Method for cleaning monocrystalline silicon wafer

Abstract

The invention relates to the technical field of semiconductor manufacturing, in particular to a cleaning method of a monocrystalline silicon wafer. The invention relates to a cleaning method of a monocrystalline silicon wafer. The cleaning method comprises the following steps: (a) carrying out pretreatment including ultrasonic treatment and dynamic pressure gradient spraying on the monocrystalline silicon wafer by adopting nano bubble water; (b) cleaning the pretreated silicon wafer by using a composite cleaning solution, wherein the composite cleaning solution comprises an APM solution and cellulase; and (c) carrying out post-treatment including plasma treatment and rinsing on the cleaned silicon wafer. Through cooperation of the steps, the residual quantity of metal ions on the surface of the silicon wafer after post-treatment can be effectively reduced, the fragment rate of the silicon wafer is greatly reduced, the cleaning time is shortened, and the energy consumption is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor manufacturing, in particular to a cleaning method of a single crystal silicon wafer. BACKGROUND

[0002] In the manufacturing process of semiconductors, the cleaning of a single crystal silicon wafer is a basic link to ensure the yield of subsequent photolithography, thin film deposition, diffusion and other key processes, and its core goal is to completely and uniformly remove various physical and chemical contaminants remaining on the surface of the silicon wafer during cutting, grinding, polishing and transmission, and to minimize damage to the surface of the silicon wafer. The prior art mainly uses a multi-tank cleaning process, and the entire cleaning process takes about 37-40 minutes, during which the wafer needs to pass through 4-5 agent tanks, 2-3 drying tanks and several intermediate ultrasonic cleaning tanks. The prior art has the following defects: 1) Insufficient cleaning effect: difficult to adapt to the complex distribution of contaminants on the surface of the silicon wafer, resulting in cleaning dead angles.

[0003] 2) Chemical residue risk: conventional cleaning processes rely on strong acids, strong bases or hydrogen peroxide, which can easily cause equipment corrosion and silicon wafer surface oxidation damage.

[0004] 3) High process complexity: multi-tank cleaning steps are complicated, time-consuming and have large fluctuations in pass rates.

[0005] Therefore, the present application is proposed. SUMMARY

[0006] One object of the present application is to provide a cleaning method of a single crystal silicon wafer to solve the technical problems of insufficient cleaning effect, chemical residue and high complexity in the existing silicon wafer cleaning process. The cleaning method of a single crystal silicon wafer can improve the cleaning effect, reduce the risk of surface damage, eliminate chemical residue, shorten the cleaning time and reduce energy consumption.

[0007] In order to achieve the above object of the present application, the following technical solutions are adopted: A cleaning method of a single crystal silicon wafer, comprising the following steps: (a) using nano-bubble water to pretreat the single crystal silicon wafer, including ultrasonic treatment and dynamic pressure gradient spraying.

[0008] (b) using a composite cleaning solution to clean the pretreated silicon wafer, the composite cleaning solution comprising an APM solution and a cellulase.

[0009] (c) performing post-treatment on the cleaned silicon wafer, including plasma treatment and rinsing.

[0010] In some embodiments, the method for preparing the nanobubble water comprises: injecting oxygen and / or nitrogen into deionized water using a gas-liquid mixing pump, and generating nanobubbles through a nanoscale pore size filter; the concentration of the nanobubbles is 10 8 -10 9 bubbles / mL.

[0011] In some embodiments, the temperature of the nanobubble water is 35-50℃.

[0012] In some embodiments, the frequency of the ultrasonic treatment is 28-40 kHz, and the time of the ultrasonic treatment is 5-8 min.

[0013] In some embodiments, the dynamic pressure gradient spraying is performed in sequence of low pressure spraying and high pressure spraying, the pressure of the low pressure spraying is 0.1-0.3 MPa, the time of the low pressure spraying is 5-8 min, the pressure of the high pressure spraying is 0.5-0.8 MPa, and the time of the high pressure spraying is 5-8 min.

[0014] In some embodiments, the mass content of the cellulase in the composite cleaning solution is 0.05%-0.1%.

[0015] In some embodiments, the APM solution comprises NH4OH, H2O2 and H2O, and the mass ratio of the NH4OH, H2O2 and H2O is (0.7-1.3):(0.7-1.3):(4.7-5.3).

[0016] In some embodiments, the temperature of the composite cleaning solution is 55-60℃.

[0017] In some embodiments, the cleaning comprises double-frequency ultrasonic treatment and spraying treatment.

[0018] In some embodiments, the frequency of the double-frequency ultrasonic cleaning is 40 kHz and 80 kHz, and the time of the double-frequency ultrasonic cleaning is 10-15 min.

[0019] In some embodiments, the spraying angle of the spraying treatment is 30 ° ~45 ° .

[0020] In some embodiments, the temperature of the plasma treatment is less than or equal to 100℃, the power of the plasma treatment is 50-100 W, and the time of the plasma treatment is 3-5 min.

[0021] In some embodiments, the rinsing agent used in the rinsing comprises a polyaspartic acid solution, and the pH of the polyaspartic acid solution is neutral.

[0022] In some embodiments, the post-processed silicon wafer has a surface metal ion residual amount less than 180 ppb.

[0023] In some embodiments, the post-processed silicon wafer has a chip rate less than or equal to 0.08%.

[0024] Compared with the prior art, the present application has the following advantages: The cleaning method of the single crystal silicon wafer of the present application, by the nano-bubble water for the pretreatment of the single crystal silicon wafer, wherein the ultrasonic treatment can remove the surface loose particles, and the dynamic pressure gradient spraying can ensure full coverage and improve the cleaning uniformity; the pretreated silicon wafer is cleaned by using the composite cleaning solution, the APM solution and the cellulase are coordinated, the APM decontamination ability is retained, the colloid residue is degraded by the biological enzyme, and the use of strong acid and strong alkali is reduced; the post-treatment can avoid high-temperature drying, and at the same time, the adaptability of the subsequent process of the silicon wafer is enhanced. The present application can effectively reduce the metal ion residual amount on the surface of the post-processed silicon wafer, greatly reduce the chip rate of the silicon wafer, shorten the cleaning time, and reduce the energy consumption. DETAILED DESCRIPTION

[0025] The embodiments of the present application will be described in detail below with reference to the examples, but those skilled in the art will understand that the following examples are only used to illustrate the present application, and should not be regarded as limiting the scope of the present application. The specific conditions are not specified in the examples, and the conventional conditions or the conditions recommended by the manufacturer are used. The reagents or instruments used are not specified by the manufacturer, and are all conventional products that can be obtained by purchase.

[0026] According to one aspect of the present application, the present application relates to a cleaning method of a single crystal silicon wafer, comprising the following steps: (a) using nano-bubble water to pretreat the single crystal silicon wafer, including ultrasonic treatment and dynamic pressure gradient spraying.

[0027] (b) using a composite cleaning solution to clean the pretreated silicon wafer, the composite cleaning solution comprising an APM solution and a cellulase.

[0028] (c) post-treating the cleaned silicon wafer, including plasma treatment and rinsing.

[0029] The cleaning method of the single crystal silicon wafer of the present application, by nano-bubble water pretreatment of the single crystal silicon wafer, wherein the ultrasonic treatment can remove the surface loose particles, and the dynamic pressure gradient spraying can ensure full coverage and improve the cleaning uniformity; the pretreated silicon wafer is cleaned by using a composite cleaning solution, the APM solution and the cellulase are coordinated, the APM decontamination ability is retained, the colloidal residue is degraded by the biological enzyme, and the use of strong acid and strong alkali is reduced; the post-treatment can avoid high-temperature drying, and at the same time, the adaptability of the subsequent process of the silicon wafer is enhanced. The present application can effectively reduce the residual amount of metal ions on the surface of the silicon wafer after post-treatment, greatly reduce the wafer breakage rate, shorten the cleaning time, and reduce the energy consumption.

[0030] In some embodiments, the method for preparing the nano-bubble water comprises: injecting oxygen (O2) and / or nitrogen (N2) into deionized water by using a gas-liquid mixing pump (such as a Venturi tube), and generating stable nano-bubbles through a nano-scale pore size filter film; the concentration of the nano-bubbles is 10 8 ~10 9 bubbles / mL, for example, 10 8 bubbles / mL, 2×10 8 bubbles / mL, 4×10 8 bubbles / mL, 5×10 8 bubbles / mL, 7×10 8 bubbles / mL, etc. The concentration of the nano-bubbles is monitored by an online turbidity meter.

[0031] In some embodiments, the temperature of the nano-bubble water is 35-50℃, for example, 35℃, 40℃, 50℃, etc. The nano-bubble water with a suitable temperature is more conducive to ensuring the pretreatment effect.

[0032] In some embodiments, the frequency of the ultrasonic treatment is 28-40 kHz, for example, 28 kHz, 300 kHz, 35 kHz, 40 kHz, etc. The time of the ultrasonic treatment is 5-8 min, for example, 5 min, 6 min, 7 min, or 8 min, etc. In some embodiments, the ultrasonic treatment is performed by placing the single crystal silicon wafer in a pre-cleaning tank containing nano-bubble water. Through the above-mentioned suitable ultrasonic treatment conditions, the surface loose particles of the silicon wafer can be better removed.

[0033] In some embodiments, the dynamic pressure gradient spraying adopts low-pressure spraying and high-pressure spraying in sequence, the pressure of the low-pressure spraying (initial spraying) is 0.1-0.3 MPa (for example, 0.1 MPa, 0.15 MPa, 0.2 MPa, 0.25 MPa or 0.3 MPa, etc.), the time of the low-pressure spraying is 5-8 min, for example, 5 min, 6 min, 7 min or 8 min, etc.; the pressure of the high-pressure spraying (late pressure) is 0.5-0.8 MPa (for example, 0.5 MPa, 0.55 MPa, 0.6 MPa, 0.7 MPa or 0.8 MPa, etc.), the time of the high-pressure spraying is 5-8 min, for example, 5 min, 6 min, 8 min, etc., the overpressure sensor feeds back and adjusts in real time, and the surface curvature difference area of the silicon wafer is covered. In some embodiments, the dynamic pressure gradient control adopts a spraying system integrated with a servo motor and a proportional valve to realize millisecond-level pressure switching, and the response time of the low-pressure spraying switching to the high-pressure spraying is <50 ms. Path planning algorithm: automatically adjust the spraying track according to the diameter of the silicon wafer (for example, 8 inches or 12 inches) to ensure full coverage.

[0034] In some embodiments, the mass content of the cellulase in the composite cleaning solution is 0.05%-0.1%, for example, 0.05%, 0.06%, 0.08%, 0.09%, 0.1% or the like, and the appropriate content of the cellulase is more conducive to ensuring the cleaning effect of the composite cleaning solution.

[0035] In some embodiments, the APM solution comprises NH4OH, H2O2 and H2O, and the mass ratio of the NH4OH, H2O2 and H2O is (0.7-1.3):(0.7-1.3):(4.7-5.3), for example, 0.7:0.7:4.7, 1:1:5, 1.3:1.3:5.3 or the like.

[0036] In some embodiments, the temperature of the composite cleaning solution is 55-60°C, for example, 55°C, 56°C, 57°C, 58°C, 59°C or 60°C or the like, and the appropriate temperature is conducive to the cleaning effect of the composite cleaning solution.

[0037] In some embodiments, the cleaning comprises double-frequency ultrasonic treatment and spraying treatment. The double-frequency ultrasonic treatment and the spraying treatment cooperate with each other, which is more conducive to ensuring the cleaning effect and reducing the fragment rate.

[0038] In some embodiments, the time of the double-frequency ultrasonic cleaning is 10-15 min, for example, 10 min, 12 min, 13 min, 14 min or 15 min or the like. The frequency of the double-frequency ultrasonic cleaning is 40 kHz and 80 kHz. The appropriate double-frequency ultrasonic cleaning condition is conducive to degrading organic matter and stripping metal ions.

[0039] In some embodiments, the spray angle of the spray treatment is 30 ° ~45 ° , for example 30 ° , 35 ° , 40 ° , 45 ° , etc. The spray treatment employs a spray system integrated with a rotating bevelled nozzle to spray at a bevelled angle of 30 ° ~45 ° to impact the edge of the silicon wafer, thereby reducing the breakage rate.

[0040] In some embodiments, the temperature of the plasma treatment is less than or equal to 100°C, for example 70°C, 80°C, 85°C, 90°C, 100°C, etc. or a range value between any two of them, for example 85~100°C; the power of the plasma treatment is 50~100W, for example 50W, 60W, 70W, 80W or 100W, etc.; the time of the plasma treatment is 3~5min, for example 3min, 4min or 5min, etc. In some embodiments, the plasma treatment is carried out under the condition of inert gas (for example argon). The core role of the above low-temperature plasma activation includes: 1) removal of residual organic matter and surface activation: high-energy particles (such as electrons, ions, radicals) in the plasma decompose trace amounts of organic matter and metal oxides on the surface of the silicon wafer through physical bombardment and chemical reaction, achieving atomic-level cleaning (residual amount <0.01ppb); under the inert gas environment, the plasma treatment can generate hydrophilic hydroxyl (-OH) groups, making the contact angle of the silicon wafer surface from 80° to <10°, significantly improving the adhesion of subsequent processes (such as film plating or bonding). 2) Inhibition of oxidation and protection of materials: the temperature of the low-temperature plasma treatment is controlled at less than 100°C, avoiding the thickening of the silicon wafer surface oxide layer caused by high-temperature drying (traditional process oxide layer thickening 1-2 nm, plasma treatment only increases 0.2-0.5 nm). Through the adjustment of radio frequency energy, the surface roughness and functional group distribution can be controlled, and the adaptability of the material to subsequent processes can be enhanced. Through the above suitable radio frequency plasma treatment conditions, the surface residual organic matter can be better removed and the hydrophilicity can be enhanced.

[0041] In some embodiments, the rinsing agent used in the rinsing includes a polyaspartic acid solution (PASP), and the pH of the polyaspartic acid solution is neutral. The environmentally friendly rinsing agent can reduce the difficulty of chemical waste liquid treatment. The advantages of using polyaspartic acid solution for rinsing include removal of ion residues and scale inhibition. PASP is a non-phosphorus, non-toxic and biodegradable scale inhibitor, which forms stable complexes with calcium, magnesium and other metal ions through chelation, preventing the deposition of water scale (such as CaCO3, CaSO4) on the surface of the silicon wafer. Its dispersion effect can suspend nano-sized particles to avoid secondary pollution, especially suitable for high-hardness and high-alkalinity rinsing environments.

[0042] The cleaning process of the present application improves cleaning uniformity by pressure segment adjustment coupled with dual-frequency ultrasonic waves; while retaining the APM decontamination capability, the process reduces the use of strong acid and strong base by biologically degrading colloidal residues; plasma activation replaces traditional drying, avoiding high-temperature drying while enhancing the suitability of the silicon wafer for subsequent processes; the advantages of the method of the present application over the traditional process include: 1) high efficiency and high cleanliness: the cleaning time is reduced by up to 30%, and the cleanliness is improved to the atomic level. 2) material protection: avoiding surface damage of the silicon wafer (such as lattice stress and micro-cracks) caused by high-temperature drying or strong acid corrosion. 3) cost and sustainability: PASP can be recycled, reducing water consumption; the energy consumption of plasma treatment is only 30% to 50% of that of the traditional process.

[0043] In some embodiments, the surface metal ion residue of the post-processed silicon wafer is less than 180 ppb, such as 0.1 ppb, 0.2 ppb, 0.3 ppb, 0.4 ppb, 0.5 ppb, 1 ppb, 5 ppb, 10 ppb, 30 ppb, 100 ppb, etc.; the cleaning effect is more excellent than that of the traditional process.

[0044] In some embodiments, the chip rate of the post-processed silicon wafer is less than or equal to 0.08%, such as 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%, 0.07%, 0.08%, etc.

[0045] The following specific examples, comparative examples are further explained.

[0046] Example 1 A cleaning method of a single crystal silicon wafer, comprising the following steps: (a) pretreatment A gas-liquid mixing pump is used to inject nitrogen into deionized water, and stable nanobubbles are generated through a nanoscale pore size filter; the concentration of the nanobubbles is 5×10 8 bubbles / mL. The single crystal silicon wafer is treated with nanobubble water including ultrasonic treatment, the temperature of the nanobubble water is 40℃, the frequency of the ultrasonic treatment is 35 kHz, and the time of the ultrasonic treatment is 6 min; then dynamic pressure gradient spraying is performed, the dynamic pressure gradient spraying adopts low-pressure spraying and high-pressure spraying in sequence, the pressure of the low-pressure spraying (initial spraying) is 0.2 MPa, the time is 6 min, the pressure of the high-pressure spraying (later pressure) is 0.6 MPa, the time is 5.5 min, and the response time of the low-pressure spraying switching to the high-pressure spraying is 35 ms.

[0047] (b) main cleaning The pretreated silicon wafer is cleaned by using a composite cleaning solution, the composite cleaning solution comprises APM solution and cellulase, the mass content of cellulase in the composite cleaning solution is 0.08%, the APM solution comprises NH4OH, H2O2 and H2O, the mass ratio of NH4OH, H2O2 and H2O is 1:1:5, and the temperature of the composite cleaning solution is 58 ℃; the cleaning comprises: first, double-frequency ultrasonic treatment, the frequency of the double-frequency ultrasonic cleaning is 40 kHz and 80 kHz, and the time of the double-frequency ultrasonic cleaning is 12 min; and then, spray treatment, the spray angle of the inclined jet nozzle is 40°.

[0048] (c) Post-treatment Under the condition of argon, the silicon wafer is treated by radio frequency plasma for 4 min at a power of 80 W; and then, the silicon wafer is rinsed by using the PASP solution for 3 times.

[0049] Example 2 A cleaning method of a single crystal silicon wafer, comprising the following steps: (a) Pretreatment The nitrogen gas is injected into the deionized water by using a gas-liquid mixing pump, and the stable nanobubbles are generated by using a nanoscale pore size filter membrane; the concentration of the nanobubbles is 7×10 8 bubbles / mL. The single crystal silicon wafer is cleaned by using the nanobubble water, the temperature of the nanobubble water is 45 ℃, the frequency of the ultrasonic treatment is 30 kHz, and the time of the ultrasonic treatment is 7 min; then, the dynamic pressure gradient spray is performed, the dynamic pressure gradient spray adopts low-pressure spray and high-pressure spray which are performed in sequence, the pressure of the low-pressure spray (initial spray) is 0.25 MPa, the time of the low-pressure spray is 7 min, the pressure of the high-pressure spray (later pressure) is 0.65 MPa, the time of the high-pressure spray is 6 min, and the response time of the low-pressure spray switching to the high-pressure spray is 40 ms.

[0050] (b) Main cleaning The pretreated silicon wafer is cleaned by using a composite cleaning solution, the composite cleaning solution comprises APM solution and cellulase, the mass content of cellulase in the composite cleaning solution is 0.065%, the APM solution comprises NH4OH, H2O2 and H2O, the mass ratio of NH4OH, H2O2 and H2O is 1:1:5, and the temperature of the composite cleaning solution is 56 ℃; the cleaning comprises: first, double-frequency ultrasonic treatment, the frequency of the double-frequency ultrasonic cleaning is 40 kHz and 80 kHz, and the time of the double-frequency ultrasonic cleaning is 13 min; and then, spray treatment, the spray angle of the inclined jet nozzle is 35°.

[0051] (c) Post-treatment Under the condition of argon, the silicon wafer is treated by radio frequency plasma for 4.5 min at a power of 85 W; and then, the silicon wafer is rinsed by using the PASP solution for 3 times.

[0052] Example 3 A cleaning method of a single crystal silicon wafer, which is different from example 1 in that: The concentration of the nanobubbles is 10 8 bubbles / mL; the temperature of the nanobubble water is 35℃, the frequency of the ultrasonic treatment is 28 kHz, the time of the ultrasonic treatment is 8 min; the pressure of the low-pressure spraying (initial spraying) is 0.1 MPa, and the pressure of the high-pressure spraying (later pressure) is 0.5 MPa.

[0053] Example 4 A cleaning method of a single crystal silicon wafer, which is different from example 1 in that: The concentration of the nanobubbles is 10 9 bubbles / mL; the temperature of the nanobubble water is 50℃, the frequency of the ultrasonic treatment is 28 kHz, the time of the ultrasonic treatment is 8 min; the pressure of the low-pressure spraying (initial spraying) is 0.3 MPa, and the pressure of the high-pressure spraying (later pressure) is 0.8 MPa.

[0054] Example 5 A cleaning method of a single crystal silicon wafer, which is different from example 1 in that: The mass content of the cellulase in the composite cleaning solution is 0.05%.

[0055] Example 6 A cleaning method of a single crystal silicon wafer, which is different from example 1 in that: The mass content of the cellulase in the composite cleaning solution is 0.1%.

[0056] Example 7 A cleaning method of a single crystal silicon wafer, which is different from example 1 in that: The time of the dual-frequency ultrasonic cleaning is 10 min; the spraying angle of the oblique jet nozzle is 45°.

[0057] Example 8 A cleaning method of a single crystal silicon wafer, which is different from example 1 in that: The time of the dual-frequency ultrasonic cleaning is 15 min; the spraying angle of the oblique jet nozzle is 30°.

[0058] Example 9 A cleaning method of a single crystal silicon wafer, which is different from example 1 in that: The radio frequency plasma treatment is performed for 3 min, and the power is 100 W.

[0059] Experimental example The single crystal silicon wafers treated by the cleaning methods of the examples are subjected to performance tests, including the residual amount of metal ions on the surface of the silicon wafer and the chip rate of the silicon wafer.

[0060] The test of the residual amount of metal ions: refer to GB / T 29849-2013.

[0061] The data of the fragment rate: obtained by using the sorting machine in the industry.

[0062] The test results are shown in Table 1.

[0063] Table 1 Test results

[0064] It can be seen from the above that the cleaning method of the single crystal silicon wafer can effectively reduce the residual amount of metal ions on the surface of the silicon wafer after the post-processing, greatly reduce the fragment rate of the silicon wafer, shorten the cleaning time and reduce the energy consumption by cooperation of the above steps.

[0065] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method of cleaning a single crystal silicon wafer, comprising: The method comprises the following steps: (a) performing pretreatment on a single crystal silicon wafer by using nanobubble water, the pretreatment comprising ultrasonic treatment and dynamic pressure gradient spraying; (b) performing cleaning on the pretreated silicon wafer by using a composite cleaning solution, the composite cleaning solution comprising an APM solution and cellulase; (c) performing post-treatment on the cleaned silicon wafer, the post-treatment comprising plasma treatment and rinsing.

2. The method of cleaning a single crystal silicon wafer according to claim 1, wherein At least one of the following features (1) to (2) is included: (1) The preparation method of the nano bubble water comprises the following steps: injecting oxygen and / or nitrogen into deionized water by using a gas-liquid mixing pump, and generating nano bubbles through a nano-scale pore diameter filter film; the concentration of the nano bubbles is 10 8 -10 9 bubbles / mL; (2) The temperature of the nanobubble water is 35-50℃.

3. The method of claim 1, wherein the single crystal silicon wafer is cleaned by the steps of: The frequency of the ultrasonic treatment is 28-40 kHz, and the time of the ultrasonic treatment is 5-8 min.

4. The method of claim 1, wherein the single crystal silicon wafer is a silicon wafer having a diameter of 200 mm or more. The dynamic pressure gradient spraying is performed in sequence of low-pressure spraying and high-pressure spraying, the pressure of the low-pressure spraying is 0.1-0.3 MPa, the time of the low-pressure spraying is 5-8 min, the pressure of the high-pressure spraying is 0.5-0.8 MPa, and the time of the high-pressure spraying is 5-8 min.

5. The method of claim 1, wherein the single crystal silicon wafer is cleaned by the method. At least one of the following features (1) to (3) is included: (1) In the composite cleaning solution, the mass content of the cellulase is 0.05%-0.1%; (2) The APM solution comprises NH4OH, H2O2 and H2O, and the mass ratio of the NH4OH, H2O2 and H2O is (0.7-1.3):(0.7-1.3):(4.7-5.3); (3) The temperature of the composite cleaning solution is 55-60℃.

6. The method of claim 1, wherein the single crystal silicon wafer is a <100> wafer. The cleaning comprises double-frequency ultrasonic treatment and spraying treatment.

7. The method of claim 6 wherein the step of applying the cleaning solution is performed at a temperature of from about 50°C to about 70°C. At least one of the following features (1) to (2) is included: (1) The frequency of the double-frequency ultrasonic cleaning is 40 kHz and 80 kHz, and the time of the double-frequency ultrasonic cleaning is 10-15 min; (2) the spraying angle of the spraying treatment is 30 ° ~45 ° .

8. The method of claim 1 wherein the single crystal silicon wafer is cleaned by the method of claim 1. The temperature of the plasma treatment is less than or equal to 100℃, the power of the plasma treatment is 50-100 W, and the time of the plasma treatment is 3-5 min.

9. The method of claim 1 wherein the single crystal silicon wafer is cleaned by the method of claim 1. The rinsing agent used in the rinsing comprises a polyaspartic acid solution, and the polyaspartic acid solution has neutral pH.

10. The method of claim 1, wherein the single crystal silicon wafer is a <100> wafer. At least one of the following features (1) to (3) is included: (1) The surface metal ion residual amount of the post-treated silicon wafer is less than 180 ppb; (2) The chip rate of the post-treated silicon wafer is less than or equal to 0.08%.

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