Cleaning liquid and cleaning method after wafer laser ablation

Abstract

The present invention belongs to the field of electronic chemicals, and specifically relates to a cleaning liquid and a cleaning method after laser ablation of a wafer. The cleaning liquid is mainly used to clean organic residues and particles after laser ablation of the wafer, and to reduce corrosion to the metal on the surface of the wafer. The composition includes an organic solvent, a metal corrosion inhibitor, a surfactant, a pH regulator and high-purity water. The organic solvent is used to dissolve organic residues; the metal corrosion inhibitor can prevent the cleaning liquid from corroding the metal on the surface of the wafer; the surfactant is used to improve the wettability of the cleaning liquid and make the particles separate from the wafer surface and enter the solution; the pH regulator maintains the alkaline environment of the cleaning liquid and enhances the cleaning effect of the melt on the wafer surface.

Description

Technical Field

[0001] The invention belongs to the field of electronic chemicals, and in particular relates to a cleaning liquid and a cleaning method after wafer laser ablation. Background Art

[0002] Some high-hardness chips need to be grooved by laser ablation before cutting. The ablation process can easily leave impurities such as wax layer, dirt, and circuit oxidation residues on the wafer surface. The residues adhere to the wafer surface for a long time and the gravity of dirt and impurities may cause chip edge collapse.

[0003] In order to avoid damage to the substrate silicon wafer caused by laser cutting and improve the product yield, a protective liquid needs to be coated on the substrate surface to form a protective film before laser processing, so that other areas of the chip can be well protected during processing and the adhesion of debris on the wafer surface can be inhibited. However, the resin component in the laser protective liquid will also produce carbonized residues during the laser ablation process, which seriously pollutes the substrate material and affects its use.

[0004] The general residue cleaning adopts high-pressure pure water or organic solvent flushing to clean the melted materials on the chip surface and the walkway, but the problem is that it needs to be cleaned in a short time after laser ablation, which can easily cause a sudden change in the surface temperature of the wafer and affect the chip quality. CN102728578 discloses a method for cleaning laser cutting paths, in which the cleaning liquid is a KOH solution, which is immersed and cleaned under the action of ultrasonic vibration. However, the use of the cleaning liquid provided in the above-mentioned prior art will cause corrosion to the pad metal layer on the surface of some wafers, affecting the performance of subsequent chip packaging. Therefore, it is a technical problem that technicians in this field urgently need to solve to develop a cleaning liquid and cleaning method that can efficiently remove carbonized residues and particles without damaging the wafer. Summary of the invention

[0005] The present invention aims to solve the problem that carbonized residues and molten particles after laser ablation of wafers in existing semiconductor integrated circuit processes are difficult to clean, and aims to provide a cleaning liquid formula after laser ablation of wafers and a use method thereof.

[0006] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is:

[0007] A cleaning solution for wafers after laser ablation can effectively clean organic residues and molten particles generated after laser ablation of the wafer. The cleaning solution mainly comprises 30-60wt% of an organic solvent, 1-5wt% of a metal corrosion inhibitor, 0.1-1.0wt% of a surfactant, a pH regulator and the remainder of ultrapure water.

[0008] The cleaning liquid after laser ablation of the wafer in the above scheme is characterized in that the organic solvent is any one of propylene glycol diacrylate, diethylene glycol hexyl ether, N-hydroxyethylethylenediaminetriacetic acid, diethylaminoethanol, dibutylaminoethanol, diglycolamine, dimethylformamide, dimethyl sulfoxide, diethyl sulfoxide, and benzylphenyl sulfoxide, or a combination of at least two of them.

[0009] In the cleaning liquid after laser ablation of the wafer in the above scheme, the metal corrosion inhibitor is a mixture of polyhydroxyphenol and phytic acid, the polyhydroxyphenol is one of tea polyphenols, tert-butylhydroquinone, ethylenediamine di-o-hydroxyphenyl sodium ferric acetate and the like, and the mass ratio of the polyhydroxyphenol to phytic acid is (1~5):1.

[0010] In the cleaning liquid after laser ablation of the wafer in the above scheme, the surfactant is a modified polyoxyethylene ether, and the modified polyoxyethylene ether refers to the introduction of sulfosuccinate groups or amide groups, specifically sodium succinic acid polyoxyethylene ether ester sulfonate or fatty acid monoethanolamide polyoxyethylene ether.

[0011] The synthesis method of the sodium succinate polyoxyethylene ether ester sulfonate is synthesized by the method of Yao Zhigang, Yu Xi, Hu Aixi and Chen Xuewei in the literature Synthesis and Properties of Polymerizable Sodium Succinate Polyoxyethylene Ether Ester Sulfonate, Chemical Research and Application, Vol. 20, No. 6.

[0012] The fatty acid monoethanolamide polyoxyethylene ether is synthesized by the method of Liu Qiling, Xu Hujun and Shen Jun in the literature Preparation and Properties of Fatty Acid Monoethanolamide Polyoxyethylene Ether, Fine Petrochemicals, Vol. 38, No. 1.

[0013] In the cleaning solution after laser ablation of the wafer in the above scheme, the pH adjuster is one of the glycine-sodium hydroxide and borax-sodium hydroxide buffer combinations, which is used to adjust the pH value of the cleaning solution to 8-12.

[0014] To achieve the above-mentioned object of the invention, the cleaning method adopted by the present invention comprises the following steps:

[0015] S1: prepare any one of the above cleaning solutions, wherein the cleaning solution comprises an organic solvent, a metal corrosion inhibitor, a surfactant, a pH regulator and ultrapure water, and introduce the cleaning solution into a chemical storage tank and an ultrasonic cleaning device of a single-chip cleaning machine, and the temperature of the cleaning solution is controlled at 25°C to 50°C;

[0016] S2: Place a laser-cut wafer on the stage of the single-wafer cleaning machine and fix the wafer by vacuum adsorption. The top of the stage is equipped with a cleaning liquid nozzle and a PVA cleaning brush. During cleaning, the nozzle moves to the center of the wafer and sprays the cleaning liquid on the surface of the wafer. The PVA cleaning brush moves down to contact the front of the wafer and removes the residue on the surface of the wafer by rotating friction.

[0017] S3: After the wafer is cleaned by PVA, it is taken out and placed in an ultrasonic cleaning device. The residue attached to the surface of the wafer is washed away by ultrasonic vibration. After the ultrasonic cleaning is completed, the wafer is taken out and placed in a hot rapid drying device for cleaning and drying.

[0018] In the above cleaning method, the thickness of the wafer after laser ablation is about 150μm~300μm; in step S2, the distance between the cleaning liquid nozzle and the wafer should not be too long to avoid excessive pressure when the cleaning liquid contacts the wafer, causing splashing of the cleaning liquid or wafer fragments, and the nozzle is 5~10cm away from the center of the wafer; the length of the PVA cleaning brush is greater than the diameter of the wafer, and the PVA cleaning brush should be located in the center of the wafer as much as possible to ensure that the entire surface of the wafer is covered during brushing. At the same time, since the nozzle is located in the center of the wafer, in order to avoid interference of the cleaning brush with the nozzle when spraying the cleaning liquid, a certain distance needs to be set, and the cleaning brush is 0.5 away from the center of the wafer when it contacts the wafer. ~1cm; maintaining a certain rotation speed during wafer cleaning can effectively remove the contaminants on the wafer surface, but too fast a rotation speed will cause the risk of fragmentation, so the rotation speed is set to 100~1000rpm, and the PVA cleaning brush rotation speed is 500~800rpm; when the cleaning liquid flow rate is low, the ability to dissolve and elute pollutants is limited, and too high a cleaning liquid flow rate will lead to waste of liquid medicine, so the cleaning liquid spray flow rate is set to 1.5~3L / min, and the cleaning time is 1~2min; in step S3, the power of the ultrasonic cleaning device is 1.5~3KW, the cleaning time is 2~5min, and the hot rapid drying device includes 60℃ ultrapure water cleaning and N2 drying.

[0019] In the above cleaning method, after cleaning the laser ablated wafer, the total number of surface defects is less than 1000, or less than 900, or less than 800. Further, for the preferred composition, the total number of defects on the wafer surface after cleaning is less than 500.

[0020] In the above cleaning method, after cleaning the wafer after laser ablation, the corrosion thickness of the solder balls on the surface is less than 100nm, or less than 80nm, or less than 60nm. Further, for the preferred composition, the corrosion thickness of the solder balls on the wafer surface after cleaning is less than 20nm.

[0021] Beneficial effects of the present invention

[0022] (1) When cleaning the wafer, the organic solvent in the cleaning solution dissolves and removes the carbonized residue. The cleaning effect on resin residue is particularly good in an alkaline environment.

[0023] (2) In order to prevent the solder balls, aluminum passivation layer and other metals on the wafer surface from being corroded during the cleaning process, the present invention reduces the corrosion of the metal by the alkaline cleaning solution by adding a metal corrosion inhibitor.

[0024] (2) To remove particles after laser ablation of the wafer, the present invention improves the wetting properties of the cleaning solution by using a surfactant and eliminates the electrical attraction between the wafer substrate and the particles due to the electric charge, making it easier for the particles to detach from the wafer surface. DETAILED DESCRIPTION

[0025] In order to better understand the present invention, the content of the present invention is further explained below in conjunction with embodiments, but the content of the present invention is not limited to the following examples.

[0026] The synthesis method of sodium succinate polyoxyethylene ether ester sulfonate described in this embodiment adopts the method of the literature Synthesis and Properties of Polymerizable Sodium Succinate Polyoxyethylene Ether Ester Sulfonate, Chemical Research and Application, Vol. 20, No. 6, Yao Zhigang, Yu Xi, Hu Aixi, and Chen Xuewei for synthesis.

[0027] The fatty acid monoethanolamide polyoxyethylene ether described in this embodiment is synthesized by the method of Liu Qiling, Xu Hujun, and Shen Jun in the literature Preparation and Properties of Fatty Acid Monoethanolamide Polyoxyethylene Ether, Fine Petrochemicals, Vol. 38, No. 1.

[0028] Comparative Example 1

[0029] Comparative Example 1 uses pure water brushing and ultrasonic vibration to clean the wafer with laser ablation cutting lanes. The wafer thickness is about 200um, the pure water temperature is increased to 40°C, the pure water nozzle is 8cm away from the center of the wafer, the cleaning brush is 0.5cm away from the center of the wafer when it contacts the wafer, the wafer speed is 400rpm, the pure water flow rate is 2L / min, the PVA cleaning brush speed is 600rpm, and the cleaning time is 1min; the power of the ultrasonic cleaning device is 2KW, the cleaning time is 3min, and the wafer is placed in a hot rapid drying device for drying after cleaning.

[0030] After drying, the surface organic residues and particles were scanned for defects, the thickness of the metal layer was tested, and the cleaning effect was evaluated by the number of defects and the corrosion of the metal. After the comparative example 1 was washed with pure water and ultrasonically vibrated, the evaluation index of the cleaning effect was shown in Table 1. The total number of surface defects was about 3240, and the tin balls were not corroded.

[0031] Comparative Example 2

[0032] Comparative Example 2 uses 20% potassium hydroxide aqueous solution to clean the wafer with laser ablation cut lines by brushing and ultrasonic vibration. The wafer cleaning steps, parameters and test methods are the same as those of Comparative Example 1. The cleaning effect of Comparative Example 2 is shown in Table 1. The total number of surface defects is about 1657, and the corrosion thickness of the solder balls is greater than 1um.

[0033] Table 1 Cleaning effect of comparative example

[0034]

[0035] Example 1

[0036] A cleaning solution for wafer laser ablation, the components of which are shown in Table 2:

[0037] Table 2 Components and contents of Example 1

[0038]

[0039] The cleaning liquid was prepared according to the components and contents listed in Table 2, and introduced into the chemical storage tank and ultrasonic cleaning device of the single-wafer cleaning machine. The temperature of the cleaning liquid was controlled at 40°C. A wafer with a cutting path ablated by laser was placed on the stage of the single-wafer cleaning machine. The wafer thickness was about 200 μm. The wafer was fixed by vacuum adsorption. The cleaning liquid nozzle on the upper part of the stage was 8 cm away from the center of the wafer. The length of the PVA cleaning brush was greater than the diameter of the wafer. When the cleaning brush was in contact with the wafer, it was 0.5 cm away from the center of the wafer. The wafer speed was 400 rpm, the cleaning liquid spray flow rate was 2 L / min, the PVA cleaning brush speed was 600 rpm, and the cleaning time was 1 min. The power of the ultrasonic cleaning device was 2 KW, the cleaning time was 3 min, and the wafer was placed in a hot rapid drying device for drying after cleaning.

[0040] After drying, the organic residues and particles on the wafer surface were scanned for defects, the thickness of the metal layer was detected, and the cleaning effect was evaluated by the number of defects and the corrosion of the metal. After Example 1 was scrubbed with the cleaning solution and ultrasonically vibrated, the cleaning effect was shown in Table 3. The total number of surface defects was about 315, and the corrosion thickness of the solder ball was about 10nm.

[0041] Example 2

[0042] The same as Example 1, except that the organic solvent is adjusted from dimethylformamide to diethylene glycol hexyl ether, and the content of diethylene glycol hexyl ether is 50%, and the other components and their contents remain unchanged, and are set as Example 2. The wafer cleaning steps, parameters and testing methods are the same as those in Example 1.

[0043] The cleaning effect is shown in Table 3. The organic solvent in this embodiment is diethylene glycol hexyl ether. Compared with Example 1, the number of defects increases to 426, but the cleaning effect is still good, the corrosion thickness of the solder ball is about 11nm, and the degree of corrosion of the cleaning liquid to the metal is low.

[0044] Example 3

[0045] The same as Example 1, only the organic solvent is adjusted from dimethylformamide to N-hydroxyethylethylenediaminetriacetic acid, the amount of N-hydroxyethylethylenediaminetriacetic acid is 50%, and the other components and contents remain unchanged, and it is set to Example 3. The wafer cleaning steps, parameters and testing methods are the same as Example 1.

[0046] The cleaning effect is shown in Table 3. The organic solvent in this embodiment is N-hydroxyethylethylenediaminetriacetic acid. Compared with Example 1, the number of defects increases to 524, but the cleaning effect is still good, the corrosion thickness of the solder ball is about 14nm, and the degree of corrosion of the cleaning liquid to the metal is low.

[0047] Example 4

[0048] The same as Example 1, only the organic solvent is adjusted from dimethylformamide to benzylphenyl sulfoxide, the benzylphenyl sulfoxide content is 50%, and the other components and contents remain unchanged, and it is set to Example 4. The wafer cleaning steps, parameters and testing methods are the same as Example 1.

[0049] The cleaning effect is shown in Table 3. The organic solvent in this embodiment is benzylphenyl sulfoxide. Compared with Example 1, the number of defects increases to 837, the cleaning effect is general, the corrosion thickness of the solder ball is about 12nm, and the corrosion degree of the cleaning liquid to the metal is low.

[0050] Example 5

[0051] The same as Example 1, only the metal corrosion inhibitor was adjusted from the tert-butylparaben-phytic acid composition to the tea polyphenol and phytic acid composition, the tea polyphenol content was 3%, the phytic acid content was 1%, and the contents of other components remained unchanged, set to Example 5, the wafer cleaning steps, parameters and testing methods were the same as Example 1.

[0052] The cleaning effect is shown in Table 3. The metal corrosion inhibitor in this embodiment is a combination of tea polyphenols and phytic acid. Compared with Example 1, the corrosion thickness of the solder ball increases to 87 nm, the corrosion degree of the cleaning liquid on the metal is average, the number of defects on the wafer surface is 358, and the cleaning effect is better.

[0053] Example 6

[0054] The same as Example 1, only the metal corrosion inhibitor was adjusted from the tert-butylparaben-phytic acid composition to a mixture of ethylenediamine di-o-hydroxyphenyl sodium ferric acetate and phytic acid, the ethylenediamine di-o-hydroxyphenyl sodium ferric acetate content was 3%, the phytic acid content was 1%, and the contents of other components remained unchanged, set to Example 6, the wafer cleaning steps, parameters and testing methods are the same as Example 1.

[0055] The cleaning effect is shown in Table 3. The metal corrosion inhibitor in this embodiment is a combination of ethylenediamine di-o-hydroxyphenyl sodium ferric acetate and phytic acid. Compared with Example 1, the corrosion thickness of the solder ball increases to 41 nm, the degree of corrosion of the metal by the cleaning liquid is still low, the number of defects on the wafer surface is 389, and the cleaning effect is better.

[0056] Example 7

[0057] Same as Example 1, only the content of tert-butylparadiphenol in the metal corrosion inhibitor composition was adjusted from 3% to 1%, and the contents of other components remained unchanged, which was set as Example 7. The wafer cleaning steps, parameters and testing methods were the same as those in Example 1.

[0058] The cleaning effect is shown in Table 3. In this embodiment, the content of the metal corrosion inhibitor tert-butyl-p-diphenol is adjusted from 3% to 1%. Compared with Example 1, the corrosion thickness of the solder ball increases to 55 nm, the corrosion degree of the cleaning liquid to the metal is average, the number of defects on the wafer surface is 413, and the cleaning effect is better.

[0059] Example 8

[0060] The same as Example 1, except that the metal corrosion inhibitor is not added and the contents of other components remain unchanged, is set as Example 8, and the wafer cleaning steps, parameters and testing methods are the same as Example 1.

[0061] The cleaning effect is shown in Table 3. This embodiment does not contain a metal corrosion inhibitor. Compared with Example 1, the corrosion thickness of the solder ball increases to 132 nm, the cleaning liquid corrodes the metal more seriously, the number of defects on the wafer surface is 388, and the cleaning effect is better.

[0062] Example 9

[0063] Same as Example 1, only the content of surfactant-modified polyoxyethylene ether is reduced to 0.2%, and the contents of other components remain unchanged, which is set as Example 9, and the wafer cleaning steps, parameters and test methods are the same as those in Example 1. .

[0064] The cleaning effect is shown in Table 3. The surfactant in this embodiment is a sulfosuccinate-modified polyoxyethylene ether. Compared with Example 1, the number of surface defects increases to 615, the cleaning effect is better, and the corrosion thickness of the solder ball remains basically unchanged at 12 nm.

[0065] Example 10

[0066] The same as Example 1, only the group introduced by the surfactant-modified polyoxyethylene ether is adjusted from sulfonyl succinate to amide group, and the contents of other components remain unchanged, and it is set to Example 10. The wafer cleaning steps, parameters and test methods are the same as Example 1.

[0067] The cleaning effect is shown in Table 3. The surfactant in this embodiment is a sulfosuccinate-modified polyoxyethylene ether. Compared with Example 1, the number of surface defects is slightly increased to 439, the cleaning effect is better, and the corrosion thickness of the solder ball is basically unchanged at 11 nm.

[0068] Embodiment 11

[0069] Same as Example 1, only the surfactant is adjusted from modified polyoxyethylene ether to octylphenol polyoxyethylene ether, and the contents of other components remain unchanged, which is set as Example 11. The wafer cleaning steps, parameters and testing methods are the same as those in Example 1.

[0070] The cleaning effect is shown in Table 3. The surfactant in this embodiment is octylphenol polyoxyethylene ether. Compared with Example 1, the number of surface defects increases to 1127, the cleaning effect is average, and the corrosion thickness of the solder ball is 22nm.

[0071] Example 12

[0072] The same as Example 1, except that the surfactant is not added and the contents of other components remain unchanged, is set as Example 11, and the wafer cleaning steps, parameters and testing methods are the same as those in Example 1.

[0073] The cleaning effect is shown in Table 3. In this embodiment, no surfactant is added. Compared with Example 1, the number of surface defects increases to 1326, the cleaning effect is average, and the corrosion thickness of the solder ball is 27 nm.

[0074] Embodiment 13

[0075] Same as Example 1, only the pH buffer composition is adjusted from glycine-sodium hydroxide to borax-sodium hydroxide, and the contents of other components remain unchanged, which is set as Example 13. The wafer cleaning steps, parameters and testing methods are the same as those in Example 1.

[0076] The cleaning effect is shown in Table 3. The pH buffer composition of this embodiment is borax-sodium hydroxide, and the pH is also adjusted to 9-10. Compared with Example 1, the number of surface defects is slightly increased to 411, the cleaning effect is better, and the corrosion thickness of the solder ball is increased to 35nm.

[0077] Embodiment 14

[0078] The same as Example 1, except that the pH buffer composition is not added, and the contents of other components remain unchanged, is set to Example 14, and the wafer cleaning steps, parameters and testing methods are the same as Example 1.

[0079] The cleaning effect is shown in Table 3. In this embodiment, no pH buffer composition is added, and the pH is about 7.5. Compared with Example 1, the number of surface defects increases to 1056, the cleaning effect is poor, the corrosion thickness of the solder ball is about 10 nm, and the corrosion degree of the cleaning liquid to the metal is low.

[0080] Embodiment 15

[0081] The cleaning solution has the same composition and content as in Example 1, except that ultrasonic cleaning is not used in the cleaning step, which is set as Example 15. The scrubbing parameters and test methods are the same as in Example 1.

[0082] The cleaning effect is shown in Table 3. This embodiment does not use ultrasonic vibration cleaning. Compared with Example 1, the number of surface defects increases to 956, the cleaning effect is general, the corrosion thickness of the solder ball is about 9nm, and the degree of corrosion of the cleaning liquid to the metal is low.

[0083] Example 16

[0084] The same as in Example 1, the formula composition and content of the cleaning solution are the same, only PVA cleaning is not used in the cleaning step, which is set as Example 16, and the ultrasonic oscillation parameters and test methods are the same as in Example 1.

[0085] The cleaning effect is shown in Table 3. This embodiment does not use PVA scrubbing. Compared with Example 1, the number of surface defects increases to 1107, the cleaning effect is poor, the corrosion thickness of the solder ball is about 7nm, and the degree of corrosion of the cleaning liquid to the metal is low.

[0086] Table 3 Cleaning effect of each embodiment

[0087]

[0088] Obviously, the above embodiments are only examples for clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from this are still within the protection scope of the invention.

Claims

1. A method for cleaning organic residues and particles after laser ablation of a wafer, characterized in that: The method comprises the following steps: S1: Prepare cleaning liquid and introduce the cleaning liquid into the chemical storage tank and ultrasonic cleaning device of the single-chip cleaning machine. The temperature of the cleaning liquid is controlled at 25℃~50℃; S2: Place a laser-ablated wafer on the stage of the single-wafer cleaning machine and fix the wafer by vacuum adsorption. The upper part of the stage is equipped with a cleaning liquid nozzle and a PVA cleaning brush. During cleaning, the nozzle moves to the position just above the center of the wafer to spray the cleaning liquid onto the surface of the wafer. The PVA cleaning brush moves down to contact the front of the wafer and removes the residue on the surface of the wafer by means of rotational friction. S3: After the wafer is cleaned by PVA, it is taken out and placed in an ultrasonic cleaning device. The residue attached to the surface of the wafer is washed away by ultrasonic vibration. After the ultrasonic cleaning is completed, the wafer is taken out and placed in a hot rapid drying device for cleaning and drying; The cleaning liquid comprises 30-60wt% of an organic solvent, 1-5wt% of a metal corrosion inhibitor, 0.1-1.0wt% of a surfactant, a pH regulator and the balance of ultrapure water; the metal corrosion inhibitor is a mixture of polyhydroxyphenol and phytic acid or a mixture of ethylenediamine di-o-hydroxyphenyl sodium ferric acetate and phytic acid, the mass ratio of the polyhydroxyphenol to the phytic acid is (1-5):1; the mass ratio of ethylenediamine di-o-hydroxyphenyl sodium ferric acetate to the phytic acid is (1-5):1; The polyhydroxyphenol is one of tea polyphenol and tert-butylhydroquinone, the surfactant is sodium succinate polyoxyethylene ether ester sulfonate or fatty acid monoethanolamide polyoxyethylene ether, and the pH regulator is one of glycine-sodium hydroxide and borax-sodium hydroxide buffer combination agents.

2. The method for cleaning organic residues and particles after laser ablation of a wafer according to claim 1, characterized in that: The organic solvent includes any one of propylene glycol diacrylate, diethylene glycol hexyl ether, N-hydroxyethylethylenediaminetriacetic acid, diethylaminoethanol, dibutylaminoethanol, diglycolamine, dimethylformamide, dimethyl sulfoxide, and diethyl sulfoxide, or a combination of at least two thereof.

3. The method for cleaning organic residues and particles after laser ablation of a wafer according to claim 1, characterized in that: The pH adjuster is used to adjust the pH value of the cleaning solution to 8~12.

4. The method for cleaning organic residues and particles after laser ablation of a wafer according to claim 1, characterized in that: The wafer thickness after laser ablation is 150 μm to 300 μm.

5. The method for cleaning organic residues and particles after laser ablation of a wafer according to claim 1, characterized in that: In step S2, the nozzle is 5-10 cm away from the center of the wafer, the length of the PVA cleaning brush is greater than the diameter of the wafer, and the cleaning brush is 0.5-1 cm away from the center of the wafer when in contact with the wafer.

6. The method for cleaning organic residues and particles after laser ablation of a wafer according to claim 1, characterized in that: The wafer rotation speed is 100~1000rpm, the cleaning liquid spray flow rate is 1.5~3L / min, the PVA cleaning brush rotation speed is 500~800rpm, and the cleaning time is 1~2min.

7. The method for cleaning organic residues and particles after laser ablation of a wafer according to claim 1, characterized in that: In step S3, the power of the ultrasonic cleaning device is 1.5-3KW, and the cleaning time is 2-4min.

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