A monocrystalline silicon wafer and a texturing method thereof

Abstract

This application discloses a monocrystalline silicon wafer and its texturing method, relating to the field of photovoltaic technology, for texturing silicon wafers. The method includes cleaning a monocrystalline silicon wafer with a damaged layer on its surface using a cleaning solution to remove the damaged layer and metallic impurities and organic contaminants on the surface of the monocrystalline silicon wafer, obtaining a cleaned monocrystalline silicon wafer. The cleaning solution is a mixture of HF and HCl with O3 flowing through it, where the volume ratio of HF is 2%–10%, the volume ratio of HCl is 0.5%–2%, and the O3 concentration is 20 ppm–60 ppm. The cleaned monocrystalline silicon wafer is then texturized to obtain a texturized monocrystalline silicon wafer. The texturized monocrystalline silicon wafer is then cleaned to remove any residual texturing solution. The texturized monocrystalline silicon wafer is then cleaned again and dried to obtain a texturized monocrystalline silicon wafer. Using a mixture of HF and HCl with O3 flowing through it for cleaning effectively removes metallic impurities, organic contaminants, and the damaged layer from the surface of the monocrystalline silicon wafer, providing good cleaning results without requiring additional damage removal steps.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic technology, and in particular to a single crystal silicon wafer and a texturing method thereof. Background Art

[0002] Texturing is a process in the production of solar cells, which can improve the light trapping effect of silicon wafers, thereby improving the conversion efficiency of solar cells. Since there is some dirt on the surface of silicon wafers, texturing includes two major parts: cleaning and removing dirt and texturing. However, for single-crystal silicon wafers, a mechanical damage layer with a certain thickness is easily formed on the surface during the slicing process. The damage layer on the surface of the single-crystal silicon wafer cannot be removed during texturing. If you want to remove the damage layer, you need to add more process steps. In addition, the current cleaning method uses a mixed solution of alkali and hydrogen peroxide, which can only effectively remove organic dirt, but cannot effectively remove metal impurities.

[0003] Therefore, how to solve the above technical problems should be the focus of technical personnel in this field. Summary of the invention

[0004] The purpose of the present application is to provide a single crystal silicon wafer and a texturing method thereof, so as to remove the damaged layer without adding extra steps during texturing, enhance the cleaning effect and reduce the texturing cost.

[0005] In order to solve the above technical problems, the present application provides a method for texturing a single crystal silicon wafer, comprising:

[0006] A single crystal silicon wafer with a damaged layer on the surface is cleaned with a cleaning liquid to remove the damaged layer and metal impurities and organic dirt on the surface of the single crystal silicon wafer, thereby obtaining a cleaned single crystal silicon wafer; the cleaning liquid is a mixed solution of HF and HCl with O3, wherein the volume ratio of HF is 2% to 10%, the volume ratio of HCl is 0.5% to 2%, and the concentration of O3 is 20ppm to 60ppm;

[0007] Performing texturing on the cleaned single crystal silicon wafer to obtain a texturized single crystal silicon wafer;

[0008] Cleaning the texturing monocrystalline silicon wafer to remove residual texturing liquid;

[0009] The texturized single crystal silicon wafer is cleaned again and dried to obtain a texturized single crystal silicon wafer.

[0010] Optionally, the step of cleaning the texturing monocrystalline silicon wafer to remove residual texturing liquid comprises:

[0011] The texturing single crystal silicon wafer is cleaned with an HCl solution containing O3 to remove residual texturing solution.

[0012] Optionally, in the HCl solution with O3 passed through to remove the residual texturing solution, the volume ratio of HCl is 0.01% to 1%, the concentration of O3 is 20ppm to 60ppm, the cleaning temperature is 20°C to 30°C, and the cleaning time is 50s to 200s.

[0013] Optionally, the step of cleaning the texturing monocrystalline silicon wafer to remove residual texturing liquid comprises:

[0014] The texturing single crystal silicon wafer is cleaned with a mixed solution of NaOH and H2O2 or a mixed solution of KOH and H2O2 to remove residual texturing solution.

[0015] Optionally, in a mixed solution of NaOH and H2O2 for removing residual texturing liquid, the volume ratio of NaOH is 0.5% to 3%, the volume ratio of H2O2 is 1% to 5%, the cleaning temperature is 30℃ to 50℃, and the cleaning time is 50s to 200s; or, in a mixed solution of KOH and H2O2 for removing residual texturing liquid, the volume ratio of KOH is 0.5% to 3%, the volume ratio of H2O2 is 1% to 5%, the cleaning temperature is 30℃ to 50℃, and the cleaning time is 50s to 200s.

[0016] Optionally, the step of cleaning the texturized single crystal silicon wafer again and drying the wafer comprises:

[0017] Using a mixed solution of HF and HCl to clean the textured single crystal silicon wafer, so as to remove metal impurities on the surface of the textured single crystal silicon wafer and make the surface of the textured single crystal silicon wafer hydrophobic, thereby obtaining a cleaned single crystal silicon wafer;

[0018] Placing the cleaned single crystal silicon wafer in a slow pull tank, and pulling the cleaned single crystal silicon wafer out of the slow pull tank; wherein the water temperature in the slow pull tank is 40° C. to 60° C., and the pulling process time is 30s to 60s;

[0019] The single crystal silicon wafer pulled out from the slow pulling tank is dried by circulating hot air.

[0020] Optionally, in the mixed solution of HF and HCl for cleaning the single crystal silicon wafer after texturing, the volume ratio of HCl is 2% to 8%, and the volume ratio of HF is 2% to 8%.

[0021] Optionally, texturing the cleaned single crystal silicon wafer to obtain a texturized single crystal silicon wafer comprises:

[0022] The cleaned single crystal silicon wafer is treated with an alkaline solution containing an auxiliary additive to obtain a textured single crystal silicon wafer with a pyramid velvet surface distributed on the surface, wherein the volume ratio of the auxiliary additive is 0.3% to 1.5%.

[0023] Optionally, the alkaline solution is a NaOH solution or a KOH solution, wherein the volume ratio of NaOH or KOH is between 0.5% and 3%.

[0024] The present application also provides a single crystal silicon wafer, which is obtained by any of the single crystal silicon wafer texturing methods described above.

[0025] The present application provides a method for texturing a single crystal silicon wafer, comprising: using a cleaning liquid to clean a single crystal silicon wafer with a damaged layer on the surface to remove the damaged layer and metal impurities and organic dirt on the surface of the single crystal silicon wafer to obtain a cleaned single crystal silicon wafer; the cleaning liquid is a mixed solution of HF and HCl with O3, the HF volume ratio is 2% to 10%, the HCl volume ratio is 0.5% to 2%, and the O3 concentration is 20ppm to 60ppm; texturing the cleaned single crystal silicon wafer to obtain a texturized single crystal silicon wafer; cleaning the texturized single crystal silicon wafer to remove residual texturizing solution; cleaning the texturized single crystal silicon wafer again and drying it to obtain a texturized single crystal silicon wafer.

[0026] It can be seen that in the method for texturing single crystal silicon wafers in the present application, when cleaning the single crystal silicon wafer before texturing, a mixed solution of HF and HCl with O3 is used to directly clean the single crystal silicon wafer with a damaged layer. The HCl in the mixed solution can react with metal impurities, and the highly oxidizing O3 can effectively oxidize organic dirt on the surface of the single crystal silicon wafer, thereby removing the metal impurities and organic dirt on the surface of the single crystal silicon wafer. At the same time, O3 can also oxidize the surface of the single crystal silicon wafer to form a silicon oxide layer. The HF in the mixed solution reacts with the silicon oxide layer, and the single crystal silicon wafer reaches a dynamic balance of oxidation and cleaning in the cleaning solution. The damaged layer is removed during the dynamic balance process, and then the cleaned single crystal silicon wafer is sequentially texturized, cleaned and dried. In the present application, metal impurities, organic dirt and damaged layer are removed at one time during the cleaning process before texturing, and the cleaning effect is good. No additional damage removal step is required, which simplifies the texturing process. At the same time, O3 is easily decomposed to produce oxygen, which can also reduce the treatment cost of the generated wastewater, thereby saving a lot of texturing costs.

[0027] In addition, the present application also provides a single crystal silicon wafer. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present application or the technical solutions of the prior art, the drawings required for use in the embodiments or the description of the prior art 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 drawings can be obtained based on these drawings without paying any creative work.

[0029] Figure 1 A flow chart of a method for texturing a single crystal silicon wafer provided in an embodiment of the present application. DETAILED DESCRIPTION

[0030] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0031] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0032] As described in the background technology section, texturing includes two major parts: cleaning and decontamination and texturing. For single-crystal silicon wafers, a mechanical damage layer with a certain thickness is easily formed on the surface during the slicing process. The damage layer on the surface of the single-crystal silicon wafer cannot be removed during texturing. If the damage layer needs to be removed, additional process steps are required. Moreover, the mixed solution of alkali and hydrogen peroxide used for cleaning can only effectively remove organic dirt, but cannot effectively remove metal impurities.

[0033] In view of this, the present application provides a method for texturing a single crystal silicon wafer, please refer to Figure 1 ,include:

[0034] Step S101: using a cleaning solution to clean a single crystal silicon wafer having a damaged layer on its surface, so as to remove the damaged layer and metal impurities and organic dirt on the surface of the single crystal silicon wafer, and obtain a cleaned single crystal silicon wafer; the cleaning solution is a mixture of HF and HCl with O3, wherein the volume ratio of HF is 2% to 10%, the volume ratio of HCl is 0.5% to 2%, and the concentration of O3 is 20ppm to 60ppm.

[0035] When removing the damaged layer, the thickness of the single-sided removal of the single crystal silicon wafer is between 0.01μm and 1μm, for example, 0.01μm, 0.05μm, 0.1μm, 0.15μm, 0.25μm, 0.35μm, 0.5μm, 0.6μm, 0.7μm, 0.8μm, 0.9μm, 0.95μm, 1μm, etc.

[0036] Among them, when the cleaning liquid is used to clean a single crystal silicon wafer with a damaged layer on the surface, the cleaning temperature (reaction temperature) is between 20°C and 50°C, for example, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, etc.; the cleaning time (reaction time) is between 50s and 300s, for example, 50s, 80s, 100s, 150s, 170s, 200s, 220s, 270s, 300s, etc.

[0037] It should be pointed out that the present application does not make any specific restrictions on the volume ratio of HF (hydrofluoric acid) and HCl (hydrochloric acid) in the cleaning solution, and the volume ratios can be selected at will. For example, the volume ratio of HF can be 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, etc.; the volume ratio of HCl can be 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2%, etc. Similarly, the present application does not make any specific restrictions on the O3 concentration in the cleaning solution, for example, the O3 concentration can be 20ppm, 21ppm, 25ppm, 30ppm, 35ppm, 40ppm, 45ppm, 49ppm, 50ppm, 55ppm, 60ppm, etc.

[0038] The role of O3 is to remove organic dirt and oxidize the surface of the single crystal silicon wafer to form a silicon oxide layer. The higher the concentration of O3, the stronger the oxidation effect and the faster the silicon oxide layer is produced. The role of HF is to react with silicon oxide. The higher the HF concentration, the faster the silicon oxide layer is removed. The role of HCl is to remove metal impurities on the single crystal silicon wafer. The higher the concentration of HCl, the faster the metal impurities are removed. However, too high a concentration of HCl will cause the solubility of O3 to decrease.

[0039] The metal impurities removed from the single crystal silicon wafer in this step include two parts. One part is the metal impurities remaining on the surface of the single crystal silicon wafer when the metal cutting wire contacts the single crystal silicon wafer during wire cutting to form the single crystal silicon wafer. The other part is the metal impurities formed during the production of single crystal silicon.

[0040] It should be pointed out that after obtaining the cleaned single crystal silicon wafer and before texturing, the cleaned single crystal silicon wafer needs to be cleaned with pure water.

[0041] Step S102: texturing the cleaned single crystal silicon wafer to obtain a texturized single crystal silicon wafer.

[0042] When the cleaned single crystal silicon wafer is textured, the thickness removed on one side is between 1 μm and 4 μm, such as 1 μm, 2 μm, 3 μm, 4 μm, etc.

[0043] Optionally, in one embodiment of the present application, the texturing of the cleaned single crystal silicon wafer to obtain the texturized single crystal silicon wafer includes: treating the cleaned single crystal silicon wafer with an alkaline solution containing an auxiliary additive to obtain a texturized single crystal silicon wafer having a pyramid velvet surface distributed on the surface, wherein the volume ratio of the auxiliary additive is between 0.3% and 1.5%.

[0044] The alkaline solution can be a NaOH solution or a KOH solution, wherein the volume ratio of NaOH or KOH is 0.5% to 3%, for example, the volume ratio of NaOH or KOH can be 0.5%, 0.8%, 1%, 1.2%, 1.5%, 1.8%, 2.0%, 2.3%, 2.5%, 3%, etc.

[0045] Auxiliary additives include but are not limited to reaction control agents, nucleating agents, and degassing agents. By adding auxiliary additives to the alkaline solution, the crystal orientation selectivity of the reaction can be stronger, the texturing process can be more controllable, and the morphology can be more uniform. The volume ratio of the auxiliary additives can be 0.3%, 0.5%, 0.7%, 0.9%, 1.0%, 1.3%, 1.5%, etc.

[0046] When using the above-mentioned alkaline solution for texturing, the reaction temperature is between 70℃ and 100℃, for example, 70℃, 75℃, 80℃, 85℃, 90℃, 95℃, 100℃, etc.; the reaction time is between 250s and 500s, for example, 250s, 300s, 350s, 500s, 450s, 500s, etc.

[0047] The above-mentioned texturing method is not specifically limited in the present application. In other embodiments of the present application, texturing is performed on the cleaned single crystal silicon wafer to obtain the texturing single crystal silicon wafer, which includes: treating the cleaned single crystal silicon wafer with an HF solution to obtain the texturing single crystal silicon wafer, wherein the texture surface of the texturing single crystal silicon wafer is in the shape of wormholes. Of course, other methods such as laser ion etching and reactive ion etching can also be used for texturing.

[0048] It should be pointed out that after the texturing is completed and before step S103 is performed, the texturing single crystal silicon wafer needs to be cleaned with pure water.

[0049] Step S103: cleaning the texturing-treated single crystal silicon wafer to remove residual texturing solution.

[0050] It should be noted that the present application does not limit the cleaning method of the single crystal silicon wafer after texturing, and the method can be selected by the user.

[0051] Optionally, as an implementable method, the texturing single crystal silicon wafer is cleaned with an HCl solution having O 3 therein to remove residual texturing solution.

[0052] In this application, there is no limitation on the content of HCl in the HCl solution with O3 and the concentration of O3 for removing the residual texturing solution, which can be set by oneself. For example, the volume ratio of HCl is 0.01% to 1%, the concentration of O3 is 20ppm to 60ppm, the cleaning temperature is 20℃ to 30℃, and the cleaning time is 50s to 200s. The volume ratio of HCl can be 0.01%, 0.05%, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.85%, 0.9%, 0.95%, 1%, etc.; the concentration of O3 can be 20ppm, 25ppm, 30ppm, 35ppm, 40ppm, 45ppm, 50ppm, 55ppm, 60ppm, etc.; the cleaning temperature can be 20℃, 23℃, 25℃, 27℃, 30℃, etc.; the cleaning time can be 50s, 80s, 100s, 120s, 150s, 200s, etc.

[0053] Optionally, as another possible implementation method, the texturing single crystal silicon wafer is cleaned with a mixed solution of NaOH and H2O2 or a mixed solution of KOH and H2O2 to remove residual texturing solution.

[0054] In this application, the content of NaOH and H2O2 in the mixed solution of NaOH and H2O2 for removing residual texturing liquid is not limited and can be set by oneself. For example, the volume ratio of NaOH is 0.5% to 3%, the volume ratio of H2O2 is 1% to 5%, the cleaning temperature is 30℃ to 50℃, and the cleaning time is 50s to 200s; wherein, the volume ratio of NaOH can be 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, etc., the volume ratio of H2O2 can be 1%, 2%, 3%, 4%, 5%, etc., the cleaning temperature can be 30℃, 35℃, 40℃, 45℃, 50℃, etc., and the cleaning time can be 50s, 80s, 100s, 150s, 180s, 200s, etc.

[0055] Similarly, the content of KOH and H2O2 in the mixed solution of KOH and H2O2 for removing residual texturing liquid is not limited in this application and can be set by oneself. For example, the volume ratio of KOH is 0.5% to 3%, the volume ratio of H2O2 is 1% to 5%, the cleaning temperature is 30℃ to 50℃, and the cleaning time is 50s to 200s; wherein, the volume ratio of KOH can be 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, etc., the volume ratio of H2O2 can be 1%, 2%, 3%, 4%, 5%, etc., the cleaning temperature can be 30℃, 35℃, 40℃, 45℃, 50℃, etc., and the cleaning time can be 50s, 80s, 100s, 150s, 180s, 200s, etc.

[0056] Compared with using a mixed solution of NaOH and H2O2 or a mixed solution of KOH and H2O2 to clean the single crystal silicon wafer after texturing, the method of using an HCl solution with O3 passing through it to clean the single crystal silicon wafer after texturing is less expensive and helps to further reduce the texturing cost.

[0057] It should be pointed out that after removing the residual texturing solution and before performing step S104, the texturing single crystal silicon wafer needs to be cleaned with pure water.

[0058] Step S104: the texturized single crystal silicon wafer is cleaned again and dried to obtain a texturized single crystal silicon wafer.

[0059] Optionally, the step of cleaning the texturized single crystal silicon wafer again and drying the wafer comprises:

[0060] Step S1041: using a mixture of HF and HCl to clean the textured single crystal silicon wafer to remove metal impurities on the surface of the textured single crystal silicon wafer and make the surface of the textured single crystal silicon wafer hydrophobic, thereby obtaining a cleaned single crystal silicon wafer.

[0061] The reaction temperature of pickling in this step is 20°C to 30°C, and the reaction time is 50s to 200s. The volume ratio of HCl (hydrochloric acid) in the HF and HCl mixture is 2% to 8%, and the volume ratio of HF (hydrofluoric acid) is 2% to 8%, wherein the volume ratio of HCl can be 2%, 3%, 4%, 5%, 6%, 7%, 8%, etc., and the volume ratio of HF can be 2%, 3%, 4%, 5%, 6%, 7%, 8%, etc.

[0062] The HF in the mixed liquid in this step can make the surface of the single crystal silicon wafer after texturing hydrophobic, and HCl reacts with the metal impurities on the surface of the single crystal silicon wafer after texturing to remove the metal impurities. The metal impurities in this step are the metal impurities inside the single crystal silicon wafer after texturing that are exposed after the surface damage layer is removed.

[0063] It should be noted that after cleaning with the HF and HCl mixed solution and before performing step S1042, the cleaned single crystal silicon wafer needs to be cleaned again with pure water.

[0064] Step S1042: placing the cleaned single crystal silicon wafer in a slow pulling tank, and pulling the cleaned single crystal silicon wafer out of the slow pulling tank; wherein the water temperature in the slow pulling tank is 40°C to 60°C, and the pulling process time is 30s to 60s.

[0065] The cleaned single crystal silicon wafer is slowly pulled with hot water to slowly dehydrate the surface of the cleaned single crystal silicon wafer, so as to facilitate subsequent drying. The water temperature in the slow pulling tank can be 40°C, 45°C, 50°C, 55°C, 60°C, etc., and the pulling process time can be 30s, 35s, 40s, 45s, 50s, 55s, 60s, etc.

[0066] Step S1043: using circulating hot air to dry the single crystal silicon wafer pulled out from the slow pulling tank.

[0067] The temperature of the circulating hot air is between 80°C and 100°C, and the drying time is between 400s and 700s.

[0068] In the method for texturing single crystal silicon wafers in the present application, when cleaning the single crystal silicon wafer before texturing, a mixed solution of HF and HCl with O3 is used to directly clean the single crystal silicon wafer with a damaged layer. The HCl in the mixed solution can react with metal impurities, and the highly oxidizing O3 can effectively oxidize organic dirt on the surface of the single crystal silicon wafer, thereby removing the metal impurities and organic dirt on the surface of the single crystal silicon wafer. At the same time, O3 can also oxidize the surface of the single crystal silicon wafer to form a silicon oxide layer. The HF in the mixed solution reacts with the silicon oxide layer, and the single crystal silicon wafer reaches a dynamic balance of oxidation and cleaning in the cleaning solution. The damaged layer is removed during the dynamic balance process, and then the cleaned single crystal silicon wafer is sequentially texturized, cleaned and dried. In the present application, metal impurities, organic dirt and damaged layer are removed at one time during the cleaning process before texturing, and the cleaning effect is good. No additional damage removal step is required, which simplifies the texturing process. At the same time, O3 is easily decomposed to produce oxygen, which can also reduce the treatment cost of the generated wastewater, thereby saving a lot of texturing costs.

[0069] The texturing method for a single crystal silicon wafer in the present application is described below using a specific case.

[0070] Step 1, pre-cleaning: Use HF and HCl mixed solution with O3 to clean the single crystal silicon wafer with a damaged layer on the surface, remove a certain thickness (thickness is 0.01μm~1μm) of the damaged layer, remove metal impurities and organic dirt on the surface of the single crystal silicon wafer, wherein the volume ratio of HF is 2%~10%, the volume ratio of HCl is 0.5%~2%, and the concentration of O3 is 20ppm~60ppm;

[0071] Step 2, cleaning the pre-cleaned single crystal silicon wafer with pure water;

[0072] Step 3, texturing: texturing the single crystal silicon wafer in step 2 using a NaOH solution containing an auxiliary additive to form a randomly distributed pyramid texture surface, wherein the thickness removed on a single side is 1 μm to 4 μm;

[0073] Step 4, using pure water to clean the single crystal silicon wafer with the pyramid velvet distributed on the surface;

[0074] Step 5, post-cleaning: using an HCl solution with O3 to clean the single crystal silicon wafer with pyramid velvet on the surface to remove residual auxiliary additives and clean the surface of the single crystal silicon wafer; wherein the volume ratio of HCl is 0.01% to 1%, the concentration of O3 is 20ppm to 60ppm, the cleaning temperature is 20℃ to 30℃, and the cleaning time is 50s to 200s;

[0075] Step 6: Clean the single crystal silicon wafer in step 5 with pure water;

[0076] Step 7, pickling: using a mixture of HF and HCl to clean the surface of the single crystal silicon wafer in step 6 to remove metal impurities, so as to make the surface of the single crystal silicon wafer hydrophobic and easy to dry; wherein the volume ratio of HCl is 2% to 8%, the volume ratio of HF is 2% to 8%, the reaction temperature is 20°C to 30°C, and the reaction time is 50s to 200s;

[0077] Step 8, washing the single crystal silicon wafer in step 7 with pure water;

[0078] Step 9, slow pulling: slow pulling with hot water to dehydrate the surface of the single crystal silicon wafer and facilitate drying, wherein the hot water temperature is 40°C to 60°C;

[0079] Step 10, drying: hot air circulation to dry the surface of the single crystal silicon wafer, wherein the drying temperature is 80°C to 100°C and the drying time is 400s to 700s.

[0080] The present application also provides a single crystal silicon wafer, which is obtained by the single crystal silicon wafer texturing method described in any of the above embodiments.

[0081] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0082] The above is a detailed introduction to the single crystal silicon wafer and its texturing method provided by the present application. This article uses specific examples to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. A method for texturing a single crystal silicon wafer, characterized in that: include: A single crystal silicon wafer with a damaged layer on the surface is cleaned with a cleaning liquid to remove the damaged layer and metal impurities and organic dirt located on the surface of the single crystal silicon wafer to obtain a cleaned single crystal silicon wafer; the cleaning liquid is a mixed solution of HF and HCl with O3, the volume ratio of HF is 2% to 10%, the volume ratio of HCl is 0.5% to 2%, and the concentration of O3 is 20ppm to 60ppm; when removing the damaged layer, the thickness removed from a single side of the single crystal silicon wafer is 0.01μm to 1μm; the cleaning temperature is between 20℃ and 50℃; the cleaning time is 50s to 100s; the metal impurities on the removed single crystal silicon wafer include two parts, one part is the metal impurities remaining on the surface of the single crystal silicon wafer when the metal cutting wire contacts the single crystal silicon wafer when the single crystal silicon wafer is formed by wire cutting, and the other part is the metal impurities formed during the production of single crystal silicon; Performing texturing on the cleaned single crystal silicon wafer to obtain a texturized single crystal silicon wafer; Cleaning the texturing monocrystalline silicon wafer to remove residual texturing liquid; The texturing single crystal silicon wafer is cleaned again and dried to obtain a texturing-completed single crystal silicon wafer; The step of cleaning the texturing monocrystalline silicon wafer to remove residual texturing liquid comprises: The texturing monocrystalline silicon wafer is cleaned with an HCl solution having O3 therein to remove the residual texturing solution; wherein, in the HCl solution having O3 therein for removing the residual texturing solution, the volume ratio of HCl is 0.05% to 1%, the concentration of O3 is 20ppm to 60ppm, the cleaning temperature is 20°C to 30°C, and the cleaning time is 150s to 200s; Alternatively, the step of cleaning the texturing monocrystalline silicon wafer to remove residual texturing liquid comprises: The texturized single crystal silicon wafer is cleaned with a mixed solution of NaOH and H2O2 or a mixed solution of KOH and H2O2 to remove residual texturizing solution; wherein, in the mixed solution of NaOH and H2O2 for removing residual texturizing solution, the volume ratio of NaOH is 0.5%~3%, the volume ratio of H2O2 is 1%~5%, the cleaning temperature is 30℃~50℃, and the cleaning time is 50s~200s; or, in the mixed solution of KOH and H2O2 for removing residual texturizing solution, the volume ratio of KOH is 0.5%~3%, the volume ratio of H2O2 is 1%~5%, the cleaning temperature is 30℃~50℃, and the cleaning time is 50s~200s.

2. The method for texturing a single crystal silicon wafer according to claim 1, characterized in that: The step of cleaning the texturing-treated single crystal silicon wafer again and drying the wafer comprises: Using a mixed solution of HF and HCl to clean the textured single crystal silicon wafer, so as to remove metal impurities on the surface of the textured single crystal silicon wafer and make the surface of the textured single crystal silicon wafer hydrophobic, thereby obtaining a cleaned single crystal silicon wafer; Placing the cleaned single crystal silicon wafer in a slow pull tank, and pulling the cleaned single crystal silicon wafer out of the slow pull tank; wherein the water temperature in the slow pull tank is 40° C. to 60° C., and the pulling process time is 30s to 60s; The single crystal silicon wafer pulled out from the slow pulling tank is dried by circulating hot air.

3. The method for texturing a single crystal silicon wafer according to claim 2, characterized in that: In the HF and HCl mixture used to clean the single crystal silicon wafer after texturing, the volume ratio of HCl is 2%~8%, and the volume ratio of HF is 2%~8%.

4. The method for texturing a single crystal silicon wafer according to any one of claims 1 to 3, characterized in that: The texturing of the cleaned single crystal silicon wafer to obtain the texturized single crystal silicon wafer comprises: The cleaned single crystal silicon wafer is treated with an alkaline solution containing an auxiliary additive to obtain a textured single crystal silicon wafer with a pyramid velvet surface distributed on the surface, wherein the volume ratio of the auxiliary additive is 0.3% to 1.5%.

5. The method for texturing a single crystal silicon wafer according to claim 4, characterized in that: The alkaline solution is a NaOH solution or a KOH solution, wherein the volume ratio of NaOH or KOH is between 0.5% and 3%.

6. A single crystal silicon wafer, characterized in that: The single crystal silicon wafer is obtained by the single crystal silicon wafer texturing method as described in any one of claims 1 to 5.

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