50 results about "Boron trichloride" patented technology

The present invention belongs to the technical field of ceramic preparation, and relates to a preparation method and device for a high-purity porous boron carbide nuclear control rod. The present invention uses boron trichloride gas as the boron source, methane as the carbon source, argon as the carrier gas and protective gas, and hydrogen as the catalytic gas and reducing gas to prepare a high-purity porous boron carbide nuclear control rod. The method of increasing the deposition temperature of boron carbide step by step and region by region from the back to the front is adopted, which can not only improve the deposition rate of boron carbide, but also ensure that the physical and mechanical properties of each part of the prepared high-purity porous boron carbide nuclear control rod are consistent. By changing the particle size of the boron carbide powder for preparing the boron carbide blank and coordinating the adjustment of temperature, flow rate, pressure and deposition time, the porosity and pore size of the prepared high-purity porous boron carbide can be regulated and a high total boron and carbon content can be obtained, so as to meet various actual requirements.

The invention belongs to the technical field of new energy batteries, and particularly relates to a method for preparing sodium tetrafluoroborate. The method uses relatively cheap and readily available ammonium fluoride, sodium bicarbonate, and boron trichloride gas as raw materials, wherein ammonium fluoride and sodium bicarbonate are added to an organic solvent and stirred uniformly to obtain a dispersion, boron trichloride gas is introduced, the dispersion is fully reacted, nitrogen is purged from the reaction liquid, and the filtrate is filtered to obtain a filtrate, which is concentrated, crystallized, filtered, washed, and dried to obtain sodium tetrafluoroborate. The method has the advantages of simple process, rapid and thorough reaction, no water by-product, and reduced preparation cost of sodium tetrafluoroborate while achieving a yield and purity equivalent to or even superior to that of existing sodium tetrafluoroborate.

The invention belongs to the technical field of ceramic preparation, and relates to a preparation method and device of a high-purity porous boron carbide nuclear control rod. The high-purity porous boron carbide nuclear control rod is prepared by taking boron trichloride gas as a boron source, methane as a carbon source, argon as a carrier gas and a protective gas and hydrogen as a catalytic gas and a reducing gas, and the deposition temperature of boron carbide is increased by adopting a step-by-step and region-divided method from back to front, so that the deposition rate of boron carbide can be increased; the physical and mechanical properties of all parts of the prepared high-purity porous boron carbide nuclear control rod can be ensured to be consistent, the porosity and aperture of the prepared high-purity porous boron carbide can be regulated and controlled by changing the particle size of the boron carbide powder for preparing the boron carbide blank and cooperatively regulating the temperature, flow, pressure and deposition duration, and the high boron-carbon total content can be obtained; therefore, various actual requirements can be met.

The invention provides ablation-resistant tantalum ethoxide modified polyborosilazane resin as well as a preparation method and application of the ablation-resistant tantalum ethoxide modified polyborosilazane resin. The preparation method comprises the following steps: S1, reacting boron trichloride, methyl dichlorosilane and hexamethyldisilazane under the protection of an inert atmosphere to obtain a polyborosilazane fluid; s2, under the protection of inert atmosphere, reacting the polyborosilazane fluid, divinyl benzene and tantalum ethoxide in the presence of a catalyst to obtain a tantalum ethoxide modified polyborosilazane oligomer fluid; s3, under the protection of inert atmosphere, heating and curing the tantalum ethoxide modified polyborosilazane oligomer fluid to obtain the ablation-resistant resin. The tantalum ethoxide modified polyborosilazane resin disclosed by the invention has a high crosslinking degree and shows excellent high temperature resistance and oxidation resistance.

The present invention discloses a boron-containing, high-temperature-resistant, near-stoichiometric silicon carbide fiber and a preparation method thereof. The preparation method includes a spinning stage, an infusibility stage, a pre-sintering stage, a densification sintering stage, and a nitriding stage, and is characterized in that: in the infusibility stage, the metal-doped polycarbosilane precursor fiber obtained in the spinning stage is subjected to a boron-doping reaction in an atmosphere containing boron trichloride and a cross-linking reaction in an atmosphere of a gaseous hydrocarbon having a carbon-carbon double bond. The method is simple to operate, has high production efficiency, low production cost, and is easy to use for large-scale industrial production. The prepared boron-containing, high-temperature-resistant, near-stoichiometric silicon carbide fiber has the advantages of low oxygen content, high degree of densification, few defects, stable structure, high tensile strength modulus, large grain size, and good high-temperature resistance, oxidation resistance, and creep resistance.

The invention provides a preparation method and device of Bi2O3-B2O3 inverse magnetic rotation glass, and the preparation method comprises the following steps: (1) placing a glass raw material in a closed heating furnace, introducing ultra-dry oxygen, and simultaneously exhausting outwards to enable the pressure in the furnace body to be P1 which is more than or equal to 1kPa and less than or equal to 5kPa; (2) heating to melt the glass raw material in the furnace body into molten glass, raising the temperature to a clarification temperature, introducing the mixed gas into the molten glass by a bubbling method, simultaneously homogenizing and stirring, and stopping introducing the mixed gas and starting defoaming and stirring when the homogenizing and stirring time reaches t1; wherein the mixed gas comprises ultra-dry oxygen and boron trichloride, the volume ratio of the ultra-dry oxygen to the boron trichloride is k, and k is (1-5): 1; (3) cooling, forming, annealing and pouring; in the step (2) and the step (3), the pressure in the furnace body is kept P1. The Bi2O3-B2O3 diamagnetic optical rotation glass prepared by the method disclosed by the invention is stable in magneto-optical performance and low in hydroxyl absorption coefficient in a middle-infrared band.

The invention provides a TOPCon battery and a preparation method thereof, and boron diffusion equipment, and the preparation method of the TOPCon battery comprises the steps: providing a silicon substrate, placing the silicon substrate in a boron diffusion furnace, introducing nitrogen into a furnace mouth region of the boron diffusion furnace, introducing oxygen and boron trichloride into the boron diffusion furnace, introducing nitrogen gas into the furnace mouth region of the boron diffusion furnace, introducing nitrogen gas into the furnace mouth region of the boron diffusion furnace, introducing nitrogen gas into the furnace mouth region of the boron diffusion furnace, and introducing nitrogen gas into the furnace mouth region of the boron diffusion furnace, the ratio of the flow of the oxygen to the flow of the boron trichloride is alpha, and alpha is more than or equal to 3.5 and less than or equal to 4.5. The nitrogen can quickly purge reaction byproducts in a low-temperature area of the furnace mouth, and sufficient oxygen is provided to completely oxidize boron trichloride into a gaseous boron oxide precursor before the boron trichloride enters a high-temperature reaction area, so that the generation of viscous low-temperature boron oxide due to insufficient oxidation is avoided; and the generation and deposition of boron oxide crystals at the furnace mouth are inhibited from two dimensions of mass transfer process and chemical reaction completeness, and the yield and average photoelectric conversion efficiency of the TOPCon battery can be remarkably improved.

Provided is a plasma processing method capable of achieving flat etching process while suppressing vertical etching.The plasma processing method for plasma-etching a titanium nitride (TiN) film that forms a metal gate and contacts an insulating film on both sides includes the step of etching the titanium nitride (TiN) film by using plasmas that are generated by using a mixed gas of boron trichloride (BCl3) gas, nitrogen (N2) gas, and nitrogen trifluoride (NF3) gas and are generated by radio-frequency power modulated by a pulse, wherein the pulse has a first period with a first amplitude as its amplitude and a second period with a second amplitude as its amplitude and wherein the second amplitude is greater than 0 and less than the first amplitude.

The titration bottle comprises a bottle body, the bottom of the bottle body is provided with a base, the inner top of the bottle body is provided with a sealing rubber plug, the sealing rubber plug is filled with a sponge block, and the top of the sealing rubber plug and the top of the sponge block are connected with a bottle cap. A dropper is inserted between the sealing rubber plug and the sponge block, the lower end of the dropper extends into the inner bottom of the bottle body, the upper end of the dropper is connected with an air bag, scale marks are arranged on the front end face of the bottle body, a containing groove is formed in the top of the base, and the bottom of the bottle body is arranged in the containing groove of the base. And a magnet is embedded in the middle of the bottom of the base. Through the arrangement of the base and the magnet, the bottle body is not prone to toppling over when accidentally collided, the safety coefficient is high, the bottle body can be firmly attracted and fixed to an iron working table through the magnet, and the safety in the using process is further improved.

A gas backflow prevention device for boron diffusion processing of a photovoltaic cell relates to the field of photovoltaic cell panel processing, and comprises a furnace tube and a nitrogen pneumatic valve, the nitrogen pneumatic valve is arranged on the furnace tube, an input end of the nitrogen pneumatic valve is provided with a backflow prevention mechanism, and the backflow prevention mechanism is used for preventing mixed gas of boron trichloride and nitrogen from flowing back. The backflow prevention mechanism comprises a valve body and a non-return assembly, and the valve body is connected with the input end of the nitrogen pneumatic valve. An anti-backflow mechanism is additionally arranged in the position, in front of the nitrogen pneumatic valve, of each furnace tube, a non-return step locking structure is adopted in each anti-backflow mechanism, when boron trichloride gas normally passes through, a non-return assembly is folded and contracted, the gas blocking condition cannot be generated, and when the nitrogen pneumatic valve is abnormal and nitrogen backflow is caused, the nitrogen backflow is prevented. When the nitrogen pneumatic valve is abnormal, the nitrogen pressure blows the non-return assembly to unfold reversely, the non-return disc is attached to the non-return step, the backflow blocking effect of airflow is achieved, and the problems of high cost and troubleshooting difficulty caused by abnormity of the nitrogen pneumatic valve are effectively solved.

The utility model discloses a boron trichloride tailing treatment device, which relates to the technical field of boron trichloride treatment, and comprises a refrigeration box body, a storage tank arranged in the refrigeration box body, a damping base arranged at the bottom of the storage tank, a bottom protecting sleeve fixedly arranged on the upper surface of the damping base, and a tank body protecting sleeve detachably arranged at the top of the bottom protecting sleeve, the upper end of the refrigeration box body is in sealing connection with the box cover, and the box cover comprises a cover body, an air channel and an air inflation and deflation channel. The storage tank with boron trichloride tailings is arranged in the refrigeration box body, the bottom protection sleeve and the tank body protection sleeve are arranged in a matched mode, the tank body of the whole storage tank is contained in the storage tank, and a good protection effect can be achieved on the whole storage tank. And meanwhile, by arranging the damping springs, when the storage tanks jolt and vibrate in the transportation process along with the refrigeration box body, the damping springs play a good damping and buffering role in the vertical direction.

The invention belongs to the technical field of boron trichloride gas detection and analysis, and particularly relates to a gas chromatographic analysis device and method for trace impurities of high-purity boron trichloride. The device comprises a sample gas inlet path used for providing uniform and quantitative sample gas to be detected; the first detection gas path is used for detecting light component impurities; the second detection gas path is used for detecting CO2-containing impurities; and the third detection gas path is used for detecting high-boiling-point impurities. According to the arrangement of the structure and the method, the gas chromatographic analysis device and the gas chromatographic analysis method for the trace impurities of the high-purity boron trichloride, which can realize high efficiency, stability and high precision and can carry out gradient separation through one-time gas inlet, are realized.

The invention belongs to the technical field of ceramic precursors, and particularly relates to a silicon-boron-carbon-nitrogen ceramic precursor with a main chain containing alkynyl and a preparation method of the silicon-boron-carbon-nitrogen ceramic precursor. Comprising the following steps: (1) dropwise adding an n-butyllithium solution into an ether solvent, stirring, continuously dropwise adding trichloroethylene, and reacting to obtain an alkynyl dilithium salt turbid solution; (2) adding boron trichloride into the alkynyl dilithium salt turbid solution to carry out primary dechlorination polycondensation reaction, and dropwise adding dichlorosilane to carry out secondary dechlorination polycondensation reaction after the reaction is completed; (3) adding hexamethyldisilazane into the system in the step (2) to carry out an end-capping reaction, collecting supernate after the reaction is finished, and distilling at normal pressure to remove the solvent, so as to obtain a silicon-boron-carbon-nitrogen ceramic precursor crude product; and (4) dissolving the silicon-boron-carbon-nitrogen ceramic precursor crude product in an organic solvent, carrying out dialysis treatment, and carrying out atmospheric distillation on the solution in a dialysis membrane to remove the solvent so as to obtain the silicon-boron-carbon-nitrogen ceramic precursor with the main chain containing alkynyl, and the ceramic yield of the silicon-boron-carbon-nitrogen ceramic precursor in the high-temperature ceramization process can reach more than 70%.

The present disclosure relates to the technical field of chemical separation, in particular to a preparation method of electronic-grade boron trichloride and the boron trichloride obtained by the same. Before the generation of the target product boron trichloride, firstly metal chlorides are generated by allowing metal impurities to react with chlorine, and since a reaction temperature of the metals and the chlorine is usually 350°C to 450°C, which is less than temperature at which the boron trichloride is generated by allowing boron carbideto react with the chlorine, two products can be generated separately under a temperature control condition. The generated metal chlorides have been vaporized at 400°C to 450°C, and are exhausted along with unreacted chlorine. After the metal impurities are removed, reaction between the boron carbide and the chlorine is performed, to generate the target product boron trichloride. According to the present disclosure, the metal chloride impurities can be deeply removed from the boron trichloride, and a removal rate reaches 95% or above. Other impurities are effectively removed through the combination of adsorption and rectification, and purity of the obtained boron trichloride reaches 99.999%, which meets 5N standards.

The invention belongs to the field of pouring resin, and particularly relates to bi-component pouring resin and a pouring method of a stator iron core. The double-component casting resin provided by the invention comprises a component A and a component B, wherein the component A comprises the following components: polyethylene glycol modified bisphenol A epoxy resin, polyether hyperbranched epoxy resin, an epoxy silane coupling agent KH-560, an epoxy silane coupling agent, first silica powder and second silica powder; the component B is prepared from the following components: methyl tetrahydrophthalic anhydride, polysebacic anhydride, a boron trichloride-n-octyl dimethyl amine compound, an epoxy group silane coupling agent KH-560, an epoxy group silane coupling agent A-187, first silicon micro powder and second silicon micro powder. The double-component casting resin provided by the invention is low in initial viscosity and long in gelation time, the operability of the casting process can be effectively improved, gaps are prevented from being formed, and a casting body formed after curing has relatively good glass transition temperature, cracking resistance and mechanical strength.

The present invention belongs to the technical field of ceramic preparation, and particularly relates to a preparation method of high-purity boron carbide spheres for nuclear protection and the high-purity boron carbide spheres. The preparation method comprises the following steps: S1. Mix boron carbide powder and graphite powder; S2. Press the mixed powder into a rod-shaped green body; Place the green body-forming mold containing the green body in a heating container and wait for sintering; S3. Heat up to 1010-1130 °C, introduce a mixed gas of inert gas and boron trichloride into the heating container, control the air pressure at 1000-1500 Pa, and keep warm for 5-8 h to obtain a boron carbide rod; S4. Process the boron carbide rod into a semi-finished boron carbide sphere; S5. Heat up to 1920-2010 °C, and keep the boron carbide sphere warm for 2-3 h under the atmosphere of inert gas and hydrogen. The present invention solves the problems existing in the boron carbide spheres prepared in the prior art, such as great forming difficulty, high manufacturing cost, low production efficiency, and low compressive strength.

The invention discloses a hole transport material, a preparation method thereof and a perovskite solar cell, the hole transport material has a structure as shown in a formula 1, and the preparation method of the hole transport material comprises the following steps: S1, adding 4, 5-dichlorophthalonitrile, phenylacetylene and a catalyst into a solvent for mixing, performing a first heating reflux reaction in an inert atmosphere to obtain a product as shown in a formula 2; and S2, mixing the product as shown in the formula 2, boron trichloride and an organic solvent, and carrying out a second heating reflux reaction in an inert atmosphere to prepare the hole transport material. According to the hole transport material, subphthalocyanine is used as a core skeleton, modification is carried out through peripheral phenylacetylene groups, a pi conjugated system is remarkably expanded while the basic structure of subphthalocyanine is maintained, and therefore the photoelectric conversion efficiency of a perovskite solar cell is improved; in addition, the hole transport material is good in thermal and chemical stability and has hydrophobicity, so that the service life of the perovskite solar cell is prolonged, and the stability of the perovskite solar cell is improved.

The invention discloses an etching method of a DTC dielectric layer, which comprises the following steps: providing a wafer, forming a first insulating layer on the wafer, forming a deep groove in the first insulating layer, forming a DTC multilayer film structure on the first insulating layer and the deep groove, forming a second insulating layer on the DTC multilayer film structure, filling the deep groove with the second insulating layer, the DTC multilayer film structure comprises a metal layer and a dielectric layer which are overlapped in sequence; covering the second insulating layer with a photoresist, and removing the photoresist in the target region through exposure and development in sequence to expose the second insulating layer in the target region; etching for the first time to remove the second insulating layer in the target area; second-time etching is carried out, etching is carried out to the preset depth in the top metal layer, and gas introduced in the second-time etching process comprises chlorine and boron trichloride; and third etching is carried out until the dielectric layer below the top metal layer is exposed, the content of boron trichloride is reduced and argon is introduced in the third etching process, and the bias power is reduced as much as possible in a range allowed by process conditions.

The invention discloses a catalyst for synthesizing p-cumylphenol and a preparation method thereof. The catalyst comprises an active component A, a carrier B and a cocatalyst C. The active component A is one or more of aluminum trichloride, tin tetrachloride, zinc chloride, ferric chloride and boron trichloride. The carrier B is one or more of silica gel and aluminum oxide; the cocatalyst C is one or more of zinc oxide, copper oxide, magnesium oxide, zirconium dioxide, titanium dioxide and boric oxide, the selectivity of the catalyst is high, and p-cumylphenol can be efficiently prepared.

The invention belongs to the technical field of ICP (Inductively Coupled Plasma) etching, and relates to a method for etching gallium oxide by ICP, which comprises the following steps of: placing a gallium oxide sample with a PR mask on a wafer in an ICP etching chamber, introducing a first gas halide and a second gas halide into the front surface of the gallium oxide sample until the interior of the etching chamber is in a stable state, and removing the first gas halide and the second gas halide from the front surface of the gallium oxide sample; continuously introducing each gas and starting radio frequency to carry out etching treatment to obtain etched gallium oxide; the first gas halide comprises boron trichloride, and the second gas halide comprises any one or a combination of at least two of hydrogen bromide, chlorine and trifluoromethane. According to the method, pollution caused by the metal mask to gallium oxide etching can be avoided, the etching roughness can be reduced, the gallium oxide etching perpendicularity can be improved, the bottom of the etched gallium oxide achieves a fillet effect, and compared with a conventional etching method, the selection ratio of gallium oxide to PR is also obviously improved.

An apparatus includes a body configured to support a substrate, a first coating, conformal on a surface of the body, that is corrosion resistant to at least one of: boron trichloride, nitrogen trifluoride, hafnium tetrachloride, aluminum trichloride, oxygen gas, chlorine gas, fluorine gas, chlorine trifluoride, hydrogen fluoride, hydrogen gas, ammonia, tungsten hexafluoride, tetrafluoromethane, titanium tetrachloride, molybdenum pentachloride, ozone, tetrafluorosilane, or hexafluoroethane, and a second coating, on the first coating, having a hardness that greater than or equal to about 8 gigapascals.

Methods open etch stop layers in an integrated environment along with metallization processes. In some embodiments, a method for opening an etch stop layer (ESL) prior to metallization may include etching the ESL with an anisotropic process using direct plasma to form helium ions that are configured to roughen the ESL for a first duration of approximately 10 seconds to approximately 30 seconds, forming aluminum fluoride on the ESL using remote plasma and nitrogen trifluoride gas for a second duration of approximately 10 seconds to approximately 30 seconds, and exposing the ESL to a gas mixture of boron trichloride, trimethylaluminum, and / or dimethylaluminum chloride at a temperature of approximately 100 degrees Celsius to approximately 350 degrees Celsius to remove aluminum fluoride from the ESL and a portion of a material of the ESL for a third duration of approximately 30 seconds to approximately 60 seconds.

The present invention discloses a preparation method of 3-(2-chloroethyl)-2-methyl-9-hydroxy-4H-pyrido[1,2-a]pyrimidin-4-one. This method uses 2-amino-3-methoxypyridine and 2-acetylbutyrolactone as raw materials, and successively undergoes cyclization reaction, chlorination reaction, and boron trichloride demethylation reaction to obtain the compound 3-(2-chloroethyl)-2-methyl-9-hydroxy-4H-pyrido[1,2-a]pyrimidin-4-one. Compared with the prior art, the present invention adopts a different method from the previous process, develops a more concise and efficient synthetic route, the process flow has low requirements for equipment, the overall three-step molar yield can reach more than 80%, and it is suitable for industrialization. This method has stable process and high reproducibility between batches.

The invention discloses a trimethyl boron preparation method and device, namely trimethyl boron is prepared by reaction of trimethyl aluminum and boron trichloride, the conversion rate of boron trichloride can reach 99%, the yield of trimethyl boron is greater than or equal to 95%, the purity is greater than 99%, the method is convenient and low in cost, and the trimethyl boron production process is simpler. Meanwhile, a set of reaction device for continuously preparing trimethyl boron is designed and developed, the reaction device is composed of a feeding system, a reaction system, a temperature control system, a product purification and collection system, a product collection system and a temperature control system, and the method and the device can efficiently produce trimethyl boron.

The invention relates to the technical field of semiconductor power device manufacturing, and discloses a method for improving metal etching residues based on dry etching. The method comprises the following steps: S1, providing a substrate layer; s2, depositing a stop layer on the substrate layer, and forming a pattern on the substrate layer on the stop layer through a photoetching process to serve as a first pattern; s3, performing wet etching on the first pattern to the substrate layer; s4, removing the photoresist in the step S2 by adopting a wet process, depositing a metal composite layer on the stop layer, and forming a pattern on the substrate layer on the metal composite layer through a photoetching process as a second pattern; and S5, the metal composite layer is subjected to metal etching, the stop layer serves as an etching end point, the bias power of metal etching is 200-250 W, and the flow of boron trichloride gas is 40-50 sccm. In this way, the problem of metal residues in the etching process can be effectively solved.

A lateral and vertical DEP method for micro-nano biological and metabolite sensors and actuators using two electric field intensities. The method specifically comprises the following steps: S1, before a metal etching process, performing resist plasma etching to form a resist profile at a side wall, wherein a high-pressure baseline formulation comprises oxygen, nitrogen, and argon in a ratio of 1:4:140 at a pressure of 1600 mT and a radiofrequency power of 1300 watts, used to generate a resist with a pre-designed angle; S2, performing metal etching, wherein a baseline instruction comprises chlorine, boron trichloride, and argon in a ratio of, but not limited to, 1:0.4:0.2, at a pressure of 8 mT, with a source power preferably of 1200 watts and a bias power preferably of 175 watts; and S3, performing metal profiling to measure the remaining thickness. The method enables a lateral attractive force of PDEP at Y in a medium.

The invention provides a light emitting diode for improving electric leakage and a preparation method thereof, and belongs to the technical field of photoelectron manufacturing. The preparation method of the light-emitting diode comprises the following steps: forming an epitaxial structure on a patterned substrate; the surface, away from the patterned substrate, of the epitaxial structure is bonded to a conductive substrate, and the patterned substrate is removed; the surface, away from the conductive substrate, of the epitaxial structure is etched, a first groove is formed, etching gas comprises chlorine and boron trichloride, the upper power of etching equipment in at least part of stages in the etching process is smaller than or equal to 500 W, and the lower power of the etching equipment in at least part of stages in the etching process is smaller than or equal to 300 W. According to the embodiment of the invention, the problem of over-etching of the epitaxial layer can be improved, and electric leakage caused by short circuit of the film layer after over-etching can be avoided.

The application discloses a SiC nanowire in-situ modified ceramic matrix composite connecting fastener and a preparation method thereof, and belongs to the technical field of ceramic matrix composite materials. The preparation method comprises the following steps: firstly, performing heat treatment on a fiber preform; then, performing CVD or CVI deposition on the fiber preform by using boron trichloride and ammonia gas / ethylene as a precursor; then, performing catalyst solution impregnation and drying; finally, performing CVI deposition on the composite preform by using trichloromethylsilane as a precursor, so that the composite preform is prepared; firstly, performing CVD or CVI deposition on the composite preform by using silicon tetrachloride and ammonia gas as a precursor; then, performing precursor solution impregnation and drying; then, performing vacuum pyrolysis treatment; finally, performing CVI deposition on the composite preform by using silicon tetrachloride and ammonia gas as a precursor, processing threads, and the connecting fastener is prepared. The application realizes rapid densification while reinforcing and toughening by means of in-situ growth of SiC nanowires, and has the advantages of short preparation period, good mechanical properties of products, high connecting efficiency and the like.

The invention belongs to the technical field of ceramic preparation, and particularly relates to a preparation method of high-purity boron-carbon spheres for nuclear protection and the high-purity boron-carbon spheres. The preparation method comprises the following steps: S1, mixing boron carbide powder with graphite powder; s2, pressing the mixed powder into a rod-shaped green body; placing the blank making mold filled with the blank body in a heating container for sintering; s3, the temperature is increased to 1010-1130 DEG C, mixed gas of inert gas and boron trichloride is introduced into the heating container, the gas pressure is controlled to be 1000-1500 Pa, heat preservation is conducted for 5-8 h, and a boron-carbon rod is obtained; s4, processing the boron-carbon rod into a semi-finished boron-carbon ball; and S5, raising the temperature to 1920-2010 DEG C, and carrying out heat preservation on the boron-carbon spheres for 2-3 hours in the atmosphere of inert gas and hydrogen. The problems of high forming difficulty, high manufacturing cost, low production efficiency, low compressive strength and the like of boron-carbon spheres prepared in the prior art are solved.

Molybdenum is etched in a highly controllable manner by performing one or more etch cycles, where each cycle involves exposing the substrate having a molybdenum layer to an oxygen-containing reactant to form molybdenum oxide followed by treatment with boron trichloride to convert molybdenum oxide to a volatile molybdenum oxychloride with subsequent treatment of the substrate with a fluorine-containing reactant to remove boron oxide that has formed in a previous reaction, from the surface of the substrate. In some embodiments the method is performed in an absence of plasma and results in a substantially isotropic etching. The method can be used in a variety of applications in semiconductor processing, such as in wordline isolation in 3D NAND fabrication.