A method for forming a silicon oxide film

Abstract

The present invention relates to the technical field of silicon materials, and discloses a film forming method of a silicon oxide film. The present invention uses a ruthenium-supported molecular sieve catalyst to catalyze diisopropylamine and phenylsilane to react and purify by rectification to obtain high-purity diisopropylamine silane, and the gas phase purity reaches 98.7-99.6%. Then, using it as a silicon source, a silicon oxide film is obtained by a plasma chemical vapor deposition method, and the content of Si element and O element is high, and the content of its impurity element C is low, which is only 8.92-15.19%. A new strategy is provided for preparing high-purity diisopropylamine silane and high-performance silicon oxide film.

Description

Technical Field

[0001] The present invention relates to the technical field of silicon materials, and in particular to a method for forming a silicon oxide film. Background Art

[0002] Silicon compounds have unique physical and chemical properties and are widely used in electrochemical energy, super-hydrophobic materials, microelectronics, etc.; It is a research hotspot to prepare high-purity silicon compounds using a novel and efficient method, such as patent CN115260223B discloses using bis(hexamethyldisilazide) calcium or bis(hexamethyldisilazide) strontium as a chlorine-free catalyst, catalyzing the dehydrogenation coupling reaction of monosilane and diisopropylamine to obtain diisopropylamine silane. Silicon oxide film has good wear resistance, insulation, chemical resistance, and light transmittance and is widely used in microelectronics, corrosion resistance, and other fields. At present, the method for preparing silicon oxide film is mainly to use diisopropylamine silane, hexamethyldisiloxane, etc. as silicon source, and to prepare by vapor deposition, atomic layer deposition, etc., and patent CN101078109B discloses using an organic aminosilane precursor, and depositing silicon oxide film on a substrate by CVD method; And the purity of the silicon precursor has a great influence on the purity of silicon oxide film, and performance. The invention aims to prepare a silicon oxide film by using high-purity diisopropylamine silane as a silicon source through a plasma chemical vapor deposition method. Summary of the invention

[0003] Technical problem to be solved: Silicon oxide film was prepared by plasma chemical vapor deposition using high-purity diisopropylamine silane as the silicon source.

[0004] Technical solution: A method for forming a silicon oxide film: using high-purity diisopropylamine silane as a silicon source and a single-crystal silicon wafer as a substrate, a dual-power source plasma chemical vapor deposition device is used to deposit a silicon oxide film on the single-crystal silicon wafer substrate; placing the single-crystal silicon wafer in a vacuum reaction chamber in the vapor deposition device, and controlling the vacuum degree of the reaction chamber to (2-10)×10 -4 Pa; oxygen and high-purity diisopropylamine silane are introduced, and the microwave power of the vapor deposition equipment is controlled to 200-250W to perform vapor deposition to obtain a silicon oxide film.

[0005] Furthermore, the flow rate of oxygen is 300-800 mL / h.

[0006] Furthermore, the flow rate of high-purity diisopropylamine silane is 200-600 mL / h.

[0007] Furthermore, the vapor deposition time is 60-90 min.

[0008] Furthermore, the preparation method of high-purity diisopropylamine silane is as follows: argon gas is introduced into the reaction kettle to exhaust the air, a ruthenium-loaded molecular sieve catalyst and diisopropylamine are added, phenylsilane is added at a temperature of -40 to -50°C, and then a reaction is carried out, the material is filtered to remove solids, and the diisopropylamine is concentrated to remove diisopropylamine. The crude product is distilled by a distillation device, and a fraction of 54-56°C is collected at a pressure of 100-120 mmHg to obtain high-purity diisopropylamine silane.

[0009] Furthermore, the masses of the ruthenium-supported molecular sieve catalyst and diisopropylamine are (8-13)% and (24-35)% of the mass of phenylsilane, respectively.

[0010] Furthermore, the reaction temperature is controlled at 135-170°C, and the reaction time is 24-48h.

[0011] Furthermore, the preparation method of the ruthenium-loaded molecular sieve catalyst is: adding HMCM-22 molecular sieve to a solution of ruthenium nitrosyl nitrate, dispersing evenly, heating and evaporating to remove the solvent, and then placing it in an atmosphere furnace and calcining it under a nitrogen range to obtain a ruthenium-loaded molecular sieve catalyst.

[0012] Further, the mass of ruthenium nitrosyl nitrate is (0.05-0.08)% of the mass of HMCM-22 molecular sieve.

[0013] Furthermore, the calcination temperature is 400-550°C and the time is 2-3h.

[0014] Technical effect: The present invention uses a ruthenium-supported molecular sieve catalyst to catalyze the reaction and distillation purification of diisopropylamine and phenylsilane to obtain high-purity diisopropylamine silane with a gas phase purity of 98.7-99.6%. Then, using it as a silicon source, a silicon oxide film is obtained by plasma chemical vapor deposition, with high contents of Si and O elements and low content of impurity element C, which is only 8.92-15.19%. This provides a new strategy for preparing high-purity diisopropylamine silane and high-performance silicon oxide films. DETAILED DESCRIPTION

[0015] To better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments. It should be understood by those skilled in the art that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0016] Example 1

[0017] 100 parts by weight of HMCM-22 molecular sieves were added to an aqueous solution containing 0.05 parts by weight of ruthenium nitrosyl nitrate, dispersed evenly, heated to evaporate and remove the solvent, and then placed in an atmosphere furnace and calcined at 400° C. for 3 hours under a nitrogen range to obtain a ruthenium-loaded molecular sieve catalyst.

[0018] Argon gas was introduced into the reactor to expel the air, 8 parts by weight of ruthenium-loaded molecular sieve catalyst and 28 parts by weight of diisopropylamine were added, and 100 parts by weight of phenylsilane were added at a temperature of -40°C. The reactor was then heated to 170°C and reacted for 24 hours. The material was filtered to remove solids, concentrated to remove diisopropylamine, and the crude product was distilled through a distillation device. At a pressure of 100 mmHg, a fraction at 54°C was collected to obtain high-purity diisopropylamine silane.

[0019] Using high-purity diisopropylamine silane as the silicon source and a single-crystal silicon wafer as the substrate, a dual-power source plasma chemical vapor deposition device was used to deposit a silicon oxide film on the single-crystal silicon wafer substrate. The single-crystal silicon wafer was placed in a vacuum reaction chamber in the vapor deposition device, and the vacuum degree of the reaction chamber was controlled to 6×10 -4 Pa; introduce oxygen and control the flow rate to 300mL / h; introduce high-purity diisopropylamine silane and control the flow rate to 200mL / h, and control the microwave power of the vapor deposition equipment to 250W, and perform vapor deposition for 60min to obtain a silicon oxide film.

[0020] Example 2

[0021] 100 parts by weight of HMCM-22 molecular sieves were added to an aqueous solution containing 0.06 parts by weight of ruthenium nitrosyl nitrate, dispersed evenly, heated to evaporate and remove the solvent, and then placed in an atmosphere furnace and calcined at 550° C. for 2 hours under a nitrogen range to obtain a ruthenium-loaded molecular sieve catalyst.

[0022] Argon gas was introduced into the reactor to expel the air, 13 parts by weight of ruthenium-loaded molecular sieve catalyst and 35 parts by weight of diisopropylamine were added, 100 parts by weight of phenylsilane were added at a temperature of -50°C, and then the reactor was heated to 135°C and reacted for 48 hours. The material was filtered to remove the solid, concentrated to remove the diisopropylamine, and the crude product was distilled through a distillation device. At a pressure of 120 mmHg, a fraction at 56°C was collected to obtain high-purity diisopropylamine silane.

[0023] Using high-purity diisopropylamine silane as the silicon source and a single-crystal silicon wafer as the substrate, a dual-power source plasma chemical vapor deposition device was used to deposit a silicon oxide film on the single-crystal silicon wafer substrate. The single-crystal silicon wafer was placed in a vacuum reaction chamber in the vapor deposition device, and the vacuum degree of the reaction chamber was controlled to be 10×10 -4 Pa; introduce oxygen and control the flow rate to 600mL / h; introduce high-purity diisopropylamine silane and control the flow rate to 400mL / h, and control the microwave power of the vapor deposition equipment to 250W, and perform vapor deposition for 90 minutes to obtain a silicon oxide film.

[0024] Example 3

[0025] 100 parts by weight of HMCM-22 molecular sieves were added to an aqueous solution containing 0.06 parts by weight of ruthenium nitrosyl nitrate, dispersed evenly, heated to evaporate and remove the solvent, and then placed in an atmosphere furnace and calcined at 550° C. for 3 hours under a nitrogen range to obtain a ruthenium-loaded molecular sieve catalyst.

[0026] Argon gas was introduced into the reactor to expel the air, 13 parts by weight of a ruthenium-loaded molecular sieve catalyst and 24 parts by weight of diisopropylamine were added, and 100 parts by weight of phenylsilane were added at a temperature of -40°C. The reactor was then heated to 150°C and reacted for 36 hours. The material was filtered to remove the solids, concentrated to remove the diisopropylamine, and the crude product was distilled through a distillation device. The fraction at 54°C was collected under a pressure of 100 mmHg to obtain high-purity diisopropylamine silane.

[0027] Using high-purity diisopropylamine silane as the silicon source and a single-crystal silicon wafer as the substrate, a dual-power source plasma chemical vapor deposition device was used to deposit a silicon oxide film on the single-crystal silicon wafer substrate. The single-crystal silicon wafer was placed in a vacuum reaction chamber in the vapor deposition device, and the vacuum degree of the reaction chamber was controlled to 2×10 -4 Pa; introduce oxygen and control the flow rate to 800mL / h; introduce high-purity diisopropylamine silane and control the flow rate to 600mL / h, and control the microwave power of the vapor deposition equipment to 200W, and perform vapor deposition for 90 minutes to obtain a silicon oxide film.

[0028] Example 4

[0029] 100 parts by weight of HMCM-22 molecular sieves were added to an aqueous solution containing 0.08 parts by weight of ruthenium nitrosyl nitrate, dispersed evenly, heated to evaporate and remove the solvent, and then placed in an atmosphere furnace and calcined at 500° C. for 3 hours under a nitrogen range to obtain a ruthenium-loaded molecular sieve catalyst.

[0030] Argon gas was introduced into the reactor to expel the air, 12 parts by weight of ruthenium-loaded molecular sieve catalyst and 35 parts by weight of diisopropylamine were added, 100 parts by weight of phenylsilane were added at a temperature of -50°C, and then the reactor was heated to 150°C and reacted for 36 hours. The material was filtered to remove the solid, concentrated to remove the diisopropylamine, and the crude product was distilled through a distillation device. At a pressure of 120 mmHg, a fraction at 56°C was collected to obtain high-purity diisopropylamine silane.

[0031] Using high-purity diisopropylamine silane as the silicon source and a single-crystal silicon wafer as the substrate, a dual-power source plasma chemical vapor deposition device was used to deposit a silicon oxide film on the single-crystal silicon wafer substrate. The single-crystal silicon wafer was placed in a vacuum reaction chamber in the vapor deposition device, and the vacuum degree of the reaction chamber was controlled to be 10×10 -4Pa; introduce oxygen and control the flow rate to 500mL / h; introduce high-purity diisopropylamine silane and control the flow rate to 400mL / h, and control the microwave power of the vapor deposition equipment to 250W, and perform vapor deposition for 60min to obtain a silicon oxide film.

[0032] Comparative Example 1

[0033] Argon gas was introduced into the reactor to expel the air, 0.004 parts of ruthenium nitrosyl nitrate, 8 parts by weight of HMCM-22, and 28 parts by weight of diisopropylamine were added, and 100 parts by weight of phenylsilane were added at a temperature of -40°C. The reactor was then heated to 170°C and reacted for 24 hours. The material was filtered to remove solids, concentrated to remove diisopropylamine, and the crude product was distilled through a distillation device. The fraction at 54°C was collected under a pressure of 100 mmHg to obtain high-purity diisopropylamine silane.

[0034] Using high-purity diisopropylamine silane as the silicon source and a single-crystal silicon wafer as the substrate, a dual-power source plasma chemical vapor deposition device was used to deposit a silicon oxide film on the single-crystal silicon wafer substrate. The single-crystal silicon wafer was placed in a vacuum reaction chamber in the vapor deposition device, and the vacuum degree of the reaction chamber was controlled to 6×10 -4 Pa; introduce oxygen and control the flow rate to 300mL / h; introduce high-purity diisopropylamine silane and control the flow rate to 200mL / h, and control the microwave power of the vapor deposition equipment to 250W, and perform vapor deposition for 60min to obtain a silicon oxide film.

[0035] The gas phase purity of diisopropylamine silane was tested by gas chromatography.

[0036] Table 1 Diisopropylamine silane gas phase purity test

[0037]

[0038] In Examples 1 to 4, ruthenium-supported molecular sieve catalysts are used as catalysts to catalyze the reaction of diisopropylamine and phenylsilane to obtain high-purity diisopropylamine silane with a gas phase purity of 98.7-99.6%, which facilitates the subsequent preparation of high-performance silicon oxide films.

[0039] Comparative Example 1 uses ruthenium nitrosyl nitrate and HMCM-22 molecular sieve as synergistic catalysts, but does not have a good catalytic effect. The reaction system is relatively complex, and the gas phase purity of diisopropylamine silane is only 86.8%.

[0040] XPS photoelectron spectroscopy was used to analyze the silicon oxide films.

[0041] Table 2 Elemental analysis of silicon oxide film

[0042] Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Si element (%) 23.13 22.93 21.14 23.05 32.18 O element (%) 67.95 64.94 63.67 66.41 11.12 C element (%) 8.92 12.13 15.19 10.54 56.70

[0043] In Example 1-4, high-purity diisopropylamine silane is used as silicone oil. Through plasma chemical vapor deposition, the silicon oxide film obtained has high content of Si and O elements and low content of impurity element C, which is only 8.92-15.19%.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A method for forming a silicon oxide film, characterized in that: The film forming method comprises: using high-purity diisopropylamine silane as a silicon source and a single crystal silicon wafer as a substrate, and using a dual-power source plasma chemical vapor deposition device to deposit a silicon oxide film on the single crystal silicon wafer substrate; placing the single crystal silicon wafer in a vacuum reaction chamber in the vapor deposition device, and controlling the vacuum degree of the reaction chamber to 2×10 -4 Pa-10×10 -4 Pa; introducing oxygen and high-purity diisopropylamine silane, and controlling the microwave power of the vapor deposition equipment to 200-250W, performing vapor deposition to obtain a silicon oxide film, wherein the content of element C in the silicon oxide film is 8.92%-15.19%; Wherein, the flow rate of the oxygen introduced is 300-800mL / h; The flow rate of high-purity diisopropylamine silane is 200-600 mL / h; The vapor deposition time is 60-90 min; The preparation method of the high-purity diisopropylamine silane is as follows: introducing argon gas into a reaction kettle to exhaust air, adding a ruthenium-loaded molecular sieve catalyst and diisopropylamine, adding phenylsilane at a temperature of -40 to -50°C, then reacting, filtering the material to remove solids, concentrating to remove diisopropylamine, and distilling the crude product through a distillation device. Under a pressure of 100-120 mmHg, a fraction of 54-56°C is collected to obtain high-purity diisopropylamine silane, wherein the mass of the ruthenium-loaded molecular sieve catalyst is 8%-13% of the mass of phenylsilane, the mass of the diisopropylamine is 24%-35% of the mass of phenylsilane, the reaction temperature is controlled at 135-170°C, the reaction time is 24-48h, and the gas phase purity of the high-purity diisopropylamine silane reaches 98.7%-99.6%.

2. The method for forming a silicon oxide film according to claim 1, wherein: The preparation method of the ruthenium-loaded molecular sieve catalyst is as follows: adding HMCM-22 molecular sieve into a solution of ruthenium nitrosyl nitrate, dispersing evenly, heating and evaporating to remove the solvent, and then placing in an atmosphere furnace and calcining under a nitrogen range to obtain the ruthenium-loaded molecular sieve catalyst.

3. The method for forming a silicon oxide film according to claim 2, wherein: The mass of the ruthenium nitrosyl nitrate is 0.05%-0.08% of the mass of the HMCM-22 molecular sieve.

4. The method for forming a silicon oxide film according to claim 2, wherein: The calcination temperature is 400-550° C. and the calcination time is 2-3 hours.

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