Silicon wafer cleaning method

Abstract

The invention provides a silicon wafer cleaning method. The silicon wafer cleaning method comprises the steps that 1, pure water is adopted to carry out first-time pure water cleaning on a silicon wafer; 2, SC-1 solution cleaning and ethanol solution cleaning are sequentially carried out on the silicon wafer, cleaning in the step 2 is circularly carried out for multiple times, and particles on the surface of the silicon wafer can be removed through ethanol solution cleaning; step 3, cleaning the silicon wafer by using a mixed solution of DHF and hydrogen peroxide so as to remove metal on the surface of the silicon wafer; and 4, carrying out secondary pure water cleaning on the silicon wafer by adopting the pure water. According to the method, the dispersibility of particles in the solution is improved by using the additive with lower cost, and a proper amount of hydrogen peroxide is added into the DHF solution, so that the metal removal capability is enhanced, and the removal rate of the particles and metals on the surface of the silicon wafer is improved. Compared with an existing cleaning method, the metal and particle removal rate is improved by about 10%.

Description

Technical Field

[0001] The invention relates to the field of semiconductor technology, and in particular to a silicon wafer cleaning method. Background Art

[0002] In the (111) crystal orientation, the density of silicon atoms is the highest, and each silicon atom forms three covalent bonds with the other three silicon atoms on the same surface, showing a dense atomic arrangement and strong chemical bonding ability. The (111) crystal orientation has a large surface micro-roughness. Due to its atomic structure, these tiny particles are more likely to remain on the surface of the silicon wafer and are more difficult to be cleaned and removed.

[0003] The existing RCA cleaning method uses SC1 solution and SC2 solution, or uses DHF process combined with ultrasonic cleaning process to clean silicon wafers. The principle of using SC1 reagent and SC2 reagent for cleaning is to use the corrosive effect of ammonia in SC-1 solution to slowly dissolve the thin natural oxide layer on the surface of the silicon wafer, and then form a new surface oxide layer through the oxidation of hydrogen peroxide. The regeneration of this oxide layer has a self-cleaning effect, and removing this oxide layer helps to remove particles and metals. The adsorption of particles on the surface of the silicon wafer is the key to affecting the cleaning ability of SC-1 solution, especially for small-size particles. Due to their small size, the surface area per unit mass or unit volume is relatively large, so they have a higher specific surface energy. It makes them more likely to adsorb with other substances (such as metal ions, other particles). This adsorption not only increases the adhesion strength of particles on the surface of the silicon wafer, but also may cause more metals and particles to be retained on the surface of the silicon wafer, thereby increasing the difficulty of cleaning. Summary of the invention

[0004] The present invention provides a silicon wafer cleaning method, which aims to improve the dispersibility of particles in a solution by using a low-cost additive, and to add a proper amount of hydrogen peroxide to a DHF solution to enhance the metal removal ability, so as to improve the removal rate of particles and metals on the surface of the silicon wafer.

[0005] In order to achieve the above purpose and other advantages, the present invention adopts the following technical solutions:

[0006] The present invention provides a silicon wafer cleaning method, which is suitable for cleaning a (111) type silicon wafer after polishing, and comprises the following steps:

[0007] Step 1: Use pure water to clean the silicon wafer for the first time;

[0008] Step 2: Cleaning the silicon wafer with SC-1 solution and ethanol solution in sequence, and performing the cleaning cycle of step 2 multiple times, wherein the ethanol solution cleaning can remove particles on the surface of the silicon wafer;

[0009] Step 3: Use a mixed solution of DHF and hydrogen peroxide to clean the silicon wafer to remove the metal on the surface of the silicon wafer;

[0010] Step 4: Use pure water to clean the silicon wafer for the second time.

[0011] According to the present invention, a silicon wafer cleaning method is provided, wherein the cleaning cycle of step 2 is performed 2 to 4 times.

[0012] According to the present invention, a silicon wafer cleaning method is provided, wherein the ethanol solution is a mixed solution of anhydrous ethanol and pure water;

[0013] The volume ratio of anhydrous ethanol to pure water is 1:1-2;

[0014] The ethanol solution cleaning time is 250 to 300 seconds;

[0015] The cleaning temperature of the ethanol solution is 20-30°C.

[0016] According to the present invention, a silicon wafer cleaning method is provided, wherein the volume ratio of the mixed solution of DHF and hydrogen peroxide is 1:15-25;

[0017] The cleaning time of the mixed solution of DHF and hydrogen peroxide is 250 to 300 seconds;

[0018] The temperature of the mixed solution of DHF and hydrogen peroxide for cleaning is 15-25°C.

[0019] According to the present invention, a silicon wafer cleaning method is provided, wherein the DHF is a mixed solution of hydrofluoric acid and water, and the volume ratio of the hydrofluoric acid to water is 1:100.

[0020] According to the present invention, a silicon wafer cleaning method is provided, wherein the cleaning time of the SC-1 solution is 250 to 300 seconds;

[0021] The cleaning temperature of the SC-1 solution is 68-72°C;

[0022] The SC-1 solution cleaning is performed under ultrasonic conditions.

[0023] According to the present invention, a silicon wafer cleaning method is provided, in which the volume ratio of ammonia water, hydrogen peroxide and pure water in the SC-1 solution is 1:2:10 to 1:2:50.

[0024] According to the present invention, a silicon wafer cleaning method is provided, wherein the first pure water cleaning time is 250 to 300 seconds;

[0025] The temperature of the first pure water washing is 15-25°C.

[0026] According to the present invention, a silicon wafer cleaning method is provided, wherein the second pure water cleaning time is 250 to 300 seconds;

[0027] The temperature of the second pure water washing is 15-25°C.

[0028] According to the present invention, a silicon wafer cleaning method is provided. The cleaned silicon wafer adopts a slow pulling process and is sent to infrared drying to complete the cleaning process of removing particles and metals on the surface of the silicon wafer. The time of the slow pulling process is 4 to 10 minutes, and the temperature during infrared drying is 70°C to 90°C.

[0029] The present invention provides a silicon wafer cleaning method, which uses low-cost additives to improve the dispersibility of particles in the solution, and adds an appropriate amount of hydrogen peroxide to the DHF solution to enhance the metal removal ability, so as to improve the removal rate of particles and metals on the surface of the silicon wafer. Compared with the existing cleaning method, the removal rate of metals and particles is improved by about 10%. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other implementation methods can be obtained based on these drawings without paying any creative work.

[0031] Figure 1 It is a schematic flow chart of a silicon wafer cleaning method provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the following specifically cites a preferred embodiment and describes it in detail with the accompanying drawings as follows.

[0033] It should be noted that it is explicitly and implicitly understood by those of ordinary skill in the art that the embodiments described in the present invention can be combined with other embodiments without conflict. Unless otherwise defined, the technical terms or scientific terms involved in the present invention should be the usual meanings understood by people with ordinary skills in the technical field to which the present invention belongs. The words "one", "a", "a", "the" and the like involved in the present invention do not indicate a quantitative limitation and may represent the singular or plural. The terms "including", "comprising", "having" and any of their variations involved in the present invention are intended to cover non-exclusive inclusions; the terms "first", "second", "third", etc. involved in the present invention are merely to distinguish similar objects and do not represent a specific ordering of objects.

[0034] The applicant has found that reducing the specific surface energy of particles on the surface of silicon wafers can help improve the dispersibility of particles (especially small particles) in the solution and the removal effect of particles. At the same time, HF solution (hydrofluoric acid solution) cleans and removes the natural oxide film on the surface, so the metal attached to the natural oxide film is dissolved in the cleaning solution again, and DHF solution cleaning can suppress the formation of natural oxide film, so the metals such as Al (aluminum), Fe (iron), Zn (zinc), Ni (nickel) on the surface can be easily removed. But as the natural oxide film dissolves into the cleaning solution, a part of precious metals such as Cu (copper) (redox potential is higher than hydrogen) will be attached to the silicon surface, resulting in the difficulty in removing metals such as Cu. Therefore, it is necessary to improve the DHF cleaning process, increase the removal ability of metals such as Cu and improve the overall metal level at the same time. At present, existing technology proves that adding surfactants and chelating agents to traditional RCA solutions can improve the particle removal ability of the system, but the factors such as high cost and large usage limit their large-scale use. Therefore, seeking a low-cost, easily available dispersant is particularly critical to improving the removal ability of particles and metals.

[0035] When it comes to method steps, the sequence illustrated in this document represents an exemplary solution, but does not mean a limitation on the sequence.

[0036] Reference Figure 1 As shown, an embodiment of the present invention provides a silicon wafer cleaning method, which is suitable for cleaning a (111) type silicon wafer after polishing, and includes the following steps:

[0037] Step 1: Use pure water to clean the silicon wafer for the first time;

[0038] Step 2: Clean the silicon wafer with SC-1 solution and ethanol solution in sequence, and perform the cleaning cycle of step 2 multiple times, wherein the ethanol solution cleaning can remove particles on the surface of the silicon wafer;

[0039] Step 3: Use a mixed solution of DHF and hydrogen peroxide to clean the silicon wafer to remove the metal on the surface of the silicon wafer;

[0040] Step 4: Use pure water to clean the silicon wafer for the second time.

[0041] The washing machine has a total of 8 tanks, namely 1 tank pure water tank, 2 tank SC-1 tank, 3 tank pure water tank, 4 tank SC-1 tank, 5 tank pure water tank, 6 tank SC-1 tank, 7 tank pure water tank, 8 tank DHF tank, and 9 tank pure water tank.

[0042] First, the silicon wafer is cleaned with pure water for the first time in tank 1. Its main function is to rinse away the initial impurities, particles and possible residual chemicals on the surface of the silicon wafer, providing a relatively clean starting point for subsequent cleaning steps.

[0043] Preferably, the first pure water cleaning time is 250 to 300 seconds, for example, 250 seconds, 260 seconds, 270 seconds, 280 seconds, 290 seconds or 300 seconds, and preferably 270 seconds.

[0044] The temperature of the first pure water washing is 15 to 25°C. For example, it may be 5°C, 8°C, 20°C, 22°C or 25°C, and is preferably 20°C.

[0045] Secondly, the SC-1 solution cleaning and ethanol solution cleaning can be cycled 2 to 4 times through tanks 2 and 3, for example, 2 times, 3 times or 4 times. Multiple cleanings can reduce the residual pollutants in a single cleaning, improve the overall cleaning quality, and ensure that the cleanliness of the silicon wafer surface meets the requirements of subsequent processes. The cycle cleaning is preferably 3 times, which can better balance the cleaning time and cost and achieve a higher particle removal rate and metal level improvement effect.

[0046] SC-1 solution cleaning is performed through two tanks. SC-1 solution is an alkaline solution composed of hydrogen peroxide (H2O2) and ammonia water (NH4OH) in a certain proportion. Through the strong oxidation of H2O2 and the dissolution of NH4OH, organic contamination is converted into water-soluble compounds and removed with the flushing of deionized water. Since the solution has strong oxidizing and complexing properties, it can oxidize metals such as Cr (chromium), Cu (copper), Zn (zinc), Ag (silver), Ni (nickel), Co (cobalt), Ca (calcium), Fe (iron), Mg (magnesium), and K (potassium) to convert them into high-valent ions, and then further react with alkali to form soluble complexes that are removed with the flushing of deionized water. For this reason, cleaning the polishing sheet with SC-1 solution can remove both organic contamination and certain metal contamination. In this embodiment, the volume ratio of ammonia water, hydrogen peroxide, and pure water in the SC-1 solution is 1:2:10 to 1:2:50.

[0047] After cleaning with SC-1 solution, it enters tank 3 for cleaning. The ethanol solution made of anhydrous ethanol and pure water has the effect of pure water overflow flushing. At this time, the pure water overflow flushing has two functions. One is to flush away the organic matter, particles and metal contamination corroded by the SC-1 solution to prevent secondary adsorption on the surface of the silicon wafer. At the same time, the pure water with a lower temperature can terminate the reaction of the high-temperature SC-1 solution.

[0048] Preferably, the cleaning time of the SC-1 solution is 250 to 300 seconds, for example, 250 seconds, 260 seconds, 270 seconds, 280 seconds, 290 seconds or 300 seconds, etc., preferably 270 seconds.

[0049] Preferably, the cleaning temperature of the SC-1 solution is 68-72°C, for example, 68°C, 69°C, 70°C, 71°C or 72°C.

[0050] Preferably, the SC-1 solution cleaning is carried out under ultrasonic conditions. Under the action of ultrasonic waves, these chemical components can more effectively penetrate into the gap between the particles and the wafer, accelerating the decomposition and removal of the particles, which helps to peel the particles from the wafer surface. In addition, ammonium hydroxide can form soluble complexes with oxidized metal ions, and these complexes are removed with the flushing of deionized water. The addition of ultrasonic waves can accelerate this process and improve the removal efficiency of metal pollutants.

[0051] Preferably, the volume ratio of the SC-1 solution is 1:2:10 to 1:2:50, for example, 1:2:10, 1:2:20, 1:2:30, 1:2:40 or 1:2:50.

[0052] A certain ratio of anhydrous ethanol is added to tank 3 to form an ethanol solution. By adjusting the ratio, the most suitable process conditions are found to achieve the best particle removal effect.

[0053] Ethanol solution: Water molecules have strong polarity and can interact with each other through hydrogen bonds. Therefore, water molecules have a strong affinity for oxides on the surface of silicon wafers. After adding ethanol to water, the polarity of the ethanol solution is significantly lower than that of water. Therefore, particles suspended in the ethanol solution are not easily adsorbed by the oxide layer on the surface of the silicon wafer, thereby improving the dispersibility of the solution.

[0054] Preferably, the volume ratio of anhydrous ethanol to pure water is 1:1-2, for example, 1:1, 1:1.2, 1:1.5, 1:1.7 or 1:2, preferably 1:1.5. The best removal effect can be achieved when the volume ratio of anhydrous ethanol to pure water is 1:1.5.

[0055] Preferably, the cleaning time with the ethanol solution is 250 to 300 s, for example, 250 s, 260 s, 270 s, 280 s, 290 s or 300 s, etc., preferably 270 s.

[0056] Preferably, the cleaning temperature of the ethanol solution is 20-30°C, for example, 20°C, 22°C, 25°C, 28°C or 30°C, etc., preferably 25°C.

[0057] The silicon wafer is then cleaned in tank 8 with a mixed solution of DHF and hydrogen peroxide to remove the metal on the surface of the silicon wafer.

[0058] DHF is a product of further dilution of hydrofluoric acid (HF). The concentration of DHF has an important influence on its etching rate and effect, so its concentration needs to be precisely controlled during use. Usually the volume ratio of hydrofluoric acid to water is set at 1:100. DHF is used to remove the natural oxide film and other contaminants on the surface of silicon wafers to ensure the quality of silicon wafers. Due to its low concentration, DHF has higher controllability and uniformity during the etching process.

[0059] Hydrofluoric acid and hydrogen peroxide can produce a synergistic effect during the silicon wafer cleaning process. While hydrofluoric acid removes the oxide film, hydrogen peroxide can oxidize the metal contaminants on the surface of the silicon wafer and adsorbed on the oxide film. The oxidized metal contaminants then react with hydrofluoric acid to form soluble metal ions or metal complexes. Therefore, this combination makes the removal of metal contaminants more thorough.

[0060] Hydrogen peroxide is added to the DHF solution, and the most suitable process ratio is found by adjusting the ratio to achieve the best metal removal effect. Preferably, the volume ratio of the mixed solution of DHF and hydrogen peroxide is 1:15 to 25, for example, it can be 1:15, 1:18, 1:20, 1:22 or 1:25, preferably 1:20.

[0061] Preferably, the cleaning time of the mixed solution of DHF and hydrogen peroxide is 250 to 300 seconds, for example, 250 seconds, 260 seconds, 270 seconds, 280 seconds, 290 seconds or 300 seconds, and preferably 270 seconds.

[0062] Preferably, the cleaning temperature of the mixed solution of DHF and hydrogen peroxide is 15-20°C, for example, 15°C, 18°C, 20°C, 22°C or 25°C, preferably 20°C.

[0063] Finally, after the cleaning is completed in tank 8, the silicon wafer is usually rinsed with pure water to remove the residual cleaning solution and metal ions. Therefore, the silicon wafer is rinsed with pure water for the second time in tank 9.

[0064] Preferably, the second pure water washing time is 250 to 300 seconds, for example, 250 seconds, 260 seconds, 270 seconds, 280 seconds, 290 seconds or 300 seconds, and preferably 270 seconds.

[0065] The temperature of the second pure water washing is 15 to 25°C. For example, it may be 5°C, 8°C, 20°C, 22°C or 25°C, and is preferably 20°C.

[0066] In addition, pure water cleaning can also be supplemented with other auxiliary means such as ultrasonic cleaning, megasonic cleaning, etc. to improve cleaning quality and efficiency.

[0067] In this embodiment, the cleaned silicon wafer is subjected to a slow pulling process and sent to infrared drying to complete the cleaning process of removing particles and metals on the surface of the silicon wafer. The slow pulling process takes 4 to 10 minutes, and the temperature during infrared drying is 70°C to 90°C.

[0068] By slowly pulling, it is possible to ensure that the cleaning liquid on the surface of the silicon wafer is fully drained, avoid liquid residue or surface contamination caused by rapid movement, and reduce the re-adsorption of surface particles and metals. At the same time, the time of the slow pulling process is set within 4 to 10 minutes, preferably 5 minutes. This helps to ensure that the cleaning liquid on the surface of the silicon wafer is fully drained, while avoiding excessive drying of the silicon wafer surface or new contamination caused by pulling for too long.

[0069] After the slow pulling is completed, the silicon wafer is sent to infrared drying. The silicon wafer is heated by infrared radiation, so that the residual water on the surface of the silicon wafer evaporates quickly to achieve the purpose of drying. At the same time, infrared radiation can also promote the vibration and friction of molecules on the surface of the silicon wafer, further removing surface particles and metals. The temperature during infrared drying is set in the range of 70℃ to 90℃, preferably set to 80℃. This temperature range helps to ensure that the water on the surface of the silicon wafer is fully evaporated, while avoiding excessively high temperatures that damage the surface of the silicon wafer or introduce new contamination.

[0070] The slow pull-up and infrared drying process can effectively reduce secondary contamination on the surface of the silicon wafer and improve the cleaning quality. At the same time, it also helps to maintain the flatness and smoothness of the silicon wafer surface, providing a better foundation for the subsequent processing steps of the silicon wafer.

[0071] Example 1

[0072] The cleaning machine used in this embodiment has a total of 8 tanks, namely, 1 pure water tank, 2 SC-1 tanks, 3 pure water tanks, 4 SC-1 tanks, 5 pure water tanks, 6 SC-1 tanks, 7 pure water tanks, 8 DHF tanks, and 9 pure water tanks. In order to ensure the consistency of the conditions of the comparative experiment, the process conditions of each step are shown in Table 1:

[0073] Table 1

[0074] step time temperature First pure water cleaning 270s-300s 20℃ First SC-1 solution cleaning 270s-300s 70℃ First ethanol solution cleaning 270s-300s 20℃-30℃ Second SC-1 solution cleaning 270s-300s 70℃ Second ethanol solution wash 270s-300s 20℃-30℃ Third SC-1 solution cleaning 270s-300s 70℃ Third ethanol solution wash 270s-300s 20℃-30℃ Hydrofluoric acid + H202 solution cleaning 270s-300s 20℃ Second pure water cleaning 270s-300s 20℃

[0075] Through different DOE (Design of Experiments) process adjustment experiments, the particle removal rate and metal level verification are carried out. The same batch of silicon wafers are experimented under different experimental conditions. The silicon wafers are measured for particles using the SP11 particle measuring machine before and after cleaning. The particle removal rate is obtained by comparing the before and after values. At the same time, the silicon wafers are sampled after cleaning and metal measurements are performed to confirm the metal level.

[0076] After batch comparison experiments, when the volume ratio of ethanol solution is set to 1:1.5 and the volume ratio of DHF and hydrogen peroxide mixed solution is set to 1:20, the particle and metal removal rates are most significantly improved, and the cleaning effect is the best. The metal level and particle level have improved by about 10%. In particular, the decrease in 0.16μm particles, 0.20μm particles, and 0.30μm particles is more obvious, and the particle removal rate has increased by about 10%. The metal contents of Na, Mg, Al, K, Ca, Cr, Fe, Ni, Cu, and Zn are all less than 1E9Atoms / cm 2 , the improvement effect of metal removal is better. The specific cleaning steps are as follows:

[0077] The silicon wafer passes through tank 1 for the first pure water cleaning, with the temperature set to 20°C and the time set to 270s; passes through tank 2 for the first SC-1 solution cleaning, with the temperature set to 70°C and the time set to 270s; passes through tank 3 for the first ethanol solution cleaning, with the temperature set to 25°C and the time set to 270s; passes through tank 4 for the second SC-1 solution cleaning, with the temperature set to 70°C and the time set to 270s; passes through tank 5 for the second ethanol solution cleaning, with the temperature set to 25°C and the time set to 270s; passes through tank 6 for the third SC-1 solution cleaning, with the temperature set to 70°C and the time set to 270s; passes through tank 7 for the third ethanol solution cleaning, with the temperature set to 25°C and the time set to 270s; passes through tank 8 for the mixed solution cleaning of DHF and hydrogen peroxide, with the temperature set to 20°C and the time set to 270s; passes through tank 9 for the second pure water cleaning, with the temperature set to 20°C and the time set to 270s.

[0078] In summary, the silicon wafer cleaning method provided by the embodiment of the present invention uses low-cost additives to improve the dispersibility of particles in the solution, and adds an appropriate amount of hydrogen peroxide to the DHF solution to enhance the metal removal ability, so as to improve the removal rate of particles and metals on the surface of the silicon wafer. Compared with the existing cleaning method, the removal rate of metals and particles is improved by about 10%.

[0079] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily mention changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims, and the above embodiments should be regarded as exemplary and non-restrictive.

Claims

1. A silicon wafer cleaning method, characterized in that: The method is suitable for cleaning (111) type silicon wafers after polishing, and comprises the following steps: Step 1: Use pure water to clean the silicon wafer for the first time; Step 2: Cleaning the silicon wafer with SC-1 solution and ethanol solution in sequence, and performing the cleaning cycle of step 2 multiple times, wherein the ethanol solution cleaning can remove particles on the surface of the silicon wafer; Step 3: Use a mixed solution of DHF and hydrogen peroxide to clean the silicon wafer to remove the metal on the surface of the silicon wafer; Step 4: Use pure water to clean the silicon wafer for the second time.

2. The silicon wafer cleaning method according to claim 1, characterized in that: The cleaning cycle of step 2 is performed 2 to 4 times.

3. The silicon wafer cleaning method according to claim 1 or 2, characterized in that: The ethanol solution is a mixed solution of anhydrous ethanol and pure water; The volume ratio of anhydrous ethanol to pure water is 1:1-2; The ethanol solution cleaning time is 250 to 300 seconds; The cleaning temperature of the ethanol solution is 20-30°C.

4. The silicon wafer cleaning method according to claim 1, characterized in that: The volume ratio of the mixed solution of DHF and hydrogen peroxide is 1:15-25; The cleaning time of the mixed solution of DHF and hydrogen peroxide is 250 to 300 seconds; The temperature of the mixed solution of DHF and hydrogen peroxide for cleaning is 15-25°C.

5. The silicon wafer cleaning method according to claim 4, characterized in that: The DHF is a mixed solution of hydrofluoric acid and water, and the volume ratio of the hydrofluoric acid to water is 1:

100.

6. The silicon wafer cleaning method according to claim 1, characterized in that: The SC-1 solution cleaning time is 250 to 300 seconds; The cleaning temperature of the SC-1 solution is 68-72°C; The SC-1 solution cleaning is performed under ultrasonic conditions.

7. The silicon wafer cleaning method according to claim 1 or 6, characterized in that: In the SC-1 solution, the volume ratio of ammonia water, hydrogen peroxide and pure water is 1:2:10 to 1:2:

50.

8. The silicon wafer cleaning method according to claim 1, characterized in that: The time of the first pure water cleaning is 250 to 300 seconds; The temperature of the first pure water washing is 15-25°C.

9. The silicon wafer cleaning method according to claim 1, characterized in that: The second pure water cleaning time is 250 to 300 seconds; The temperature of the second pure water washing is 15-25°C.

10. The silicon wafer cleaning method according to claim 1, characterized in that: The cleaned silicon wafers are slowly pulled and sent to infrared drying to complete the cleaning process of removing particles and metals on the surface of the silicon wafers. The slow pulling process takes 4 to 10 minutes, and the temperature during infrared drying is 70°C to 90°C.

Images