KR102397700B1 - Cleaning composition - Google Patents

Abstract

The present invention relates to a cleaning composition for dry foreign matter after glass CMP, and more particularly, after CMP slurry process treatment, it removes silica-based slurry dry foreign matter that is dried on the glass and is not easily removed, and removes the glass. It relates to a composition that can be cleaned without contamination.

Description

Cleaning composition {CLEANING COMPOSITION}

The present invention relates to a cleaning composition for cleaning dry foreign matter remaining on a substrate after a CMP process, and more particularly, to a silica-based slurry drying on glass that is dried on glass and not easily removed after CMP slurry process treatment It relates to a composition capable of removing foreign substances and cleaning the glass without contaminating the glass.

In general, chemical mechanical polishing or planarization CMP (Chemical Mechanical Polishing or Planarization) refers to dispersing an arbitrary material on the surface of a substrate, for example, a wafer or glass, and dispersing the surface through a physical process such as polishing and a chemical process such as oxidation or chelation. It refers to the process of planarizing through the process.

CMP slurry has different components depending on the film quality to be polished. When polishing metal films such as tungsten and copper, silica (SiO ₂ ) is used as an abrasive particle, and a metal oxide film is formed to help mechanical polishing. Oxidizing agents are sometimes included, and ceria (CeO ₂ ) particles are used to polish insulating films such as silicon oxide (SiO ₂ ) and silicon nitride (Si3N4).

The purpose of the cleaning process (post-CMP cleaning) is to remove residues from the CMP step and subsequent processes from the surface of a semiconductor material without optionally etching the metal, leaving foreign substances on the surface, or contaminating the material. In addition, it is desirable not to affect the underlying film quality from corrosion by various mechanisms such as etching and metal corrosion.

The advantage of the CMP process is that multi-layer wiring and wide area planarization of 0.2 μm or less are possible, and the number of processes can be reduced. In addition, it has the characteristics of reducing foreign matter due to non-flatness and facilitating removal of defects existing on the film surface. On the other hand, there are many process variables of CMP itself, so it is affected by mechanical reliability, pad, slurry, etc., and there is a possibility of scratching due to CMP. It also has a disadvantage that the production cost is not cheap.

Cleaning solutions contain chemicals that have multiple actions during the cleaning process. The cleaning agent is a component of the solution that removes residual CMP slurry particles and metal particles from the surface of the material. In general, compositions containing corrosion inhibitors, surfactants and chelating agents have also been developed. The chelating agent is used for the purpose of re-adsorbing metal impurities in the solution by binding with the metal material in the cleaning solution, but it is known that the chelating agent itself may exhibit a disadvantage of remaining as a foreign material component.

Regarding the existing CMP slurry cleaner, Korean Patent Publication No. 10-2006-0126527) and Patent Publication No. 10-2014-0101005 disclose the contents of the cleaning solution after CMP. These compositions basically include a quaternary ammonium salt (Tetra Methyl Ammonium Hydroxide), and it is common to include a metal corrosion inhibitor and a chelating agent. For example, corrosion inhibitors include ascorbic acid, gallic acid, organic amines, etc., and are included for the purpose of protecting the underlying metal. The chelating agent is usually an aliphatic alcohol compound containing a mercapto group, thioglycerol, or an alkaline compound.

The quaternary ammonium salt of the composition is generally a strong substance that decomposes organic matter by the action of OH ions or a strong alkali of pH 12 or higher, and there is a risk of erosion to the lower metal or other membranes, and is a hazardous substance due to volatilization or human contact is known as And it is accompanied by a peculiar smell of ammonia, and when exposed to air, the quaternary ammonium salt reacts strongly with CO ₂ and is gradually acidified, which may have a disadvantage in that the performance is deteriorated. In addition, in spite of such strong decomposition of organic components, there is a disadvantage in that it is not possible to remove the dried foreign substances of the silica-based slurry material.

The additives of the corrosion inhibitor or chelating agent each have their own advantages, but there is a concern that these additives also remain during cleaning and may cause defects such as water marks.

Korean Patent Registration No. 10-0700860 and Patent Publication No. 10-2007-0003854 disclose acid-based post-CMP cleaning agents. In general, it is disclosed that dilute hydrofluoric acid, citric acid, oxalic acid and the like are used. These compositions may also be difficult to handle as acidic, and there may be a chemical impact due to the pH characteristics of the slurry component, and organic matter decomposition performance may be insufficient to remove silica-based dry foreign matter.

Accordingly, the present inventors developed a composition capable of removing silica-based dry foreign matter, which is generally difficult to remove, having a neutral pH, not a strong acid or strong base, in order to solve the conventional problems of the CMP stripper composition. was completed.

Korean Patent Registration 10-0700860 Republic of Korea Patent Publication 10-2007-0003854 Republic of Korea Patent Publication 10-2006-0126527 Republic of Korea Patent Publication 10-2014-0101005

The present invention is to solve the above problems, it is characterized in that it is a neutral composition rather than a strong acid or strong base composition, thereby minimizing the erosion of the lower film quality, increasing the safety of handling, and does not contain additional solid additives. In particular, an object of the present invention is to provide a composition for cleaning silica-based dry foreign substances that may occur due to the characteristics of a CMP process applied to a small or large-area glass that has not yet been commercialized.

In order to achieve the above object, the present invention facilitates the removal of silica-based dry foreign matter dried together with neutral ammonium fluoride that can replace strong alkaline quaternary ammonium salts or acidic substances and additives used in conventional cleaning compositions. It provides a composition comprising an aprotic amide-based compound and a protic glycol-based compound component.

More specifically, the present invention in one embodiment 1.0 to 15% by weight of an aqueous fluoride solution selected from the group consisting of ammonium fluoride, hydrofluoric acid, and mixtures thereof, 10 to 30% by weight of an aprotic amide-based compound %, it provides a cleaning composition comprising 10 to 30% by weight of the protic glycol-based compound and ultrapure water as the remainder.

According to the present invention, there is provided a composition capable of removing contaminants remaining on a substrate (including a glass substrate) after a CMP process, in particular, silica-based drying foreign substances. In particular, the composition is characterized in that it has excellent cleaning properties capable of quickly removing dried foreign substances within minutes under room temperature conditions in a neutral state rather than a strong acid or strong base condition, and at the same time does not contain a solid additive.

In addition, when the cleaning composition of the present invention is used, it is possible to use a contact-type brush on the substrate for shortening the cleaning time, as well as to dilute the cleaning composition in ultrapure water as needed to remove foreign substances from the slurry. It has a saving effect and is excellent in terms of worker safety and environment.

1 is a real photograph showing a state before and after peeling off the residual dried foreign material after CMP applied on a glass substrate, (a) is a substrate on which the dry foreign material remains, (b) is a substrate manufactured in an embodiment of the present invention The board|substrate after removing a dry foreign material using a cleaning composition is shown.
2 is a real photograph showing the appearance before and after peeling off the residual dried foreign material after CMP applied on the glass substrate, in Examples (a) to (c), the dried foreign material is completely removed after treatment with the prepared cleaning composition; substrate, Comparative Example (a) is a substrate with a small amount of dry foreign matter remaining using the cleaning composition prepared in Comparative Example 4, Comparative Example (b) is a substrate from which dry foreign matter is not removed with the cleaning composition prepared in Comparative Example 1 am.

Hereinafter, the present invention will be described in detail.

According to one embodiment of the present invention, the present invention is a fluoride aqueous solution selected from the group consisting of ammonium fluoride, ammonium bifluoride, hydrofluoric acid, and mixtures thereof in an amount of 1.0 to 15% by weight, a ratio It provides a cleaning composition comprising 10 to 30% by weight of a protic amide-based compound, 10 to 30% by weight of a protic glycol-based compound, and ultrapure water as the remainder.

In order to remove silica-based dry foreign matter, a stock solution of a general fluoride compound and a diluted solution thereof can be used, but in order to secure excellent cleaning properties, ammonium fluoride (AF), ammonium difluoride (ammonium fluoride, AF), according to an embodiment of the present invention, can be used. It is preferable to use a fluorinated compound selected from the group consisting of bifluoride (ABF), hydrofluoric acid (HF), and mixtures thereof.

According to an embodiment of the present invention, the aqueous solution of ammonium fluoride is preferably included in an amount of 1.0 to 15% by weight based on the total weight of the composition. When included in an amount of less than 1.0% by weight, it is difficult to ensure sufficient cleaning properties of dry foreign substances, and when included in an amount exceeding 15% by weight, it is difficult to expect an effect of sufficient cleaning property improvement compared to the added amount, and on the contrary, the unit price of the entire composition may increase. there is.

In the composition according to one embodiment of the present invention, the aprotic amide-based compound appears to promote the action of the aqueous ammonium fluoride solution and accelerate the penetration and swelling of the polymer in the dry foreign material to aid peeling. The aprotic amide compound according to an embodiment of the present invention is specifically, methyl formamide (N-methyl formamide, NMF), methyl-2-pyrrolidone (N-methyl-2-pyrrolidone, NMP), dimethyl Propionamide (N,N-dipropionamide, DMPA), diethyl formamide (DEF), ethyl-2-pyrrolidone (N-Ethyl-2-pyrrolidone, NEP), dimethylacetamide (DMAC) , may be selected from the group consisting of ethyl formamide (N-ethyl formamide, NEF) and mixtures thereof.

In one embodiment of the present invention, the aprotic amide-based compound is preferably included in the detergent composition of the present invention in an amount of 10 to 30% by weight. When included in less than 10% by weight, the cleaning rate of dry foreign substances is lowered, and when included in excess of 30% by weight, there is a problem that penetration into the polymer and the swelling effect are not sufficiently exhibited.

In the composition according to one embodiment of the present invention, the protic glycol-based compound increases the cleaning property of the composition, serves to increase the stability in the composition of the ammonium fluoride compound, and allows the dissolved foreign material to spread well in the cleaning agent for rapid removal. seems to help

In one embodiment of the present invention, the protic glycol-based compound is specifically ethylene glycol (ethylene glycol, EG), propylene glycol (PG), diethylene glycol monoethyl ether (EDG), Diethylene glycol monobutyl ether (BDG), diethylene glycol monomethyl ether (MDG), ethylene glycol monoethyl ether (EEG), propylene glycol monoether It may be selected from the group consisting of (propylene glycol monobutyl ether, PGMBE), tripropylene glycol monoethyl ether (TPGMEE) and triethylene glycol monobutyl ether (TEGMBE), and mixtures thereof. .

Since the composition according to an embodiment of the present invention can be further diluted with ultrapure water as necessary, it is possible to improve unit cost competitiveness and operational stability in manufacturing, and further has an environmental-friendly advantage.

In one embodiment of the present invention, the present invention is ammonium fluoride (ammonium fluoride) and ammonium bifluoride (ammonium bifluoride) 1.0 to 15% by weight, methyl-2-pyrrolidone (N-methyl-2-Pyrrolidone, NMP) and Dimethylpropionamide (N,N-dipropionamide, DMPA) 10-30 wt%, diethylene glycol monoethyl ether (EDG) and diethylene glycol monobutyl ether (BDG) 10-30 wt% It provides a dry foreign material cleaning composition after CMP containing ultrapure water as a weight% and the remainder.

Hereinafter, the present invention will be described in more detail through examples. These examples are only for illustrating the present invention, and it will be apparent to those of ordinary skill in the art that the scope of the present invention is not to be construed as being limited by these examples.

Examples 1 to 9. Preparation of dry foreign material cleaning stripper composition after CMP

Through the manufacturing process according to an embodiment of the present invention, a dry foreign material cleaning composition of the present invention comprising an aqueous ammonium fluoride solution, an aprotic amide compound and a protic glycol compound was prepared, and this was used in Examples 1 to 9 Specifically described. Components and contents of each composition are summarized in Table 1 below.

Comparative Examples 1 to 5.

As a quaternary ammonium salt aqueous solution, the dry foreign material cleaning compositions of Comparative Examples 1 to 3 comprising an aqueous solution of tetramethylammonium hydroxide, an aprotic amide compound, and a protic glycol compound were prepared. The content of each composition is in a range similar to that of the above example, but in order to confirm the performance of the aprotic amide-based compound, a non-amide-based compound was added, and the components of the protic glycol-based compound were mixed differently. In addition, the content of the ammonium fluoride aqueous solution and the aprotic amide-based compound was reduced to confirm the optimal cleaning performance content. Components and contents for each composition are summarized in Table 1 below.

#Example Ingredients Composition content (%) Dissension
ammonium amide compounds proton
glycol-based ultrapure water Dissension
ammonium amide
compound proton
glycol-based ultrapure water Example 1 AF NMP EDG DI One 25 25 49 Example 2 AF NMP EDG DI 5 10 30 55 Example 3 AF NMP EDG DI 15 30 10 45 Example 4 AF NMP BDG DI 7 30 25 38 Example 5 AF DMPA EDG DI 7 25 25 43 Example 6 AF DMPA EDG DI 15 20 25 40 Example 7 ABF NEF BDG DI 5 20 30 55 Example 8 ABF NMP EDG DI 7 30 25 38 Example 9 ABF DMPA BDG DI 15 30 25 30 #comparative example ammonium fluoride or
quaternary ammonium salt proton
glycol-based ultrapure water ammonium fluoride or
quaternary ammonium salt proton
glycol-based ultrapure water Comparative Example 1 AF EL* EDG DI 7 30 25 38 Comparative Example 2 TMAH DMPA EDG DI 7 15 25 53 Comparative Example 3 TMAH DMPA EDG DI 15 15 25 45 Comparative Example 4 AF NMP EDG DI 0.5 30 25 44.5 Comparative Example 5 AF DMPA EDG DI 15 5 25 55

TMAH: Tetramethylammonium hydroxide

BDG : Diethylene glycol monobutyl ether

EDG : Diethylene glycol monoethyl ether

AF : Ammonium Fluoride 40%

ABF : Ammonium Bifluoride 40%

NMP: N-Methyl-2-Pyrrolidone

NEF: N-Ethyl-Formamide

DMPA: N,N-Dimethyl Propionamide

*EL: Ethyl Lactate: Non-amide compounds

Experimental Example 1. Evaluation of cleaning properties

In order to evaluate the cleaning properties of the cleaning composition prepared in one embodiment of the present invention to the dried foreign matter after the CMP process, after the etching and development process for pattern formation, the glass substrate on which the wiring is formed was immersed in the cleaning composition.

Specifically, 200ml of the detergent composition prepared in Example of the present invention was put into a beaker at room temperature, and stirred at 100 rpm using a magnetic bar. A specimen coated with a silica slurry dry foreign material was immersed in the composition for 300 seconds to wash the dry foreign material. Then, the specimen was taken out, washed with ultrapure water, dried, and analyzed whether the dried foreign matter remained on the substrate.

Since it is easy to distinguish the presence or absence of dry foreign matter with the naked eye, the same experimenter closely analyzed whether or not the dried foreign matter was removed by the same method, and the results are shown in Table 2 and FIGS. 1 to 2 below.

division Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 peelability O O O O O O O O O division Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 peelability △ X X △ △

[Judgment criteria for cleaning dry foreign matter]

Upon visual inspection,

O: Dry foreign matter is completely peeled off on the glass substrate.

Δ: Some dry foreign matter remains on the glass substrate.

X: Dry foreign matter is not clearly removed on the glass substrate.

As shown in Table 1, it was confirmed that the compositions prepared in Examples 1 to 9 of the present invention were very excellent in cleaning properties despite various composition changes within the scope of the present invention.

On the other hand, when cleaning using the compositions prepared in Comparative Examples 1 to 5, dry foreign matter is not well removed, and increasing the TMAH content to improve cleaning properties is considered to have a negative effect on various films produced in the subsequent process. .

On the other hand, as a result of measuring the cleaning power of the composition according to the embodiment of the present invention, a tendency to increase the cleaning power according to the increase in the content of ammonium fluoride is observed. The cleaning power is also expected to be adjustable. However, when the amount of ammonium fluoride exceeds 15% in the total composition, no significant increase in cleaning power was observed.

In addition, as can be seen in Comparative Example, when ammonium fluoride was used at 1.0% or less, it was confirmed that the cleaning power of the composition was reduced, and as in Comparative Example 5, even when the amide-based compound was added at 10% or less, the cleaning power of the composition was reduced. it can be seen that

In addition, as shown in Comparative Example 1, when a non-amide-based compound is used instead of an amide-based compound, it can be confirmed that the cleaning power of the composition is greatly reduced. It is judged that it plays a certain role in improving the cleaning properties of the entire composition by accelerating penetration and swelling into the polymer.

In addition, in order to evaluate the degree of cleaning properties of the compositions prepared in Examples and Comparative Examples of the present invention, FIGS. 1 and 2 are photographs taken of the substrate after the cleaning agent treatment.

Referring to FIG. 1 , it can be seen that the dried foreign matter is observed cloudy on the entire substrate after CMP before (a) the cleaning solution treatment, and it can be observed that it is completely removed after the cleaning solution treatment (b).

Referring to FIG. 2 , when comparing and judging the cleaning power of each composition, in the case of treatment with the compositions of Examples 1, 6, and 8, it can be seen that the dry foreign matter generated after CMP is completely removed, but the same It can be observed that, when treated with the composition of Comparative Example 2 in which TMAH is applied as the main component of the cleaning solution under the conditions, the dry foreign matter generated after CMP is not removed at all.

This is an example showing that certain components of the CMP slurry cannot be removed with TMAH. On the other hand, in Comparative Example 3, some cleaning power seems to be improved when the TMAH content is increased, but as described above, this is not recommended because there is a concern that may cause additional problems in the subsequent process.

So far, with respect to the present invention, the preferred embodiments have been looked at. Those of ordinary skill in the art to which the present invention pertains will understand that the present invention can be implemented in a modified form without departing from the essential characteristics of the present invention.

Claims (3)

0.5 to 15% by weight of an aqueous fluoride solution selected from the group consisting of ammonium fluoride, ammonium bifluoride, hydrofluoric acid, and mixtures thereof;
10-30 wt% of an aprotic amide-based compound;
10-30 wt% of a protic glycol-based compound; and
As a cleaning composition comprising ultrapure water as the remainder,
The aprotic amide compound is dimethylpropionamide (N,N-dipropionamide, DMPA), diethyl formamide (DEF), ethyl formamide (N-ethyl formamide, NEF), and a group consisting of mixtures thereof is selected from
The protic glycol-based compound is ethylene glycol (EG), propylene glycol (PG), diethylene glycol monoethyl ether (EDG), diethylene glycol monobutyl ether (Diethylene glycol monobutyl) ether, BDG), diethylene glycol monomethyl ether (MDG), ethylene glycol monoethyl ether (EEG), propylene glycol monobutyl ether (PGMBE), tri A detergent composition selected from the group consisting of propanol glycol monoethyl ether (tripropylene glycol monoethyl ether, TPGMEE), triethylene glycol monobutyl ether (TEGMBE), and mixtures thereof. delete delete

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