CN112355884A

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Publication number: CN112355884A
Application number: CN202011220177.4A
Authority: CN
Inventors: 王辰伟; 刘玉岭; 罗翀; 王胜利; 孙鸣; 高宝红
Original assignee: Tianjin Jingling Microelectronic Material Co ltd; Hebei University of Technology
Current assignee: Tianjin Jingling Microelectronic Material Co ltd; Hebei University of Technology
Priority date: 2020-11-05
Filing date: 2020-11-05
Publication date: 2021-02-12
Anticipated expiration: 2040-11-05
Also published as: CN112355884B

Abstract

The invention discloses a control method for CMP (chemical mechanical polishing) rate selectivity of a multilayer copper interconnection barrier layer, and aims to provide a method capable of controlling removal rates of different materials so as to control butterfly pits and etch pits. Adding the polishing solution into a polishing machine, and polishing under the conditions that the working pressure is 1-2PSI, the rotating speed of a polishing disc is 80-100 revolutions per minute, the rotating speed of a polishing head is 78-98 revolutions per minute and the flow of the polishing solution is 200-; the polishing solution consists of the following components: 5-20% of silica sol, 0.001-10% of functional component, 0.001-10% of surfactant and the balance of deionized water; the functional component consists of an agent A, an agent B and an agent C, wherein the agent A is any one of an FA/O chelating agent, tetrahydroxyethyl ethylenediamine, ethylenediamine and triethanolamine, and the agent B is any one of copper sulfate, copper glycinate, copper citrate and copper citrate chelate; the agent C is one or any mixture of potassium nitrate, potassium citrate and potassium tartrate. The method can improve the yield and the yield of chips.

Description

Control method for CMP rate selectivity of multi-layer copper interconnection barrier layer

Technical Field

The invention relates to the technical field of chemical mechanical polishing, in particular to a control method of CMP (chemical mechanical polishing) rate selectivity of a multilayer copper interconnection barrier layer, an alkaline polishing solution and a preparation method of the alkaline polishing solution.

Background

With the reduction of the integrated circuit technology node, when chemical mechanical planarization is carried out, due to the existence of the disc-shaped pits and the etching pits, a plurality of adverse effects are brought to the multilayer copper wiring, such as the influence of the lamination effect, the influence of RC delay and the like, high planarization cannot be realized after CMP, uneven defects are left on the surface of a wafer, and the yield of a chip are directly influenced if the defects are excessive. Therefore, the requirements for the depth of the dishing and the etching pits are becoming more and more stringent.

During the polishing of the barrier layer, since a plurality of materials such as Cu and tetraethyl orthosilicate (TEOS) exist simultaneously, and the removal rate of each material cannot be well controlled, disk pits and etch pits are aggravated, and the yield and yield of a chip are affected, so that the barrier layer CMP is the most challenging step in the multilayer copper wiring CMP. Polishing slurry is one of the key factors in CMP, directly affecting the polishing process and results. At present, the barrier layer polishing solution generally adopted internationally is mainly acidic. Since acidic polishing solutions are highly corrosive and easy to corrode equipment, and Cu has a high corrosion rate under acidic conditions, a variety of corrosion inhibitors such as Benzotriazole (BTA) and its derivatives, which are difficult to clean and have high mechanical strength, are generally used in the polishing solutions to inhibit the removal rate of Cu in the grooves. However, BTA has toxicity and is difficult to decompose. Moreover, hydrogen peroxide is mostly adopted as an oxidant internationally, and self-decomposition of the hydrogen peroxide becomes an important restriction factor of the stability of the polishing solution. Therefore, the invention is a polishing liquid which does not add BTA and oxidizer, can improve the stability of the polishing liquid and is necessary to realize the effective control of the disc pits and the etching pits.

Disclosure of Invention

The invention aims to provide a control method which can control the removal rate of different materials in the chemical mechanical polishing process of a multilayer copper interconnection barrier layer so as to effectively realize the rate selectivity of butterfly pits and etching pits.

It is another object of the present invention to provide an alkaline polishing solution that facilitates control of dishing and erosion pits.

Still another object of the present invention is to provide a method for preparing a polishing slurry, which is simple and suitable for mass production.

The technical scheme adopted for realizing the purpose of the invention is as follows:

a control method for CMP rate selectivity of a multilayer copper interconnection barrier layer comprises the following steps: adding the polishing solution into a polishing machine, and polishing under the conditions that the working pressure is 1-2PSI, the rotating speed of a polishing disc is 80-100 revolutions per minute, the rotating speed of a polishing head is 78-98 revolutions per minute and the flow of the polishing solution is 200-; the polishing solution comprises the following components in percentage by mass: 5-20% of silica sol, 0.001-10% of functional component, 0.001-10% of surfactant and the balance of deionized water; the functional component consists of an agent A, an agent B and an agent C, wherein the agent A is any one of an FA/O chelating agent, tetrahydroxyethyl ethylenediamine, ethylenediamine and triethanolamine, and the agent B is any one of copper sulfate, copper glycinate, copper citrate and copper citrate chelate; the agent C is one or any mixture of potassium nitrate, potassium citrate, potassium tartrate, ammonium citrate and ammonium sulfate; the pH value of the polishing solution is 7.5-10.5.

The agent A is an FA/O chelating agent, the agent B is citric acid chelated copper, and the agent C is potassium citrate.

The ratio of the citric acid chelated copper to the potassium citrate is 1-2: 1.

according to the mass percentage, the FA/O chelating agent is 0.05-0.1%, the citric acid chelated copper is 0.5-1%, and the potassium citrate is 0.5-1%.

The surfactant is one or any mixture of dodecyl dimethyl amine oxide, fatty alcohol-polyoxyethylene ether, FA/O surfactant, fatty alcohol-polyoxyethylene ether, polyvinylpyrrolidone, fatty alcohol-polyoxyethylene ether ammonium sulfate, sodium dodecyl benzene sulfonate, ammonium dodecyl sulfate and dodecyl benzene sulfonic acid.

The alkaline polishing solution comprises the following components in percentage by mass: 5-20% of silica sol, 0.001-10% of functional component, 0.001-10% of surfactant and the balance of deionized water; the functional component consists of an agent A, an agent B and an agent C, wherein the agent A is any one of an FA/O chelating agent, tetrahydroxyethyl ethylenediamine, ethylenediamine and triethanolamine, and the agent B is any one of copper sulfate, copper glycinate, copper citrate and copper citrate chelate; the agent C is one or any mixture of potassium nitrate, potassium citrate, potassium tartrate, ammonium citrate and ammonium sulfate; the pH value of the polishing solution is 7.5-10.5.

The agent A is an FA/O chelating agent, the agent B is citric acid chelated copper, and the agent C is potassium citrate; according to the mass percentage, the FA/O chelating agent is 0.05-0.1%, the citric acid chelated copper is 0.5-1%, and the potassium citrate is 0.5-1%.

A preparation method of an alkaline polishing solution comprises the following steps: sequentially adding the agent A, the agent B, the agent C and the surfactant into a proper amount of deionized water according to the component amount, and uniformly stirring in a step-by-step mixing manner; then adding the mixture into silica sol, uniformly stirring, and finally complementing the mixture with deionized water to obtain the alkaline polishing solution.

Compared with the prior art, the invention has the beneficial effects that:

1. the control method for the CMP rate selectivity of the multilayer copper interconnection barrier layer can control the removal rate of different materials by using the polishing solution without BTA and oxidant under specific process conditions, thereby effectively realizing the control on the butterfly pits and the etching pits, reducing the influence of the butterfly pits and the etching pits on the planarization and being beneficial to improving the yield and the yield of chips.

2. The control method of the invention adopts the FA/O chelating agent, the citric acid chelated copper and the potassium citrate to compound and is used for controlling the rate selection of the barrier layer, the rate selectivity is controllable and adjustable, and the TEOS rate: the CU rate can reach 0.8, the disc pits and the etching pits can be effectively controlled, and the disc pits and the etching pits can be effectively controlled to be reduced to the angstrom level.

3. The alkaline polishing solution does not contain BTA and an oxidant, can effectively improve the stability of the polishing solution, and has the stable time of about 90 days.

4. The polishing solution is alkaline, has the pH of 7.5-10.5, does not corrode equipment, and does not pollute the environment.

5. The alkaline polishing solution uses nano SiO₂The sol is used as a polishing liquid abrasive material, and has high concentration, good dispersion degree and small hardness.

6. The alkaline polishing solution disclosed by the invention is composed of silica sol, functional components and deionized water, is simple in components and good in stability, can be prepared from domestic raw materials, and is low in price.

7. The preparation method of the alkaline polishing solution is simple and is suitable for the requirement of large-scale industrial production.

Drawings

FIG. 1 is a graph showing a comparison of dishing before and after polishing in accordance with example 3 of the present invention;

FIG. 2 is a graph showing a comparison of pits before and after polishing in example 3 of the present invention.

Detailed Description

The invention is described in detail below with reference to the figures and specific examples.

The control method for the CMP rate selectivity of the multilayer copper interconnection barrier layer can effectively control the formation of butterfly pits and etch pits by controlling the removal speed of different metals, thereby achieving the purpose of planarization.

The agent A in the functional component is used as a pH value regulator, a buffering agent and a chelating agent and mainly plays a role in dissolving Cu²⁺Chelate synthesisIs a copper amine complex which is easy to dissolve in water and is removed; the reaction of agent B and agent A in water results in the formation of a large amount of free Cu in solution²⁺Under CMP conditions, Cu²⁺Can oxidize copper to Cu⁺The removal of copper is accelerated; the main function of agent C is to remove TEOS.

The working principle of the invention is illustrated by compounding the FA/O chelating agent, the citric acid chelated copper and the potassium citrate as an example:

1. FA/O type II chelator removal mechanism:

FA/O type II chelating agent for Cu²⁺Chelating to form a water-soluble copper amine complex, thereby breaking the ionization balance of insoluble substances, leading the reaction formula to be carried out rightwards and accelerating the removal of Cu.

Cu²⁺+2R(NH₂)₄→[Cu(R(NH₂)₄)₂]²⁺

2. The mechanism of citrate chelated copper and chelator removal:

the reaction of the citric acid chelated copper with the chelating agent in water results in the production of a large amount of free Cu in solution²⁺Under CMP conditions, Cu²⁺Can oxidize copper to generate Cu⁺The reaction formula is as follows:

the more chelating agent, the free Cu²⁺The more, Cu under CMP conditions²⁺Can overcome the reaction potential epitaxy, and can react with non-reaction or weak reaction. With Cu²⁺Increasing the reaction formula to the right, and accelerating the removal of copper.

3. The mechanism of potassium citrate removal is:

in alkaline solution, TEOS and OH^-Produces weak hydrolysis reaction to generate slightly soluble silicate SiO₃^2-Due to SiO₃^2-Has low solubility, and limits further hydrolysis of TEOS. But K ionized by potassium citrate⁺With SiO₃^2-Binding to form a more soluble K₂SiO₃With K⁺And SiO₃^2-And the combination accelerates the hydrolysis of TEOS in the solution and promotes the removal of TEOS medium. The reaction is as follows:

SiO₂+2OH^-→SiO₃^2-+H₂O

SiO₃^2-+2K⁺→K₂SiO₃

example 1

Taking 250ml of silica sol with the abrasive mass fraction of 40%, wherein the grain diameter is 50nm-90nm, and the dispersion degree is +/-3%; 5g of citric acid chelated copper; 5g of potassium citrate; 0.5g of FA/O type II chelating agent. 3g of fatty alcohol-polyoxyethylene ether and 1g of dodecyl benzene sulfonic acid. The preparation method comprises the following steps: mixing an FA/O II type chelating agent, citric acid chelated copper, potassium citrate, fatty alcohol-polyoxyethylene ether and dodecylbenzene sulfonic acid, adding a proper amount of ionized water, adding the mixture into silica sol, uniformly stirring the mixture in a step-by-step mixing manner, finally supplementing the mixture to 1000g with deionized water, and continuously uniformly stirring the mixture to obtain the polishing solution S1.

And (3) test monitoring: the pH value of the polishing solution is 9.5, and the particle size is 80-120 nm.

Test and test: using prepared polishing solution S1 on an AMAT-LK CMP type polishing machine produced by Applied Materials; working pressure Z₁：1psi、Z₂：1.7psi、Z₃：1.5psi、Z₄：1.5psi、Z₅1.5 psi; the rotational speed of the throwing disc is 80 r/min; the head throwing speed is 78 r/min; the flow rate of the polishing solution was 300 ml/min. Polishing a 300mm pattern sheet, cleaning, and measuring the rate by using a medium film thickness tester and a four-probe resistivity measuring instrument. The dishing and erosion pits of the wafer before and after the barrier layer polishing were measured by an Atomic Force Microscope (AFM) manufactured by Veeco precision instruments. The results are shown in Table 1.

Example 2

Taking 250ml of silica sol with the abrasive mass fraction of 40%, wherein the grain diameter is 50nm-90nm, and the dispersion degree is +/-3%; 10g of citric acid chelated copper; 5g of potassium citrate; 3g of fatty alcohol-polyoxyethylene ether and 1g of dodecyl benzene sulfonic acid. 0.5g of FA/O II chelating agent as pH regulator, buffer and chelating agent. The preparation method comprises the following steps: mixing an FA/O II type chelating agent, citric acid chelated copper, potassium citrate, fatty alcohol-polyoxyethylene ether and dodecylbenzene sulfonic acid, adding a proper amount of ionized water, adding the mixture into silica sol, uniformly stirring the mixture in a step-by-step mixing manner, finally supplementing the mixture to 1000g with deionized water, and continuously uniformly stirring the mixture to obtain the polishing solution S2.

Test and test: using prepared polishing solution S2 on an AMAT-LK CMP type polishing machine produced by Applied Materials; working pressure Z₁：1psi、Z₂：1.7psi、Z₃：1.5psi、Z₄：1.5psi、Z₅1.5 psi; the rotational speed of the throwing disc is 80 r/min; the head throwing speed is 78 r/min; the flow rate of the polishing solution was 300 ml/min. Polishing a 300mm pattern sheet, cleaning, and measuring the rate by using a medium film thickness tester and a four-probe resistivity measuring instrument. The dishing and erosion pits of the wafer before and after the barrier layer polishing were measured by an Atomic Force Microscope (AFM) manufactured by Veeco precision instruments. The results are shown in Table 1.

Example 3

Taking 250ml of silica sol with the abrasive mass fraction of 40%, wherein the grain diameter is 50nm-90nm, and the dispersion degree is +/-3%; 10g of citric acid chelated copper; 10g of potassium citrate; 3g of fatty alcohol-polyoxyethylene ether and 1g of dodecyl benzene sulfonic acid. 0.5g of FA/O II chelating agent as pH regulator, buffer and chelating agent. The preparation method comprises the following steps: mixing an FA/O II type chelating agent, citric acid chelated copper, potassium citrate, fatty alcohol-polyoxyethylene ether and dodecylbenzene sulfonic acid, adding a proper amount of ionized water, adding the mixture into silica sol, uniformly stirring the mixture in a step-by-step mixing manner, finally supplementing the mixture to 1000g with deionized water, and continuously uniformly stirring the mixture to obtain the polishing solution S3.

Test and test: with prepared polishingThe liquid S3 is Applied to an AMAT-LK CMP type polishing machine produced by Applied Materials; working pressure Z₁：1psi、Z₂：1.7psi、Z₃：1.5psi、Z₄：1.5psi、Z₅1.5 psi; the rotational speed of the throwing disc is 80 r/min; the head throwing speed is 78 r/min; the flow rate of the polishing solution was 300 ml/min. Polishing a 300mm pattern sheet, cleaning, and measuring the rate by using a medium film thickness tester and a four-probe resistivity measuring instrument. The dishing and erosion pits of the wafer before and after the barrier layer polishing were measured by an Atomic Force Microscope (AFM) manufactured by Veeco precision instruments. The results are shown in Table 1.

Example 4

Taking 250ml of silica sol with the abrasive mass fraction of 40%, wherein the grain diameter is 50nm-90nm, and the dispersion degree is +/-3%; 10g of citric acid chelated copper; 10g of potassium citrate; 3g of fatty alcohol-polyoxyethylene ether and 1g of dodecyl benzene sulfonic acid. And 1g of FA/O II chelating agent as a pH value regulator, a buffering agent and a chelating agent. The preparation method comprises the following steps: mixing an FA/O II type chelating agent, citric acid chelated copper, potassium citrate, fatty alcohol-polyoxyethylene ether and dodecylbenzene sulfonic acid, adding a proper amount of ionized water, adding the mixture into silica sol, uniformly stirring the mixture in a step-by-step mixing manner, finally supplementing the mixture to 1000g with deionized water, and continuously uniformly stirring the mixture to obtain the polishing solution S4.

Test and test: using prepared polishing solution S4 on an AMAT-LK CMP type polishing machine produced by Applied Materials; working pressure Z₁：1psi、Z₂：1.7psi、Z₃：1.5psi、Z₄：1.5psi、Z₅1.5 psi; the rotational speed of the throwing disc is 80 r/min; the head throwing speed is 78 r/min; the flow rate of the polishing solution was 300 ml/min. Polishing a 300mm pattern sheet, cleaning, and measuring the rate by using a medium film thickness tester and a four-probe resistivity measuring instrument. The dishing and erosion pits of the wafer before and after the barrier layer polishing were measured by an Atomic Force Microscope (AFM) manufactured by Veeco precision instruments. The results are shown in Table 1.

TABLE 1 four polishing solution pair rates and dishing and erosion pit repair capabilities

As can be seen from the polishing rates in Table 1, as the content of the chelating agent of FA/O type II increases, free Cu is present in the slurry²⁺Increase, under CMP conditions, Cu²⁺The ions may oxidize and accelerate the copper removal rate. And the content of citric acid chelated copper is increased, the speed of copper is basically unchanged, and the removal rate of the medium can be improved. The introduction of CAK can enable the removal rate CU to achieve 1:5 of TEOS, and the rate selection ratio is remarkably improved.

FIGS. 1 and 2 are graphs showing a comparison of dishing and erosion pit before and after polishing with the polishing solution S3 obtained in example 3, respectively, and it can be seen from FIGS. 1 and 2 that at the same time, dishing pits can be removed from the polishing solution S3

Down to

The etch pits may be formed of

Down to

The control method for the CMP rate selectivity of the multilayer copper interconnection barrier layer can control the removal rate of different materials by using the polishing solution without BTA and oxidant under specific process conditions, thereby effectively realizing the control on the butterfly pits and the etching pits, reducing the influence of the butterfly pits and the etching pits on the planarization and being beneficial to improving the yield and the yield of chips.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

Translated fromChinese

1.一种用于多层铜互连阻挡层CMP速率选择性的控制方法，其特征在于，包括下述步骤：将抛光液加入抛光机中，在工作压力为1-2PSI、抛盘转速为80-100转/分、抛头转速为78-98转/分、抛光液流量为200-300ml/min的条件下抛光；所述抛光液按质量百分比计由下述组分组成：硅溶胶5-20％，功能型组分0.001-10％，表面活性剂0.001-10％，去离子水余量；所述功能型组分由A剂、B剂及C剂组成，所述A剂为FA/O螯合剂、四羟基乙基乙二胺、乙二胺及三乙醇胺中的任一种，所述B剂为硫酸铜、甘氨酸铜、柠檬酸铜及柠檬酸螯合铜中的任一种；所述C剂为硝酸钾、柠檬酸钾、酒石酸钾、柠檬酸铵及硫酸铵中的一种或者任意混合；所述抛光液的pH值为7.5—10.5。1. a control method for multi-layer copper interconnection barrier layer CMP rate selectivity, is characterized in that, comprises the following steps: polishing liquid is added in polishing machine, at working pressure, be 1-2PSI, throwing disk rotating speed is 80 -100 rpm, polishing head rotation speed of 78-98 rpm, polishing liquid flow rate of 200-300ml/min; the polishing liquid is composed of the following components by mass percentage: silica sol 5- 20%, functional component 0.001-10%, surfactant 0.001-10%, deionized water balance; the functional component is composed of A, B and C, and the A is FA/ Any one of O chelating agent, tetrahydroxyethylethylenediamine, ethylenediamine and triethanolamine, and the B agent is any one of copper sulfate, copper glycinate, copper citrate and chelated copper citrate; The C agent is one of potassium nitrate, potassium citrate, potassium tartrate, ammonium citrate and ammonium sulfate, or any combination thereof; the pH value of the polishing liquid is 7.5-10.5.

2.根据权利要求1所述的用于多层铜互连阻挡层CMP速率选择性的控制方法，其特征在于，所述A剂为FA/O螯合剂，所述B剂为柠檬酸螯合铜，所述C剂为柠檬酸钾。2. The control method for multi-layer copper interconnection barrier CMP rate selectivity according to claim 1, wherein the A agent is a FA/O chelating agent, and the B agent is a citric acid chelating agent Copper, the C agent is potassium citrate.

3.根据权利要求2所述的用于多层铜互连阻挡层CMP速率选择性的控制方法，其特征在于，所述柠檬酸螯合铜与柠檬酸钾的比例为1-2：1。3 . The method for controlling the rate selectivity of CMP of a multilayer copper interconnection barrier layer according to claim 2 , wherein the ratio of the chelated copper citrate to potassium citrate is 1-2:1. 4 .

4.根据权利要求2所述的用于多层铜互连阻挡层CMP速率选择性的控制方法，其特征在于，按质量百分比计，所述FA/O螯合剂为0.05-0.1％，所述柠檬酸螯合铜为0.5-1％，所述柠檬酸钾为0.5-1％。4. The method for controlling the CMP rate selectivity of a multilayer copper interconnection barrier layer according to claim 2, wherein, by mass percentage, the FA/O chelating agent is 0.05-0.1%, and the The chelated copper citrate is 0.5-1%, and the potassium citrate is 0.5-1%.

5.根据权利要求3所述的用于多层铜互连阻挡层CMP速率选择性的控制方法，其特征在于，所述表面活性剂为十二烷基二甲基氧化胺、脂肪醇聚氧乙烯醚、FA/O表面活性剂、脂肪醇聚氧乙烯醚、聚乙烯吡咯烷酮、脂肪醇聚氧乙烯醚硫酸铵、十二烷基硫酸钠、十二烷基苯磺酸钠、十二烷基硫酸铵、十二烷基苯磺酸中的一种或任意混合。5. The method for controlling the CMP rate selectivity of a multilayer copper interconnection barrier layer according to claim 3, wherein the surfactant is dodecyl dimethyl amine oxide, fatty alcohol polyoxygen Vinyl ether, FA/O surfactant, fatty alcohol polyoxyethylene ether, polyvinylpyrrolidone, fatty alcohol polyoxyethylene ether ammonium sulfate, sodium lauryl sulfate, sodium dodecylbenzenesulfonate, dodecyl One of ammonium sulfate and dodecylbenzenesulfonic acid or any mixture.

6.一种碱性抛光液，其特征在于，按质量百分比计由下述组分组成：硅溶胶5-20％，功能型组分0.001-10％，表面活性剂0.001-10％，去离子水余量；所述功能型组分由A剂、B剂及C剂组成，所述A剂为FA/O螯合剂、四羟基乙基乙二胺、乙二胺及三乙醇胺中的任一种，所述B剂为硫酸铜、甘氨酸铜、柠檬酸铜及柠檬酸螯合铜中的任一种；所述C剂为硝酸钾、柠檬酸钾、酒石酸钾、柠檬酸铵及硫酸铵中的一种或者任意混合；所述抛光液的pH值为7.5—10.5。6. An alkaline polishing liquid, characterized in that it is composed of the following components by mass percentage: 5-20% of silica sol, 0.001-10% of functional components, 0.001-10% of surfactant, deionized The remaining amount of water; the functional component is composed of agent A, agent B and agent C, and the agent A is any one of FA/O chelating agent, tetrahydroxyethylethylenediamine, ethylenediamine and triethanolamine The B agent is any one of copper sulfate, copper glycinate, copper citrate and citric acid chelated copper; the agent C is potassium nitrate, potassium citrate, potassium tartrate, ammonium citrate and ammonium sulfate. One or any mixture; the pH value of the polishing liquid is 7.5-10.5.

7.根据权利要求6所述的碱性抛光液，其特征在于，所述A剂为FA/O螯合剂，所述B剂为柠檬酸螯合铜，所述C剂为柠檬酸钾；按质量百分比计，所述FA/O螯合剂为0.05-0.1％，所述柠檬酸螯合铜为0.5-1％，所述柠檬酸钾为0.5-1％。7. alkaline polishing liquid according to claim 6, is characterized in that, described A agent is FA/O chelating agent, described B agent is citric acid chelated copper, and described C agent is potassium citrate; In terms of mass percentage, the FA/O chelating agent is 0.05-0.1%, the chelated copper citrate is 0.5-1%, and the potassium citrate is 0.5-1%.

8.根据权利要求6所述的碱性抛光液，其特征在于，所述表面活性剂为十二烷基二甲基氧化胺、脂肪醇聚氧乙烯醚、FA/O表面活性剂、脂肪醇聚氧乙烯醚、聚乙烯吡咯烷酮、脂肪醇聚氧乙烯醚硫酸铵、十二烷基硫酸钠、十二烷基苯磺酸钠、十二烷基硫酸铵、十二烷基苯磺酸中的一种或任意混合。8. The alkaline polishing liquid according to claim 6, wherein the surfactant is dodecyl dimethyl amine oxide, fatty alcohol polyoxyethylene ether, FA/O surfactant, fatty alcohol Polyoxyethylene ether, polyvinylpyrrolidone, fatty alcohol polyoxyethylene ether ammonium sulfate, sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, ammonium dodecyl sulfate, dodecylbenzenesulfonic acid One or any combination.

9.一种权利要求6所述碱性抛光液的制备方法，其特征在于，包括下述步骤：按组分量将所述A剂、B剂、C剂及表面活性剂依次加入适量去离子水中，通过逐级混合的方式搅拌均匀；之后加入到硅溶胶中搅拌均匀，最后使用去离子水补足，得到本发明的碱性抛光液。9. a preparation method of the described alkaline polishing liquid of claim 6, is characterized in that, comprises the following steps: described A agent, B agent, C agent and surfactant are successively added to an appropriate amount of deionized water by component amount , stir evenly by step-by-step mixing; then add it into the silica sol and stir evenly, and finally use deionized water to make up, to obtain the alkaline polishing liquid of the present invention.