Single-side texturing method for monocrystalline silicon wafer

Abstract

The invention belongs to the field of monocrystalline silicon wafer texturing, and particularly relates to a monocrystalline silicon wafer single-side texturing method, which comprises the following steps of: sequentially carrying out cleaning pretreatment and alkali polishing on a monocrystalline silicon wafer; putting the monocrystalline silicon wafer into the hollow groove of the carrier plate; and feeding the monocrystalline silicon wafer into the first spraying chamber at a uniform speed through the carrier plate, and corroding the front surface of the monocrystalline silicon wafer in a manner of spraying the texturing liquid through the automatic spraying device to obtain the single-surface textured monocrystalline silicon wafer. Only the front surface of the monocrystalline silicon wafer is textured, the process is simple, and high-temperature equipment is not needed; the texturing process is carried out on the carrier plate, so that the fragment rate can be obviously reduced; the polishing and etching thickness of the monocrystalline silicon wafer is reduced, the silicon material loss is reduced, the cost is reduced, and meanwhile, the finished monocrystalline silicon wafer is thinned, so that the possibility is provided for flexible cells and assemblies; and the texturing reaction is not carried out on the back surface, so that a pyramid-shaped textured surface is not formed, and the efficiency of the final battery piece is improved.

Description

Technical Field

[0001] The invention belongs to the field of texturing of single crystal silicon wafers, and in particular relates to a single-side texturing method of a single crystal silicon wafer. Background Art

[0002] Traditional heterojunction cells (HJT) use double-sided texturing with symmetrical front and back structures. The double-sided rate of HJT can reach more than 90% (up to 98%), but the symmetrical texture structure will lead to higher interface recombination, which has an adverse effect on the passivation of the silicon substrate. HJT with single-sided texturing (front texturing, back polishing) solves this problem better. The back polishing significantly improves the passivation effect of the silicon substrate compared to the back texturing. The front surface is a pyramid-shaped texture surface to reduce the reflection of the incident light. The back polishing has a high reflectivity. The long-wave light source passing through the monocrystalline silicon wafer can be reflected on the back of the monocrystalline silicon wafer and then absorbed by the silicon substrate again, which can significantly increase the short-circuit current of the battery and increase the open-circuit voltage of the battery.

[0003] The existing single-sided texturing process of monocrystalline silicon wafers is to first use metal ion catalysis to wet-texture the monocrystalline silicon wafers on both sides, then use a diffusion furnace to oxidize both sides, then use a chain device to remove the film on the back side of the single-sided film, and finally polish the back side of the monocrystalline silicon wafer with the back film removed, so as to obtain a single-sided texturing monocrystalline silicon wafer with the front side texturized and the back side polished. On the one hand, this process route requires the addition of high-temperature diffusion equipment and chain cleaning equipment to the existing heterojunction battery production line. The process route is long and the process flow is complicated. It has certain requirements for floor space, electricity, exhaust, and sewage discharge, and requires high cost investment. On the other hand, when using wet double-sided texturing, both sides of the monocrystalline silicon wafer are corroded, resulting in an increase in the amount of corrosion of the monocrystalline silicon wafer, a decrease in the thickness of the monocrystalline silicon wafer, and a decrease in the mechanical properties of the monocrystalline silicon wafer. In addition, high-temperature equipment also increases the probability of fragmentation, resulting in an increase in the fragmentation rate. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a method for single-sided texturing of a monocrystalline silicon wafer. The single-sided texturing method of a monocrystalline silicon wafer provided by the present invention has a simple process, does not require high-temperature equipment, can significantly reduce the fragmentation rate and improve the single-sided texturing yield.

[0005] The invention provides a method for texturing a single surface of a monocrystalline silicon wafer.

[0006] Specifically, a method for texturing a single side of a monocrystalline silicon wafer comprises the following steps: The single crystal silicon wafer is sequentially subjected to cleaning pretreatment and alkali polishing to obtain a double-sided polished single crystal silicon wafer; Putting a plurality of the double-sided polished single crystal silicon wafers into the hollow grooves of the carrier plate; The carrier plate on which the double-sided polished single-crystalline silicon wafer is placed is sent into the first spray chamber of an automatic spray device and is moved and transported at a first speed, and the front side of the double-sided polished single-crystalline silicon wafer is corroded by spraying a texturing liquid to obtain a single-sided texturing single-crystalline silicon wafer with a pyramid texturing surface formed on the front side; wherein the texturing liquid comprises a second alkali liquid, a texturing additive and deionized water, the volume proportions of the second alkali liquid and the texturing additive in the texturing liquid are 1-3% and 2-4% respectively, the temperature of the texturing liquid is 75-85°C, the spraying time is 4-8min, and the bottom width of the pyramid texturing surface is 2-3 microns; The single-sided textured single crystal silicon wafer is sent into the second spray chamber of the automatic spray device through a carrier plate for spray cleaning, and the carrier plate is moved and transported at a second speed in the second spray chamber; The cleaned single-sided textured single crystal silicon wafer is sent into the drying chamber of the automatic spraying device for drying through a carrier plate, and the carrier plate is moved and transported at a third speed in the drying chamber; Take out the dried single-sided textured single crystal silicon wafer.

[0007] According to some embodiments of the present invention, the second spray chamber comprises an alkaline cleaning liquid spraying area, an acid liquid spraying area and a deionized water spraying area in sequence; wherein the alkaline cleaning liquid is an alkaline hydrogen peroxide solution, and the acid liquid is an aqueous solution of hydrofluoric acid.

[0008] According to some embodiments of the present invention, the alkaline hydrogen peroxide solution is composed of a third alkali solution and a hydrogen peroxide solution mixed in a volume ratio of 1:10, the third alkali solution includes any one of a potassium hydroxide standard solution with a concentration of 48% by mass and a sodium hydroxide standard solution with a concentration of 45% by mass, the hydrogen peroxide solution is a hydrogen peroxide standard solution with a concentration of 31% by mass, and the hydrofluoric acid aqueous solution is composed of a hydrofluoric acid standard solution with a concentration of 49% by mass and deionized water mixed in a volume ratio of 1:9; first, the alkaline hydrogen peroxide solution can be used to remove molecular impurities, and then the acid solution can be used to remove ionic impurities and silicon dioxide, and finally the residual alkaline hydrogen peroxide, acid solution and other impurities can be removed by deionized water to achieve the purpose of thorough cleaning.

[0009] According to some embodiments of the present invention, the drying gas in the drying chamber uses industrial grade nitrogen GN2, the drying temperature is 75-85° C., and the drying time is 8-16 min.

[0010] According to some embodiments of the present invention, the specific steps of sequentially performing cleaning pretreatment and alkali polishing on the single crystal silicon wafer to obtain a double-sided polished single crystal silicon wafer include: The monocrystalline silicon wafer is immersed in a room temperature acidic cleaning solution in a cleaning tank for cleaning pretreatment, and the cleaning pretreatment time is 5-10 minutes. The acidic cleaning solution includes a mixed solution of hydrofluoric acid and hydrochloric acid; the mixed solution of hydrofluoric acid and hydrochloric acid is conducive to removing impurities such as heavy metals on the surface of the silicon wafer, and preventing impurities from adhering to the surface of the silicon wafer, which makes it difficult to perform operations such as polishing and texturing on the silicon wafer; preferably, after the monocrystalline silicon wafer is cleaned pretreatment, it can also be placed in deionized water for bubbling cleaning, and the cleaning time is 1-5 minutes. After cleaning, replace with new deionized water, and clean 1-3 times, which is conducive to removing unreacted hydrofluoric acid and hydrochloric acid on the surface of the monocrystalline silicon wafer, as well as other impurities, to avoid affecting subsequent processes; Immersing the cleaned and pre-treated single crystal silicon wafer in a first alkali solution in an alkali polishing tank for alkali polishing, wherein the first alkali solution is an aqueous solution of potassium hydroxide or sodium hydroxide, and the reaction temperature of the alkali polishing is 70-80° C. and the time is 1-3 minutes; the corrosion effect of the first alkali solution can remove the damaged surface of the single crystal silicon wafer, thereby improving the flatness of the surface of the single crystal silicon wafer; A double-sided polished single-crystal silicon wafer is obtained, with the front and back sides etched to a thickness of 2-2.5 microns.

[0011] According to some embodiments of the present invention, the double-sided polished single-crystal silicon wafer loses 0.2-0.3g in weight; on the one hand, the etching thickness required for polishing the silicon wafer is small, which reduces the loss of silicon material and thus reduces the cost; on the other hand, the finished silicon wafer is thinned, and the thin silicon wafer has good flexibility, providing the possibility for flexible batteries and components.

[0012] According to some embodiments of the present invention, the first speed, the second speed and the third speed are the same, which are 1-5 m / min.

[0013] According to some embodiments of the present invention, the second alkali solution includes any one of a potassium hydroxide standard solution with a concentration of 48% by mass and a sodium hydroxide standard solution with a concentration of 45% by mass.

[0014] According to some embodiments of the present invention, the carrier includes a plurality of loading units, each of which is provided with a hollow groove, and the inner side of the hollow groove is provided with a hook suitable for carrying the single crystal silicon wafer; through the solution of carrying the single crystal silicon wafer by the carrier provided with the hollow groove, on the one hand, the single crystal silicon wafer is not easy to slide, thus avoiding the spraying and stamping to move the silicon wafer, without the risk of wafer falling, and reducing the fragmentation rate; at the same time, compared with the conventional direct placement on the roller for transmission, the carrier carrying and transmission avoids the generation of roller marks, thereby improving the yield of the single crystal silicon wafer; on the other hand, through the design of the hollow groove, the texturing liquid sprayed onto the front of the single crystal silicon wafer by the automatic spraying device can flow back from the edge of the single crystal silicon wafer through the hollow groove to the groove below the first spray chamber, and return to the automatic spraying device through the circulation recovery device for reuse; the recovery and reuse of the texturing liquid reduces the consumption of the texturing liquid, which is conducive to cost reduction.

[0015] According to some embodiments of the present invention, a first manipulator is provided at the entrance of the first spray chamber of the automatic spray device, and a second manipulator is provided at the exit of the drying chamber of the automatic spray device. The double-sided polished single-crystalline silicon wafer is placed on the carrier by the first manipulator, and the dried single-sided textured single-crystalline silicon wafer is taken out by the second manipulator.

[0016] Compared with the prior art, the present invention has the following beneficial effects: (1) The process is simple and does not require high-temperature equipment, thus avoiding the risk of single-crystal silicon wafers being broken due to high temperature. This can significantly reduce the fragmentation rate and improve the yield of single-crystal silicon wafers. In addition, texturing, cleaning, and drying are all automatically completed in the texturing device, which can save equipment floor space, electricity, exhaust, sewage, manpower, and other costs. (2) After double-sided polishing, single-sided texturing is performed. Only one side of the monocrystalline silicon wafer participates in the texturing reaction. The etching thickness required for polishing the monocrystalline silicon wafer is small, which reduces the loss of silicon material and thus reduces the cost. At the same time, the finished monocrystalline silicon wafer is thinned, and the thin monocrystalline silicon wafer has good flexibility, which provides the possibility for flexible batteries and components. Moreover, there is no texturing reaction on the back side, and no pyramid-shaped texturing is formed. Compared with the conventional texturing monocrystalline silicon wafer (double-sided texturing first, then back polishing), the back surface of the monocrystalline silicon wafer is smoother. The flatness of the back surface of the monocrystalline silicon wafer is significantly improved, which is beneficial to improve the final efficiency of the battery cell. (3) Using a hollow carrier plate to carry single-crystal silicon wafers can not only reduce the fragmentation rate and improve the silicon wafer yield, but also prevent the single-crystal silicon wafers from sliding, thus avoiding the movement of the silicon wafers by spraying and punching. Compared with conventional roller transmission, the carrier plate can avoid the generation of roller marks, further improving the single-crystal silicon wafer yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which: Figure 1 The present invention is a flowchart of a method for texturing a single side of a monocrystalline silicon wafer according to an embodiment of the present invention. DETAILED DESCRIPTION

[0018] In order to make the purpose and technical solution of the present invention clearer and easier to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. The specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0019] Unless otherwise specified, the raw materials, reagents or devices in the following examples can be obtained from conventional commercial sources or by existing known methods.

[0020] See also Figure 1 , describing a single-sided texturing method for a single-crystal silicon wafer according to an embodiment of the present invention.

[0021] A method for texturing a single side of a monocrystalline silicon wafer according to an embodiment of the present invention comprises the following steps: S01, sequentially performing cleaning pretreatment and alkali polishing on a single crystal silicon wafer to obtain a double-sided polished silicon wafer; It should be noted that the cleaning pretreatment and alkali polishing are carried out in the cleaning tank and the alkali polishing tank respectively. The cleaning tank contains a room temperature acidic cleaning solution, and the alkali polishing tank contains a first alkali solution. Specifically, the single crystal silicon wafers can be evenly inserted into the flower basket first, and then the single crystal silicon wafers in the flower basket are immersed in the acidic cleaning solution in the cleaning tank for cleaning pretreatment, and then the single crystal silicon wafers in the flower basket after cleaning pretreatment are immersed in the first alkali solution in the alkali polishing tank for alkali polishing to obtain double-sided polished single crystal silicon wafers.

[0022] S02, placing a plurality of the double-sided polished single crystal silicon wafers into the hollow grooves of the carrier plate; It should be noted that taking the double-sided polished single-crystalline silicon wafer out of the flower basket and placing it into the hollow groove of the carrier can be automatically completed by the robot arm of the automatic spraying device; each carrier is provided with a number of hollow grooves, each of which can hold a single-sided polished single-crystalline silicon wafer separately, and multiple double-sided polished single-crystalline silicon wafers can be processed at the same time through the carrier, thereby improving the efficiency of texturing; and using the solution of using the carrier to carry the single-crystalline silicon wafer, the single-crystalline silicon wafer is not easy to slide, there is no risk of falling wafers, the fragmentation rate is low, and the yield is high.

[0023] S03, sending the carrier plate with the double-sided polished single-crystalline silicon wafer placed thereon into the first spray chamber of an automatic spray device and moving it at a first speed, anisotropically etching the front side of the double-sided polished single-crystalline silicon wafer by spraying a texturing liquid, and obtaining a single-sided texturing single-crystalline silicon wafer with a pyramid texturing surface formed on the front side; wherein the texturing liquid comprises a second alkali liquid, a texturing additive and deionized water, the volume proportions of the second alkali liquid and the texturing additive in the texturing liquid are 1-3% and 2-4% respectively, the temperature of the texturing liquid is 75-85°C, the spraying time is 4-8min, and the bottom width of the pyramid texturing surface of the single-sided texturing single-crystalline silicon wafer is 2-3 microns; Specifically, the texturing additive is any one of V01 of Shichuang Energy TS53 series or H03-H06D of Xiaochen Technology H series; It should be noted that the first spray chamber is located above the transmission carrier and is provided with a spray head, and a trough body is located below the transmission carrier. The sprayed texturing liquid only contacts the front side of the double-sided polished single-crystalline silicon wafer, and the texturing liquid flows back from the edge of the double-sided polished single-crystalline silicon wafer through the hollow groove of the carrier to the lower trough body, and returns to the automatic spraying device through the circulation recovery device for reuse. The texturing liquid reacts with the single-crystalline silicon wafer on the front side of the double-sided polished single-crystalline silicon wafer, and utilizes the principle of anisotropic corrosion to form a pyramid-shaped velvet surface on the front side of the single-crystalline silicon wafer.

[0024] S04, sending the single-sided textured single crystal silicon wafer into the second spray chamber of the automatic spray device through a carrier plate for spray cleaning, and the carrier plate is moved and transported at a second speed in the second spray chamber; S05, sending the cleaned single-sided textured single crystal silicon wafer into the drying chamber of the automatic spraying device for drying through a carrier, wherein the carrier moves and transports at a third speed in the drying chamber; S06, taking out the dried single-sided textured single crystal silicon wafer; It should be noted that the dried single-sided textured single-crystalline silicon wafer can be taken out from the carrier and stored in the flower basket by the robot of the automatic spraying device.

[0025] The entire process from step S02 to step S06 is automatically performed by an automatic spraying device, with a simple procedure, a short process flow, less equipment, and a low fragmentation rate.

[0026] In some specific embodiments of the present invention, the texturing additive is any one of V01 of Shichuang Energy TS53 series or H03-H06D of Xiaochen Technology H series.

[0027] In some specific embodiments of the present invention, the second spray chamber comprises an alkaline cleaning liquid spraying area, an acid liquid spraying area and a deionized water spraying area in sequence; wherein the alkaline cleaning liquid is an alkaline hydrogen peroxide solution, and the acid liquid is an aqueous solution of hydrofluoric acid; Specifically, the alkaline hydrogen peroxide solution is composed of a third alkali solution and a hydrogen peroxide solution mixed in a volume ratio of 1:10, the third alkali solution is any one of a potassium hydroxide standard solution with a concentration of 48% by mass and a sodium hydroxide standard solution with a concentration of 45% by mass, the hydrogen peroxide solution is a hydrogen peroxide standard solution with a concentration of 31% by mass, and the hydrofluoric acid aqueous solution is composed of a hydrofluoric acid standard solution with a concentration of 49% by mass and deionized water mixed in a volume ratio of 1:9.

[0028] The single-sided texturing monocrystalline silicon wafer that has completed single-sided texturing in the first spray chamber is sent to the second spray chamber and sprayed with alkaline cleaning liquid, acid liquid and deionized water in succession, which can better remove the second alkaline liquid remaining after texturing of the silicon wafer and thoroughly clean the silicon wafer.

[0029] In some specific embodiments of the present invention, the drying gas in the drying chamber uses industrial grade nitrogen GN2, the drying temperature is 75-85°C, and the drying time is 8-16min; after the single-sided texturing single crystal silicon wafer is cleaned, it is sent to the drying chamber for drying, and the entire process is seamless and efficient.

[0030] In some specific embodiments of the present invention, the single crystal silicon wafer is sequentially subjected to cleaning pretreatment and alkali polishing to obtain a double-sided polished single crystal silicon wafer. The specific steps include: S11, immersing the single crystal silicon wafer in a room temperature acidic cleaning solution in a cleaning tank for cleaning pretreatment, the cleaning pretreatment time is 5-10 minutes, the acidic cleaning solution includes a mixed solution of hydrofluoric acid and hydrochloric acid, and the acidic cleaning solution is a mixed solution of a hydrofluoric acid standard solution with a concentration of 49% by mass, a hydrochloric acid standard solution with a concentration of 37% by mass, and deionized water; the mixed solution of hydrofluoric acid and hydrochloric acid is conducive to removing impurities such as heavy metals on the surface of the silicon wafer, and preventing impurities from adhering to the surface of the silicon wafer, making it difficult to perform polishing, texturing, and other operations on the silicon wafer; Specifically, in the cleaning pretreatment, the mixing volume ratio of hydrofluoric acid, hydrochloric acid and deionized water in the acid cleaning solution is 1.17:1.18:97.65; the single crystal silicon wafer reacts in the acid cleaning solution at room temperature for 7 minutes; Specifically, after the single crystal silicon wafer is pre-treated for cleaning, it can also be placed in deionized water for bubbling cleaning, the cleaning time is 1-5 minutes, and new deionized water is replaced after cleaning, and cleaning is performed 1-3 times, which is beneficial to remove the unreacted hydrofluoric acid and hydrochloric acid on the surface of the single crystal silicon wafer, as well as other impurities, to avoid affecting the subsequent process; S12, immersing the cleaned and pretreated single crystal silicon wafer into the first alkali solution in the alkali polishing tank for alkali polishing, wherein the first alkali solution is an aqueous solution of potassium hydroxide or sodium hydroxide, and the reaction temperature of the alkali polishing is 70-80° C., and the time is 1-3 min. Specifically, the first alkali solution can be a mixed solution of a potassium hydroxide standard solution with a mass fraction of 48% or a sodium hydroxide standard solution with a mass fraction of 45% and deionized water; the corrosive effect of the first alkali solution can remove the damaged surface of the single crystal silicon wafer, thereby improving the flatness of the surface of the single crystal silicon wafer; Specifically, in the alkali polishing, the volume proportion of potassium hydroxide solution or sodium hydroxide solution in the first alkali solution is 2.5-5%; the single crystal silicon wafer is reacted in the alkali polishing tank for 2 minutes, and the reaction temperature is 80°C; S13, obtaining a double-sided polished single-crystal silicon wafer with 2-2.5 microns of thickness etched off on both the front and back sides; specifically, the double-sided polished single-crystal silicon wafer loses 0.2-0.3 g in weight.

[0031] In some specific embodiments of the present invention, the first speed, the second speed and the third speed are the same, which are 1-5 m / min; the entire process does not require pauses or speed changes, the operation is simple, and the process time is shortened.

[0032] In some specific embodiments of the present invention, the second alkali solution is any one of a potassium hydroxide standard solution with a concentration of 48% by mass and a sodium hydroxide standard solution with a concentration of 45% by mass.

[0033] In some specific embodiments of the present invention, the carrier includes a plurality of loading units, each of the loading units is provided with a hollow groove, and the inner side of the hollow groove is provided with a hook suitable for carrying the single crystal silicon wafer.

[0034] In some specific embodiments of the present invention, a first manipulator is provided at the entrance of the first spray chamber of the automatic spray device, and a second manipulator is provided at the exit of the drying chamber of the automatic spray device. The double-sided polished single-crystalline silicon wafer is placed on the carrier by the first manipulator, and the dried single-sided textured single-crystalline silicon wafer is taken out by the second manipulator; placing the single-crystalline silicon wafer on the carrier and taking the single-crystalline silicon wafer out from the carrier are both completed by the manipulator, thereby achieving a higher degree of automation, shortening the process time, improving efficiency, and reducing labor costs.

[0035] In order to make it easier to understand and implement the present invention, the following more specific and detailed embodiments that are easier to implement are provided as references. Through the description and performance results of the following specific embodiments, the embodiments of the present invention and their advantages will also be apparent.

[0036] Example 1 Several single crystal silicon wafers were evenly inserted into the flower basket and pre-cleaned in the cleaning tank. The pre-cleaning used a mixed solution of hydrofluoric acid with a concentration of 49% by mass, hydrochloric acid with a concentration of 37% by mass and deionized water. The mixed volume ratio was 1.17:1.18:97.65. The pre-cleaning temperature was 20°C and the pre-cleaning time was 7 minutes. Then, the single crystal silicon wafer was placed in deionized water for bubbling cleaning. The cleaning time was 3 minutes. After cleaning, the water was changed again and the cleaning times were 2 times. After the cleaning pretreatment is completed, the single crystal silicon wafer is transferred to the alkali polishing tank for alkali polishing. The alkali polishing uses the first alkali solution to perform alkali polishing on both sides of the single crystal silicon wafer. The first alkali solution is a mixed solution of a potassium hydroxide standard solution with a concentration of 48% by mass and deionized water. The proportion of the potassium hydroxide standard solution with a concentration of 48% by mass in the mixed solution is 3%; the reaction temperature of the double-sided polishing is 80°C, and the reaction time of the double-sided polishing is 2 minutes; The double-sided polished single-crystalline silicon wafer is taken out from the flower basket by the first manipulator and put into the carrier slot. The carrier carrying the single-crystalline silicon wafer is sent into the first spray chamber of the automatic spray device. The carrier is transported in the first spray chamber at a first speed of 3m / min. Once the double-sided polished single-crystalline silicon carried by the carrier enters the first spray chamber, the texturing liquid heated to 80°C is sprayed on the front of the single-crystalline silicon wafer through the spray head for corrosion. The texturing liquid uses a mixed solution composed of a standard sodium hydroxide solution with a concentration of 45% by mass, a texturing additive and deionized water. The texturing additive uses V01 of the TS53 series of Time Energy. The volume proportions of the standard sodium hydroxide solution with a concentration of 45% by mass and the texturing additive are 1.5% and 3.5% respectively, and the rest is deionized water. The texturing liquid spraying time is 5 minutes. Under the action of the second alkali solution and the texturing additive, the upper surface of the single-crystalline silicon wafer forms a pyramid-shaped velvet surface with a bottom width of 2.8 microns using the anisotropic corrosion principle; The carrier carries the single-sided texturing monocrystalline silicon wafer into the second spray chamber, and an automatic spray device is used to spray alkaline cleaning liquid, acid and deionized water on the monocrystalline silicon wafer in sequence to clean the monocrystalline silicon wafer; the cleaning liquid is an alkaline hydrogen peroxide solution, which is composed of a mixture of potassium hydroxide with a mass fraction of 48% and hydrogen peroxide with a mass fraction of 31% in a volume ratio of 1:10; the acid is an aqueous solution of hydrofluoric acid, which is composed of a mixture of hydrofluoric acid with a mass fraction of 49% and deionized water in a volume ratio of 1:9; the second speed of the carrier transmission is 3m / min; The carrier carries the cleaned single crystal silicon wafer into the drying chamber for drying. The drying process uses industrial grade nitrogen GN2 as the drying gas, the drying temperature is 80°C, the drying time is 10 minutes, and the third speed of the carrier transmission is 3m / min; the dried single crystal silicon wafer is taken out from the carrier by the second manipulator and stored in the basket for subsequent processes; A single-sided textured single-crystalline silicon wafer with a reflectivity of 11.9% was obtained.

[0037] Example 2 Several single crystal silicon wafers were evenly inserted into the flower basket and pre-cleaned in the cleaning tank. The pre-cleaning used a mixed solution of hydrofluoric acid with a concentration of 49% by mass, hydrochloric acid with a concentration of 37% by mass and deionized water. The mixed volume ratio was 1.17:1.18:97.65. The pre-cleaning temperature was 20°C and the pre-cleaning time was 7 minutes. Then, the single crystal silicon wafer was placed in deionized water for bubbling cleaning. The cleaning time was 3 minutes. After cleaning, the water was changed again and the cleaning times were 2 times. After the cleaning pretreatment is completed, the single crystal silicon wafer is transferred to the alkali polishing tank for alkali polishing. The alkali polishing uses the first alkali solution to perform alkali polishing on both sides of the single crystal silicon wafer. The first alkali solution is a mixed solution of a potassium hydroxide standard solution with a concentration of 48% by mass and deionized water. The proportion of the potassium hydroxide standard solution with a concentration of 48% by mass in the mixed solution is 3%; the reaction temperature of the double-sided polishing is 70°C, and the reaction time of the double-sided polishing is 3 minutes; The double-sided polished single-crystal silicon wafer is taken out from the flower basket by the first manipulator and put into the carrier slot. The carrier carries the single-crystal silicon wafer into the texturing room. The texturing liquid is fully mixed and heated to 85°C in the slot of the first spray chamber through the bubbling and heating system. Then the solution is pumped to the spray head by the pump and sprayed on the front of the single-crystal silicon wafer by the automatic spray device for corrosion. At the same time, the carrier is continuously and uniformly transported in the automatic spray device. The texturing liquid uses a mixed solution composed of a standard potassium hydroxide solution with a concentration of 48% by mass, a texturing additive and deionized water. The texturing additive is V01 of the TS53 series of Shichuang Energy. The volume proportions of the standard potassium hydroxide solution with a concentration of 48% by mass and the texturing additive are 2.5% and 3.0% respectively, and the rest is deionized water. The texturing liquid spraying time is 8 minutes, and the first speed of the carrier transmission is 2m / min. Under the action of the second alkali solution and the texturing additive, the upper surface of the single-crystal silicon wafer forms a pyramid-shaped velvet surface with a bottom width of 2.5 microns by the principle of anisotropic corrosion. The carrier carries the single-sided texturing monocrystalline silicon wafer into the second spray chamber, and uses an automatic spray device to spray alkaline cleaning liquid, acid and deionized water on the monocrystalline silicon wafer in sequence to clean the monocrystalline silicon wafer; the cleaning liquid is an alkaline hydrogen peroxide solution, which is composed of a mixture of potassium hydroxide with a mass fraction of 48% and hydrogen peroxide with a mass fraction of 31% in a volume ratio of 1:10; the acid is an aqueous solution of hydrofluoric acid, which is composed of a mixture of hydrofluoric acid with a mass fraction of 49% and deionized water in a volume ratio of 1:9; the second speed of the carrier transmission is 2m / min; The carrier carries the cleaned single crystal silicon wafer into the drying chamber for drying. The drying process uses industrial grade nitrogen GN2 as the drying gas, the drying temperature is 75°C, the drying time is 15 minutes, and the third speed of the carrier transmission is 2m / min; the dried single crystal silicon wafer is taken out from the carrier by the second manipulator and stored in the basket for subsequent processes; A single-sided textured single-crystalline silicon wafer with a reflectivity of 11.46% was obtained.

[0038] Example 3 Several single crystal silicon wafers were evenly inserted into the flower basket and pre-cleaned in the cleaning tank. The pre-cleaning used a mixed solution of hydrofluoric acid with a concentration of 49% by mass, hydrochloric acid with a concentration of 37% by mass and deionized water. The mixed volume ratio was 1.17:1.18:97.65. The pre-cleaning temperature was 20°C and the pre-cleaning time was 7 minutes. Then, the single crystal silicon wafer was placed in deionized water for bubbling cleaning. The cleaning time was 3 minutes. After cleaning, the water was changed again and the cleaning times were 2 times. After the cleaning pretreatment is completed, the single crystal silicon wafer is transferred to the alkali polishing tank for alkali polishing. The alkali polishing uses the first alkali solution to perform alkali polishing on both sides of the single crystal silicon wafer. The first alkali solution is a mixed solution of a potassium hydroxide standard solution with a concentration of 48% by mass and deionized water. The proportion of the potassium hydroxide standard solution with a concentration of 48% by mass in the mixed solution is 3%; the reaction temperature of the double-sided polishing is 80°C, and the reaction time of the double-sided polishing is 2 minutes; The double-sided polished single-crystal silicon wafer is taken out from the flower basket by the first manipulator and put into the carrier slot. The carrier carries the single-crystal silicon wafer into the texturing room. The texturing liquid is fully mixed in the slot of the first spray chamber through the bubbling and heating system and heated to 81°C. Then the solution is pumped to the spray head by the pump and sprayed on the front of the single-crystal silicon wafer by the automatic spray device for corrosion. At the same time, the carrier starts to be transported at a uniform speed while spraying from the automatic spray device. The texturing liquid uses a mixed solution composed of a standard sodium hydroxide solution with a concentration of 45% by mass, a texturing additive and deionized water. The texturing additive is V01 of the TS53 series of Shichuang Energy. The volume proportions of the standard sodium hydroxide solution with a concentration of 45% by mass and the texturing additive are 1.8% and 3.0% respectively, and the rest is deionized water. The texturing liquid spraying time is 4 minutes, and the first speed of the carrier transmission is 4m / min. Under the action of the first alkali solution and the texturing additive, the upper surface of the single-crystal silicon wafer forms a pyramid-shaped velvet surface with a bottom width of 2.7 microns by the principle of anisotropic corrosion. The carrier carries the single-sided texturing monocrystalline silicon wafer into the second spray chamber, and uses an automatic spray device to spray alkaline cleaning liquid, acid and deionized water on the monocrystalline silicon wafer in sequence to clean the monocrystalline silicon wafer; the cleaning liquid is an alkaline hydrogen peroxide solution, which is composed of a mixture of potassium hydroxide with a mass fraction of 48% and hydrogen peroxide with a mass fraction of 31% in a volume ratio of 1:10; the acid is an aqueous solution of hydrofluoric acid, which is composed of a mixture of hydrofluoric acid with a mass fraction of 49% and deionized water in a volume ratio of 1:9; the second speed of the carrier transmission is 4m / min; The carrier carries the cleaned single crystal silicon wafer into the drying chamber for drying. The drying process uses industrial grade nitrogen GN2 as drying gas, the drying temperature is 80°C, the drying time is 10 minutes, and the third speed of the carrier transmission is 4m / min; the dried single crystal silicon wafer is taken out from the carrier by the second manipulator and stored in the basket for subsequent processes; A single-sided textured single-crystalline silicon wafer with a reflectivity of 11.37% was obtained.

[0039] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for texturing a single side of a monocrystalline silicon wafer, characterized in that: The steps include: The single crystal silicon wafer is sequentially subjected to cleaning pretreatment and alkali polishing to obtain a double-sided polished single crystal silicon wafer; Putting a plurality of the double-sided polished single crystal silicon wafers into the hollow grooves of the carrier plate; The carrier plate on which the double-sided polished single-crystalline silicon wafer is placed is sent into the first spray chamber of an automatic spray device and is moved and transported at a first speed, and the front side of the double-sided polished single-crystalline silicon wafer is corroded by spraying a texturing liquid to obtain a single-sided texturing single-crystalline silicon wafer with a pyramid texturing surface formed on the front side; wherein the texturing liquid comprises a second alkali liquid, a texturing additive and deionized water, the volume proportions of the second alkali liquid and the texturing additive in the texturing liquid are 1-3% and 2-4% respectively, the temperature of the texturing liquid is 75-85°C, the spraying time is 4-8min, and the bottom width of the pyramid texturing surface is 2-3 microns; The single-sided textured single crystal silicon wafer is sent into the second spray chamber of the automatic spray device through a carrier plate for spray cleaning, and the carrier plate is moved and transported at a second speed in the second spray chamber; The cleaned single-sided textured single crystal silicon wafer is sent into the drying chamber of the automatic spraying device for drying through a carrier plate, and the carrier plate is moved and transported at a third speed in the drying chamber; Take out the dried single-sided textured single crystal silicon wafer.

2. The method for single-sided texturing of a single-crystal silicon wafer according to claim 1, characterized in that: The second spray chamber comprises an alkaline cleaning liquid spraying area, an acid liquid spraying area and a deionized water spraying area in sequence; wherein the alkaline cleaning liquid is an alkaline hydrogen peroxide solution, and the acid liquid is an aqueous solution of hydrofluoric acid.

3. The method for single-sided texturing of a single-crystal silicon wafer according to claim 2, characterized in that: The alkaline hydrogen peroxide solution is composed of a third alkali solution and a hydrogen peroxide solution mixed in a volume ratio of 1:10, the third alkali solution includes any one of a potassium hydroxide standard solution with a concentration of 48% by mass and a sodium hydroxide standard solution with a concentration of 45% by mass, the hydrogen peroxide solution is a hydrogen peroxide standard solution with a concentration of 31% by mass, and the hydrofluoric acid aqueous solution is composed of a hydrofluoric acid standard solution with a concentration of 49% by mass and deionized water mixed in a volume ratio of 1:

9.

4. The method for single-sided texturing of a single-crystal silicon wafer according to claim 1, characterized in that: The drying gas in the drying chamber uses industrial grade nitrogen GN2, the drying temperature is 75-85°C, and the drying time is 8-16 minutes.

5. The method for single-sided texturing of a single-crystal silicon wafer according to claim 1, characterized in that: The specific steps of sequentially performing cleaning pretreatment and alkali polishing on the single crystal silicon wafer to obtain a double-sided polished single crystal silicon wafer include: Immersing the single crystal silicon wafer in a room temperature acidic cleaning solution in a cleaning tank for cleaning pretreatment, the cleaning pretreatment time is 5-10 minutes, and the acidic cleaning solution includes a mixed solution of hydrofluoric acid and hydrochloric acid; Immersing the cleaned and pre-treated single crystal silicon wafer in a first alkali solution in an alkali polishing tank for alkali polishing, wherein the first alkali solution is an aqueous solution of potassium hydroxide or sodium hydroxide, and the reaction temperature of the alkali polishing is 70-80° C. and the time is 1-3 minutes; A double-sided polished single-crystal silicon wafer is obtained, with the front and back sides etched to a thickness of 2-2.5 microns.

6. The method for single-sided texturing of a single-crystal silicon wafer according to claim 5, characterized in that: The double-sided polished single crystal silicon wafer loses 0.2-0.3 g in weight.

7. The method for single-sided texturing of a single-crystal silicon wafer according to claim 1, characterized in that: The first speed, the second speed and the third speed are the same, which are 1-5 m / min.

8. The method for texturing a single side of a single crystal silicon wafer according to claim 1, characterized in that: The second alkali solution includes any one of a potassium hydroxide standard solution with a concentration of 48% by mass and a sodium hydroxide standard solution with a concentration of 45% by mass.

9. The method for single-sided texturing of a single-crystal silicon wafer according to claim 1, characterized in that: The carrier plate includes a plurality of loading units, each of which is provided with a hollow groove, and the inner side of the hollow groove is provided with a hook suitable for carrying the single crystal silicon wafer.

10. The method for single-sided texturing of a single-crystal silicon wafer according to claim 1, characterized in that: A first manipulator is provided at the entrance of the first spray chamber of the automatic spray device, and a second manipulator is provided at the exit of the drying chamber of the automatic spray device. The double-sided polished single-crystalline silicon wafer is placed on the carrier by the first manipulator, and the dried single-sided textured single-crystalline silicon wafer is taken out by the second manipulator.

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