Novel etching solution formula in semiconductor material etching process

Abstract

The invention relates to a novel etching solution formula in a semiconductor material etching process, which comprises sodium chlorite, hydrogen peroxide, purified water, sodium acetate and organic acid, the pH value of a selective etching solution is 3.0-5.5, and in the etching solution, the mass concentration of the sodium chlorite is 3g / L-5 g / L, the mass concentration of ammonium bicarbonate is 10g / L-15g / L, the volume concentration of ammonia water is 6mL / L-10mL / L, and the volume concentration of the organic acid is 0.5-1.5 g / L. The acid ammonium hydrogen comprises oxalate, organic acid and hydrogen peroxide, the hydrochloric acid accounts for 6-15%, the hydrogen peroxide accounts for 7-14%, and the purified water accounts for 5-10%, the silicon nitride wet-process removal general method is that a hot phosphoric acid solution and 85% strong phosphoric acid are mixed with a small amount of water, the temperature is controlled to be 100-130 DEG C, the etching rate of furnace tube silicon nitride is about # imgabs0 #, and the etching rate of CVD silicon nitride is higher. The etching rate is greatly influenced, and the actual result needs to be measured according to different conditions.

Description

Technical Field

[0001] This application relates to the technical field of etching solutions, and specifically to a new etching solution formulation for semiconductor material etching processes. Background Art

[0002] Wet etching is a technique in which the material to be etched is immersed in an etching solution for etching, and it is an isotropic etching method. The silicon wafer is immersed in a certain chemical reagent or reagent solution, so that the surface of the part of the film that is not masked by the resist reacts with the reagent and is removed. For example, a solution containing hydrofluoric acid is used to etch a silicon dioxide film, and phosphoric acid is used to etch an aluminum film, etc. This etching process carried out in a liquid environment is called the "wet" process. Its advantages are simple operation, low requirements for equipment, easy to achieve mass production, and good etching selectivity.

[0003] The current etching solution has a formulation composed of the following components in weight percentages: ammonium fluoride 30 - 35%, hydrofluoric acid 4 - 8%, hydrogen chloride 3 - 5%, surfactant 0.1 - 0.25%, and the balance is ultrapure water. The surfactant includes fluorinated alcohol and fluorinated carboxylic acid. By adding the combination of fluorinated alcohol and fluorinated carboxylic acid as the surfactant, the contact angle of the etching solution can be reduced, the wettability of the etching solution can be improved, the etching solution has excellent wettability, low surface tension, and few bubbles, can uniformly etch the silicon dioxide film under the photoresist without generating silicon dioxide residue, and has no effect on the photoresist, and has good application prospects.

[0004] Regarding the above related technologies, the inventor believes there are the following technical defects: The etching solutions in the prior art usually include hydrofluoric acid, hydrogen chloride, ammonium fluoride, and water, but defoaming agent components need to be added, and the wettability of the etching solution is insufficient, and the phenomenon of uneven etching easily occurs. When the etching solution is prepared, a suitable blending effect cannot be achieved, affecting the use of the etching solution. Summary of the Invention

[0005] In order to improve the technical problem that the etching solution cannot achieve a suitable blending effect, this application provides a new etching solution formulation for semiconductor material etching processes.

[0006] A new etching solution formulation for semiconductor material etching processes provided by this application adopts the following technical solutions:

[0007] A new etching solution formulation for a semiconductor material etching process, including sodium chlorite, hydrogen peroxide, and pure water, further including sodium acetate and organic acid. The pH value of the selective etching solution is 3.0 - 5.5. In the etching solution, the mass concentration of sodium chlorite is 3g / L - 5g / L, the mass concentration of ammonium bicarbonate is 10g / L - 15g / L, the volume concentration of ammonia water is 6mL / L - 10mL / L. The ammonium bicarbonate includes oxalate, organic acid, and hydrogen peroxide. The hydrochloric acid accounts for 6% - 15%, the hydrogen peroxide accounts for 7% - 14%, and the pure water accounts for 5% - 10%.

[0008] By adopting the above technical solution, using the above new semiconductor material etching solution formulation, it is possible to achieve precise selective etching function during the semiconductor manufacturing process, optimize the etching efficiency, control the etching rate, improve the etching precision, while ensuring the stability and operation safety of the etching solution, adapt to different material surface treatment requirements, avoid excessive damage to the material surface, and thus improve the manufacturing quality and performance of semiconductor devices. The pH value, concentration ratio, and the synergistic effect of each component of this etching solution formulation enable it to exhibit excellent performance in various etching processes, effectively reducing the process cost, shortening the production cycle, and reducing environmental pollution, providing an efficient and environmentally friendly etching solution for the semiconductor industry.

[0009] Optionally, the sodium chlorite accounts for 3 - 8% of the total weight of the selective etching solution, preferably 4 - 10%, more preferably 5 - 12%, and most preferably 7%. The volume ratio of the oxidation solution to ammonium bicarbonate is 2:10 - 5:20.

[0010] By adopting the above technical solution, further improving the etching efficiency and precision of the selective etching solution, while controlling the composition of the etching solution, ensuring the selectivity and stability of the semiconductor material during the etching process, optimizing the etching rate, reducing unnecessary damage and material waste. The appropriate concentration of sodium chlorite and the adjustment of the volume ratio of the oxidation solution to ammonium bicarbonate effectively improve the reactivity and uniformity of the etching solution, ensure its adaptability under different etching conditions, reduce process variability, and at the same time reduce the possible environmental pollution during the production process, ultimately achieving a high-quality and high-efficiency semiconductor manufacturing process and improving the stability and reliability of the product.

[0011] Optionally, the oxalate is oxalic acid, and the oxalic acid accounts for 0.2 - 5.5% of the total weight of the selective etching solution, preferably 0.5 - 6%, more preferably 0.8 - 8%, and most preferably 4%. 10g of pure water, 5g of ammonium fluoride, 6g of oxalic acid, 8g of ammonium sulfate, 40g of glycerol, and 20g of barium sulfate account for 0.8 - 10% of the total weight of the selective etching solution, preferably 0.9 - 15%, more preferably 1.75 - 20%, and most preferably 8%.

[0012] By adopting the above technical solutions, the composition of the selective etching solution is effectively adjusted, the reactivity and stability of the etching solution are optimized, the etching selectivity and precision for specific semiconductor materials are improved. The appropriate addition of oxalates (such as oxalic acid) helps to enhance the corrosion ability of the etching solution for specific materials while avoiding excessive damage to other materials. The optimization of the ratio of pure water, ammonium fluoride, oxalic acid, ammonium sulfate, glycerol, and barium sulfate significantly improves the uniformity and stability of the etching solution, ensuring the uniformity and consistency during the etching process.

[0013] Optionally, the surfactant includes concentrated hydrochloric acid, concentrated nitric acid, glacial acetic acid, hydrofluoric acid, and disodium hydrogen phosphate. The surfactant accounts for 4 - 9% of the total weight of the selective etching solution, preferably 10 - 15%. The pH value of the selective etching solution is 7 - 9, preferably 8.

[0014] By adopting the above technical solutions, the surface activity and reactivity of the selective etching solution are significantly improved, and the adhesion and reaction rate of the etching solution to the surface of semiconductor materials during the treatment process are optimized. The reasonable ratio of the surfactant, especially the use of concentrated hydrochloric acid, concentrated nitric acid, glacial acetic acid, hydrofluoric acid, and disodium hydrogen phosphate, helps to enhance the permeability and wettability of the etching solution on the surface of complex materials, thereby improving the uniformity and selectivity of etching. The pH value of the selective etching solution is controlled between 7 and 9, ensuring the stability and applicability of the liquid, avoiding excessive corrosion of the materials, enabling precise control of the etching process, improving the surface quality of semiconductor devices, reducing errors and material waste in production, and ensuring an efficient and environmentally friendly etching process.

[0015] Optionally, the pH value of the semiconductor selective etching solution is 5 - 10. The semiconductor selective etching solution is composed of a semiconductor oxidation solution and nickel chloride. The semiconductor oxidation solution includes hydrogen peroxide, and the nickel chloride includes ferric trichloride, hydrogen peroxide, and hydrofluoric acid. The fluorinated alcohols in the surfactant component are a mixture of two or more of trifluoroethanol, tetrafluoropropanol, and octafluoropentanol in any proportion.

[0016] By adopting the above technical solutions, precise control of the selective etching of semiconductor materials is achieved, and the reactivity and stability of the etching solution are improved. The pH value of the selective etching solution is controlled between 5 and 10, effectively ensuring fine control of different materials during the etching process and avoiding excessive corrosion. The formulation composed of the semiconductor oxidation solution and nickel chloride, combined with the synergistic effects of hydrogen peroxide, ferric trichloride, hydrogen peroxide, and hydrofluoric acid, can provide efficient oxidation and corrosion capabilities under different etching requirements while maintaining the precision of selective etching. The fluorinated alcohols (such as trifluoroethanol, tetrafluoropropanol, and octafluoropentanol) in the surfactant component are used in combination, enhancing the surface activity of the etching solution, improving the wettability and permeability of the etching solution on the material surface, and further improving the uniformity and efficiency during the etching process.

[0017] Optionally, the hydrogen peroxide accounts for 8-15% of the total weight of the semiconductor selective etching solution, preferably 15-30%, more preferably 20-25%, and most preferably 24.5%; the volume ratio of the semiconductor oxidation solution to the nickel chloride is 1:8-7:1.

[0018] By adopting the above technical solution, the etching effect and control accuracy of the semiconductor selective etching solution are significantly improved. The optimization of the proportion of hydrogen peroxide (8-15%, preferably 15-30%) enhances the oxidizing property of the etching solution, thereby accelerating the etching rate, improving the reaction efficiency, and better controlling the selectivity during the etching process. The adjustment of the volume ratio of the semiconductor oxidation solution to nickel chloride (1:8-7:1) can optimize the reaction balance between the two, enabling the etching solution to maintain stable reactivity and high efficiency under different conditions, ensuring the uniformity and accuracy of the etching on the material surface, avoiding unnecessary damage to the semiconductor material, achieving efficient and precise semiconductor surface treatment, improving the process quality in the manufacturing process, reducing material waste and costs, while also improving production efficiency and environmental friendliness.

[0019] Optionally, for nitric acid, hydrofluoric acid, bromic acid, phosphoric acid, and sodium chloride, the etching solution accounts for 0.1-3% of the total weight of the semiconductor selective etching solution, preferably 0.2-1.5%, and more preferably 0.5%.

[0020] By adopting the above technical solution, the reasonable addition of components such as nitric acid, hydrofluoric acid, bromic acid, phosphoric acid, and sodium chloride can adjust the chemical activity and corrosiveness of the etching solution, making it have stronger selectivity and higher efficiency during the surface treatment of semiconductor materials. The concentration range of the etching solution accounting for 0.1-3% of the total weight, especially at 0.2-1.5% and more preferably 0.5%, ensures the stability and high efficiency of the etching solution, while avoiding excessive corrosion or damage to the material. Through precise ingredient formulation, fine processing of different semiconductor materials can be achieved, improving etching uniformity and selectivity, optimizing the production process, reducing material waste, lowering production costs, and enhancing the quality and performance of semiconductor devices.

[0021] Optionally, the common method for wet removal of silicon nitride is a hot phosphoric acid solution. 85% concentrated phosphoric acid is mixed with a small amount of water, and the temperature is controlled at 100-130°C. The etching rate of the furnace tube silicon nitride is approximately And it will be higher for CVD silicon nitride. The etching rate will be greatly affected, and the actual results should be measured according to different conditions. In order to increase the selectivity ratio for silicon oxide, a silicon wafer with nitrogen is placed, a certain amount of silicon is dissolved, and low-temperature phosphoric acid at 110-140°C is used. The main reaction is between silicon nitride and water, and phosphoric acid only acts as a catalyst in this reaction to prepare the etching solution.

[0022] By adopting the above technical solutions, wet etching of silicon nitride is effectively carried out using hot phosphoric acid solution. At the same time, by controlling the temperature and solution composition, the selectivity to silicon dioxide is improved, the silicon nitride layer is accurately removed, the etching rate is optimized, and the etching effects of different types of silicon nitride (such as furnace tube silicon nitride and CVD silicon nitride) under different conditions are ensured. Thus, an efficient and accurate silicon nitride removal process is achieved, the selectivity and efficiency of the etching solution are enhanced, the impact on the silicon wafer during the etching process is minimized, and at the same time, the controllability and stability of the manufacturing process are improved to meet the requirements in high-precision integrated circuit manufacturing.

[0023] Optionally, for the sodium chlorite, ammonium bicarbonate, and ammonia water, the corrosion inhibitor preferably contains fluorocarboxylic acids such as perfluorohexanoic acid, perfluoro-2-methyl-3,6,8-trioxanonanoic acid, and perfluoro-2-methyl-3-oxahexanoic acid; the corrosion inhibitor accounts for 1-3% of the total weight of the semiconductor selective etching solution, preferably 1.3-2%, more preferably 1.5-4%, and most preferably 2%.

[0024] By adopting the above technical solutions, components such as sodium chlorite, ammonium bicarbonate, and ammonia water can be introduced into the semiconductor selective etching solution, and combined with the addition of fluorocarboxylic acid-based corrosion inhibitors (such as perfluorohexanoic acid, perfluoro-2-methyl-3,6,8-trioxanonanoic acid, and perfluoro-2-methyl-3-oxahexanoic acid), the stability and corrosion protection performance of the etching solution are optimized, the protection of sensitive materials and efficient etching during the etching process are ensured, while the selectivity and precision of the etching solution are improved, effectively preventing corrosion of the equipment, and enhancing the persistence of the etching solution to meet the requirements in high-precision semiconductor manufacturing processes, and improving production efficiency and product quality.

[0025] Optionally, the ammonium fluoride is 20-25%, hydrofluoric acid is 2-5%, hydrogen chloride is 4-4.5%, the surfactant is 0.4-0.7%, and the inorganic base accounts for 0.1-12% of the total weight of the semiconductor selective etching solution, preferably 0.4-8%, more preferably 0.5-5%, and most preferably 3%.

[0026] By adopting the above technical solutions, the proportions of components such as ammonium fluoride, hydrofluoric acid, and hydrogen chloride can be effectively adjusted in the semiconductor selective etching solution, and a surfactant and an inorganic base are added to optimize the chemical reactivity and stability of the etching solution, achieving efficient and precise selective etching during the etching process. This not only improves the selective removal ability of specific materials but also enhances the adhesion and surface activity of the etching solution, preventing over-etching and equipment damage. The addition of the inorganic base helps to adjust the pH value of the etching solution, control the reaction rate, thereby optimizing the etching precision and process reliability to meet the precise etching requirements in high-demand semiconductor manufacturing processes.

[0027] Optionally, in addition to sodium chlorite, hydrofluoric acid, bromic acid, phosphoric acid, etc. can be used to replace acetic acid sodium and organic acids. The dosage of acetic acid sodium and organic acids is 6 mL / L - 10 mL / L of the total weight of the etching solution, and the optimal effect is achieved at 0.5 - 6%; in addition to sodium chlorite and oxalate, hydrogen peroxide stabilizers can also be dodecyl alcohol polyoxyethylene ether, octylphenol polyoxyethylene 5 ether, octylphenol polyoxyethylene 5 ether, polyoxyethylene alkylphenol ether, and polyoxyethylene fatty alcohol ether. The dosage of the hydrogen peroxide stabilizer is preferably 0.8 - 8% of the total weight of the etching solution. Organic acids can be acetic acid, phenol, o-cresol, m-cresol, p-cresol, butyric acid, valeric acid, glycine, etc. The dosage of the organic acid is 5% - 10% of the total weight of the etching solution, preferably 0.8 - 5%; the fluorinated alcohol can be replaced by trifluoroethanol, tetrafluoropropanol, octafluoropentanol, etc., and organic acids can be acetic acid, phenol, o-cresol, m-cresol, p-cresol, butyric acid, valeric acid, glycine, etc. The total dosage of the etching additive is 0.3 - 5% of the weight of the etching solution, and the dosage of the etching additive should be greater than 0.4% and less than 3.5%, otherwise it will affect the overall performance of the etching solution. The corrosion inhibitor preferably contains fluorinated carboxylic acids such as perfluorohexanoic acid, perfluoro-2-methyl-3,6,8-trioxanonanoic acid, and perfluoro-2-methyl-3-oxahexanoic acid, and its dosage is also 0.2 - 4% of the weight of the etching solution, optionally 0.1 - 3%.

[0028] By adopting the above technical solutions, the proportions of components such as sodium acetate, organic acid, hydrogen peroxide stabilizer, fluorinated alcohol, and organic acid in the semiconductor etching solution are flexibly adjusted to optimize the stability and selectivity of the etching solution, thereby improving the etching accuracy and controlling the reaction rate. By replacing traditional stabilizers and corrosion inhibitors, such as using sodium chlorite, hydrofluoric acid, bromic acid, etc., the chemical properties of the etching solution can be effectively adjusted, reducing the corrosion of non-target materials and enhancing the selective removal ability during the etching process. Using fluorinated acetic acid-based corrosion inhibitors can further enhance the corrosion resistance of the etching solution, extend the service life of the equipment, and improve the etching accuracy and production efficiency at the same time.

[0029] In summary, the present application includes at least one of the following beneficial technical effects:

[0030] 1. The common method for wet removal of silicon nitride is a hot phosphoric acid solution. 85% concentrated phosphoric acid is mixed with a small amount of water, and the temperature is controlled at 100 - 130 °C. The etching rate of furnace tube silicon nitride is approximately And it will be higher for CVD silicon nitride. The etching rate will be greatly affected, and the actual results should be measured according to different conditions. In order to increase the selectivity ratio for silicon oxide, a silicon wafer with nitrogen is placed, a certain amount of silicon is dissolved, and low-temperature phosphoric acid at 110 - 140 °C is used. The main reaction is between silicon nitride and water, and phosphoric acid only acts as a catalyst in this reaction to prepare the etching solution.

[0031] 2. By optimizing the proportion of each component and adjusting the pH value, the etching solution can achieve precise selective etching, effectively avoiding damage to non-target materials. Especially for the surface treatment requirements of different semiconductor materials, precise removal of different materials can be achieved.

[0032] 3. The new etching solution formula optimizes the synergistic effect between components, improves the reactivity and uniformity of the etching solution, can effectively control the etching rate and precision, avoid over-etching or uneven etching, and improves the etching precision and device quality.

[0033] 4. By using appropriate component ratios, such as adding corrosion inhibitors, stabilizers, etc., the stability of the etching solution is improved, the corrosion risk to equipment and the environment is reduced, and the safety during the operation process is ensured.

[0034] 5. During the etching process, it can reduce material waste, reduce environmental pollution during the production process. At the same time, it optimizes the process, shortens the production cycle, reduces production costs, and meets the requirements of environmental protection and efficient production.

[0035] 6. The components of the etching solution can be adjusted according to different semiconductor materials, providing high adaptability. And during long-term use, the performance stability of the etching solution is strong, reducing the replacement frequency and extending the service life of the equipment.

[0036] 7. This etching solution formula is not only applicable to traditional silicon-based materials, but also can be applied to a wider range of semiconductor material processing fields, especially the etching of some special materials (such as silicon nitride, silicon oxide, etc.), expanding its application scope. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic structural diagram of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] The following will further elaborate on this application Figure 1 in conjunction with the attached drawings.

[0039] The embodiments of this application disclose a new etching solution formula in a semiconductor material etching process. Referring to Figure 1 , a new etching solution formula in a semiconductor material etching process includes sodium chlorite, hydrogen peroxide and pure water, and also includes sodium acetate and organic acid. The pH value of the selective etching solution is 3.0 - 5.5. In the etching solution, the mass concentration of sodium chlorite is 3 g / L - 5 g / L, the mass concentration of ammonium bicarbonate is 10 g / L - 15 g / L, the volume concentration of ammonia water is 6 mL / L - 10 mL / L. The ammonium bicarbonate includes oxalate, organic acid and hydrogen peroxide. Hydrochloric acid accounts for 6% - 15%, hydrogen peroxide accounts for 7% - 14%, and pure water accounts for 5% - 10%.

[0040] Sodium chlorite accounts for 3-8% of the total weight of the selective etching solution, preferably 4-10%, more preferably 5-12%, and most preferably 7%. The volume ratio of the oxidation solution to ammonium bicarbonate is 2:10-5:20.

[0041] The oxalate is oxalic acid, which accounts for 0.2-5.5% of the total weight of the oxalic acid selective etching solution, preferably 0.5-6%, more preferably 0.8-8%, and most preferably 4%. 10 g of pure water, 5 g of ammonium fluoride, 6 g of oxalic acid, 8 g of ammonium sulfate, 40 g of glycerol, and 20 g of barium sulfate account for 0.8-10% of the total weight of the selective etching solution, preferably 0.9-15%, more preferably 1.75-20%, and most preferably 8%.

[0042] The surfactant includes concentrated hydrochloric acid, concentrated nitric acid, glacial acetic acid, hydrofluoric acid, and disodium hydrogen phosphate. The surfactant accounts for 4-9% of the total weight of the selective etching solution, preferably 10-15%. The pH value of the selective etching solution is 7-9, preferably 8.

[0043] The pH value of the semiconductor selective etching solution is 5-10. The semiconductor selective etching solution is composed of a semiconductor oxidation solution and nickel chloride. The semiconductor oxidation solution includes hydrogen peroxide, and the nickel chloride includes ferric trichloride, hydrogen peroxide, and hydrofluoric acid. The fluorinated alcohol in the surfactant component is a mixture of two or more of trifluoroethanol, tetrafluoropropanol, and octafluoropentanol in any proportion.

[0044] Hydrogen peroxide accounts for 8-15% of the total weight of the semiconductor selective etching solution, preferably 15-30%, more preferably 20-25%, and most preferably 24.5%. The volume ratio of the semiconductor oxidation solution to nickel chloride is 1:8-7:1.

[0045] Nitric acid, hydrofluoric acid, bromic acid, phosphoric acid, and sodium chloride. The etching solution accounts for 0.1-3% of the total weight of the semiconductor selective etching solution, preferably 0.2-1.5%, and more preferably 0.5%.

[0046] The common method for wet removal of silicon nitride is a hot phosphoric acid solution. 85% concentrated phosphoric acid is mixed with a small amount of water, and the temperature is controlled at 100-130°C. The etching rate of the furnace tube silicon nitride is approximately And it will be higher for CVD silicon nitride. The etching rate will be greatly affected. The actual results should be measured according to different conditions. In order to increase the selectivity ratio for silicon oxide, silicon wafers doped with nitrogen are put in, a certain amount of silicon is dissolved, and low-temperature phosphoric acid at 110-140°C is used. The main reaction substances are silicon nitride and water, and phosphoric acid only acts as a catalyst in this reaction to prepare the etching solution.

[0047] Sodium chlorite, ammonium bicarbonate, ammonia water. The corrosion inhibitor preferably contains fluorocarboxylic acids such as perfluorohexanoic acid, perfluoro-2-methyl-3,6,8-trioxanonanoic acid, and perfluoro-2-methyl-3-oxahexanoic acid; the corrosion inhibitor accounts for 1-3% of the total weight of the semiconductor selective etching solution, preferably 1.3-2%, more preferably 1.5-4%, and most preferably 2%.

[0048] Ammonium fluoride 20-25%, hydrofluoric acid 2-5%, hydrogen chloride 4-4.5%, surfactant 0.4-0.7%, inorganic base accounts for 0.1-12% of the total weight of the semiconductor selective etching solution, preferably 0.4-8%, more preferably 0.5-5%, and most preferably 3%.

[0049] Example 1

[0050] In addition to sodium chlorite, organic acids such as sodium acetate can also be replaced with hydrofluoric acid, bromic acid, phosphoric acid, etc. The dosage of sodium acetate and organic acids is 6 mL / L - 10 mL / L of the total weight of the etching solution, and the best effect is achieved with 0.5-6%; in addition to sodium chlorite and oxalate, hydrogen peroxide stabilizers can also be dodecyl alcohol polyoxyethylene ether, octylphenol polyoxyethylene 5 ether, octylphenol polyoxyethylene 5 ether, polyoxyethylene alkylphenol ether, and polyoxyethylene fatty alcohol ether. The dosage of the hydrogen peroxide stabilizer is preferably 0.8-8% of the total weight of the etching solution. Organic acids can be acetic acid, phenol, o-methylphenol, m-methylphenol, p-methylphenol, butyric acid, valeric acid, glycine, etc. The dosage of organic acids is 5%-10% of the total weight of the etching solution, and preferably 0.8-5%; fluorinated alcohols can be replaced with trifluoroethanol, tetrafluoropropanol, octafluoropentanol, etc., and organic acids can be acetic acid, phenol, o-methylphenol, m-methylphenol, p-methylphenol, butyric acid, valeric acid, glycine, etc. The total dosage of the etching additive is 0.3-5% of the weight of the etching solution, and the dosage of the etching additive should be greater than 0.4% and less than 3.5%, otherwise it will affect the overall performance of the etching solution. The corrosion inhibitor preferably contains fluorocarboxylic acids such as perfluorohexanoic acid, perfluoro-2-methyl-3,6,8-trioxanonanoic acid, and perfluoro-2-methyl-3-oxahexanoic acid, and its dosage is also 0.2-4% of the weight of the etching solution, and optionally 0.1-3%.

[0052] Example 2

[0053] In addition to sodium chlorite, hydrofluoric acid, bromic acid, phosphoric acid, etc. can be used to replace sodium acetate and organic acids. The dosage of sodium acetate and organic acids is 8 mL / L to 12 mL / L of the total weight of the etching solution, and the optimal effect is achieved with 0.8% to 8%; in addition to sodium chlorite and oxalate, hydrogen peroxide stabilizers can also be dodecyl alcohol polyoxyethylene ether, octylphenol polyoxyethylene 5 ether, octylphenol polyoxyethylene 5 ether, polyoxyethylene alkylphenol ether, and polyoxyethylene fatty alcohol ether. The dosage of the hydrogen peroxide stabilizer is preferably 1% to 10% of the total weight of the etching solution. Organic acids can be acetic acid, phenol, o-cresol, m-cresol, p-cresol, butyric acid, valeric acid, glycine, etc. The dosage of the organic acid is 7% to 12% of the total weight of the etching solution, preferably 1% to 7%; the fluorinated alcohol can be replaced with trifluoroethanol, tetrafluoropropanol, octafluoropentanol, etc., and the organic acid can be acetic acid, phenol, o-cresol, m-cresol, p-cresol, butyric acid, valeric acid, glycine, etc. The total dosage of the etching additive is 0.5% - 7% of the weight of the etching solution, and the dosage of the etching additive should be greater than 0.6% and less than 3.7%, otherwise it will affect the overall performance of the etching solution. The corrosion inhibitor is preferably a fluorinated carboxylic acid such as perfluorohexanoic acid, perfluoro-2-methyl-3,6,8-trioxanonanoic acid, perfluoro-2-methyl-3-oxahexanoic acid, and its dosage is also 0.4% - 6% of the weight of the etching solution, and optionally 0.3% - 5%.

[0054] Example 3

[0055] In addition to sodium chlorite, hydrofluoric acid, bromic acid, phosphoric acid, etc. can be used to replace sodium acetate and organic acids. The dosage of sodium acetate and organic acids is 10 mL / L to 14 mL / L of the total weight of the etching solution, and the optimal effect is achieved with 1% to 10%; in addition to sodium chlorite and oxalate, hydrogen peroxide stabilizers can also be dodecyl alcohol polyoxyethylene ether, octylphenol polyoxyethylene 5 ether, octylphenol polyoxyethylene 5 ether, polyoxyethylene alkylphenol ether, and polyoxyethylene fatty alcohol ether. The dosage of the hydrogen peroxide stabilizer is preferably 2% to 12% of the total weight of the etching solution. Organic acids can be acetic acid, phenol, o-cresol, m-cresol, p-cresol, butyric acid, valeric acid, glycine, etc. The dosage of the organic acid is 9% to 14% of the total weight of the etching solution, preferably 3% to 9%; the fluorinated alcohol can be replaced with trifluoroethanol, tetrafluoropropanol, octafluoropentanol, etc., and the organic acid can be acetic acid, phenol, o-cresol, m-cresol, p-cresol, butyric acid, valeric acid, glycine, etc. The total dosage of the etching additive is 0.7% - 9% of the weight of the etching solution, and the dosage of the etching additive should be greater than 0.8% and less than 3.9%, otherwise it will affect the overall performance of the etching solution. The corrosion inhibitor is preferably a fluorinated carboxylic acid such as perfluorohexanoic acid, perfluoro-2-methyl-3,6,8-trioxanonanoic acid, perfluoro-2-methyl-3-oxahexanoic acid, and its dosage is also 0.6% - 8% of the weight of the etching solution, and optionally 0.5% - 7%.

[0056] Comparative Example 1

[0057] In addition to sodium chlorite, hydrofluoric acid, bromic acid, phosphoric acid, etc. can be used to replace sodium acetate and organic acids. The dosage of sodium acetate and organic acids is 4 mL / L to 8 mL / L of the total weight of the etching solution, and the optimal effect is achieved at 0.3% to 4%. In addition to sodium chlorite and oxalate, hydrogen peroxide stabilizers can also be dodecyl alcohol polyoxyethylene ether, octylphenol polyoxyethylene 5 ether, octylphenol polyoxyethylene 5 ether, polyoxyethylene alkylphenol ether, and polyoxyethylene fatty alcohol ether. The dosage of the hydrogen peroxide stabilizer is preferably 0.6% to 6% of the total weight of the etching solution. Organic acids can be acetic acid, phenol, o-cresol, m-cresol, p-cresol, butyric acid, valeric acid, glycine, etc. The dosage of the organic acid is 3% to 8% of the total weight of the etching solution, preferably 0.6% to 3%. Fluoroalcohols can be replaced by trifluoroethanol, tetrafluoropropanol, octafluoropentanol, etc., and organic acids can be acetic acid, phenol, o-cresol, m-cresol, p-cresol, butyric acid, valeric acid, glycine, etc. The total dosage of the etching additive is 0.1% - 3% of the weight of the etching solution, and the dosage of the etching additive should be greater than 0.2% and less than 3.3%, otherwise it will affect the overall performance of the etching solution. The corrosion inhibitor preferably contains fluoro carboxylic acids such as perfluorohexanoic acid, perfluoro-2-methyl-3,6,8-trioxanonanoic acid, perfluoro-2-methyl-3-oxahexanoic acid, and its dosage is also 0 - 2% of the weight of the etching solution, and the optional value is 1.5%.

[0058] The above are all preferred embodiments of this application, and the protection scope of this application is not limited thereby. Therefore, all equivalent changes made according to the structure, shape, and principle of this application should be covered within the protection scope of this application.

Claims

1. A novel etching solution formula for a semiconductor material etching process, comprising sodium chlorite, hydrogen peroxide and purified water, characterized in that: It also includes sodium acetate and organic acid, the pH value of the selective etching solution is 3.0-5.5, in the etching solution, the mass concentration of the sodium chlorite is 3g / L-5g / L, the mass concentration of the ammonium bicarbonate is 10g / L-15g / L, the volume concentration of the ammonia water is 6mL / L-10mL / L, the ammonium bicarbonate includes the oxalate, the organic acid and hydrogen peroxide, the hydrochloric acid accounts for 6%-15%, the hydrogen peroxide accounts for 7%-14%, and the pure water accounts for 5%-10%.

2. The novel etching solution formulation in a semiconductor material etching process according to claim 1, characterized in that: The sodium chlorite accounts for 3-8% of the total weight of the selective etching solution, preferably 4-10%, more preferably 5-12%, and most preferably 7%. The volume ratio of the oxidizing solution to ammonium hydrogen phosphate is 2:10-5:

20.

3. The novel etching solution formulation in a semiconductor material etching process according to claim 1, characterized in that: The oxalate is oxalic acid, which accounts for 0.2-5.5% of the total weight of the oxalic acid selective etching solution, preferably 0.5-6%, more preferably 0.8-8%, and most preferably 4%; the pure water 10g, ammonium fluoride 5g, oxalic acid 6g, ammonium sulfate 8g, glycerol 40g, and barium sulfate 20g account for 0.8-10% of the total weight of the selective etching solution, preferably 0.9-15%, more preferably 1.75-20%, and most preferably 8%.

4. The novel etching solution formulation in a semiconductor material etching process according to claim 1, characterized in that: The surfactant includes concentrated hydrochloric acid, concentrated nitric acid, glacial acetic acid, hydrofluoric acid, and disodium hydrogen phosphate. The surfactant accounts for 4-9% of the total weight of the selective etching solution, preferably 10-15%. The pH value of the selective etching solution is 7-9, preferably 8%.

5. The novel etching solution formulation in a semiconductor material etching process according to claim 1, characterized in that: The pH value of the semiconductor selective etching solution is 5-10. The semiconductor selective etching solution is composed of a semiconductor oxidation solution and nickel chloride. The semiconductor oxidation solution includes hydrogen peroxide. The nickel chloride includes ferric chloride, hydrogen peroxide, and hydrofluoric acid. The fluorine-containing alcohol in the surfactant component is a mixture of any proportion of two or more of trifluoroethanol, tetrafluoropropanol, and octafluoropentanol.

6. The novel etching solution formulation in a semiconductor material etching process according to claim 1, characterized in that: The hydrogen peroxide accounts for 8-15% of the total weight of the semiconductor selective etching solution, preferably 15-30%, more preferably 20-25%, and most preferably 24.5%; the volume ratio of the semiconductor oxidizing solution to the nickel chloride is 1:8-7:

1.

7. The novel etching solution formulation in a semiconductor material etching process according to claim 1, characterized in that: The nitric acid, hydrofluoric acid, bromic acid, phosphoric acid, and sodium chloride in the etching solution account for 0.1 to 3% of the total weight of the semiconductor selective etching solution, preferably 0.2 to 1.5%, and more preferably 0.5%.

8. The novel etching solution formulation in a semiconductor material etching process according to claim 1, characterized in that: The common method of wet removal of silicon nitride is hot phosphoric acid solution, 85% concentrated phosphoric acid mixed with a small amount of water, the temperature is controlled at 100-130°C, and the etching rate of silicon nitride on furnace tube is about For CVD silicon nitride, the etching rate will be higher and will be greatly affected. The actual results should be measured according to different conditions. In order to improve the selectivity of silicon oxide, a silicon wafer containing nitrogen is placed, a certain amount of silicon is dissolved, and low-temperature phosphoric acid at 110 to 140°C is used. The main bodies of the reaction are silicon nitride and water. Phosphoric acid only acts as a catalyst in this reaction to prepare the etching solution.

9. The novel etching solution formulation in a semiconductor material etching process according to claim 1, characterized in that: The sodium chlorite, ammonium bicarbonate, and ammonia water, the anti-corrosion agent is preferably a fluorinated carboxylic acid such as perfluorohexanoic acid, perfluoro-2-methyl-3,6,8-trioxanoic acid, and perfluoro-2-methyl-3-oxahexanoic acid; the anti-corrosion agent accounts for 1 to 3% of the total weight of the semiconductor selective etching solution, preferably 1.3 to 2%, more preferably 1.5 to 4%, and most preferably 2%.

10. The novel etching solution formulation in a semiconductor material etching process according to claim 1, characterized in that: The ammonium fluoride is 20-25%, the hydrofluoric acid is 2-5%, the hydrogen chloride is 4-4.5%, the surfactant is 0.4-0.7%, and the inorganic base accounts for 0.1-12% of the total weight of the semiconductor selective etching solution, preferably 0.4-8%, more preferably 0.5-5%, and most preferably 3%.

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