dimethylbenzene, trimethylamine and other main raw materials on a chloromethylated polystyrene cross-linked microsphere skeleton through suspension polymerization, chloromethylation and amination. Preferably, a trimethylbenzyl ammonium-based gel-type divinylbenzene cross-linked adsorbent or a mixed resin mixed with this adsorbent is selected, which has a stronger adsorption function for anionic electrolytes in water, especially small molecular organic matter. Further preferably, a high-purity model of this type of adsorbent is selected to ensure and meet the special requirement of ΔTOC ≤ 1 μg / l.

[0020] The complex reaction treatment uses a boron absorbent, which is a monodisperse porous absorbent, including methylamine-based granular beads or chelating resins. The boron absorbent can be made by grafting aliphatic polyols or aromatic polyhydroxyphenols onto a polymer skeleton; preferably, in order to overcome the limitations of porous hydrophobic polymer skeletons that are not easy to infiltrate and affect mass transfer, and the defects that the cross-linking agent divinylbenzene in the skeleton contains multiple isomers and significantly affects the performance of the polymer structure, polymethacrylate (GMA, chemical formula C7H) with strong hydrophilicity and increased average pore size after grafting is used. 10 O3) and ethylene glycol dimethacrylate (EDM, chemical formula C 10 H 14 O4) is used as the skeleton matrix, and NMDG is grafted on the macroporous particle skeleton of the copolymer dissolved in dimethyl sulfoxide solution to prepare the efficient boron absorbent GMA-EDM-NMDG; further preferably, a dimethylformamide deionized water mixture is used to enhance the resin swelling to increase the pore size and functional group density, and a porous chloromethyl polystyrene cross-linked resin that can provide more active sites for adsorption after cross-linking and has better structure and mechanical properties is used as the polymer skeleton carrier (CMPS), and a more stretchy polyhydroxy fatty long-chain polyol is used as the functional monomer, and a one-step adsorption method is used, stirring, eluting, and drying to obtain a monodisperse porous resin boron absorbent containing ortho- and meta-dihydroxy functional groups.

[0021] Catalytic decomposition treatment uses a metal catalyst, preferably a supported metal nanoparticle catalyst, which is a multiphase metal catalyst that directly bonds with a copolymer skeleton such as styrene and acrylic acid to form a polymer complex using a transition metal as a complex; more preferably, noble metal nanoparticles such as Pd or Pt are dispersed and distributed on the surface of a dimethylhydroxyethylbenzylammonium polymer carrier phase to prepare a UP grade palladium-supported resin or platinum-supported resin; further, a polystyrene-divinylbenzene cross-linked polymer functionalized with a trimethylamine quaternary ammonium group is used as a solid phase carrier, and a static adsorption method and a one-step reduction method are used to utilize a coordinated covalent bond. A heterogeneous gel-type or macroporous resin matrix catalyst formed by complexing heterogeneous platinum group metal (palladium, platinum, ruthenium, rhodium, osmium, iridium) ion precursors and reducing and transforming them, typically, such as: gel-type polystyrene-supported nano-palladium metal catalyst; also optionally, using amine-functionalized PS microspheres as polymer carriers, applying the heterogeneous condensation method based on the principle of thermodynamics, using liquid bimetallic solution as precursor salt, adding stabilizers and reducing agents to synthesize nanoparticle dispersions, and mixing with the PS microsphere dispersion, stirring, filtering, and drying, thereby obtaining a nano alloy composite particle catalyst.

[0022] Ion polishing treatment uses two ion exchangers with alkaline and acidic groups pre-mixed in a certain proportion. The preferred non-regenerative high-purity mixed ion exchanger has a TOC dissolution amount of ≤1μg / l and a metal dissolution amount of ≤0.1ng / l.

[0023] Specifically, the ultraviolet light of the ultraviolet lamp used in the first-order decomposition treatment and the second-order decomposition treatment is used for decomposition treatment, and the target decomposition dose can be predicted and dynamically controlled by the kinetic model. The construction method of the molecular dynamics calculation model (VUV Dosing CalcEM) includes: when molecules absorb ultraviolet radiation, they can obtain energy, and the amount of absorbed energy is related to the incident wavelength. According to Einstein's law, the photon energy absorbed by 1 mol of TOC molecules is shown in Formula 1 (unit: eV). The required ultraviolet dose depends on the ultraviolet intensity and exposure time, as shown in Formula 2. The core of the reaction is the hydroxyl radical (OH·), and the OH· produced by homolysis when the 185nm ultraviolet light irradiates the water flow can oxidize organic matter into carbon dioxide, water and intermediate products (Formulas 3 and 4).

[0024] (Formula 1) (Formula 2) (Formula 3) (Formula 4) Among them, E is the photon energy, h is Planck's constant, c is the speed of light, λ is the radiation wavelength, D is the target decomposition dose of ultraviolet light, I is the radiation intensity, and t is the radiation time.

[0025] Based on the material balance at the mixing point and the equality of mass flow input and output, the decomposition reaction zone volume of the first-order decomposition treatment can be obtained by combining the first-order rate equation: , through (Formula 5), ​​the amount of micro-pollution in primary pure water can be further calculated. and the first-order cycle ratio R m , after the first-order decomposition treatment and the first-order absorption exchange treatment, the target decomposition dose D of the first-order decomposition treatment is adjusted pm , and obtain the amount of micro-pollution in secondary pure water , see (Formula 6), the amount of micro-pollution in secondary pure water The calculation process is as follows: (Formula 5) (Formula 6) Among them, R m is the first-order cycle ratio, R m 0.1-10, Q mr is the amount of secondary pure water refluxed, Q me is the amount of secondary pure water stored in the pure water storage tank; is the volume of the decomposition reaction zone for the first-order decomposition treatment, RE mdi For the decomposition efficiency of deep desalination treatment, TOC me is the amount of micro-pollution in secondary pure water, TOC mi is the amount of micro-pollution in pure water. R m is the cycle ratio of the first-order treatment, K m1 , K m2 is the reaction rate constant, For example, when R m =0.1, the amount of micro-pollution after the primary pure water is mixed with the reflux secondary pure water of the first-order cycle :

[0026] Through the above calculation, the present invention can achieve the target decomposition dose D through the first-order decomposition process. pm , the cycle ratio R of the first-order treatment m And other related factors, predict or preset the amount of micro-pollution in secondary pure water .

[0027] Considering the pipeline characteristics, based on the material balance at the mixing point of the pure water storage tank and the equality of mass flow input and output, the decomposition reaction zone volume of the second-order decomposition treatment can be obtained by combining the first-order rate equation: , see (Formula 7), and then through the dosage calculation formula and related operations, the ultrapure water micro-pollution amount can be obtained , see (Formula 8), the amount of micro-pollution in ultrapure water The calculation process is as follows:

[0028] (Formula 7) (Formula 8) Among them, R p is the second-order circulation ratio, R p At 0.2-0.8, Q pr is the amount of reflux ultrapure water, Q pe Indicates the amount of ultrapure water used in downstream semiconductor processes, D pe is the target decomposition dose for the second-order decomposition process, TOC pe is the amount of micro-contamination in ultrapure water, is the concentration gradient of micro-pollutant dissolution observed in ultrapure water reflux, v is the second-order decomposition treatment rate, K t is the time constant, K p1 , K p2 , K p3 is the reaction rate constant, λ is the characteristic coefficient of the pipe network, satisfying formula (9): (Formula 9) L is the length of the pipe network. There are many optional access positions for the return pipe. It can be set at the outlet of the membrane microparticle separator, or downstream along the water supply network. For example, it can be set near the ultrapure water use point so as to supply water to the semiconductor process water point more stably and accurately. Therefore, it is preferred that L includes the total length of the water supply network and the return network. Due to the precipitation factor of the pipeline material, the micro-pollution amount of the return water returned to the pure water storage tank in the second-order cycle will be slightly increased compared with the micro-pollution amount of ultrapure water supplied to the downstream semiconductor process. The present invention summarizes the experimental data of this factor, and thus introduces the pipe network characteristic coefficient λ, which is beneficial to improving the actual calculation accuracy.

[0029] Normally, the second-order circulation ratio is not adjusted much, but the pipe network flow rate will change, because the flow rate will fluctuate with the water consumption. If the pipe diameter remains unchanged, the pipe flow rate will change accordingly. In practice, the second-order decomposition processing rate v is also equivalent to the pipe flow rate.

[0030] Through the above-mentioned deep treatment, first-order circulation, fine treatment and second-order circulation, the present invention can provide ultrapure water that meets the following water quality conditions for a long time and stably: Trace metals <0.1 ng / l, TOC <0.5 μg / l, DO <1μg / l, B <1 ng / l, H2O2 <1μg / l, particle number concentration larger than 0.05μm <0.1pcs / mL.

[0031] In a second aspect, the present invention also provides a device for running the control method, comprising a circulating deep treatment system, a pure water storage tank and a circulating fine treatment system connected in sequence; A circulating deep treatment system, including a deep desalination device, a first-order mixed photolysis absorber and a membrane degasser, wherein the water outlet of the membrane degasser is controlled to be connected to a pure water storage tank and a water inlet of the deep desalination device; A circulating fine treatment system includes a membrane absorber, a second-order mixed photolysis absorber, a membrane degasser and a membrane microparticle separator, wherein the water outlet of the membrane microparticle separator is controlled to be connected to an ultrapure water point and a pure water storage tank; The first-order hybrid photodecomposition absorber is compatible with the first-order decomposition zone and the first-order absorption exchange zone downstream thereof; the second-order hybrid photodecomposition absorber is compatible with the second-order decomposition zone and the second-order absorption exchange zone downstream thereof; The membrane absorber includes a hydrogen dissolving membrane and a hydrogen supply pipeline, which provides hydrogen-filled water with a dissolved hydrogen concentration of more than 0.05 mg / l to the downstream second-order mixed photolysis absorber.

[0032] A first-order mixed photolysis absorber compatible with the first-order decomposition zone and the first-order absorption exchange zone downstream thereof, and a second-order mixed photolysis absorber compatible with the second-order decomposition zone and the second-order absorption exchange zone downstream thereof, their basic structures can be found in patent CN115636557B, and the main differences are that the order and processing time of each functional processing zone in the first-order absorption exchange zone and the second-order absorption exchange zone are different, and the improved functions of the grouping regulation of the radiation light source in the first-order decomposition zone and the second-order decomposition zone are different.

[0033] Preferably, the deep desalination equipment includes at least one of a continuous electric desalination device, a mixed ion exchange tower, and a composite ion exchange tower.

[0034] Preferably, it also includes a control unit and an online detection unit; The detection unit includes a liquid level detector arranged in the pure water storage tank, and sampling points arranged at the water inlet of the deep desalination equipment, the water outlet of the membrane degasser and the membrane microparticle separator, and detection equipment connected to the sampling points; The control unit is connected to the liquid level detector, the first distribution actuator and the second distribution actuator signals. According to the feedback value of the liquid level detector, the first distribution actuator is driven to distribute the return water volume of the secondary pure water in proportion to the opening, thereby forming a first-order circulation ratio. According to the amount of ultrapure water used for the process, the second distribution actuator is driven to distribute the return water volume of the ultrapure water in proportion to the opening, thereby forming a second-order circulation ratio.

[0035] Preferably, in the direction of water flow, the first-order absorption and exchange zone includes a stacked positive adsorption layer, a complex reaction layer and an ion polishing layer, and the second-order absorption and exchange zone includes a stacked catalytic decomposition layer and an ion polishing layer; The control unit adjusts the target decomposition dose of the first-order decomposition zone and / or the target decomposition dose of the second-order decomposition zone according to the feedback result of the detection device.

[0036] The detection equipment includes at least one of a TOC analyzer, a dissolved oxygen analyzer, a microparticle analyzer, and a boron concentration analyzer. Preferably, the control unit adjusts the target decomposition dose of the first-order decomposition zone and the target decomposition dose of the second-order decomposition zone according to the feedback result of the detection equipment. Specifically, according to the micro-pollution amount of the primary pure water and the first-order circulation ratio, the target decomposition dose of the first-order decomposition treatment is adjusted to control the micro-pollution amount of the secondary pure water. And according to the micro-pollution amount of the secondary pure water and the second-order circulation ratio, the target decomposition dose of the second-order decomposition treatment is adjusted to control the micro-pollution amount of the ultrapure water. With lower processing energy consumption, for example, the ultraviolet target decomposition dosage in the first-order decomposition treatment and the second-order decomposition treatment is predicted and dynamically adjusted, and the quality and water volume of the output ultrapure water are regulated.

[0037] The present invention has at least the following beneficial effects: (1) The present invention can provide high-quality ultrapure water for semiconductor manufacturing processes through the deep treatment system and fine treatment system designed by the new process. Through the dual circulation strategy of the first-order circulation and the second-order circulation, the ultrapure water that meets the requirements of the semiconductor process can be stably and controllably output. While ensuring that the key indicators of the output water such as trace metals, TOC (total organic carbon), DO (dissolved oxygen), boron content and hydrogen peroxide meet or exceed the strict semiconductor industry standards, a stable ultrapure water output is provided.

[0038] (2) The present invention automatically sets and adjusts the target decomposition dose of the decomposition treatment through the simulated output of the pure water storage tank liquid level, the determination of the amount of micro-pollution, and the actual demand for ultrapure water for the downstream semiconductor process, controls the ignition of the ultraviolet lamp and the working state of the decomposition absorber, so that the system as a whole forms an economic operation effect of energy saving and consumption reduction on the basis of circulating water storage and adapting to the downstream water consumption, and can provide ultrapure water for semiconductor processes for a long time with high quality, reduce the consumption of water production energy and operating load, improve the efficiency and economy of the system, and according to the variable current output of the ballast, reduce the current intensity, reduce the power output, and extend the life of the lamp tube while reducing energy consumption. The molecular dynamics model (VUV Dosing Calc EM) based on the decomposition of TOC by active oxygen species not only provides an analytical means for regulating the target decomposition dose of the first-order and second-order decomposition treatment, but also provides a prediction method for calculating the reduction of TOC in water. By coupling the empirical coefficient, the target decomposition dose of the hybrid photolysis absorber and the output of water quality indicators are accurately predicted, and can be extended to the design selection and engineering application practice of the traditional ultraviolet decomposition total organic carbon device, which has universal practical value.

[0039] (3) The coordinated work of the control unit, the online detection unit and the dual circulation system of the present invention not only keeps the water quality indicators (such as trace metals, TOC, DO, boron content, hydrogen peroxide, etc.) within the set range, but also avoids the fluctuation of water quality and the decline of effluent quality caused by various factors such as raw water quality changes, material performance degradation, dissolution pollution of flowing materials, changes in equipment operating parameters, secondary micro-pollution, unreasonable energy matching of decomposition radiation sources, and equipment aging when the equipment is in continuous operation; it can also adjust the working current and power of the radiation light source according to the water volume and water quality stability, effectively reduce energy consumption on the basis of ensuring water quality, and provide an intelligent ultrapure water treatment and control method and device. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 The process flow chart of the present invention for stably outputting ultrapure water for semiconductor process; Figure 2 It is a process flow chart of the fine treatment and second-stage circulation of the present invention.

[0041] Explanation of the reference numerals: 11-continuous electric desalination device, 12-first-order mixed photolysis absorber, 13-first membrane degasser, 101-first sampling point, 102-second sampling point, 21-pure water storage tank, 22-membrane absorber, 23-second-order mixed photolysis absorber, 24-second membrane degasser, 25-membrane microparticle separator, 26-sampling pool, 201-third sampling point, 202-fourth sampling point, 203-fifth sampling point, 204-sixth sampling point. DETAILED DESCRIPTION

[0042] In order to better understand the above technical solution, the above technical solution will be described in detail below in combination with the specification and specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0043] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The singular forms "a", "said" and "the" used in the embodiments of the present invention and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings, and "multiple" generally includes at least two.

[0044] It should also be noted that the term "includes", "comprising" or any other variation thereof is intended to cover non-exclusive inclusion, so that a commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprising a ..." do not exclude the existence of other identical elements in the commodity or device including the elements.

[0045] See also Figure 1 , a method for regulating and controlling the stable output of ultrapure water for semiconductor process, specifically comprising the following steps: S1 deep treatment, purifies the pre-treated primary pure water into secondary pure water, including: S1.1 Deep desalination treatment: The primary pure water enters the continuous electric desalination device 11 to further remove anions and cations to obtain deep desalted water; S1.2 First-order decomposition treatment: The deep desalted water enters the first-order mixed photolysis absorber 12, passes through the first-order decomposition zone, and obtains primary decomposed water; wherein, the first-order decomposition treatment uses a number of independently controlled radiation light sources, the radiation light source includes a VUV / UV low-pressure high-intensity mercury vapor or a low-pressure high-intensity amalgam arc discharge light source with a radiation wavelength of 185nm; the target decomposition dose of the first-order decomposition treatment is 100-800mJ / cm 2 Continuously adjustable; S1.3 First-order absorption and exchange treatment: the decomposed water flows through the first-order absorption and exchange zone of the first-order mixed photolysis absorber 12, and is sequentially subjected to positive adsorption treatment, complexation reaction treatment and ion polishing treatment. The ratio of the treatment time of the positive adsorption treatment, complexation reaction treatment and ion polishing treatment is (1-4): (1-12): (1-6), preferably (1-4): (8-10): (1-4); The positive charge adsorption treatment uses a positive charge adsorbent, which is a positive charge adsorption resin with an amine polyhydroxyl functional group or a mixed resin mixed with a positive charge adsorption resin with an amine polyhydroxyl functional group; The complexation reaction treatment uses a boron absorbent; Ion polishing uses a mixed ion exchanger with basic and acidic groups.

[0046] S1.4 Degassing treatment: The water body after the first-order absorption exchange treatment enters the first membrane degasser 13 to remove dissolved gases and volatiles to obtain secondary pure water; the secondary pure water at the outlet of the first membrane degasser 13 is sampled and tested online, and the online test results are fed back to the control unit; S2 first-order cycle: return part of the secondary pure water flowing out of the first membrane degasser 13 to perform steps S1.1-S1.4, and the secondary pure water that is not returned is stored in the pure water storage tank 21. According to the analog output of the real-time change of the liquid level in the pure water storage tank 21, the actuator is driven to distribute the return water volume of the secondary pure water according to the proportional opening to form a first-order circulation ratio, and according to the micro-pollution amount of the primary pure water and the first-order circulation ratio, the target decomposition dose of the first-order decomposition treatment is adjusted to control the micro-pollution amount of the secondary pure water.

[0047] Preferably, the first-order cycle ratio R m : R m =Q mr / Q me Q me =Q mt -Q mr R m In 0.1-10, Among them, Q mt Indicates the total amount of secondary pure water obtained by deep treatment, Q mrIndicates the amount of secondary pure water refluxed, Q me Indicates the amount of secondary pure water stored in the pure water storage tank 21.

[0048] After deep treatment and first-order circulation, the water quality of the secondary pure water in the pure water storage tank 21 reaches: Resistivity>18.1 MΩ·cm, TOC<5.0 μg / l, B<5 ng / l, DO<5 μg / l; preferably, resistivity>18.2 MΩ·cm, TOC<3 μg / l, B<3 ng / l, DO<2 μg / l.

[0049] S3 fine treatment: purify secondary pure water into ultrapure water, including: S3.1 Hydrogenation treatment: secondary pure water is output from the pure water storage tank 21 and enters the membrane absorber 22, hydrogen gas with a purity greater than 99.9% is introduced into the membrane absorber 22, and hydrogenated water with a dissolved hydrogen concentration greater than 0.05 mg / l is obtained; S3.2 Second-order decomposition treatment: The hydrogen-filled water enters the second-order mixed photolysis absorber 23, passes through the second-order decomposition zone, and obtains secondary decomposed water; wherein, the second-order decomposition treatment uses a number of independently controlled radiation light sources, the radiation light source includes a VUV / UV low-pressure high-intensity mercury vapor or a low-pressure high-intensity amalgam arc discharge light source with a radiation wavelength of 185nm; the target decomposition dose of the second-order decomposition treatment is 200-1000mJ / cm 2 Continuously adjustable; S3.3 Second-order absorption and exchange treatment: The secondary decomposed water flows through the second-order absorption and exchange zone of the second-order mixed photolysis absorber 23, and undergoes catalytic decomposition treatment and ion polishing treatment in sequence. The treatment time ratio of the catalytic decomposition treatment and the ion polishing treatment is 1: (1-50), preferably 1: (2.5-20); Catalytic decomposition treatment uses a metal catalyst, preferably a supported metal nanoparticle catalyst; Ion polishing uses a mixed ion exchanger with basic and acidic groups.

[0050] S3.4 Degassing and ultrafiltration treatment: The water body after the second-order absorption exchange treatment enters the second membrane degasser 24 and the membrane particle separator 25 for degassing and solid-liquid separation treatment to remove dissolved gases, volatiles and particles to obtain ultrapure water.

[0051] S4 second-order cycle: according to the water consumption of the downstream semiconductor process, ultrapure water with a margin is output, and the remaining ultrapure water is distributed and refluxed by a voltage-stabilizing actuator to perform steps S3.1-3.4 to form a second-order circulation ratio; according to the micro-contamination amount of the secondary pure water and the second-order circulation ratio, the target decomposition dose of the second-order decomposition treatment is adjusted to control the micro-contamination amount of the ultrapure water, and the output ultrapure water micro-contamination amount is monitored online in real time, and compared with the ultrapure water micro-contamination amount obtained by the aforementioned preset and control.

[0052] Second order cycle ratio R p satisfy: R p =Q pr / Q pe Q pe =Q pt -Q pr Among them, R p At 0.2-0.8, Q pt Indicates the total amount of ultrapure water obtained through fine treatment, Q pr Indicates the amount of ultrapure water refluxed, Q pe Indicates the amount of ultrapure water used in downstream semiconductor processes; The quality of the ultrapure water produced by the above method is as follows: Trace metals <0.1ng / l, TOC <0.5μg / l, DO <1μg / l, B <1ng / l, H2O2 <1μg / l, particle number concentration larger than 0.05μm <0.1pcs / mL.

[0053] In order to run the control method, the present invention also provides a corresponding device, including a circulating deep treatment system, a pure water storage tank 21 and a circulating fine treatment system connected in sequence, wherein: (1) Circulation deep treatment system, including: (1.1) Deep desalination equipment, including at least one of a continuous electric desalination device 11, a mixed ion exchange tower, and a composite ion exchange tower; (1.2) a first-order hybrid photolysis absorber 12, integrating a compatible first-order decomposition zone and a first-order absorption exchange zone downstream thereof; The target decomposition dose of UV light in the first-order decomposition zone is 300-800 mJ / cm 2 , the TOC mass concentration of the water at the outlet of the first-order mixed photolysis absorber 12 is below 5 μg / l, preferably less than 3 μg / l, more preferably less than 2 μg / l; In the direction of water flow, the first-order absorption and exchange zone includes a positive adsorption layer, a complex reaction layer and an ion polishing layer in sequence. According to the ratio of treatment time, the thickness ratio of the positive adsorption layer, the complex reaction layer and the ion polishing layer is designed to be about (1-4): (1-12): (1-6), preferably (1-4): (8-10): (1-4); wherein the positive adsorption layer includes a positively charged adsorbent, and the positively charged adsorbent is a positively charged adsorption resin with an amine polyhydroxyl functional group or a mixed resin mixed with a positively charged adsorption resin with an amine polyhydroxyl functional group; the complex reaction layer includes a boron absorbent; and the ion polishing layer includes a mixed ion exchanger with a basic group and an acidic group respectively; (1.3) a first membrane degasser 13, comprising a membrane contact degassing device; (2) First-stage circulation pipeline: In addition to being normally connected to the pure water storage tank 21, the water outlet of the first membrane degasser 13 is also provided with a first-stage circulation pipeline to connect it to the water inlet of the desalination equipment, so as to return a certain proportion of the secondary pure water to the circulation deep treatment system; The first-order detection unit includes a liquid level detector arranged in the pure water storage tank 21, a first sampling point 101 arranged at the water inlet of the deep desalination equipment, a second sampling point 102 arranged at the water outlet of the first membrane degasser 13, and a detection device connecting the sampling points (101, 102); the detection device includes but is not limited to at least one of a TOC analyzer, a dissolved oxygen analyzer, a boron analyzer, and a dissolved silicon analyzer. The measured data of the detection device is transmitted to the control unit, and the target decomposition dose of the first-order decomposition treatment is adjusted according to the first-order circulation ratio and the micro-pollution amount of the primary pure water to control the micro-pollution amount of the secondary pure water; or, the target decomposition dose of the first-order decomposition treatment is adjusted according to the first-order circulation ratio, the micro-pollution amount of the primary pure water, and the micro-pollution amount in the target secondary pure water. That is, the above parameters have controllability related to each other.

[0054] (3) Circulation fine treatment system, including: (3.1) A membrane absorber 22, comprising a hydrogen dissolving membrane and a hydrogen supply pipeline, for dissolving hydrogen into the secondary pure water to obtain hydrogen-filled water with a dissolved hydrogen concentration of more than 0.05 mg / l; (3.2) A second-order hybrid photodecomposition absorber 23, which integrates a compatible second-order decomposition zone and a second-order absorption exchange zone downstream thereof; the target decomposition dose of ultraviolet light in the second-order decomposition zone is 200-1000 mJ / cm 2 , the TOC mass concentration of the water at the outlet of the second-order mixed photolysis absorber 23 is below 0.5 μg / l, preferably below 0.3 μg / l; In the direction of water flow, the second-order absorption exchange zone includes a catalytic reaction layer and an ion polishing layer in sequence. According to the ratio of treatment time, the thickness ratio of the catalytic reaction layer to the ion polishing layer is 1: (1-50), preferably 1: (1.2-50), and more preferably 1: (2.5-20); (3.3) a second membrane degasser 24 and a membrane microparticle separator 25, comprising a membrane contact degasser and an ultrafiltration device connected in sequence; (4) Secondary circulation pipeline: In addition to being normally connected to the downstream water point of the ultrapure water output port, the outlet of the membrane microparticle separator 25 is also provided with a secondary circulation pipeline to connect it to the pure water storage tank 21, so as to return a certain proportion of ultrapure water for fine treatment, thereby meeting the real-time changing process water demand while ensuring the water quality requirements; The second-order detection unit includes a third sampling point 201 disposed at the water outlet of the membrane microparticle separator 25 and a detection device connected to the third sampling point 201. The detection device can be shared with the detection device in the first-order detection unit or set separately, including but not limited to at least one of a TOC analyzer, a dissolved oxygen analyzer, a boron analyzer, a microparticle analyzer, a H2O2 analyzer, and a dissolved silicon analyzer. The measured data of the detection device is transmitted to the control unit, and the target decomposition dose of the second-order decomposition treatment is adjusted according to the micro-pollution amount of the secondary pure water and the second-order circulation ratio to control the micro-pollution amount of the ultrapure water; or the target decomposition dose of the second-order decomposition treatment is adjusted according to the micro-pollution amount of the secondary pure water, the second-order circulation ratio, and the target micro-pollution amount of the ultrapure water. That is, the above parameters have interrelated controllability.

[0055] (5) A control unit, wherein the control unit is connected to the signals of the aforementioned first-order detection unit and the second-order detection unit, including but not limited to being connected to the signals of the liquid level detector, the first distribution actuator and the second distribution actuator, and drives the first distribution actuator to distribute the return water volume of the secondary pure water in proportion to the opening according to the feedback value of the liquid level detector, thereby forming a first-order circulation ratio, and drives the second distribution actuator to distribute the return water volume of the ultrapure water in proportion to the opening according to the amount of ultrapure water used for the process, thereby forming a second-order circulation ratio.

[0056] In order to make the control method and device for stably outputting ultrapure water for semiconductor process of the present invention easier to understand, the overall process and control method are further explained on the basis of the aforementioned core control method and device: During the startup phase, all light sources designed for the first-order decomposition zone and the second-order decomposition zone can be turned on to perform micro-pollution treatment in maximum power mode, so that the output ultrapure water can quickly meet the water consumption and water quality requirements; In the stable operation stage, according to the detection results of the detection unit on the amount of micro-pollution in the primary pure water and the amount of micro-pollution in the secondary pure water and the formed first-order circulation ratio, the target decomposition dose of the first-order decomposition treatment is adjusted and controlled in comparison with the preset amount of micro-pollution in the secondary pure water. When the amount of micro-pollution in the secondary pure water is low, especially when it is significantly better than the preset value or the predicted value, the TOC kinetic model calculates the preferred lower target decomposition dose, and the current output of part of the radiation light source in the first-order decomposition zone can be adjusted by adjusting the ballast to reduce the current intensity and the power output. At the same time, according to the real-time detection results of the online detection device, it is determined whether the amount of micro-pollution in the secondary pure water at the outlet of the first membrane degasser 13 meets the preset requirements. If the requirements are met, it can be determined to maintain the state of the radiation light source or continue to adjust it according to the detected micro-pollution index; When the micro-pollution amount of the secondary pure water rises above the preset value (that is, a certain micro-pollution index exceeds the threshold), the TOC kinetic model calculates the preferred higher target decomposition dose, and the current output of some radiation light sources in the first-order decomposition zone can be adjusted by adjusting the ballast, gradually increasing the current intensity and increasing the power output. At the same time, according to the real-time detection results of the online detection device, it is determined whether the micro-pollution amount of the secondary pure water at the outlet of the first membrane degasser 13 meets the preset requirements, and it is chosen to maintain the state of the radiation light source or continue to increase the current intensity and increase the power output until the requirements are met.

[0057] When the amount of ultrapure water used in the downstream semiconductor process is reduced, especially when it is significantly lower than the average consumption of process water and presents a stable state, a relatively high second-order circulation ratio is formed for a long time, and the secondary pure water in the pure water storage tank 21 is thereby further diluted. The preferred lower target decomposition dose is calculated by the TOC kinetic model, and the operating current of the radiation light source in the second-order decomposition zone can be appropriately reduced by adjusting the ballast, thereby reducing the power output. Based on the monitoring of the micro-pollution amount of ultrapure water at the outlet of the membrane microparticle separator 25, the radiation dose provided by the second-order mixed photolysis absorber 23 is determined while ensuring the stability of the system.

[0058] In general, the first-order circulation ratio, the amount of micro-pollution of primary pure water, the amount of micro-pollution of secondary pure water, and the target decomposition dose of the first-order decomposition treatment are closely related, while the amount of micro-pollution of secondary pure water, the amount of micro-pollution of ultrapure water, the second-order circulation ratio, and the target decomposition dose of the second-order decomposition treatment are closely related. Based on multiple simulation test comparisons, the present invention proposes the above-mentioned control method and device for stable output of ultrapure water for semiconductor process. Example

[0059] The method for controlling the stable output of ultrapure water for semiconductor process of this embodiment is applied to the test line for the localization substitution of ultrapure water for nano-process semiconductor. The device used specifically includes a circulating deep treatment system, a pure water storage tank 21 and a circulating fine treatment system connected in sequence; the circulating deep treatment system mainly provides S1 deep treatment and S2 first-order circulation; the circulating fine treatment system, see the attached Figure 2 , mainly providing S3 fine processing and S4 second-order cycle.

[0060] The specific processing technology is as follows: S1 deep treatment, purifying the pre-treated primary pure water into secondary pure water, including: S1.1 Deep desalination treatment: The pretreated primary pure water enters the continuous electric desalination device 11 to further remove anions and cations to obtain deep desalted water; S1.2 First-order decomposition treatment: The deep desalted water enters the first-order mixed photolysis absorber 12 (the first-order mixed photolysis absorber 12 is compatible with the first-order decomposition zone and the first-order absorption exchange zone downstream thereof), and after decomposition treatment, primary decomposed water is obtained; the first-order decomposition treatment uses 9 independently controlled 185nm low-pressure high-intensity mercury discharge lamps 155W (3 groups × 3, VioPure); the target decomposition dose of ultraviolet light for the first-order decomposition treatment is 100-800mJ / cm 2 Continuously adjustable; S1.3 First-order absorption and exchange treatment: It includes positive adsorption treatment, complex reaction treatment and ion polishing treatment in sequence, and the ratio of the treatment time of positive adsorption treatment, complex reaction treatment and ion polishing treatment is 1:8:2; wherein, the positive adsorption treatment adopts a positively charged adsorbent, and the positively charged adsorbent is a positively charged adsorption resin with amine polyhydroxyl functional groups; the complex reaction treatment uses a boron absorbent; and the ion polishing treatment adopts a mixed ion exchanger with basic groups and acidic groups respectively.

[0061] S1.4 Degassing treatment: The water body after the first-order absorption exchange treatment enters the first membrane degasser 13 to remove dissolved gases and volatiles to obtain secondary pure water; the secondary pure water at the outlet of the first membrane degasser 13 is sampled and tested online, and the online test results are fed back to the control unit; S2 first-order cycle: Part of the secondary pure water flowing out of the first membrane degasser 13 is circulated back and forth to perform steps S1.1-S1.4, and the secondary pure water that is not refluxed is stored in the pure water storage tank 21. The amount of stored water and the amount of refluxed water are controlled by the liquid level detector. According to the feedback value of the liquid level detector, the actuator is driven to distribute the water according to the proportional opening, forming a first-order circulation ratio; After deep treatment and first-order circulation, the water quality of the secondary pure water in the pure water storage tank 21 at least reaches: resistivity 18.10MΩ.cm, TOC concentration 2.1μg / l, boron (B) concentration 2ng / l, DO concentration 1.3μg / l.

[0062] S3 fine processing: S3.1 Hydrogen charging treatment: secondary pure water is output from the pure water storage tank 21 to the membrane absorber 22. The membrane absorber 22 is equipped with a gas transfer membrane ArrayforceTM 10×28 (provided by Cobetter). Hydrogen with a purity greater than 99.9% is introduced into the membrane absorber 22. The hydrogen concentration of the hydrogen-charged water at the liquid phase outlet of the membrane absorber 22 is monitored to be 0.05 mg / l by a Dextens 62101 hydrogen dissolving instrument connected to the fourth sampling point 202; S3.2 Second-order decomposition treatment: hydrogen-filled water at SV = 500h -1Entering the second-order mixed photolysis absorber 23 (the second-order mixed photolysis absorber 23 is compatible with the second-order decomposition zone and the second-order absorption exchange zone downstream thereof), after the second-order decomposition treatment, secondary decomposed water is obtained; the second-order decomposition treatment uses 12 independently controlled 185nm low-pressure high-intensity mercury discharge lamps 155W in total (6 groups × 2, VioPure); the target decomposition dose of ultraviolet light for the second-order decomposition treatment is 200-1000mJ / cm 2 Continuously adjustable; S3.3 Second-order absorption exchange treatment: The secondary decomposed water undergoes catalytic decomposition treatment and ion polishing treatment in sequence, and the treatment time ratio of catalytic decomposition treatment and ion polishing treatment is 1:7; wherein, the catalytic decomposition treatment adopts platinum nanoparticle catalyst Pd@PS-DVB-QA (prepared in the laboratory, particle size measured by JEM-100CX image 1.5±0.2nm); the ion polishing treatment adopts electronic grade UPS resin Monojet 6040U (Sunresin).

[0063] A fifth sampling point 203 is set at the outlet of the second-order mixed photolysis absorber 23, and the fifth sampling point 203 is connected to the combined sampling valve of the ALH2O2Analyzer and the Sievers M500e Online TOC Analyzer to analyze the mass concentration of H2O2 and TOC online; S3.4 Degassing and ultrafiltration treatment: The water body after the second-order absorption exchange treatment enters the second membrane degasser 24 for degassing treatment (using deoxygenation membrane SEPAREL EF-120, provided by Sinochem), and then enters the membrane particle separator 25 for solid-liquid separation treatment (using ultrafiltration membrane APA6SN, provided by Cobetter) to remove dissolved gases, volatiles and particles to obtain ultrapure water.

[0064] S4 second-order cycle: According to the water consumption of the downstream semiconductor manufacturing process, ultrapure water with a margin is output, and the remaining ultrapure water is distributed and refluxed by a voltage-stabilizing actuator, and then recirculated to perform steps S3.1-3.4 to form a circulation ratio of the second-order treatment; the micro-contamination amount of the output ultrapure water is monitored online in real time, and the target decomposition dose of the second-order decomposition treatment is adjusted according to the amount of ultrapure water used in the process. A sampling pool 26 is set at the outlet of the membrane microparticle separator 25, and a sixth sampling point 204 is set in the sampling pool 26. The sampled water of the sixth sampling point 204 is transported to three analyzers, Orbisphere 510, PMS Ultra DI50 and NexION 5000 ICP-MS, in real time, to detect the concentrations of DO, microparticles (>0.05 μm) and boron online, respectively, and the output ultrapure water is monitored online in real time.

[0065] After the water quality index of ultrapure water was basically stable, water was passed for two days continuously, and the water quality became more stable. The detection data of the outflow port of the membrane microparticle separator 25 of this embodiment is shown in Table 1.

[0066] Table 1 Detection data of various micro-pollution indicators

[0067] Catalyst space velocity for catalytic decomposition treatment: 500h -1 The catalyst filling height is 0.1m, the UPS resin layer height in the ion polishing area is 0.7m, and the second-order mixed photolysis absorber 23 is Type-Ⅱ-1000, with a standard configuration of 12 185nm lamps (6 groups × 2). The VUV Dosing Calc EM is used to verify the target UV decomposition dose of the actual lamps in the second-order mixed photolysis absorber 23: According to the experimental model, the design dose to achieve the target TOC reduction concentration is 514 mJ / cm 2 , the dose ratio adjustment factor is 1.36, so the radiation dose calculated for the second-order hybrid photolysis absorber 23 is 698 mJ / cm 2 , the actual calculated concentration of TOC is 0.2μg / L, which is basically consistent with the measured value of 0.19μg / L. Other design data are shown in Table 2.

[0068] Table 2 Design parameters of second-order hybrid photolysis absorber 23 (U-PMB)

[0069] By using the above device, the quality of the output ultrapure water can reach: TOC<0.5 μg / l, DO<1 μg / l, B<1 ng / l, H2O2<1 μg / l, particle number concentration larger than 0.05 μm<0.1 pcs / mL.

[0070] By changing the additional circulation coefficient and adjusting the actuator opening, we can obtain the second-order circulation return water volume Q of 1, 1.5, 2, 2.5 and 3 CMH respectively. pr , record the TOC measurement value at the outlet of the water collection chamber of the second-order hybrid photolysis absorber 23, and compare it with the VUV Dosing Calc EM calculated value. The experimental data are shown in Table 3: Table 3 Experimental data record table of second-order mixed photolysis absorber 23

[0071] As can be seen from the results, the experimental study of the second-order mixed photolysis absorber 23 is reproducible, and the relative error formed by the second-order decomposition concentration predicted by VUV Dosing CalcEM and the measured value at the outlet of the second-order mixed photolysis absorber 23 is small, and a higher design accuracy can be obtained. Therefore, the present invention can set suitable water quality and water output according to the water demand of the downstream semiconductor process, ensure stable and continuous water supply on the basis of high water quality, and can quickly adjust and predict the technical effect with the change of downstream demand, and adjust the radiation light source parameters of the decomposition zone, and reduce energy consumption and save costs on the basis of ensuring high-quality and stable supply of ultrapure water.

[0072] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they are aware of the basic creative concepts. Therefore, the present invention is intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention. Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention.

Claims

1. A method for controlling the stable output of ultrapure water for semiconductor process, characterized in that: The following steps are involved: S1 deep treatment: deep desalination treatment, first-order decomposition treatment, first-order absorption exchange treatment and degassing treatment are carried out on the primary pure water to obtain secondary pure water; S2 first-order cycle: reflow part of the secondary pure water obtained in step S1 for further treatment in step S1, and store the secondary pure water not reflowed in the pure water storage tank; S3 fine treatment: hydrogenation treatment of the secondary pure water output from the pure water storage tank to make the dissolved hydrogen concentration above 0.05mg / l, followed by second-order decomposition treatment, second-order absorption exchange treatment, degassing and ultrafiltration treatment to obtain ultrapure water; S4 second-stage cycle: According to the water consumption of the downstream semiconductor process, ultrapure water is output stably, and the remaining ultrapure water is refluxed for step S3 fine treatment.

2. The control method according to claim 1, characterized in that: The first-order decomposition process and the second-order decomposition process respectively use a number of independently controlled ultraviolet radiation light sources to perform ultraviolet decomposition processes; The target decomposition dose for the first-order decomposition treatment is 100-800 mJ / cm 2 Continuously adjustable; The target decomposition dose for the second-order decomposition treatment is 200-1000 mJ / cm 2 Continuously adjustable.

3. The control method according to claim 2, characterized in that: In step S2, according to the simulated output result of the pure water storage tank liquid level, the return water volume of the secondary pure water is proportionally distributed to form a first-order circulation ratio, and according to the micro-pollution volume of the primary pure water and the first-order circulation ratio, the target decomposition dosage of the first-order decomposition treatment is adjusted to control the micro-pollution volume of the secondary pure water; Among them, the water quality of the secondary pure water in the pure water storage tank reaches: Resistivity>18.1 MΩ·cm, TOC<5.0 μg / l, B<5 ng / l, DO<5 μg / l.

4. The control method according to claim 3, characterized in that: According to the amount of micro-pollution in primary pure water and the first-order cycle ratio R m , after the first-order decomposition treatment and the first-order absorption exchange treatment, the target decomposition dose D of the first-order decomposition treatment is adjusted pm , and obtain the amount of micro-pollution in secondary pure water , the amount of micro-pollution in secondary pure water Satisfies formula (1): （1） Among them, RE mdi To improve the desalination efficiency, D pm is the target decomposition dose for the first-order decomposition process, is the amount of micro-pollution in secondary pure water, is the amount of micro-pollution in pure water. Rm is the circulation ratio of the first-order treatment K m1 , K m2 is the reaction rate constant.

5. The control method according to claim 3 or 4, characterized in that: In step S4, the amount of ultrapure water refluxed is proportionally distributed according to the amount of ultrapure water used in the process to form a second-order circulation ratio, and the target decomposition dose of the second-order decomposition treatment is adjusted according to the amount of micro-pollution in the secondary pure water and the second-order circulation ratio to control the amount of micro-pollution in the ultrapure water; The quality of the output ultrapure water reaches: Trace metals <0.1 ng / l, TOC <0.5 μg / l, DO <1 μg / l, B <1 ng / l, H2O2 <1 μg / l, particle number concentration larger than 0.05 μm <0.1 pcs / mL.

6. The control method according to claim 5, characterized in that: According to the secondary pure water micro-pollution , second-order circulation ratio R p and the pipe network characteristic coefficient λ, after second-order decomposition treatment, second-order absorption exchange treatment, degassing and ultrafiltration treatment, the target decomposition dose D of the second-order decomposition treatment is adjusted pe , get the ultrapure water micro-pollution , micro-pollution in ultrapure water Satisfies formula (2): （2） Among them, D pe is the target decomposition dose for the second-order decomposition process, is the amount of micro-pollution in secondary pure water, R p is the cyclic ratio processed by the second-order decomposition, λ is the characteristic coefficient of the pipe network, satisfying formula (3): （3） L is the length of the pipe network; is the concentration gradient of micro-pollutant dissolution observed in the ultrapure water reflux, v is the second-order decomposition treatment rate, Kt is the time constant, K p1 , K p2 , K p3 is the reaction rate constant.

7. The control method according to claim 1 or 2, characterized in that: The first-order absorption exchange treatment includes positive adsorption treatment, complex reaction treatment and ion polishing treatment in sequence, and the treatment time ratio of the positive adsorption treatment, complex reaction treatment and ion polishing treatment is (1-4): (1-12): (1-6); The second-order absorption exchange treatment includes catalytic decomposition treatment and ion polishing treatment in sequence, and the treatment time ratio of the catalytic decomposition treatment and the ion polishing treatment is 1: (1-50).

8. A device for running the control method according to any one of claims 1 to 7, characterized in that: It includes a circulating deep treatment system, a pure water storage tank and a circulating fine treatment system connected in sequence; A circulating deep treatment system, including a deep desalination device, a first-order mixed photolysis absorber and a membrane degasser, wherein the water outlet of the membrane degasser is controlled to be connected to a pure water storage tank and a water inlet of the deep desalination device; A circulating fine treatment system includes a membrane absorber, a second-order mixed photolysis absorber, a membrane degasser and a membrane microparticle separator, wherein the water outlet of the membrane microparticle separator is controlled to be connected to an ultrapure water point and a pure water storage tank; The first-order hybrid photodecomposition absorber is compatible with the first-order decomposition zone and the first-order absorption exchange zone downstream thereof; the second-order hybrid photodecomposition absorber is compatible with the second-order decomposition zone and the second-order absorption exchange zone downstream thereof; The membrane absorber includes a hydrogen dissolving membrane and a hydrogen supply pipeline, which provides hydrogen-filled water with a dissolved hydrogen concentration of more than 0.05 mg / l to the downstream second-order mixed photolysis absorber.

9. The device according to claim 8, characterized in that Also includes a control unit and a detection unit; The detection unit includes a liquid level detector arranged in the pure water storage tank, sampling points arranged at the water inlet of the deep desalination equipment, the water outlet of the membrane degasser and the membrane microparticle separator, and detection equipment connected to the sampling points; The control unit is connected to the liquid level detector, the first distribution actuator and the second distribution actuator signal. According to the feedback value of the liquid level detector, the first distribution actuator is driven to distribute the return water volume of the secondary pure water in proportion to the opening, forming a first-order circulation ratio. According to the amount of ultrapure water used in the process, the second distribution actuator is driven to distribute the return water volume of the ultrapure water in proportion to the opening, forming a second-order circulation ratio.

10. The device according to claim 9, characterized in that In the direction of water flow, the first-order absorption and exchange zone includes a stacked positive adsorption layer, a complex reaction layer and an ion polishing layer, and the second-order absorption and exchange zone includes a stacked catalytic decomposition layer and an ion polishing layer; The control unit adjusts the target decomposition dose of the first-order decomposition zone and / or the target decomposition dose of the second-order decomposition zone according to the feedback result of the detection device.

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