CN110951401A

CN110951401A - Polishing solution and preparation method and application thereof

Info

Publication number: CN110951401A
Application number: CN201911286102.3A
Authority: CN
Inventors: 李涛; 孙大陟
Original assignee: Southwest University of Science and Technology
Current assignee: Southwest University of Science and Technology; Southern University of Science and Technology
Priority date: 2019-12-13
Filing date: 2019-12-13
Publication date: 2020-04-03
Anticipated expiration: 2039-12-13
Also published as: CN110951401B

Abstract

The invention relates to a chemical mechanical polishing solution, a preparation method and application thereof. The invention utilizes inorganic filler zirconium phosphate as polishing abrasive particles. Compared with the traditional flaky alumina, the novel polishing material has the advantages of better dispersity, high stability and unobvious sedimentation effect. In addition, the zirconium phosphate has a two-dimensional lamellar structure, and can generate directional arrangement when being subjected to external force, so that the orientation of the abrasive particles is optimized, the optimized polishing abrasive particles are more stable in the polishing process, the scratches are less, the whole polishing system is more stable, and a better polishing effect can be achieved.

Description

Polishing solution and preparation method and application thereof

Technical Field

The invention relates to the field of chemical mechanical polishing solution, in particular to polishing solution and a preparation method and application thereof.

Background

Metal materials have received extensive attention over the past decades due to their potential applications in the fields of national defense, aerospace, chemical, electronics, mechanical manufacturing, and the like. When the metal material is adopted, higher requirements are put forward on the performances of the overall flatness, roughness, defects and the like of the surface of the metal alloy product. Therefore, a series of processes such as turning, grinding, etc. must be performed to reduce the roughness of the surface. Sometimes, depending on the roughness requirement, a polishing process may be performed at a later stage to further reduce the roughness. In recent years, the ability of Chemical Mechanical Polishing (CMP) processes to provide planarization polishing of metal materials has received wide acceptance. Especially in the current development environment, the shrinking feature size of integrated circuits is driving the development of Chemical Mechanical Polishing (CMP) technology, which brings new possibilities for the development of innovative semiconductor manufacturing processes.

The chemical mechanical polishing solution used in the CMP process generally comprises abrasive particles, an oxidizing agent, a pH adjusting agent, a corrosion inhibitor, a dispersing agent, and the like, and is used for polishing a metal material with uneven morphology by using colloidal slurry consisting of the abrasive particles dispersed in various chemical solutions, thereby achieving a planarization polishing effect. However, for aluminum alloys, the hardness is low and scratches are easily generated during the CMP process, i.e., for CMP systems, the aluminum alloys have a high sensitivity to scratches. Further, it is known that an aluminum alloy is highly chemically corroded, and microstructure corrosion (pitting corrosion, intergranular corrosion, etc.) is likely to occur. Microstructural corrosion is caused by the presence of intermetallic particles, which may be anodes or cathodes. The corrosion sensitivity presents challenges to the chemistry of the slurry. Therefore, balancing mechanical abrasive particle mechanical polishing and chemical attack polishing is considered to be a key issue for the feasibility of aluminum alloy CMP processes.

CN1398938A provides a chemical mechanical global planarization polishing solution for multilayer copper wiring of a very large scale integrated circuit, which has small damage, high flatness and easy cleaning; the device is not corroded, and the environment is not polluted; the selectivity is strong, and the speed is high; the price is cheap and the cost is low. The method is used for chemical mechanical global planarization polishing of the multilayer copper wiring of the ultra-large scale integrated circuit. Further, CN1560161A provides a water-based nano-diamond polishing solution and a manufacturing method thereof, and the provided polishing solution can be used for ultra-precision polishing of various optoelectronic crystals, computer hard disk substrates, optical components and devices, and copper-connected semiconductor integrated circuits, etc., and reduces the surface roughness of products to sub-nanometer level. CN1621469A provides a chemical mechanical polishing solution, which utilizes the rich surface hydroxyl of the abrasive particles and the excellent monodispersity of the abrasive particles in an aqueous solution, is used for global planarization polishing of an interlayer medium in an IC processing process, avoids submicron scratch on a polished surface, and has high flatness, easy cleaning and high polishing rate. The method can be used for the CMP fine polishing process in the manufacturing process of the ultra-large scale integrated circuit and the precision polishing of other optical materials. However, the polishing solution has poor dispersibility, low stability, obvious sedimentation effect and poor polishing effect.

Disclosure of Invention

In view of the problems in the prior art, the invention aims to provide a chemical mechanical polishing solution, a preparation method and application thereof. In addition, the zirconium phosphate has a lamellar structure, and can generate directional arrangement when being subjected to external force, so that the orientation of the abrasive particles is optimized, the optimized polishing abrasive particles are more stable in the polishing process, fewer scratches are generated, the whole polishing system is more stable, and a better polishing effect can be achieved.

In order to achieve the purpose, the invention adopts the following technical scheme:

in a first aspect, the present invention provides a chemical mechanical polishing solution, which comprises abrasive particles, a dispersant, an oxidant, a corrosion inhibitor, a pH adjuster, a stabilizer, and a solvent.

The novel polishing material has better dispersibility, high stability and unobvious settling effect compared with the traditional flaky alumina. In addition, the zirconium phosphate has a two-dimensional lamellar structure, and can generate directional arrangement when being subjected to external force, so that the orientation of the abrasive particles is optimized, the optimized polishing abrasive particles are more stable in the polishing process, the scratches are less, the whole polishing system is more stable, and a better polishing effect can be achieved.

The sum of the mass percentages of the components of the polishing solution is 100%.

In a preferred embodiment of the present invention, the content of the abrasive grains in the chemical mechanical polishing liquid is 8 to 15% by mass, for example, 8%, 8.5%, 9%, 9.5%, 10%, 10.5%, 11%, 11.5%, 12%, 12.5%, 13%, 13.5%, 14%, 14.5%, or 15%, but is not limited to the above-mentioned values, and other values not listed in the above range are also applicable.

Preferably, the chemical mechanical polishing liquid contains 1-5% by weight of the dispersant, such as 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, or 5%, but not limited to the listed values, and other values not listed in the range are also applicable.

Preferably, the content of the oxidizing agent in the chemical mechanical polishing solution is 0.5-2% by mass, and may be, for example, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, or 2%, but is not limited to the listed values, and other values not listed in the range are also applicable.

Preferably, the amount of the corrosion inhibitor in the chemical mechanical polishing solution is 0.1-0.5% by mass, and may be, for example, 0.1%, 0.14%, 0.18%, 0.22%, 0.26%, 0.3%, 0.34%, 0.38%, 0.42%, 0.46%, or 0.5%, but is not limited to the listed values, and other values not listed in the range are also applicable.

Preferably, the chemical mechanical polishing solution contains 0.1-0.5% by mass of the stabilizer, such as 0.1%, 0.14%, 0.18%, 0.22%, 0.26%, 0.3%, 0.34%, 0.38%, 0.42%, 0.46%, or 0.5%, but not limited to the listed values, and other values not listed in the range are also applicable.

Preferably, the chemical mechanical polishing solution contains 77-90.3% by weight of the solvent, such as 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90% or 90.3%, but not limited to the listed values, and other values not listed in the range are also applicable.

As a preferred technical scheme of the invention, the dispersing agent comprises polyethylene glycol.

Preferably, the oxidizing agent includes a water-soluble oxidizing agent, such as potassium permanganate, sodium chlorate, sodium perchlorate, and the like, but is not limited to the listed types, and other types not listed in the scope are also applicable, and hydrogen peroxide is preferred.

Preferably, the corrosion inhibitor comprises an ionic corrosion inhibitor, such as quinoline, ethylene diamine tetraacetic acid, hexadecylamine, methylbenzotriazole, benzotriazole and the like, but is not limited to the listed types, and other types not listed in the scope are equally applicable, preferably benzotriazole.

Preferably, the stabilizer comprises sodium dodecylbenzenesulfonate and polyvinyl alcohol.

Preferably, the pH modifier comprises a water-soluble green environmental-friendly modifier, preferably a combination of 1 or at least 2 of salicylic acid, citric acid or phosphoric acid, such as a combination of salicylic acid and citric acid, a combination of citric acid and phosphoric acid, a combination of phosphoric acid and salicylic acid, and the like, but is not limited to the listed combinations, and other combinations not listed within the scope are equally applicable.

Preferably, the solvent comprises water.

As a preferable technical scheme of the invention, the dispersant also comprises sodium polyacrylate or polyacrylamide.

As a preferred technical solution of the present invention, the abrasive grains are zirconium phosphate nanosheets.

Preferably, the abrasive particles have a diameter of 0.1 to 10 μm, and may be, for example, 0.1 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, or 10 μm, but are not limited to the listed values, and other values not listed in this range are equally applicable.

In a preferred embodiment of the present invention, the chemical mechanical polishing liquid has a pH of 2 to 4, for example, 2, 2.2, 2.4, 2.6, 2.8, 3, 3.2, 3.4, 3.6, 3.8, or 4, but is not limited to the above-mentioned values, and other values not listed in the range are also applicable.

In a second aspect, the present invention provides a method for preparing the chemical mechanical polishing solution according to the first aspect, the method comprising: and sequentially adding abrasive particles, a dispersing agent, a pH regulator, an oxidant, a corrosion inhibitor and a stabilizer into a solvent and stirring to obtain the chemical mechanical polishing solution.

As a preferred embodiment of the present invention, the stirring speed is 1000-3000r/min, such as 1000r/min, 1200r/min, 1400r/min, 1600r/min, 1800r/min, 2000r/min, 2200r/min, 2400r/min, 2600r/min, 2800r/min or 3000r/min, but not limited to the listed values, and other values not listed in the range are also applicable.

As a preferred technical solution of the present invention, the preparation method comprises: sequentially adding abrasive particles, a dispersing agent, a pH regulator, an oxidant, a corrosion inhibitor and a stabilizer into a solvent and stirring to obtain the chemical mechanical polishing solution; wherein the stirring speed is 1000-3000 r/min; the mass percentage of abrasive particles in the chemical mechanical polishing solution is 8-15%; the mass percentage of the dispersing agent in the chemical mechanical polishing solution is 1-5%; the mass percentage of the oxidant in the chemical mechanical polishing solution is 0.5-2%; the mass percentage of the corrosion inhibitor in the chemical mechanical polishing solution is 0.1-0.5%; the mass percentage of the stabilizer in the chemical mechanical polishing solution is 0.1-0.5%; the content of the solvent in the chemical mechanical polishing solution is 77-90.3%; the dispersant comprises polyethylene glycol; the oxidizing agent comprises a water-soluble oxidizing agent; the corrosion inhibitor comprises an ionic corrosion inhibitor; the stabilizer comprises sodium dodecyl benzene sulfonate and polyvinyl alcohol; the pH regulator comprises a water-soluble green environment-friendly regulator; the solvent comprises water; the dispersant also comprises sodium polyacrylate or polyacrylamide; the abrasive particles are zirconium phosphate nano-sheets; the diameter of the abrasive particles is 0.1-10 μm; the pH value of the polishing solution is 2-4.

In a third aspect, the present invention provides the use of the chemical mechanical polishing liquid according to the first aspect for polishing aluminum alloys, low carbon steels and red copper.

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

(1) compared with the abrasive particles in the traditional polishing solution, the abrasive particles in the chemical mechanical polishing solution provided by the invention have the advantages of better dispersibility, high stability and unobvious sedimentation effect.

(2) Because the zirconium phosphate has a lamellar structure, the zirconium phosphate can be directionally arranged when being subjected to external force, so that the orientation of the abrasive particles is optimized, the optimized polishing abrasive particles are more stable in the polishing process, fewer scratches are generated, the whole polishing system is more stable, and a better polishing effect can be achieved; the roughness of the sample surface after polishing is less than 60 nm.

Drawings

FIG. 1 is an SEM photograph of abrasive grains of example 1 of the present invention.

The present invention is described in further detail below. The following examples are merely illustrative of the present invention and do not represent or limit the scope of the claims, which are defined by the claims.

Detailed Description

The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings.

To better illustrate the invention and to facilitate the understanding of the technical solutions thereof, typical but non-limiting examples of the invention are as follows:

example 1

The embodiment provides a chemical mechanical polishing solution, which includes 10% by mass of 1.2 μm zirconium phosphate nanosheet, 1% of polyethylene glycol (with a polymerization degree of 600) and sodium polyacrylate (with a molecular weight of 10000), 1% of 30 wt% hydrogen peroxide, 0.5% of sodium dodecyl benzene sulfonate and benzotriazole, 0.25% of sodium dodecyl benzene sulfonate and polyvinyl alcohol (PVA,1799 type, 10%), and the balance water; the pH of the chemical mechanical polishing solution is 3;

the preparation method of the polishing solution comprises the following steps:

sequentially adding abrasive particles, a dispersing agent, an oxidant, a corrosion inhibitor and a stabilizing agent into water according to mass fraction, and stirring for 5min under the condition of 1500r/min to obtain the chemical mechanical polishing solution; wherein the pH regulator is citric acid.

Polishing a 6063# aluminum alloy sample by using the chemical mechanical polishing solution by using a polishing machine, and adding a proper amount of the prepared chemical mechanical polishing solution during polishing; further, in this example, the above aluminum alloy samples were polished under the same conditions using the fujimi 103 polishing solution, and the results are detailed in table 1. The SEM photograph of the abrasive grains is shown in fig. 1.

Example 2

The embodiment provides a chemical mechanical polishing solution, which includes 13.5% by mass of 0.5 μm zirconium phosphate nanosheet, 2% of polyethylene glycol (with a polymerization degree of 600) and sodium polyacrylate (with a molecular weight of 20000), 2% of 30 wt% of hydrogen peroxide, 0.22% of sodium dodecyl benzene sulfonate and benzotriazole, 0.5% of sodium dodecyl benzene sulfonate and polyvinyl alcohol (PVA,1799 type, 10%), and the balance of water; the pH of the chemical mechanical polishing solution is 4;

the preparation method of the chemical mechanical polishing solution comprises the following steps:

sequentially adding abrasive particles, a dispersing agent, an oxidant, a corrosion inhibitor and a stabilizing agent into water according to mass fraction, and stirring for 5min under the condition of 1000r/min to obtain the polishing solution; wherein the pH regulator is citric acid.

Polishing a 6063# aluminum alloy sample by using the chemical mechanical polishing solution by using a polishing machine, and adding a proper amount of the prepared chemical mechanical polishing solution during polishing; further, in this example, the above aluminum alloy samples were polished under the same conditions using the fujimi 103 polishing solution, and the results are detailed in table 1.

Example 3

The embodiment provides a chemical mechanical polishing solution, which comprises 12% by mass of 2 μm zirconium phosphate nanosheets, 1.7% by mass of polyethylene glycol (with a polymerization degree of 900) and polyacrylamide (with a molecular weight of 20000), 1.7% by mass of ferric nitrate solution, 0.4% by mass of benzotriazole, 0.4% by mass of sodium dodecyl sulfate and polyvinyl alcohol (PVA, type 1799, 10%), and the balance of water; the pH of the chemical mechanical polishing solution is 2.5;

sequentially adding abrasive particles, a dispersing agent, a pH regulator, an oxidant, a corrosion inhibitor and a stabilizer into water according to the mass fraction, and stirring for 10min at 2000r/min to obtain the chemical mechanical polishing solution; wherein the pH regulator is salicylic acid.

Polishing the 20# low-carbon steel sample by using the chemical mechanical polishing solution by using a polishing machine, and adding a proper amount of the prepared chemical mechanical polishing solution during polishing; further, in this example, the aforementioned low carbon steel samples were polished under the same conditions using the foumi 103 polishing solution, and the results are detailed in table 1.

Example 4

This example provides a chemical mechanical polishing solution, which includes 15% by mass of 9 μm zirconium phosphate nanosheet, 3% of polyethylene glycol (with a polymerization degree of 500) and polyacrylamide (with a molecular weight of 20000), 1.3% of 30 wt% of aqueous hydrogen peroxide solution, 0.1% of benzotriazole, and 0.18% of sodium dodecyl sulfate and polyvinyl alcohol (PVA, type 1799, 10%), with the balance being water; the pH of the chemical mechanical polishing solution is 2;

sequentially adding abrasive particles, a dispersing agent, a pH regulator, an oxidant, a corrosion inhibitor and a stabilizer into water according to the mass fraction, and stirring for 10min under the condition of 2600r/min to obtain the chemical mechanical polishing solution; wherein the pH regulator is salicylic acid.

Example 5

The embodiment provides a chemical mechanical polishing solution, which includes 12% by mass of 2 μm zirconium phosphate nanosheets, 1.2% by mass of polyethylene glycol (degree of polymerization 2000) and polyacrylamide (molecular weight 30000), 0.5% by mass of nitric acid, 0.3% by mass of sodium dodecylbenzenesulfonate and polyvinyl alcohol (PVA,1799 type, 10%), and the balance of water; the pH of the chemical mechanical polishing solution is 3;

sequentially adding abrasive particles, a dispersing agent, a pH regulator, an oxidant, a corrosion inhibitor and a stabilizer into water according to mass fraction, and stirring for 20min under the condition of 1500r/min to obtain the chemical mechanical polishing solution; wherein the pH regulator is citric acid and salicylic acid.

Polishing the T2 red copper sample by the chemical mechanical polishing solution by a polishing machine, and adding a proper amount of the prepared chemical mechanical polishing solution during polishing; further, in this example, the copper sample was polished under the same conditions using the foumi 103 polishing solution, and the results are shown in table 1.

Example 6

The embodiment provides a chemical mechanical polishing solution, which comprises 8.5% by mass of 0.7 μm zirconium phosphate nanosheets, 4% of polyethylene glycol (polymerization degree 4000) and polyacrylamide (molecular weight 30000), 0.5% of 30% of hydrogen peroxide, 0.46% of sodium dodecyl benzene sulfonate, 0.1% of sodium dodecyl sulfate and polyvinyl alcohol (PVA,1799 type, 10%), and the balance of water; the pH of the chemical mechanical polishing solution is 3.4;

sequentially adding abrasive particles, a dispersing agent, a pH regulator, an oxidant, a corrosion inhibitor and a stabilizer into water according to mass fraction, and stirring for 20min under the condition of 3000r/min to obtain the chemical mechanical polishing solution; wherein the pH regulator is citric acid and salicylic acid.

TABLE 1 test results of the samples in the examples

It can be seen from the results of the above embodiments that, because the abrasive zirconium phosphate in the chemical mechanical polishing solution provided by the present invention has a lamellar structure, and is oriented when an external force is applied, the orientation of the abrasive particles is optimized, so that the optimized polishing abrasive particles are more stable in the polishing process, the scratches are less, the whole polishing system is more stable, and the chemical mechanical polishing solution has a good polishing effect.

The preferred embodiments of the present invention have been described in detail, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.

It should be noted that the various technical features described in the above embodiments can be combined in any suitable manner without contradiction, and the invention is not described in any way for the possible combinations in order to avoid unnecessary repetition.

In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.

Claims

1. The chemical mechanical polishing solution is characterized by comprising abrasive particles, a dispersing agent, an oxidizing agent, a corrosion inhibitor, a pH regulator, a stabilizing agent and a solvent.

2. The chemical mechanical polishing solution according to claim 1, wherein the abrasive grains in the chemical mechanical polishing solution are 8 to 15% by mass;

preferably, the mass percentage of the dispersing agent in the chemical mechanical polishing liquid is 1-5%;

preferably, the mass percentage of the oxidant in the chemical mechanical polishing solution is 0.5-2%;

preferably, the mass percentage of the corrosion inhibitor in the chemical mechanical polishing solution is 0.1-0.5%;

preferably, the mass percentage content of the stabilizer in the chemical mechanical polishing solution is 0.1-0.5%;

preferably, the chemical mechanical polishing solution contains 77-90.3% of solvent by mass.

3. The chemical mechanical polishing solution according to claim 1 or 2, wherein the dispersant comprises polyethylene glycol;

preferably, the oxidant comprises a water-soluble oxidant, preferably hydrogen peroxide;

preferably, the corrosion inhibitor comprises an ionic corrosion inhibitor, preferably benzotriazole;

preferably, the stabilizer comprises sodium dodecylbenzene sulfonate and polyvinyl alcohol;

preferably, the pH adjuster comprises a water-soluble green environmental-friendly adjuster, preferably a combination of 1 or at least 2 in salicylic acid, citric acid or phosphoric acid;

preferably, the solvent comprises water.

4. The chemical mechanical polishing solution according to any one of claims 1 to 3, wherein the dispersant further comprises sodium polyacrylate or polyacrylamide.

5. The chemical mechanical polishing solution according to any one of claims 1 to 4, wherein the abrasive particles are zirconium phosphate nanoplates;

preferably, the abrasive particles have a diameter of 0.1 to 10 μm.

6. The chemical mechanical polishing solution according to any one of claims 1 to 5, wherein the chemical mechanical polishing solution has a pH of 2 to 4.

7. The method of preparing a chemical mechanical polishing solution according to any of claims 1 to 6, comprising: and sequentially adding abrasive particles, a dispersing agent, a pH regulator, an oxidant, a corrosion inhibitor and a stabilizer into a solvent and stirring to obtain the polishing solution.

8. The method as claimed in claim 7, wherein the stirring speed is 1000-3000 r/min.

9. The method of claim 8, comprising: sequentially adding abrasive particles, a dispersing agent, a pH regulator, an oxidant, a corrosion inhibitor and a stabilizer into a solvent and stirring to obtain the chemical mechanical polishing solution; wherein the stirring speed is 1000-3000 r/min; the mass percentage of abrasive particles in the chemical mechanical polishing solution is 8-15%; the mass percentage of the dispersing agent in the chemical mechanical polishing solution is 1-5%; the mass percentage of the oxidant in the chemical mechanical polishing solution is 0.5-2%; the mass percentage of the corrosion inhibitor in the chemical mechanical polishing solution is 0.1-0.5%; the mass percentage of the stabilizer in the chemical mechanical polishing solution is 0.1-0.5%; the content of the solvent in the chemical mechanical polishing solution is 77-90.3%; the chemical mechanical dispersant comprises polyethylene glycol; the oxidizing agent comprises a water-soluble oxidizing agent; the corrosion inhibitor comprises an ionic corrosion inhibitor; the stabilizer comprises sodium dodecyl benzene sulfonate and polyvinyl alcohol; the pH regulator comprises a water-soluble green environment-friendly regulator; the solvent comprises water; the dispersant also comprises sodium polyacrylate or polyacrylamide; the abrasive particles are zirconium phosphate nano-sheets; the diameter of the abrasive particles is 0.1-10 μm; the pH value of the polishing solution is 2-4.

10. Use of the chemical mechanical polishing solution according to any one of claims 1 to 6 for polishing aluminum alloys, low carbon steels and red copper.