Novel diffusion process for TVS (Transient Voltage Suppressor) chip
By using composite treatment liquid and ultrasonic cleaning technology, the problem of poor cleaning effect of silicon wafers is solved, the on-chip yield of TVS chips is improved, and more efficient silicon wafer processing and diffusion processes are achieved.
Patent Information
- Application Number
- CN202411477880.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-22
- Publication Date
- 2024-12-31
AI Technical Summary
During the preparation of TVS chips, the silicon wafer cleaning effect is poor, which affects the on-chip yield of the final product.
The silicon wafer is cleaned using a composite treatment liquid, including surfactant, complexing agent, buffering agent, oxidant, alkali treatment agent and dispersant. Combined with ultrasonic cleaning and drying, an oxide film is formed and photolithography, corrosion and diffusion processes are carried out.
Improve the cleaning effect and on-chip yield of silicon wafers, enhance cleaning through surfactants, remove metal ions through complexing agents, maintain pH stability of buffers, improve oxidation performance by oxidizing agents, adjust pH of alkaline treatment agents and dispersants to prevent dirt deposition , ensuring the quality of the diffusion process.
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of silicon wafer manufacturing, and in particular to a new diffusion process for TVS chips. Background Art
[0002] TVS diode, also known as transient suppression diode, is a new type of highly efficient circuit protection device commonly used. It has extremely fast response time and high surge absorption capacity. It is used in conjunction with components such as resistors and capacitors for transient high voltage suppression protection. When its two ends are subjected to a momentary high energy impact, TVS can change the impedance value between the two ends from high impedance to low impedance at a very high speed to absorb a momentary large current and clamp the voltage at its two ends to a predetermined value, thereby protecting the subsequent circuit components from the impact of transient high voltage spike pulses. TVS is widely used in various types of protective electronic circuits, with broad market prospects and large development space. In the process of TVS chip preparation, it is usually necessary to undergo a diffusion process. Usually, the silicon wafer needs to be cleaned before the diffusion process. The commonly used cleaning method is relatively simple, which sometimes leads to poor cleaning effect on the silicon wafer, thus affecting the final TVS chip product's on-chip yield. Summary of the invention
[0003] In order to improve the cleaning effect of silicon wafers and thus improve the on-chip yield of products, the present application provides a new diffusion process for TVS chips.
[0004] This application provides a new diffusion process for TVS chips, which adopts the following technical solutions: A new diffusion process for TVS chip includes the following steps: Cleaning: soaking the silicon wafer in a composite treatment liquid for treatment, then taking it out for ultrasonic cleaning, and finally drying it to obtain a cleaned silicon wafer; wherein the raw materials of the composite treatment liquid include the following components in parts by weight: 1 to 5 parts of a surfactant, 5 to 10 parts of a complexing agent, 2 to 6 parts of a buffer, 3 to 7 parts of an oxidant, 1 to 3 parts of an alkali treatment agent, 0.5 to 2 parts of a dispersant, and 70 to 80 parts of water; Oxidation: Oxidize the cleaned silicon wafer to form an oxide film; Glue coating: Coat the surface of the oxide film with photoresist, and use photolithography to remove the oxide film in the area where diffusion is required to form a trench area; Etching: Put the trenched silicon wafer into the etching solution to form a shallow trench; Glue removal: Remove the photoresist on the surface of the silicon wafer and clean the silicon substrate; Attach source: Attach diffusion source to the surface of the silicon substrate, diffuse in the shallow trench, and form an outer deep junction layer; De-filming: Remove the oxide film and clean the silicon substrate; Attach source again: Attach diffusion source to the surface area of the silicon substrate, and all areas are diffused to form an inner layer Shallow knot layer, complete diffusion.
[0005] By adopting the above technical scheme, the silicon wafer is immersed in the composite treatment liquid, the surfactant enhances the cleaning effect, the chelating agent removes metal ions, the buffer maintains the pH stability of the solution, the oxidant improves the oxidation cleaning efficiency, the alkaline treatment agent adjusts the pH of the solution, and the dispersant prevents the re-deposition of dirt, and then ultrasonic cleaning is performed, and finally drying is performed, thereby improving the cleaning effect of the silicon wafer, and then the diffusion process is carried out to improve the on-chip yield of the final product.
[0006] In a specific implementation scheme, the cleaning step is: first pre-clean the silicon wafer with anhydrous ethanol, then immerse the silicon wafer in a composite treatment solution for treatment, then take it out for ultrasonic cleaning, and finally dry it to obtain a cleaned silicon wafer.
[0007] By adopting the above technical solution and pre-cleaning the surface of the silicon wafer with anhydrous ethanol, organic pollutants on the surface of the silicon wafer can be effectively removed, thereby improving the subsequent treatment effect.
[0008] In a specific embodiment, in the cleaning step, the silicon wafer is immersed in the composite treatment solution for 5-10 minutes.
[0009] By adopting the above technical solution, the immersion time of the silicon wafer in the composite treatment liquid is further limited, which effectively improves the uniformity and cleaning effect of the silicon wafer surface treatment and avoids surface damage caused by insufficient treatment due to too short immersion time or too long immersion time.
[0010] In a specific embodiment, in the cleaning step, the temperature of ultrasonic cleaning is 30-40°C.
[0011] By adopting the above technical solution, the temperature of ultrasonic cleaning is further limited, which can effectively improve the cleaning efficiency and ensure the cleanliness of the silicon wafer surface, while preventing the silicon wafer from being damaged by excessive temperature.
[0012] In a specific embodiment, the surfactant includes one or more of polyoxyethylene nonylphenol ether, sodium lauryl sulfate, and polyoxyethylene sorbitan monooleate.
[0013] By adopting the above technical scheme, polyoxyethylene nonylphenol ether, sodium dodecyl sulfate, and polyoxyethylene sorbitan monooleate can effectively reduce the interfacial tension between the liquid and the silicon wafer during the cleaning process, improve the wettability of the composite treatment liquid on the surface of the silicon wafer, and synergize with the chelating agent to jointly improve the capture effect of the composite treatment liquid on the pollutants on the surface of the silicon wafer, thereby enhancing the cleaning effect.
[0014] In a specific embodiment, the complexing agent includes one or more of ethylenediaminetetraacetic acid sodium salt, trisodium citrate, and sodium isethionate.
[0015] By adopting the above technical solution, ethylenediaminetetraacetic acid sodium salt has a strong complexing effect and can form a stable complex with a variety of metal ions, thereby improving the cleaning effect.
[0016] In a specific embodiment, the buffer includes one or more of sodium carbonate, sodium dihydrogen phosphate, and sodium acetate.
[0017] In a specific embodiment, the oxidant includes one of hydrogen peroxide, potassium permanganate and sodium hypochlorite.
[0018] By adopting the above technical solution, hydrogen peroxide is a low-carbon and environmentally friendly oxidant, which can oxidize organic pollutants into substances that are easy to remove, and at the same time has a certain oxidizing effect on metal ions, thereby improving the removal effect.
[0019] In a specific embodiment, the alkali treatment agent includes one or more of sodium hydroxide, potassium carbonate, and barium hydroxide.
[0020] In a specific embodiment, the dispersant includes one or more of sodium polyacrylate, sodium polymethacrylate, and polyvinyl alcohol.
[0021] By adopting the above technical solution, sodium polyacrylate, sodium polymethacrylate and polyvinyl alcohol enable the composite treatment liquid to form a uniform dispersion layer on the surface of the silicon wafer, effectively avoiding the aggregation of impurity particles during the treatment process and improving the cleanliness of the silicon wafer surface.
[0022] In summary, the present application includes at least one of the following beneficial technical effects: 1. In the present application, the silicon wafer is immersed in a composite treatment solution, the surfactant enhances the cleaning effect, the complexing agent removes metal ions, the buffer maintains the pH stability of the solution, the oxidant improves the oxidation cleaning efficiency, the alkaline treatment agent adjusts the pH of the solution, and the dispersant prevents the dirt from re-depositing, and then ultrasonic cleaning is performed, and finally drying is performed, thereby improving the cleaning effect of the silicon wafer, and then the diffusion process is performed, thereby improving the intra-chip yield of the final product; 2. In this application, the use of anhydrous ethanol to pre-clean the surface of the silicon wafer can effectively remove organic pollutants on the surface of the silicon wafer and improve the subsequent treatment effect; 3. This application further limits the immersion time of the silicon wafer in the composite treatment solution, which effectively improves the uniformity and cleaning effect of the silicon wafer surface treatment and avoids surface damage caused by insufficient treatment due to too short immersion time or too long immersion time. DETAILED DESCRIPTION
[0023] The present application is further described in detail below with reference to the embodiments.
[0024] All raw materials in the embodiment can be obtained commercially. The surfactant includes but is not limited to a mixture of one or more of polyoxyethylene nonylphenol ether, sodium lauryl sulfate, and polyoxyethylene sorbitan monooleate, and polyoxyethylene nonylphenol ether is preferred in this application; the complexing agent includes but is not limited to a mixture of one or more of ethylenediaminetetraacetic acid sodium salt, trisodium citrate, and sodium isethionate, and is preferably a mixture of ethylenediaminetetraacetic acid sodium salt and trisodium citrate in this application; the buffer includes but is not limited to a mixture of one or more of sodium carbonate, sodium dihydrogen phosphate, and sodium acetate, and is preferably sodium carbonate in this application; the oxidant includes but is not limited to one of hydrogen peroxide, potassium permanganate, and sodium hypochlorite, and is preferably hydrogen peroxide in this application; the alkali treatment agent includes but is not limited to a mixture of one or more of sodium hydroxide, potassium carbonate, and barium hydroxide, and is preferably sodium hydroxide in this application; the dispersant includes but is not limited to a mixture of one or more of sodium polyacrylate, sodium polymethacrylate, and polyvinyl alcohol, and is preferably a mixture of sodium polyacrylate and polyvinyl alcohol in this application.
[0025] Preparation Example Preparation Example 1 Preparation Example 1 provides a method for preparing a composite treatment solution, comprising the following steps: 1kg of surfactant, 5kg of complexing agent, 2kg of buffer, 3kg of oxidant, 1kg of alkali treatment agent and 0.5kg of dispersant are added into 70kg of water, stirred and mixed evenly to obtain a composite treatment liquid; wherein the surfactant is polyoxyethylene nonylphenol ether; the complexing agent is a mixture of sodium salt of ethylenediaminetetraacetic acid and trisodium citrate, and the weight ratio of sodium salt of ethylenediaminetetraacetic acid to trisodium citrate is 1:1; the buffer is sodium carbonate; the oxidant is hydrogen peroxide; the alkali treatment agent is sodium hydroxide; the dispersant is a mixture of sodium polyacrylate and polyvinyl alcohol, and the weight ratio of sodium polyacrylate to polyvinyl alcohol is 2:1.
[0026] Preparation Example 2 Preparation Example 2 provides a method for preparing a composite treatment solution, comprising the following steps: 3kg of surfactant, 7.5kg of complexing agent, 4kg of buffer, 5kg of oxidant, 2kg of alkali treatment agent and 1.2kg of dispersant are added into 75kg of water, stirred and mixed evenly to obtain a composite treatment liquid; wherein the surfactant is polyoxyethylene nonylphenol ether; the complexing agent is a mixture of sodium salt of ethylenediaminetetraacetic acid and trisodium citrate, and the weight ratio of sodium salt of ethylenediaminetetraacetic acid to trisodium citrate is 1:1; the buffer is sodium carbonate; the oxidant is hydrogen peroxide; the alkali treatment agent is sodium hydroxide; the dispersant is a mixture of sodium polyacrylate and polyvinyl alcohol, and the weight ratio of sodium polyacrylate to polyvinyl alcohol is 2:1.
[0027] Preparation Example 3 Preparation Example 3 provides a method for preparing a composite treatment solution, comprising the following steps: 5kg of surfactant, 10kg of complexing agent, 6kg of buffer, 7kg of oxidant, 3kg of alkali treatment agent and 2kg of dispersant are added into 80kg of water, stirred and mixed evenly to obtain a composite treatment liquid; wherein the surfactant is polyoxyethylene nonylphenol ether; the complexing agent is a mixture of sodium salt of ethylenediaminetetraacetic acid and trisodium citrate, and the weight ratio of sodium salt of ethylenediaminetetraacetic acid to trisodium citrate is 1:1; the buffer is sodium carbonate; the oxidant is hydrogen peroxide; the alkali treatment agent is sodium hydroxide; the dispersant is a mixture of sodium polyacrylate and polyvinyl alcohol, and the weight ratio of sodium polyacrylate to polyvinyl alcohol is 2:1.
[0028] Preparation Example 4 The difference between Preparation Example 4 and Preparation Example 2 is that the complexing agent is ethylenediaminetetraacetic acid sodium salt; the remaining steps are consistent with Preparation Example 2.
[0029] Preparation Example 5 The difference between Preparation Example 5 and Preparation Example 2 is that the complexing agent is trisodium citrate; the remaining steps are consistent with Preparation Example 2.
[0030] Preparation Example 6 The difference between Preparation Example 6 and Preparation Example 2 is that the dispersant is sodium polyacrylate; the remaining steps are consistent with Preparation Example 2.
[0031] Preparation Example 7 The difference between Preparation Example 7 and Preparation Example 2 is that the dispersant is polyvinyl alcohol; the remaining steps are consistent with Preparation Example 2. Example
[0032] Example 1 Embodiment 1 provides a novel diffusion process for a TVS chip, comprising the following steps: Cleaning: The silicon wafer was immersed in the composite treatment solution in Preparation Example 1 for 5 minutes, then taken out and ultrasonically cleaned at 30° C., and finally dried with a nitrogen flow to obtain a cleaned silicon wafer; Oxidation: Place the cleaned silicon wafer in a mixture of N2, O2 and water vapor. A silicon dioxide oxide film is formed on the surface; Gluing: photoresist is coated on the surface of the oxide film, and the oxide film in the area where diffusion is required is removed by photolithography to form a trench area; Corrosion: The trenched silicon wafer is placed in a corrosion-resistant basket, and then the basket is placed in a basket filled with corrosion-resistant The etching solution is nitric acid, hydrofluoric acid, glacial acetic acid and pure water in a volume ratio of The solution formed by mixing the two materials in a ratio of 15:7.5:5.5:5.5 was corroded at -5°C for 3 minutes to form a deep Shallow groove with a depth of 10-20um; Degumming: remove the photoresist on the surface of the silicon wafer and clean the silicon substrate; Attaching source: attaching the diffusion source on the surface of the silicon substrate, diffusing it in the shallow groove at 1250℃ for 15 minutes to form 30-50um outer deep junction layer; the diffusion source is a phosphorus liquid source; film removal: remove the oxide film and clean the silicon substrate; re-attach the source: attach the diffusion source to the surface area of the silicon substrate, and all areas are diffused at 1200℃ 3.5h, a 10-20um inner shallow junction layer is formed and diffusion is completed.
[0033] Example 2 The difference between Example 2 and Example 1 is that, in the cleaning step, the silicon wafer is immersed in the composite treatment solution in Preparation Example 2 for treatment for 5 minutes, then taken out and ultrasonically cleaned at 30°C, and finally blown dry with a nitrogen flow to obtain a cleaned silicon wafer; the remaining steps are consistent with Example 1.
[0034] Example 3 The difference between Example 3 and Example 1 is that in the cleaning step, the silicon wafer is immersed in the composite treatment solution in Preparation Example 3 for treatment for 5 minutes, then taken out and ultrasonically cleaned at 30°C, and finally blown dry with a nitrogen flow to obtain a cleaned silicon wafer; the remaining steps are consistent with Example 1.
[0035] Example 4 The difference between Example 4 and Example 1 is that, in the cleaning step, the silicon wafer is immersed in the composite treatment solution in Preparation Example 4 for treatment for 5 minutes, then taken out and ultrasonically cleaned at 30°C, and finally blown dry with a nitrogen flow to obtain a cleaned silicon wafer; the remaining steps are consistent with Example 1.
[0036] Example 5 The difference between Example 5 and Example 1 is that, in the cleaning step, the silicon wafer is immersed in the composite treatment solution in Preparation Example 5 for treatment for 5 minutes, then taken out and ultrasonically cleaned at 30°C, and finally blown dry with a nitrogen flow to obtain a cleaned silicon wafer; the remaining steps are consistent with Example 1.
[0037] Example 6 The difference between Example 6 and Example 1 is that, in the cleaning step, the silicon wafer is immersed in the composite treatment solution in Preparation Example 6 for treatment for 5 minutes, then taken out and ultrasonically cleaned at 30°C, and finally blown dry with a nitrogen flow to obtain a cleaned silicon wafer; the remaining steps are consistent with Example 1.
[0038] Example 7 The difference between Example 7 and Example 1 is that, in the cleaning step, the silicon wafer is immersed in the composite treatment solution in Preparation Example 7 for treatment for 5 minutes, then taken out and ultrasonically cleaned at 30°C, and finally blown dry with a nitrogen flow to obtain a cleaned silicon wafer; the remaining steps are consistent with Example 1.
[0039] Example 8 The difference between Example 8 and Example 2 is that, in cleaning, the silicon wafer is first pre-cleaned with anhydrous ethanol, then the silicon wafer is immersed in the composite treatment solution in Preparation Example 2 for treatment for 5 minutes, then taken out and ultrasonically cleaned at 30°C, and finally blown dry with a nitrogen flow to obtain a cleaned silicon wafer; the remaining steps are consistent with Example 2.
[0040] Example 9 The difference between Example 9 and Example 8 is that, in cleaning, the silicon wafer is first pre-cleaned with anhydrous ethanol, then the silicon wafer is immersed in the composite treatment solution in Preparation Example 2 for treatment for 7.5 minutes, then taken out and ultrasonically cleaned at 30°C, and finally blown dry with a nitrogen flow to obtain a cleaned silicon wafer; the remaining steps are consistent with Example 8.
[0041] Example 10 The difference between Example 10 and Example 8 is that, in cleaning, the silicon wafer is first pre-cleaned with anhydrous ethanol, then the silicon wafer is immersed in the composite treatment solution in Preparation Example 2 for treatment for 10 minutes, then taken out and ultrasonically cleaned at 30°C, and finally blown dry with a nitrogen flow to obtain a cleaned silicon wafer; the remaining steps are consistent with Example 8.
[0042] Embodiment 11 The difference between Example 11 and Example 9 is that, in cleaning, the silicon wafer is first pre-cleaned with anhydrous ethanol, then the silicon wafer is immersed in the composite treatment solution in Preparation Example 2 for treatment for 7.5 minutes, then taken out and ultrasonically cleaned at 35°C, and finally blown dry with a nitrogen flow to obtain a cleaned silicon wafer; the remaining steps are consistent with Example 9.
[0043] Example 12 The difference between Example 12 and Example 9 is that, in cleaning, the silicon wafer is first pre-cleaned with anhydrous ethanol, then the silicon wafer is immersed in the composite treatment solution in Preparation Example 2 for treatment for 7.5 minutes, then taken out and ultrasonically cleaned at 40°C, and finally blown dry with a nitrogen flow to obtain a cleaned silicon wafer; the remaining steps are consistent with Example 9.
[0044] Comparative Example Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that, in cleaning, the silicon wafer is first placed in a 60°C potassium hydroxide solution for treatment for 12 minutes, taken out and ultrasonically cleaned at 40°C; then the silicon wafer is placed in an 80°C nitric acid solution for treatment for 12 minutes, taken out and cleaned with pure water, and finally blown dry with a nitrogen flow to obtain a cleaned silicon wafer; the remaining steps are consistent with Example 1.
[0045] Performance testing On-chip yield; remove the oxide layer formed by diffusion from the silicon wafer after diffusion in each embodiment and comparative example, perform a second photolithography, form an etching area in the center of the shallow groove area, corrode the etching area to form a deep groove, and finally perform passivation, surface metallization, and cutting to form a TVS chip; obtain the on-chip yield of the TVS chip.
[0046] Table 1 Performance test results of TVS chips sample On-chip yield (%) Example 1 97.3 Example 2 97.5 Example 3 97.5 Example 4 97.0 Example 5 96.9 Example 6 96.9 Example 7 96.8 Example 8 97.9 Example 9 98.5 Example 10 98.0 Embodiment 11 99.7 Example 12 99.1 Comparative Example 1 93.1 In combination with Examples 1-3 and Comparative Example 1, the on-wafer yield of the products in Examples 1-3 is relatively high. It can be seen that the composite treatment liquid in the present application is used to clean the silicon wafer, the surfactant in the composite treatment liquid enhances the cleaning effect, the chelating agent removes metal ions, the buffer maintains the pH stability of the solution, the oxidant improves the oxidation cleaning efficiency, the alkaline treatment agent adjusts the pH of the solution, and the dispersant prevents the redeposition of dirt, thereby improving the cleaning effect of the silicon wafer, thereby improving the on-wafer yield of the final product.
[0047] Combining Example 2, Example 4 and Example 5, the product in Example 2 has the highest on-chip yield. It can be seen that when preparing the composite treatment liquid, the complexing agent is preferably a mixture of ethylenediaminetetraacetic acid sodium salt and trisodium citrate, and the cleaning effect of the composite treatment liquid is better.
[0048] Combining Example 2, Example 6 and Example 7, the product in Example 2 has the highest on-chip yield, which shows that when preparing the composite treatment liquid, the dispersant is preferably a mixture of sodium polyacrylate and polyvinyl alcohol, and the cleaning effect of the composite treatment liquid is better.
[0049] Combining Example 2 and Example 8, the on-chip yield of the product in Example 8 is higher. It can be seen that when using the composite processing liquid to clean the silicon wafer, pre-cleaning with anhydrous ethanol first can effectively remove organic pollutants on the surface of the silicon wafer and improve subsequent processing effects, thereby improving the on-chip yield of the final product.
[0050] In combination with Examples 8-10, the product in Example 9 has the highest on-chip yield. It can be seen that when the composite treatment liquid is used to clean the silicon wafer, the immersion time of the silicon wafer in the composite treatment liquid is increased, and the on-chip yield of the final product shows a trend of first increasing and then decreasing.
[0051] Combining Example 9, Example 11 and Example 12, the product in Example 11 has the highest on-chip yield. It can be seen that when the silicon wafer treated with the composite treatment liquid is ultrasonically cleaned, the cleaning temperature is increased, and the on-chip yield of the final product shows a trend of first increasing and then decreasing.
[0052] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.
Claims
1. A new diffusion process for TVS chip, characterized by: The following steps are involved: Cleaning: soaking the silicon wafer in a composite treatment solution for treatment, then taking it out for ultrasonic cleaning, and finally drying it to obtain a cleaned silicon wafer; wherein the raw materials of the composite treatment solution include the following components in parts by weight: 1-5 parts of a surfactant, 5-10 parts of a complexing agent, 2-6 parts of a buffer, 3-7 parts of an oxidant, 1-3 parts of an alkali treatment agent, 0.5-2 parts of a dispersant, and 70-80 parts of water; Oxidation: Oxidize the cleaned silicon wafer to form an oxide film; Gluing: Coat the surface of the oxide film with photoresist, and use photolithography to form the area where diffusion is required. The oxide film is removed to form a trench area; etching: the trenched silicon wafer is placed in the etching solution to form a shallow trench; debonding: the photoresist on the surface of the silicon wafer is removed and the silicon substrate is cleaned; source attachment: the diffusion source is attached to the surface of the silicon substrate and diffused in the shallow trench to form an outer deep junction layer; De-filming: remove the oxide film and clean the silicon substrate; attach the source again: attach the diffusion source to the surface area of the silicon substrate, and all areas are diffused to form the inner layer Shallow knot layer, complete diffusion.
2. A novel diffusion process for TVS chip according to claim 1, characterized in that: The cleaning steps are: firstly pre-cleaning the silicon wafer with anhydrous ethanol, then immersing the silicon wafer in a composite treatment liquid for treatment, then taking it out for ultrasonic cleaning, and finally drying to obtain a cleaned silicon wafer.
3. The novel diffusion process for TVS chip according to claim 2, characterized in that: In the cleaning step, the silicon wafer is immersed in the composite treatment solution for 5-10 minutes.
4. The novel diffusion process for TVS chip according to claim 3, characterized in that: In the cleaning step, the temperature of ultrasonic cleaning is 30-40°C.
5. The novel diffusion process for TVS chip according to claim 1, characterized in that: The surfactant includes one or more of polyoxyethylene nonylphenol ether, sodium lauryl sulfate, and polyoxyethylene sorbitan monooleate.
6. The novel diffusion process for TVS chip according to claim 1, characterized in that: The complexing agent includes one or more of ethylenediaminetetraacetic acid sodium salt, trisodium citrate, and sodium isethionate.
7. The novel diffusion process for TVS chip according to claim 1, characterized in that: The buffer includes one or more of sodium carbonate, sodium dihydrogen phosphate, and sodium acetate.
8. The novel diffusion process for TVS chip according to claim 1, characterized in that: The oxidant includes one of hydrogen peroxide, potassium permanganate and sodium hypochlorite.
9. The novel diffusion process for TVS chip according to claim 1, characterized in that: The alkali treatment agent includes one or more of sodium hydroxide, potassium carbonate and barium hydroxide.
10. A novel diffusion process for TVS chip according to claim 1, characterized in that: The dispersant includes one or more of sodium polyacrylate, sodium polymethacrylate, and polyvinyl alcohol.