Advanced treatment process of low-concentration gas in integrated circuit production process

Abstract

The invention belongs to the technical field of gas treatment, and particularly discloses an advanced treatment process of low-concentration gas in an integrated circuit production process, which comprises the following steps: efficiently and deeply purifying ppm-level propylene glycol methyl ether acetate, isopropanol, methylbenzene, butanone and other organic gases to ppb level through a catalytic oxidation treatment system; the technical problems of high cost, low mineralization rate, long time consumption, low purification degree and easy generation of secondary pollution when the traditional treatment process is used for treating low-concentration gas are effectively solved. The process aims at treatment of low-concentration industrial gas in the integrated circuit production process, high-energy-consumption processes such as concentration are not needed, the degradation rate of direct gas treatment is increased to 99% or above, and the mineralization rate is increased to 95% or above.

Description

Technical Field

[0001] The invention belongs to the technical field of gas processing, and in particular relates to a deep processing technology for low-concentration gas in the production process of integrated circuits. Background Art

[0002] In the field of integrated circuit manufacturing, a variety of organic substances such as propylene glycol methyl ether acetate, isopropyl alcohol, toluene, butanone, etc. are widely used. In a specific production process, these organic substances will continue to circulate in the production environment in a low-concentration gaseous form, forming a circulating gas system that needs to be treated. Propylene glycol methyl ether acetate, as a solvent in photoresist, plays a key role in the performance of photoresist, but in the production environment, its gaseous form may affect the accuracy and quality of the photolithography process, cause contamination of the chip surface, and thus reduce the performance and yield of the chip. Isopropyl alcohol is used in multiple process links such as cleaning, photolithography and drying. Isopropyl alcohol in gaseous form may adsorb particles to form aerosols, affect the cleanliness of the chip surface, and react with other substances, which will have an adverse effect on chip performance. Toluene may participate in the reaction or remain in some processes. Its presence will affect the chip packaging process and cause the performance of the packaging material to deteriorate. Butanone may interfere with the dielectric properties of the chip in the production of integrated circuits, causing changes in the electrical properties of the chip, thereby affecting the quality and performance of the product.

[0003] At present, the treatment process for these low-concentration organic circulating gases faces many difficulties. Traditional treatment methods have problems to varying degrees when dealing with these substances. Taking the adsorption method as an example, when dealing with propylene glycol methyl ether acetate, due to its different chemical properties, the adsorption sites of the adsorbent may be quickly saturated, and desorption is difficult, affecting the regeneration and reuse of the adsorbent; for isopropanol, its volatility may cause energy loss and reduced treatment efficiency during the adsorption process; and for toluene and butanone, due to their different chemical structures, the selective adsorption capacity of the adsorbent may be insufficient, resulting in poor purification effect. At the same time, traditional treatment methods often require a series of complex operations under high temperature environments, involving the coordinated operation of multiple equipment, such as zeolite wheels, adsorption systems, desorption systems, etc. The entire process is cumbersome and time-consuming, and the purification effect is difficult to achieve ideal requirements. In addition, the related operation and maintenance costs are high, and there are certain safety hazards.

[0004] Catalytic oxidation technology is often used to treat organic gases of various concentrations. Studies have shown that the use of nano-scale, high-surface-weight catalysts can still have good adsorption and catalytic conversion effects on low-concentration pollutants. Under the conditions of catalytic oxidation reaction initiation, the active sites on the catalyst surface are excited to produce superoxide free radicals (·O2 -), hydroxyl radicals (·OH) and other active substances can oxidize organic matter in the gas into small molecules until they are completely mineralized into carbon dioxide. Catalytic oxidation technology can convert organic matter in the gas into carbon dioxide and water without concentration, with high and stable treatment efficiency. Compared with traditional methods such as adsorption and combustion, catalytic oxidation technology can more conveniently treat low-concentration gases and achieve a removal effect of more than 99%. In addition, when using catalytic oxidation technology to treat low-concentration gases, it will not cause damage to IC equipment, which helps to protect the stability and safety of IC production lines and reduce production risks.

[0005] The present invention applies catalytic oxidation technology to the deep treatment process of low-concentration gas in the production process of integrated circuits. The composite catalyst is composed of oxide nanoparticle carriers and active metal nanoparticles and placed in a catalytic oxidation reaction system. The organic components in the ppm-level gas can be directly introduced without adsorption concentration to quickly purify the organic components in the ppm-level gas to the ppb level and convert them into carbon dioxide and water. The present invention provides a feasible method for deep treatment of low-concentration gas in the production process of integrated circuits, which has practical industrial significance of safety, low cost and high efficiency. Summary of the invention

[0006] The present invention aims to provide an efficient, safe and low-cost catalytic oxidation deep treatment process for treating low-concentration organic circulating gases such as propylene glycol methyl ether acetate, isopropyl alcohol, toluene, butanone, etc. in the production process of integrated circuits, so as to overcome the defects of existing treatment processes.

[0007] In order to solve the above technical problems, the technical solution of the present invention is to use an oxide nanoparticle carrier and active metal nanoparticles to form a composite catalyst, which is placed in a catalytic oxidation reaction system. The gas is directly introduced without adsorption and concentration, and the organic components in the ppm-level gas are quickly and deeply purified to the ppb level and converted into carbon dioxide and water.

[0008] The composite catalyst in the catalytic oxidation treatment system is composed of an oxide nanoparticle carrier and active metal nanoparticles, wherein the active metal nanoparticles are one or more of Pt, Au, Ag, Ru, Pd and Ir, with a content of 0.1-2.0wt% and a particle size of 0.1-5 nm; the oxide nanoparticle carrier is a single oxide or a solid solution of multiple oxides selected from TiO2, CeO2, ZrO2, Fe2O3, Al2O3, with a particle size of 5-50 nm.

[0009] The catalytic oxidation deep treatment process has a treatment time range of 5-55 s, a reaction temperature range of 60-120°C, and an ultraviolet light wavelength range of 160-400 nm. Organic components such as propylene glycol methyl ether acetate, isopropanol, toluene, butanone, etc. in the circulating gas undergo catalytic oxidation reactions with oxygen at the active sites of the composite catalyst and are ultimately converted into carbon dioxide and water.

[0010] Compared with the prior art, the present invention has the following advantages: 1. The composite catalyst with a specific composition is prepared by conventional chemical methods, which is relatively low in cost and easy to mass produce, effectively improving the catalytic oxidation treatment efficiency of organic circulating gases such as propylene glycol methyl ether acetate, isopropanol, toluene, and butanone; 2. No complicated pre-treatment process such as adsorption concentration is required. Low-concentration circulating gas can be directly and quickly treated. When the gas concentration is lower than 100 ppm, the treatment time in the catalytic oxidation system ranges from 5 to 55 seconds, which can achieve efficient deep purification and help improve product quality and production stability in the integrated circuit production process; 3. Through catalytic oxidation reaction, it can achieve deep purification of organic gases of various components, and can purify organic gases at the ppm level to the ppb level, while reducing the generation of secondary pollution, which is more conducive to environmental protection; 4. The process has good adaptability. Under the conditions of different reactor sizes, different air volumes and long-term continuous catalytic oxidation reactions, the composite catalyst can still maintain good performance and does not need to be replaced frequently, which reduces the operation and maintenance costs of the gas treatment equipment and is conducive to continuous production in the integrated circuit industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0012] Figure 1 : TEM image of 0.25 wt% Pt-TiO2.

[0013] Figure 2 : XRD pattern of 0.25 wt% Pt-TiO2.

[0014] Figure 3 : The purification effect diagram of Example 1.

[0015] Figure 4 : The purification effect diagram of Example 2. DETAILED DESCRIPTION

[0016] For ease of understanding, the deep processing process of low-concentration gas in the integrated circuit production process is described below in conjunction with an embodiment. It should be understood that the described embodiment is a part of the embodiment 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 creative work are within the scope of protection of the present invention.

[0017] Example 1 Step 1: Stir an appropriate amount of TiO2 (P25) with a stabilizer, a reducing agent, etc., add chloroplatinic acid, and prepare a slurry with a precious metal content of 0.25 wt%. After sufficient reaction and treatment, a composite catalyst 0.25 wt% Pt-TiO2 powder is obtained, in which nano-scale Pt particles are generated, TiO2 and Pt are evenly dispersed, and the particle size of Pt is about 3 nm; Step 2: Grind the catalyst powder, mix it with anhydrous ethanol (or water) and polytetrafluoroethylene dispersion to form a catalyst slurry. After the slurry is evenly dispersed, use air as shear gas to atomize the slurry and spray it evenly on the cylindrical nickel foam. Dry the catalyst-loaded nickel foam and test it on a machine. Step 3: Place the catalyst-loaded nickel foam catalyst plate into the catalytic oxidation system, and carry out catalytic oxidation reaction under the conditions of temperature of 80°C and ultraviolet light irradiation of wavelength of 254 nm. Pass 5 SLM of gas containing 25 ppm (i.e. 2500 ppb) of propylene glycol methyl ether acetate into the catalytic oxidation system. The overall gas treatment time is 55 seconds, the degradation rate is 99.4%, the mineralization rate is 96.3%, and the outlet concentration of the gas is reduced to 15.0 ppb. The specific results are shown in Figure 3 .

[0018] Example 2 This embodiment is a deep treatment process for low-concentration gas in the integrated circuit production process. The difference from the embodiment 1 is that the overall treatment time of the gas in step 3 is 10 s, the degradation rate is 99.1%, the mineralization rate is 95.8%, and the outlet concentration of the gas is reduced to 22.5 ppb. The specific results are shown in Figure 4 .

[0019] The foregoing description of specific exemplary embodiments of the present invention is for the purpose of illustration and demonstration. These descriptions are not intended to limit the present invention to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the present invention and various different selections and changes. The scope of the present invention is intended to be limited by the claims and their equivalents.

Claims

1. A deep treatment process of low-concentration gas in the production process of integrated circuits, characterized in that: The following steps are involved: Introducing low-concentration gas into the catalytic oxidation treatment system, using composite catalysts, triggering catalytic oxidation reactions under appropriate temperature and light conditions, oxidizing organic gases into carbon dioxide and water at the active sites of the catalyst, achieving efficient deep purification, purifying organic gases at the ppm level to the ppb level; The deep purification is specifically manifested in that when the concentration of organic matter in the gas is lower than 100 ppm, a degradation rate of more than 99% and a mineralization effect of more than 95% can be achieved through a catalytic oxidation treatment system.

2. The catalytic oxidation deep treatment process according to claim 1, wherein the treatment time ranges from 5 to 55 s, the reaction temperature ranges from 60 to 120 °C, and the ultraviolet light wavelength ranges from 160 to 400 nm.

3. The gas described in claim 1 includes but is not limited to propylene glycol methyl ether acetate, isopropyl alcohol, toluene, butanone and other volatile solvents commonly used in the production process of integrated circuits.

4. The composite catalyst according to claim 1 is composed of an oxide nanoparticle carrier and active metal nanoparticles, characterized in that: The active metal nanoparticles are one or more of Pt, Au, Ag, Ru, Pd and Ir, with a content of 0.1-2.0 wt % and a particle size of 0.1-5 nm; The oxide nanoparticle carrier is a single oxide or a solid solution of multiple oxides selected from TiO2, CeO2, ZrO2, Fe2O3 and Al2O3, and has a particle size of 5-50 nm.

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