Annealing process for processing semiconductor seamless stainless steel electronic clean tube

Abstract

The application discloses an annealing process for processing semiconductor seamless stainless steel electronic clean pipes and belongs to the technical field of metal material heat treatment. The process places austenitic seamless stainless steel pipes containing deformation-induced martensite in a controlled atmosphere annealing furnace, first heat-insulates at a low temperature recovery temperature, then uses a nonlinear increasing heating mode to cross a martensite reverse transformation temperature zone and complete reverse transformation and special grain boundary reconstruction, and then heat-insulates at a high temperature locking temperature for a short time. Meanwhile, a hydrogen atmosphere pulse modulation is applied during the annealing process, and a trace amount of a synergistic active medicament is added in stages, a trace amount of oxygen is injected before cooling to a set temperature, and a chromium oxide passivation film is formed on the surface of the pipe. The process can improve the proportion of low sigma grain boundaries, improve the uniformity of the surface layer structure, reduce residual stress, inhibit abnormal grain growth, promote the enrichment of chromium elements in the surface passivation film, and improve the corrosion resistance, surface stability and subsequent clean service adaptability of the electronic clean pipe.

Description

Technical Field

[0001] This invention belongs to the field of stainless steel tubing processing technology for semiconductor manufacturing, and specifically relates to an annealing process for processing seamless stainless steel electronic clean tubes for semiconductors. Background Technology

[0002] Seamless stainless steel electronic cleanroom tubing used in semiconductor manufacturing systems not only transports high-purity gases, chemical media, and process fluids, but also directly affects particle precipitation, metal ion contamination, gas purity fluctuations, and the long-term stable operation of the system. These tubing materials typically require low surface roughness, high microstructure uniformity, and stable corrosion resistance. Therefore, controlling the surface and subsurface microstructure is particularly crucial during the annealing process following cold forming.

[0003] In the prior art, Chinese patent CN111684107B discloses stainless steel components and their manufacturing methods. This technology mainly involves forming a passivation layer with a thickness of 2-20 nm on the surface of the stainless steel base material and controlling the chromium atom concentration on the outermost surface of the passivation layer to reduce the risk of metal leaching and particle shedding when in contact with semiconductor processing liquids. Its application extends beyond the stainless steel components themselves to devices or containers made from these components that come into contact with semiconductor processing liquids, focusing on solving the problem of metal impurity contamination during the storage and transportation of semiconductor processing liquids. While the prior art involves control of the chromium atom concentration in the passivation layer, it focuses more on controlling the composition of the passivation layer and suppressing impurity leaching. It does not provide techniques for treating chromium-rich passivation films or for preparing trace amounts of synergistic agents containing excited second-response controlled hydrogen during annealing.

[0004] Therefore, it is still necessary to propose an annealing process that can combine gradient phase transition control, surface activation treatment and in-situ passivation construction to meet the comprehensive requirements of cleanliness, structural stability and corrosion resistance for seamless stainless steel electronic clean tubes for semiconductors. Summary of the Invention

[0005] To address the aforementioned deficiencies, this invention provides an annealing process for processing seamless stainless steel electronic clean tubes for semiconductors, comprising the following steps: 1) Place the cold-worked, deformed austenitic seamless stainless steel tube containing deformation-induced martensite in an annealing furnace with atmosphere control function; 2) The austenitic seamless stainless steel tube is subjected to a gradient phase transformation recovery and grain boundary engineering synergistic control heat treatment; 3) During or at least covering the reverse transformation and special grain boundary reconstruction stages in step 2), hydrogen atmosphere pulse modulation and surface self-nano-coupling treatment are simultaneously implemented to form a chromium-rich passivation film on the inner and outer surfaces of the tube. Step 2) includes: First, a low-temperature recovery and heat preservation process is carried out at a low-temperature recovery temperature T1, wherein the low-temperature recovery temperature T1 is 20℃~50℃ lower than the deformation-induced martensite reversal initiation temperature As. Then, the furnace temperature is increased from the low-temperature recovery temperature T1 to the reversal transformation end temperature T2 at a nonlinear increasing heating rate, so as to cross the martensitic reversal transformation temperature region and carry out reversal transformation and special grain boundary reconstruction. Finally, a short-term high-temperature locking was performed at the high-temperature locking temperature T3 to allow limited migration of austenite grains, followed by cooling after holding at that temperature.

[0006] Furthermore, during the gradient phase transformation recovery and grain boundary engineering synergistic control heat treatment process in step 2), a trace amount of synergistic active agent is added, wherein the trace amount of synergistic active agent comprises, by weight: Borane-modified reducing agent 35 to 60 parts, wherein the borane-modified reducing agent is a borohydride composite salt, used to promote the efficient reduction of stainless steel surface and subsurface oxides and reduce interfacial energy during the high-temperature annealing stage. 8 to 20 parts of rare earth activator, wherein the rare earth activator is used to promote grain boundary activation, reduce interfacial energy and facilitate recrystallization during the martensite reversal process in the annealing process; Five to ten parts of hydrogenation promoting component, wherein the hydrogenation promoting component is a chemically modified polymeric hydrogen donor precursor, which is formed by graft copolymerization with commercially available silane nitrogen heterocyclic compounds to form a polymer containing controllable dehydrogenation functional groups. The reagent system is added in stages within the specific annealing temperature range, so that hydrogen and oxide film components and Cr migration behavior have a synergistic effect, thereby promoting the formation of chromium-rich passivation film and nanograin boundary structure.

[0007] The borohydride complex salt is one or more of the following: boronane-tert-butylamine complex, boronane-dimethylamine complex, boronane-morpholine complex, boronane-pyridine complex, boronane-tetrahydrofuran complex, boronane-trimethylamine complex, and 2-methylpyridineborane complex. The rare earth activator is one or more of lanthanum oxide (La2O3) nanoparticles, cerium oxide (CeO2) nanoparticles, yttrium oxide (Y2O3) nanoparticles, terbium oxide (Tb4O7) nanoparticles, dysprosium oxide (Dy2O3) nanoparticles, or neodymium oxide (Nd2O3) nanoparticles. The rare earth powder is ball-milled to adjust the particle size to 25nm to 100nm. Furthermore, the raw materials for preparing the hydrogenation promoting component, by weight, include the following components: 15 to 35 parts of silane-based hydrogen donor precursor, wherein the silane-based hydrogen donor precursor is one or more of methoxysilane and ethoxysilane containing Si–H functional groups. 3 to 12 parts of nitrogen-containing heterocyclic hydrogen precursor; 0.5 to 5 parts coupling agent; 25 to 55 parts of a heat-stable polymeric carrier, wherein the heat-stable polymeric carrier is one or more of polyimide, polyetherimide, or polyaryletherketone. 0.5 to 3 parts of a self-crosslinking initiator, wherein the self-crosslinking initiator is a peroxide or an organic persulfate; The organic dispersion medium consists of 80 to 220 parts, wherein the organic dispersion medium is one or more of N-methylpyrrolidone, dimethylformamide, or butyl acetate.

[0008] Furthermore, the silane-based hydrogen donor precursor is one or more of triethoxysilane, trimethoxysilane, triethylsilane, methyldiethoxysilane, and triisopropylsilane.

[0009] Further, the nitrogen-containing heterocyclic hydrogen precursor is one or more of imidazole, 2-methylimidazolium, benzimidazole, pyrazole, 1,2,4-triazole, and 2-aminothiazole.

[0010] Further, the coupling agent is one or more of γ-methacryloyloxypropyltrimethoxysilane, 3-aminopropyltriethoxysilane, or γ-glycidoxypropyltrimethoxysilane.

[0011] Furthermore, the hydrogenation promoting component is prepared by the following method: A1: Add the thermally stable polymeric carrier to the organic dispersion medium and disperse it at 300 rpm to 80 rpm for 0.5 h to 3 h under the conditions of 30 ℃ to 80 ℃ to obtain the polymeric carrier dispersion system; A2: Add a nitrogen-containing heterocyclic hydrogen precursor to the polymer carrier dispersion system, stir at 300 rpm to 700 rpm for 0.5 h to 2 h at 25 °C to 60 °C, then add a silane hydrogen donor precursor, controlling the addition time to 0.5 h to 2 h, and continue stirring the reaction for 1 h to 4 h to obtain a premixed reaction system. A3: Add coupling agent and self-crosslinking initiator to the premixed reaction system, heat to 60℃~120℃ under nitrogen protection, and keep the reaction at this temperature for 2h~8h to allow the silane hydrogen donor precursor, nitrogen heterocyclic hydrogen-containing precursor and thermally stable polymer support to undergo graft copolymerization and crosslinking reaction to obtain a polymer precursor system containing controllable dehydrogenation functional groups; A4: The polymer precursor system is subjected to reduced pressure at 50℃ to 90℃ to remove part of the organic dispersion medium, and the solid content of the system after removal is controlled to be 20wt% to 60wt%. Then, it is vacuum dried at 60℃ to 120℃ for 4h to 20h, pulverized and passed through a 100-500 mesh sieve to obtain the hydrogenation promoting component.

[0012] Further, the staged temperature control in step 2) to raise the furnace temperature from the low-temperature recovery temperature T1 to the reversal transformation end temperature T2 at a non-linearly increasing heating rate is as follows: within the temperature range from the low-temperature recovery stage temperature T1 to 30°C above the deformation-induced martensitic reversal transformation initiation temperature As, the heating rate is 0.5°C / min to 2°C / min; within the temperature range from 30°C above the deformation-induced martensitic reversal transformation initiation temperature As to T2, the heating rate is 3°C / min to 5°C / min; wherein, the reversal transformation end temperature T2 is 20°C to 50°C above the austenitizing end temperature Af (i.e., the temperature value of T2 is any determined temperature within the range of Af plus 20°C to 50°C), the high-temperature locking temperature T3 is 30°C to 80°C above the reversal transformation end temperature T2 (i.e., the temperature value of T3 is any determined temperature within the range of T2 plus 30°C to 80°C), and the holding time at temperature T3 is 1 min to 5 min.

[0013] Furthermore, step 2) is carried out entirely in a mixture of protective and reducing atmospheres, the mixture being composed of argon and hydrogen, with hydrogen accounting for 10% to 30% of the volume; the pulse frequency of the hydrogen atmosphere pulse modulation process in step 3) is 0.1 Hz to 1 Hz, the instantaneous pressure of hydrogen varies in a rectangular wave or sine wave between 10 kPa to 50 kPa above the furnace base pressure and the base pressure, and the hydrogen atmosphere pulse modulation at least covers the reverse transformation and special grain boundary reconstruction processes in step 2).

[0014] Furthermore, in step 3), after the hydrogen atmosphere pulse modulation treatment is completed and before the pipe cools to below 100°C, oxygen with a volume fraction of 50ppm to 500ppm is injected into the furnace and kept at that temperature for 10min to 30min, so that the oxygen reacts in situ with the surface layer of the pipe after the hydrogen atmosphere pulse modulation and surface self-nano coupling treatment to form a chromium-rich oxide passivation film.

[0015] The beneficial effects of this invention are as follows: 1. This application sets up three continuous heat treatment stages: low-temperature recovery, reverse transformation reconstruction, and high-temperature locking. This allows the dislocation entanglements, shear bands, and deformation-induced martensite accumulated in the surface and subsurface layers after cold working to be recovered, reverse transformed, and stabilized in stages. It no longer relies on a single high-temperature solid solution to uniformly eliminate defects. Therefore, it is more conducive to reducing local stress concentration, improving the microstructure inheritance relationship, and maintaining a relatively uniform austenite grain state.

[0016] 2. Based on the gradient heating path, this application limits the reverse transformation process to a controlled temperature range and heating rate range, so that the transformation of martensite to austenite can proceed in an orderly manner on the already formed recovery structure. This increases the probability of formation and retention of lattice grain boundaries at low Σ coincidence positions such as Σ3, Σ9, and Σ27, reduces the microstructure dispersion problems caused by insufficient reverse transformation and abnormal grain growth, and has a direct effect on improving the stability of the inner surface of electronic clean tubes and the reliability of subsequent service.

[0017] 3. This application introduces hydrogen atmosphere pulse modulation during the annealing process, combined with trace amounts of synergistic active agents containing borane-modified reducing agents, rare earth activators, and hydrogenation-promoting components. This allows surface cleaning, interface activation, surface self-nano-sizing, and chromium enrichment processes to be completed continuously within the same heat treatment process. Combined with subsequent trace oxygen injection, a denser chromium-rich oxide passivation film can be formed in situ on the tube surface. The resulting tube not only exhibits better corrosion resistance but also has a more uniform surface structure and a more stable passivation film bonding, making it more suitable for long-term use in the high-cleanliness environments of semiconductor manufacturing. Attached Figure Description

[0018] The invention will now be described in more detail with reference to embodiments and the accompanying drawings. Figure 1 This is a diagram showing the staged temperature control gradient phase transition control temperature and heating rate regulation in step 2) of this application, in which the furnace temperature is raised from T1 to T2 at a non-linear incremental heating rate. Figure 2 The images show XPS depth profiles of the passivation films in the embodiments and comparative examples of this application. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] All the reagents used in this application are commercially available. The CAS number of the borane tert-butylamine complex is 7337453, the CAS number of the borane dimethylamine complex (i.e., dimethylamine borane) is 74942, the CAS number of the borane morpholine complex (morpholine borane) is 4856955, the CAS number of the borane trimethylamine complex (i.e., trimethylamine borane) is 75229, the CAS number of the borane pyridine complex (pyridine borane) is 110510, and the CAS number of the borane tetrahydrofuran complex is 14044656.

[0021] The γ-methacryloyloxypropyltrimethoxysilane used is KH-570, CAS number 2530-85-0; 3-aminopropyltriethoxysilane is KH-550, CAS number 919-30-2; γ-glycidoxypropyltrimethoxysilane is the commonly used KH-560, CAS number 2530-83-8. The CAS numbers for triethoxysilane, trimethoxysilane, triethylsilane, methyldiethoxysilane, and triisopropylsilane are 998301, 2487903, 617867, 2031621, and 6485796 respectively.

[0022] Example 1 This embodiment provides an annealing process for processing seamless stainless steel electronic clean tubes for semiconductors, wherein the hydrogenation promoting component used is prepared by the following method: A1: Weigh 25 parts of polyimide and add it to 150 parts of N-methylpyrrolidone. Stir and disperse at 300 rpm for 3 hours at 55°C to obtain a polymer carrier dispersion system.

[0023] A2: Add 3 parts of imidazole to the polymer carrier dispersion system, stir at 500 rpm for 2 hours at 25°C, then add 20 parts of triethoxysilane and 15 parts of methyldiethoxysilane, controlling the addition time to 1.2 hours, and continue stirring for 1 hour to obtain a premixed reaction system.

[0024] A3: Add 2 parts of γ-methacryloxypropyltrimethoxysilane and 3 parts of dicumyl peroxide to the premixed reaction system, heat to 120°C under nitrogen protection, and keep the reaction at this temperature for 8 hours to allow the silane hydrogen donor precursor, the nitrogen heterocyclic hydrogen-containing precursor, and the thermally stable polymer support to undergo graft copolymerization and crosslinking reaction to obtain a polymer precursor system containing controllable dehydrogenation functional groups.

[0025] A4: The polymer precursor system was subjected to reduced pressure at 70°C to remove part of the organic dispersion medium, and the solid content of the system after removal was controlled to be 20wt%. Then, it was vacuum dried at 120°C for 10h, pulverized and passed through a 100-mesh sieve to obtain the hydrogenation promoting component.

[0026] 60 parts of borane-tetrahydrofuran complex, 14 parts of cerium oxide nanoparticles and 5 parts of the above hydrogenation promoting component were mixed to obtain a trace synergistic active agent, wherein the cerium oxide nanoparticles had a particle size of 60 nm after ball milling.

[0027] This embodiment provides an annealing process for processing seamless stainless steel electronic clean tubes for semiconductors, including the following steps: 1) 304L austenitic seamless stainless steel tubing was selected, with a cold working deformation of 55% and a deformation-induced martensite volume fraction of 12%. Testing revealed that the deformation-induced martensite reversal initiation temperature (As) was 645℃, and the austenitization completion temperature (Af) was 780℃. The tubing was placed in an annealing furnace with atmosphere control, filled with a mixture of argon and hydrogen, with a hydrogen component of 18%.

[0028] 2) The tubing was subjected to a gradient phase transformation recovery and grain boundary engineering synergistic heat treatment. First, the tubing was held at a low-temperature recovery temperature of 625℃ for 35 minutes. Then, the furnace temperature was increased to 675℃ at a rate of 1.2℃ / min, and further increased to the inversion completion temperature of 830℃ at a rate of 5.0℃ / min. Afterward, the temperature was increased to the high-temperature locking temperature of 885℃ and held for 1 minute. During the low-temperature recovery holding stage, the inversion stage, and the high-temperature locking stage, trace amounts of the synergistic active agent (20%, 50%, and 30% of the total amount) were atomized with argon carrier gas, respectively.

[0029] 3) In step 2), hydrogen atmosphere pulse modulation and surface self-nano-coupling treatment are performed synchronously throughout the entire process. The pulse frequency is set to 0.1Hz, and the instantaneous hydrogen pressure varies sinusoidally between 50kPa above the furnace baseline pressure and the baseline pressure. The pulse covers the latter half of the low-temperature recovery stage, the reverse transformation stage, and the high-temperature lock-in stage. After the pulse modulation is completed, before the tube cools to below 100°C, 500ppm oxygen is injected into the furnace and held for 30 minutes to form a chromium-rich oxide passivation film.

[0030] like Figure 1As shown, the nonlinear incremental heating path defined in the technical solution of this application is not a simple segmentation of the annealing temperature, but rather a targeted control of the deformation-induced martensite reversal process and the austenite grain boundary reconstruction process. Within the temperature range of T1 to 30°C above As, a relatively low heating rate of 0.5°C / min to 2°C / min is used to ensure sufficient recovery of highly entangled dislocations, shear bands, and substructural defects in the surface and subsurface layers after cold working. This promotes the gradual release of local stress and provides a relatively uniform microstructure for subsequent inversion transformation. Within the temperature range of 30°C above As to T2, the heating rate is increased to 3°C / min to 5°C / min to ensure the orderly progression of martensite to austenite transformation on the established recovered microstructure. This avoids insufficient inversion transformation and disordered microstructure inheritance due to excessively rapid heating, as well as grain coarsening caused by prolonged stagnation in the sensitive temperature range. This is more conducive to the formation and retention of lattice grain boundaries at low Σ overlap positions such as Σ3, Σ9, and Σ27. After the temperature rises to T2, which is 20°C to 50°C above As, the temperature is then increased to above T2. By maintaining a temperature within the T3 range of 30℃ to 80℃ for 1 to 5 minutes, residual substructures and local trace phases can be eliminated through short-term high-temperature treatment, after the inversion transformation has been basically completed. At the same time, grain migration is controlled within a limited range to prevent abnormal growth. This temperature trajectory achieves directional elimination of martensite, optimization of grain boundary characteristics, and homogenization of the microstructure. On the other hand, it also provides more stable surface microstructure conditions for subsequent hydrogen atmosphere pulse modulation, making the surface more prone to self-nano-sizing and forming short-range channels that facilitate the rapid diffusion of chromium. This promotes the dense formation of a chromium-rich passivation film, ultimately enabling the pipe to achieve a lower level of surface defects, a higher degree of grain boundary order, and better corrosion resistance and cleanliness compatibility.

[0031] Example 2 This embodiment provides an annealing process for processing seamless stainless steel electronic clean tubes for semiconductors, wherein the hydrogenation promoting component used is prepared by the following method: A1: Weigh 40 parts of polyetherimide and add it to 220 parts of dimethylformamide. Stir and disperse at 800 rpm for 1.5 h at 30 °C to obtain a polymer carrier dispersion system.

[0032] A2: Add 4 parts of 2-methylimidazole and 3 parts of benzimidazole to the polymer carrier dispersion system, stir at 300 rpm for 0.5 h at 60 °C, add 15 parts of trimethoxysilane, control the addition time to 2 h, and continue stirring for 2.5 h to obtain a premixed reaction system.

[0033] A3: Add 5 parts of 3-aminopropyltriethoxysilane and 0.5 parts of ammonium persulfate to the premixed reaction system, heat to 90°C under nitrogen protection, and keep the reaction at this temperature for 2 hours to allow the silane hydrogen donor precursor, the nitrogen heterocyclic hydrogen-containing precursor, and the thermally stable polymer support to undergo graft copolymerization and crosslinking reaction to obtain a polymer precursor system containing controllable dehydrogenation functional groups.

[0034] A4: The polymer precursor system was subjected to reduced pressure at 50°C to remove part of the organic dispersion medium, and the solid content of the system after removal was controlled to be 60wt%. Then, it was vacuum dried at 90°C for 4 hours, pulverized and passed through a 500-mesh sieve to obtain the hydrogenation promoting component.

[0035] 35 parts of borane-dimethylamine complex, 12 parts of lanthanum oxide nanoparticles, 8 parts of yttrium oxide nanoparticles, and 8 parts of the above-mentioned hydrogenation promoting component were mixed to obtain a trace synergistic active agent, wherein the particle size of lanthanum oxide nanoparticles and yttrium oxide nanoparticles was 25 nm after ball milling.

[0036] This embodiment provides an annealing process for processing seamless stainless steel electronic clean tubes for semiconductors, including the following steps: 1) 316L austenitic seamless stainless steel tubing was selected, with a cold working deformation of 60% and a deformation-induced martensite volume fraction of 18%. Testing revealed that the deformation-induced martensite reversal initiation temperature (As) was 660℃, and the austenitization completion temperature (Af) was 795℃. The tubing was placed in an annealing furnace with atmosphere control, filled with a mixture of argon and hydrogen, with a hydrogen component of 30%.

[0037] 2) The tubing was subjected to a gradient phase transformation recovery and grain boundary engineering synergistic heat treatment. First, the tubing was held at a low-temperature recovery temperature of 610℃ for 50 min; then, the furnace temperature was increased to 690℃ at a rate of 0.5℃ / min, and further increased to the inversion completion temperature of 830℃ at a rate of 4.0℃ / min; subsequently, the temperature was increased to the high-temperature locking temperature of 860℃ and held for 5 min. During the low-temperature recovery holding stage, the inversion stage, and the high-temperature locking stage, trace amounts of the synergistic active agent (20%, 50%, and 30% of the total amount) were atomized with argon carrier gas, respectively.

[0038] 3) In step 2), hydrogen atmosphere pulse modulation and surface self-nano-coupling treatment are performed synchronously throughout the entire process. The pulse frequency is set to 0.5Hz, and the instantaneous hydrogen pressure varies in a rectangular wave pattern between 10kPa above the furnace baseline pressure and the baseline pressure. The pulse covers the entire process of reverse transformation and special grain boundary reconstruction. After the pulse modulation is completed, before the tube cools to below 100°C, 50ppm oxygen is injected into the furnace and held for 20 minutes to form a chromium-rich oxide passivation film.

[0039] Example 3 This embodiment provides an annealing process for processing seamless stainless steel electronic clean tubes for semiconductors, wherein the hydrogenation promoting component used is prepared by the following method: A1: Weigh 55 parts of polyarylether ketone and add it to 80 parts of butyl acetate. Stir and disperse at 500 rpm for 0.5 h at 80 °C to obtain a polymer carrier dispersion system.

[0040] A2: Add 6 parts of 1,2,4-triazole and 6 parts of 2-aminothiazole to the polymer carrier dispersion system, stir at 700 rpm for 1 h at 40 °C, then add 12 parts of triethylsilane and 12 parts of triisopropylsilane, control the addition time to be 0.5 h, and continue stirring for 4 h to obtain a premixed reaction system.

[0041] A3: Add 0.5 parts of γ-methacryloxypropyltrimethoxysilane and 1.5 parts of potassium persulfate to the premixed reaction system, heat to 60°C under nitrogen protection, and keep the reaction at this temperature for 5 hours to allow the silane hydrogen donor precursor, the nitrogen heterocyclic hydrogen-containing precursor, and the thermally stable polymer support to undergo graft copolymerization and crosslinking reaction to obtain a polymer precursor system containing controllable dehydrogenation functional groups.

[0042] A4: The polymer precursor system is subjected to reduced pressure at 90°C to remove part of the organic dispersion medium, and the solid content of the system after removal is controlled to be 40wt%. Then, it is vacuum dried at 60°C for 20h, pulverized and passed through a 300-mesh sieve to obtain the hydrogenation promoting component.

[0043] 48 parts of 2-methylpyridineborane complex, 8 parts of dysprosium oxide nanopowder, and 10 parts of the above-mentioned hydrogenation promoting component were mixed to obtain a trace amount of synergistic active agent, wherein the dysprosium oxide nanopowder had a particle size of 100 nm after ball milling.

[0044] This embodiment provides an annealing process for processing seamless stainless steel electronic clean tubes for semiconductors, including the following steps: 1) 316L VOD high-purity austenitic seamless stainless steel tubing was selected, with a cold working deformation of 45% and a deformation-induced martensite volume fraction of 7%. Testing revealed that the deformation-induced martensite reversal initiation temperature (As) was 635℃, and the austenitization completion temperature (Af) was 770℃. The tubing was placed in an annealing furnace with atmosphere control, filled with a mixture of argon and hydrogen, with a hydrogen component of 10%.

[0045] 2) The tubing was subjected to a gradient phase transformation recovery and grain boundary engineering synergistic heat treatment. First, the tubing was held at a low-temperature recovery temperature of 600℃ for 25 minutes. Then, the furnace temperature was increased to 665℃ at a rate of 2.0℃ / min, followed by a further increase at a rate of 3.0℃ / min to the inversion completion temperature of 790℃. Afterward, the temperature was increased to a high-temperature locking temperature of 870℃ and held for 3 minutes. During the low-temperature recovery holding stage, the inversion stage, and the high-temperature locking stage, trace amounts of the synergistic active agent (20%, 50%, and 30% of the total amount) were atomized with argon carrier gas, respectively.

[0046] 3) In step 2), hydrogen atmosphere pulse modulation and surface self-nano-coupling treatment are performed synchronously throughout the entire process. The pulse frequency is set to 1.0 Hz, and the instantaneous hydrogen pressure varies sinusoidally between 30 kPa above the furnace baseline pressure and the baseline pressure. The pulse covers the entire process of reverse transformation and special grain boundary reconstruction. After the pulse modulation is completed, before the tube cools to below 100°C, 200 ppm oxygen is injected into the furnace and held for 10 minutes to form a chromium-rich oxide passivation film.

[0047] Comparative Example 1 The annealing process for processing seamless stainless steel electronic clean tubes for semiconductors provided in Comparative Example 1 differs from that in that it uses the same 316L austenitic seamless stainless steel tube as in Example 2, but the rest of the process is modified to a conventional single-step bright annealing process. It does not employ gradient phase transformation recovery and grain boundary engineering synergistic heat treatment, does not add trace amounts of synergistic active agents, and does not implement hydrogen atmosphere pulse modulation and surface self-nano-coupling treatment. Specifically, the tube is placed in a mixture of argon and hydrogen, with a hydrogen integral of 25%, and heated to 1050℃ at a uniform rate of 4.0℃ / min. After holding at this temperature for 5 minutes, it is cooled to obtain the sample of Comparative Example 1.

[0048] Comparative Example 2 The annealing process for processing seamless stainless steel electronic clean tubes for semiconductors provided in this comparative example is the same as that in Example 2, except that no trace amount of synergistic active agent is added, and the other raw materials, temperature path, gas mixture composition, hydrogen atmosphere pulse modulation parameters and oxygen injection conditions are the same, resulting in the sample of Comparative Example 2.

[0049] Comparative Example 3 This comparative example provides an annealing process for processing seamless stainless steel electronic clean tubes for semiconductors. Except for step 2), which is replaced with conventional constant-rate heating annealing, the raw materials, trace amounts of synergistic active agents, hydrogen atmosphere pulse modulation parameters, and oxygen injection conditions are all the same as in Example 2. Specifically, the 316L austenitic seamless stainless steel tube used in Example 2 is heated uniformly from room temperature to 860°C at a rate of 4.0°C / min in an argon and hydrogen mixture with a hydrogen gas fraction of 30%. After holding at this temperature for 5 minutes, it is cooled. During this process, the same hydrogen atmosphere pulse modulation and subsequent oxygen injection treatment as in Example 2 are simultaneously implemented to obtain the sample of Comparative Example 3.

[0050] Comparative Example 4 The comparative example provides an annealing process for processing seamless stainless steel electronic clean tubes for semiconductors. Except for replacing the hydrogenation promoting component in the trace synergistic active agent with 8 parts of trimethoxysilane instead of the self-prepared polymeric hydrogen donor precursor in Example 2, the other raw materials, temperature path, mixed gas composition, hydrogen atmosphere pulse modulation parameters, and oxygen injection conditions are the same as in Example 2, resulting in sample 4 of the comparative example.

[0051] Test case To verify the formation state of the chromium-rich passivation film on the inner surface of the pipes after annealing in Examples 1-3 and Comparative Examples 1-4, X-ray photoelectron spectroscopy depth profiling was performed on the three groups of samples. Specifically, 10 mm long annular samples were cut from the same axial position of the pipes obtained in Examples 2, 2, and 3, respectively. The annular samples were cut axially and unfolded, and their inner surface was used as the test surface. The test area was selected within a range of 20 mm to 50 mm from the pipe end to avoid interference from the heat-affected zone of the cut and end disturbances on the surface film composition. Three samples were prepared in parallel for each group. The samples were sequentially ultrasonically cleaned with anhydrous ethanol, acetone, and deionized water for 5 min each, followed by vacuum drying at 40°C for 30 min. After drying, they were stored in a clean desiccator and tested within 12 hours to minimize the influence of airborne organic pollutants on the surface analysis results.

[0052] The testing instrument used was an X-ray photoelectron spectrometer. Monochromatic Al Kα rays were used as the excitation source, with a photon energy of 1486.6 eV. The vacuum level in the analysis chamber was controlled at 5 × 10⁻⁶ eV. -7Below Pa, the sample surface was first scanned using a full spectrum, with a binding energy range of 0 eV to 1200 eV, to determine the surface elemental composition. Subsequently, high-resolution narrow-region scans of Cr 2p, Fe 2p, O 1s, and C 1s were performed for subsequent chemical state peak delineation and atomic concentration calculations. Depth profiling was performed using Ar ion beam sputtering, with the ion acceleration voltage set to 2 kV–3 kV, the beam current controlled at 0.5 μA–2 μA, and the sputtering area set to 2 mm × 2 mm. Sputtering was performed layer by layer at fixed time intervals, each sputtering lasting 30–60 s. Elemental composition data at the surface, near-surface, and deeper layers were recorded, and the depths corresponding to each sputtering time were converted to equivalent sputtering depths using standard SiO2 film calibration. Data points at 0 nm, 2 nm, 4 nm, 6 nm, 8 nm, 10 nm, and 12 nm were preferably recorded for depth profiling.

[0053] During the testing process, the C 1s peak at 284.8 eV was used as the binding energy correction benchmark. The Cr and Fe elemental spectra at various depths were fitted to calculate the Cr / Fe atomic ratio. The Cr 2p peak was also split to distinguish metallic chromium, trivalent chromium oxides, and other chromium-containing oxides, thus obtaining the relative content of Cr2O3. Simultaneously, depths with a Cr / Fe atomic ratio greater than 1.5 were used as the criterion for determining the effective thickness of the chromium-rich layer. By comparing the Cr / Fe atomic ratio variation curves, effective thickness of the chromium-rich layer, and relative Cr2O3 content at different sputtering depths in Examples 2, 2, and 3, the effects of the synergistic active agent containing hydrogenation-promoting components and gradient phase change temperature control on the formation of the chromium-rich passivation film were evaluated. The above test results were used to characterize the chromium enrichment degree, film continuity, and depth distribution differences of the inner surface passivation film after treatment with different annealing paths and agent conditions. The test results are shown in Table 1.

[0054] Table 1 Test results show that the surface Cr / Fe atomic ratio of Example 2 is 2.35, significantly higher than that of Comparative Example 2 (1.72) and Comparative Example 3 (1.86). This indicates that under gradient phase change temperature control and pulsed hydrogen atmosphere conditions, the introduction of a synergistic active agent with hydrogenation-promoting components facilitates the formation of a chromium-rich layer on the pipe surface. With increasing sputtering depth, the Cr / Fe atomic ratio of Example 2 remains consistently high, with an effective chromium-rich layer thickness of 7.8 nm, higher than that of Comparative Example 2 (3.7 nm) and Comparative Example 3 (5.4 nm). This demonstrates that the synergistic effect of the self-prepared agent and gradient phase change temperature control helps to expand the stable existence range of the chromium-rich layer. Simultaneously, the relative Cr2O3 content in Example 2 reaches 78%, also higher than that of Comparative Examples 2 and 3, indicating that this process can promote the formation of a denser chromium-rich oxide passivation film.

[0055] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0056] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An annealing process for processing of semiconductor seamless stainless steel electronic clean tube, characterized by, Includes the following steps: 1) Place the cold-worked, deformed austenitic seamless stainless steel tube containing deformation-induced martensite in an annealing furnace with atmosphere control function; 2) The austenitic seamless stainless steel tube is subjected to a gradient phase transformation recovery and grain boundary engineering synergistic control heat treatment; 3) During or at least covering the reverse transformation and special grain boundary reconstruction stages in step 2), hydrogen atmosphere pulse modulation and surface self-nano-coupling treatment are simultaneously implemented to form a chromium-rich passivation film on the inner and outer surfaces of the tube. Step 2) includes: First, a low-temperature recovery and heat preservation process is carried out at a low-temperature recovery temperature T1, wherein the low-temperature recovery temperature T1 is 20℃~50℃ lower than the deformation-induced martensite reversal initiation temperature As. Then, the furnace temperature is increased from the low-temperature recovery temperature T1 to the reversal transformation end temperature T2 at a nonlinear increasing heating rate, so as to cross the martensitic reversal transformation temperature region and carry out reversal transformation and special grain boundary reconstruction. Finally, a short-term high-temperature locking was performed at the high-temperature locking temperature T3 to allow limited migration of austenite grains, followed by cooling after holding at that temperature.

2. The annealing process of claim 1, wherein: In step 2), during the synergistic control of gradient phase transformation recovery and grain boundary engineering heat treatment, a trace amount of synergistic active agent is added. The trace synergistic active agent comprises, by weight, the following components: 35 to 60 parts of borane-modified reducing agent, wherein the borane-modified reducing agent is a borohydride complex salt; 8 to 20 parts of rare earth activator; Five to ten parts of hydrogenation promoting component, wherein the hydrogenation promoting component is a chemically modified polymeric hydrogen donor precursor; The borohydride complex salt is one or more of the following: boronane-tert-butylamine complex, boronane-dimethylamine complex, boronane-morpholine complex, boronane-pyridine complex, boronane-tetrahydrofuran complex, boronane-trimethylamine complex, and 2-methylpyridineborane complex. The rare earth activator is one or more of lanthanum oxide nanoparticles, cerium oxide nanoparticles, yttrium oxide nanoparticles, terbium oxide nanoparticles, dysprosium oxide nanoparticles, or neodymium oxide nanoparticles. The rare earth powder is ball-milled to adjust the particle size to 25 nm to 100 nm.

3. The annealing process of claim 2, wherein, The raw materials for preparing the hydrogenation promoting component, by weight, include the following components: 15 to 35 parts of silane-based hydrogen donor precursor, wherein the silane-based hydrogen donor precursor is one or more of methoxysilane and ethoxysilane containing Si–H functional groups. Nitrogen heterocyclic hydrogen-containing precursor: 3 to 12 parts; 0.5 to 5 parts of coupling agent; 25 to 55 parts of a heat-stable polymeric carrier, wherein the heat-stable polymeric carrier is one or more of polyimide, polyetherimide, or polyaryletherketone. 0.5 to 3 parts of a self-crosslinking initiator, wherein the self-crosslinking initiator is a peroxide or an organic persulfate; The organic dispersion medium consists of 80 to 220 parts, wherein the organic dispersion medium is one or more of N-methylpyrrolidone, dimethylformamide, or butyl acetate.

4. The annealing process of claim 3, wherein, The silane-based hydrogen donor precursor is one or more of triethoxysilane, trimethoxysilane, triethylsilane, methyldiethoxysilane, and triisopropylsilane.

5. The annealing process of claim 3, wherein, The nitrogen-containing heterocyclic hydrogen precursor is one or more of imidazole, 2-methylimidazolium, benzimidazole, pyrazole, 1,2,4-triazole, and 2-aminothiazole.

6. The annealing process of claim 3, wherein, The coupling agent is one or more of γ-methacryloxypropyltrimethoxysilane, 3-aminopropyltriethoxysilane, or γ-glycidoxypropyltrimethoxysilane.

7. The annealing process of claim 3, wherein, The hydrogenation-promoting component is prepared by the following method: A1: Add the thermally stable polymeric carrier to the organic dispersion medium and disperse it at 300 rpm to 80 rpm for 0.5 h to 3 h under the conditions of 30 ℃ to 80 ℃ to obtain the polymeric carrier dispersion system; A2: Add a nitrogen-containing heterocyclic hydrogen precursor to the polymer carrier dispersion system, stir at 300 rpm to 700 rpm for 0.5 h to 2 h at 25 °C to 60 °C, then add a silane hydrogen donor precursor, controlling the addition time to 0.5 h to 2 h, and continue stirring the reaction for 1 h to 4 h to obtain a premixed reaction system. A3: Add coupling agent and self-crosslinking initiator to the premixed reaction system, heat to 60℃~120℃ under nitrogen protection, and keep the reaction at this temperature for 2h~8h to allow the silane hydrogen donor precursor, nitrogen heterocyclic hydrogen-containing precursor and thermally stable polymer support to undergo graft copolymerization and crosslinking reaction to obtain a polymer precursor system containing controllable dehydrogenation functional groups; A4: The polymer precursor system is subjected to reduced pressure at 50℃ to 90℃ to remove part of the organic dispersion medium, and the solid content of the system after removal is controlled to be 20wt% to 60wt%. Then, it is vacuum dried at 60℃ to 120℃ for 4h to 20h, pulverized and passed through a 100-500 mesh sieve to obtain the hydrogenation promoting component.

8. The annealing process of claim 1, wherein, The staged temperature control in step 2) to raise the furnace temperature from the low-temperature recovery temperature T1 to the reversal transformation end temperature T2 with a non-linearly increasing heating rate is as follows: within the temperature range from the low-temperature recovery stage temperature T1 to 30°C above the deformation-induced martensitic reversal transformation initiation temperature As, the heating rate is 0.5°C / min to 2°C / min; within the temperature range from 30°C above the deformation-induced martensitic reversal transformation initiation temperature As to T2, the heating rate is 3°C / min to 5°C / min; wherein, the reversal transformation end temperature T2 is 20°C to 50°C above the austenitizing end temperature Af, the high-temperature locking temperature T3 is 30°C to 80°C above the reversal transformation end temperature T2, and the holding time at temperature T3 is 1 min to 5 min.

9. The annealing process of claim 1, wherein, Step 2) is carried out entirely in a mixture of protective and reducing atmospheres, which consists of argon and hydrogen, with hydrogen accounting for 10% to 30% of the volume. In step 3), the pulse frequency of the hydrogen atmosphere pulse modulation process is 0.1 Hz to 1 Hz, and the instantaneous pressure of the hydrogen gas varies in a rectangular or sinusoidal wave pattern between the instantaneous pressure and the furnace base pressure, which is 10 kPa to 50 kPa higher than the base pressure. The hydrogen atmosphere pulse modulation at least covers the reverse transformation and special grain boundary reconstruction processes in step 2).

10. The annealing process of claim 1 or 9, wherein, In step 3), after the hydrogen atmosphere pulse modulation treatment is completed and before the pipe cools to below 100°C, oxygen with a volume fraction of 50ppm to 500ppm is injected into the furnace and kept at that temperature for 10min to 30min, so that the oxygen reacts in situ with the surface layer of the pipe after the hydrogen atmosphere pulse modulation and surface self-nano coupling treatment to form a chromium-rich oxide passivation film.

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