KR101396929B1 - Cleaning solution for removing impurity and method of removing impurity using the same - Google Patents

Abstract

A cleaning liquid capable of removing impurities remaining on the surface of a component of a chemical vapor deposition apparatus used for manufacturing a semiconductor device by a single cleaning process and a method for removing impurities using the same. The cleaning liquid comprises 2 to 50% by volume of ammonium fluoride compound and excess water. The cleaning liquid having such a composition can effectively remove impurities including silicon or aluminum remaining on the surface of the component of the chemical vapor deposition apparatus by performing only a single cleaning process.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a cleaning liquid for removing impurities and a method for removing impurities using the same.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning liquid for removing impurities and a method for removing impurities using the same, and more particularly, to a cleaning liquid for effectively removing impurities remaining on the surfaces of components of a device for forming a semiconductor device and a method for removing impurities using the same .

A deposition apparatus for forming the thin film and etching apparatuses for etching the thin film are required in order to form thin films or thin films constituting a semiconductor device. Particularly, since the chemical vapor deposition apparatus for forming the thin film is exposed to a process using fluorine compound, chlorine compound or plasma having high corrosivity, the components constituting the chemical vapor deposition apparatus are highly resistant to corrosion of the above compounds and plasma As shown in Fig.

When the ceramic material is exposed several to several times in the deposition process of the thin film using the deposition gas or the plasma, impurities including silicon or carbon are formed on the surface due to the chemical reaction. The impurities adhering to the surfaces of the components act as a contaminant source for contaminating the thin film formed by being separated in the form of particles in the process of forming a thin film for manufacturing a semiconductor device thereafter. Therefore, in order to prevent impurities released from the surface of the component from acting as a contamination source of the thin film, a separate cleaning process for removing the impurities attached to the surfaces of the components is required.

The cleaning process for removing the impurities attached to the component differs depending on the type of the component, but most of the silicon material and the HF aqueous solution, which is easy to dissolve the compound, are used, and an alkaline solution such as NH ₄ OH is sometimes used. However, since most of the parts are made of a material having neither acid resistance nor alkali resistance, the impurities are removed and the surface damage of the parts can not be avoided. Such surface irregularities have irregularities on the surface of the parts. These irregularities act as factors of particle generation during the process, shortening the service life of the parts, deteriorating the quality of semiconductor devices, and lowering the yield.

HF, HNO ₃ , HCl, CH ₃ COOH, H ₂ SO ₄ , and alkaline chemicals such as NaOH, KOH, NH ₄ OH, and the like can be used as acidic etching agents for removing impurities adhered to components In the case of acidic solutions, the use liquid itself is classified as a highly toxic drug having ductility under atmospheric pressure, so that the use and emission regulations of the drug are strengthened and the application thereof is strictly restricted. Furthermore, the cleaning liquid composed of the acidic solution is very toxic and not only deteriorates the environment of the cleaning process, but also has a very high risk of being weakened by contact with the human body or inhaling the vapor.

Since the basic cleaning liquid containing the basic compound has residual contaminants on the surfaces of the parts of the devices even after the cleaning process, the reprocessing cleaning process using the acidic cleaning liquid must be repeatedly carried out. It is difficult to apply the method of the present invention.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a cleaning liquid which can remove impurities remaining in parts of a chemical vapor deposition apparatus for manufacturing semiconductor devices by a single cleaning process without damaging the base material.

Another object of the present invention is to provide a method for effectively removing impurities remaining in parts of the chemical vapor deposition apparatus using the cleaning liquid for removing impurities.

Therefore, in order to accomplish the object of the present invention, the cleaning liquid for removing impurities according to an embodiment of the present invention includes 2 to 50% by volume of an ammonium fluoride compound and a residual amount of water (H ₂ O).

As an example, the cleaning liquid for removing impurities includes hydrogen peroxide water, and preferably has a composition comprising 10 to 33% by volume of the ammonium fluoride compound, 15 to 33% by volume of hydrogen peroxide, and excess water.

According to another aspect of the present invention, there is provided a method for removing impurities according to an embodiment of the present invention. First, a cleaning liquid for removing impurities existing in an apparatus part containing 2 to 50% by volume of an ammonium fluoride compound and excess water is prepared . Next, a cleaning process using the impurity removing cleaning liquid is performed on the components of the chemical vapor deposition equipment. As a result, silicon or aluminum-containing impurities remaining on the surface of the component of the chemical vapor deposition equipment can be cleanly removed from the component.

As one example, the cleaning process is carried out by providing a cleaning fluid for the removal of impurities is kept at a temperature of 75 to 80 ℃, and the impurity comprises silicon oxide (SiO _2), aluminum oxide and aluminum fluoride and the like.

The impurity cleaning solution of the present invention as described above is applied to a cleaning process for removing impurities remaining on the surfaces of components of the exposed equipment in the chemical vapor deposition process so that the impurities are reattached to the surfaces of the components So that contamination can be minimized. In addition, damage to components can be minimized by having a high etch rate for the impurities without eroding the components. In addition, the impurities adhering to the surfaces of the parts can be effectively removed only by a single cleaning process, not a repeated cleaning process, so that the cleaning time can be remarkably shortened.

Hereinafter, preferred embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the technical idea of the present invention. However, the present invention is not limited to the embodiments described herein but may be embodied in various forms. Rather, the embodiments disclosed herein are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art.

The cleaning liquid composition for removing impurities according to the present invention is applied to a cleaning process for removing impurities remaining in parts of chemical vapor deposition apparatuses for forming a thin film for forming semiconductor devices or electronic circuits. In particular, the cleaning liquid has a composition comprising an ammonium fluoride compound and water, or a composition comprising an ammonium fluoride compound, hydrogen peroxide water, and water.

The characteristics of the cleaning liquid for removing impurities will be described in detail. First, the cleaning liquid for removing impurities is applied to a cleaning process for removing impurities adhering to the surfaces of components constituting the chemical vapor deposition apparatus, so that the substances constituting the impurities are cleaned And has a characteristic capable of minimizing contamination such as being reattached to the parts in the process. Second, the cleaning liquid for removing impurities has a high etching rate characteristic with respect to the impurities without eroding or corroding the components in the cleaning step of the impurities. Thirdly, the cleaning liquid for removing impurities has the property that the impurities can be removed from the parts by a single cleaning process, and the cleaning time can be remarkably shortened.

Examples of the impurities remaining in the components constituting the chemical vapor deposition apparatus for forming the thin film include oxide (SiO ₂ ), aluminum oxide and aluminum fluoride. The impurities may be present in the chemical vapor deposition process, or may be present alone or in combination. The components constituting the chemical vapor deposition apparatus are made of, for example, ceramic, aluminum, quartz, stainless steel, or the like.

Cleaning liquid for impurity removal 1

The cleaning liquid according to an embodiment of the present invention has a composition including an ammonium fluoride compound and water. Specifically, when the content of the ammonium fluoride compound is less than 2 vol% among the components constituting the cleaning liquid, it is not easy to remove impurities including silicon or aluminum, and when the content of the ammonium fluoride compound is less than 50 vol% The surface of the component of the chemical vapor deposition apparatus is damaged. Therefore, the cleaning liquid contains 2 to 50% by volume ammonium fluoride compound, preferably 10 to 35% by volume ammonium fluoride compound.

Examples of the ammonium fluoride compound include ammonium fluoride (NH ₄ F) tetraalkyl ammonium fluoride, and ammonium hydrogen-fluoride (NH ₄ HF ₂ ). Examples of the alkyl group contained in the tetraalkylammonium fluoride include a methyl group, an ethyl group, a propyl group, and a butyl group.

As an example, the ammonium hydrogen fluoride (NH ₄ HF ₂₎ is M ^I in the aqueous solution Is ionized to [HF ₂ ] ^- (M ^I = NH ₄ ⁺ ) and reacts with impurities (SiO ₂ ), respectively, to have the following reaction formula. Therefore, these impurities bind to the NH ^{4 +} ion of the aqueous solution to form a water-soluble complex (M ^I [HF ₂ ] ^- + Si ⁴⁺ O ₂ ² - = M ₂ ^I [SiF ₆ ] do.

That is, the cleaning liquid for removing impurities according to an embodiment of the present invention has a composition comprising 2 to 50% by volume of an ammonium fluoride compound and 50 to 98% by volume of water, wherein 10 to 35% by volume of the ammonium fluoride compound and 65 to 90% And 90% by volume.

Cleaning solution for removing impurities 2

A cleaning liquid according to another embodiment of the present invention has a composition including an ammonium fluoride compound, hydrogen peroxide water, and water. Specifically, when the content of the ammonium fluoride compound is less than 10% by volume among the respective components contained in the cleaning liquid, it is not easy to remove impurities including silicon or aluminum, and the content of the ammonium fluoride compound is 33% The washing etching rate of the chemical liquid may be reduced. Therefore, the cleaning liquid contains 10 to 33% by volume ammonium fluoride compound, preferably 21 to 30% by volume ammonium fluoride compound. Examples of the ammonium fluoride compound contained in the cleaning liquid include ammonium fluoride (NH ₄ F) tetraalkyl ammonium fluoride, and ammonium hydrogen-fluoride (NH ₄ HF ₂ ).

If the content of the hydrogen peroxide solution contained in the cleaning solution is less than 15 vol%, removal of impurities including silicon or aluminum is not easy, and when the content of the hydrogen peroxide solution exceeds 33 vol%, the influence of the hydrogen peroxide solution The pollutant removal reaction is inhibited. Thus, the rinse solution comprises about 15 to 33% by volume hydrogen peroxide water, preferably about 19 to 30% by volume hydrogen peroxide.

In the cleaning liquid, the hydrogen peroxide solution is dissolved in the water to induce the oxidation reaction of the impurities. That is, in the cleaning liquid, the hydrogen peroxide water generates an acid (H +) and reacts with a substance of the impurity remaining on the component to oxidize the impurity.

The cleaning liquid having the compositions as described above can cleanly remove the impurities adhering to the surface of the parts of the chemical vapor deposition apparatus by performing a single cleaning process, so that the impurity removal time can be remarkably reduced. In addition, it is possible to prevent the parts from being damaged or the surface damage in the cleaning step for removing the impurities. In addition, by removing the impurities, generation of particles can be prevented during formation of a thin film using the chemical vapor deposition apparatus to which the component is applied, and the service life of the component can be dramatically prolonged. Furthermore, since the cleaning liquid does not contain a fuming toxic chemical, the cleaning liquid has characteristics capable of solving the problem of environmental pollution.

How to remove impurities

The method for removing impurities existing on parts of an apparatus according to the present invention is a method for removing impurities adsorbed or remaining on the surfaces of components of a chemical vapor deposition apparatus applied for manufacturing a semiconductor device using the impurity cleaning liquids described above, And the contamination of the environment can be prevented while performing the process.

The impurity removing method may include firstly an impurity removing first cleaning liquid having a composition containing 2 to 50% by volume of an ammonium fluoride compound ammonium fluoride compound and 15 to 33% by volume of a hydrogen peroxide aqueous solution, 10 to 33% by volume of the ammonium fluoride compound, And a second cleaning liquid having a composition including excess water. Here, the detailed description of the first cleaning liquid for removing impurities and the second cleaning liquid is omitted because it has been described in detail in the cleaning liquid for removing impurities.

A cleaning process is then performed for about 6 to 10 hours to provide a cleaning liquid having the composition described above to remove impurities remaining or attached to the surfaces of the components of the apparatus.

As an example, the cleaning step for removing the impurities can be performed by impregnating the cleaning tank containing the first cleaning liquid for removing impurities with components remaining or adhered to the impurities. As another example, the cleaning step for removing the impurities may be performed by impregnating the cleaning tank containing the second cleaning liquid with the components to which the impurities are attached.

The first cleaning liquid and the second cleaning liquid are provided to perform the cleaning process while maintaining the temperature of 70 to 80 ° C so that the ions of the compounds contained in the cleaning liquids are maximally activated. That is, the first cleaning liquid and the second cleaning liquid contained in the cleaning tank have a temperature of about 70 to 80 캜.

Examples of the components constituting the chemical vapor deposition apparatus include materials such as ceramics, aluni, quartz, and stainless steel. Impurities adsorbed or remaining on the surfaces of the components include silicon oxide (SiO ₂ ), silicon oxide ₂ ), aluminum oxide and aluminum fluoride.

Thereafter, the parts subjected to the impurity removal process may be further subjected to a rinsing process and a drying process using water. As an example, the rinsing process may be performed by impregnating the components in a rinsing tank containing water in which ultrasonic waves are generated. Further, the drying process can be performed by supplying heated nitrogen gas to the component.

In the method for removing impurities using the cleaning liquids listed above, the impurities can be removed without re-adsorption by a single cleaning step. In addition, since it does not react with the ceramic material or the quartz material at all, it is possible to minimize the damage of the component made of such a material.

Example  One

A first cleaning liquid containing 15 vol% of ammonium hydrogen fluoride (NH ₄ HF ₂ ) and excess water is prepared in order to remove impurities composed of aluminum oxide existing on the surface of the ceramic material applied to the chemical vapor deposition apparatus Respectively. Next, as shown in the photograph shown in Fig. 1, the parts having the impurities adhered thereto were immersed in the first cleaning liquid having a temperature of 80 DEG C contained in the cleaning bath for about 8 hours. Subsequently, the components immersed in the cleaning liquid were cleaned with deionized water, treated for 120 seconds in deionized water having an ultrasonic energy of about 40 KHz, and subjected to a spin drying process. Thereafter, the presence or absence of the impurities remaining in the part was evaluated. The results are shown in the photograph of Fig.

Referring to FIG. 2, it can be seen that the first cleaning liquid having the above composition can cleanly remove impurities adhered to the ceramic component by only a single cleaning process without damaging the surface of the component.

Example  2

22% by volume of ammonium hydrogen fluoride (NH ₄ HF ₂ ), 23% by volume of hydrogen peroxide, and an excess of water was prepared, and impurities adhering to the ceramic part were removed by the same method as in Example 1. The results are shown in the photograph of Fig.

Referring to FIG. 3, it can be seen that the second cleaning liquid having the above composition can cleanly remove the ceramic impurities without damaging the surface of the parts by a single cleaning process.

Comparative Example

A comparative example comprising 25 to 35% by volume of potassium hydroxide, 50 to 60% by volume of hydrogen peroxide, 1 to 5% by volume of an etchant or potassium hydroxide of the comparative example comprising extra water, 5 to 20% by volume of hydrogen peroxide, After the etching solution was prepared, the impurities adhering to the ceramic component were removed by the same method as in Example 1. The result is shown in the photograph of Fig.

Referring to FIG. 4, it was confirmed that the cleaning liquid of the comparative example having the above composition can not cleanly remove the ceramic impurities by a single cleaning process.

The cleaning liquid according to the present invention can cleanly remove the impurities adhering to the surface of the parts of the chemical vapor deposition apparatus by performing a single cleaning process, thereby remarkably reducing the cleaning time for removing the impurities. In addition, it is possible to prevent damage to the component or to minimize surface damage at the time of cleaning to remove the impurities. In addition, by removing the impurities, generation of particles can be prevented during formation of a thin film using the chemical vapor deposition apparatus to which the component is applied, and the service life of the component can be dramatically prolonged. Furthermore, since the cleaning liquid does not contain a fuming toxic chemical, the cleaning liquid has characteristics capable of solving the problem of environmental pollution.

Fig. 1 is a photograph of the surface of a chemical vapor deposition apparatus part to which an impurity is attached.

Fig. 2 is a photograph of the surface of a component subjected to the cleaning process according to the first embodiment of the present invention. Fig.

Fig. 3 is a photograph of a surface of a component subjected to a cleaning process according to the second embodiment of the present invention. Fig.

FIG. 4 is a photograph of a surface of a component subjected to a cleaning process according to a comparative example of the present invention. FIG.

Claims (10)

1. A cleaning liquid for removing silicon or aluminum-containing impurities remaining on a surface of a component of a chemical vapor deposition equipment, Is present in a device part comprising 10 to 33% by volume of ammonium hydrogen-fluoride (NH ₄ HF ₂ ) or tetraalkyl ammonium fluoride, 15 to 33% by volume of hydrogen peroxide, and excess water A cleaning liquid for removing impurities. delete delete delete Is present in a device component comprising 10 to 33% by volume of ammonium hydrogen-fluoride (NH ₄ HF ₂ ) or tetraalkyl ammonium fluoride, 15 to 33% by volume of hydrogen peroxide, and excess water Providing a cleaning liquid for removing impurities; And And removing the silicon or aluminum-containing impurities remaining on the surface of the component of the chemical vapor deposition equipment by performing a cleaning process using the cleaning liquid. delete 6. The method according to claim 5, wherein the cleaning step is performed by providing the cleaning liquid for removing impurities which is maintained at a temperature of 70 to 80 占 폚. The method of claim 5, wherein the impurity removing method impurities present in the components of the apparatus characterized in that it comprises at least one selected from the group consisting of silicon oxide (SiO _2), aluminum oxide and aluminum fluoride. 6. The method of claim 5, wherein the component of the apparatus comprises at least one material selected from the group consisting of ceramic, aluminum, quartz, and stainless steel. 6. The method according to claim 5, further comprising a rinsing process using water and a drying process using nitrogen gas after removing the impurities.

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