JP4952257B2 - Cleaning composition for semiconductor manufacturing apparatus member and cleaning method using the same - Google Patents

Description

  The present invention relates to a cleaning composition for a semiconductor manufacturing apparatus member and a cleaning method using the same, and particularly to a surface of a member in which a ceramic coating is applied to an anodized aluminum substrate surface, such as a process chamber. The present invention relates to a cleaning composition suitable for removing adhered substances and a cleaning method using the same.

  The semiconductor manufacturing process consists of various processes such as CVD (Chemical Vapor Deposition) film formation process and plasma etching process. Among these processes, for example, the etching process generates plasma in the process chamber and does not need to be on the wafer. Etch the part. In such an etching process, substances scattered during etching adhere to the inner wall surface of the process chamber. For this reason, in the process of processing many wafers, the thickness of the deposits deposited on the process chamber increases, which peels off and causes generation of particles. Therefore, it is necessary to periodically remove deposits deposited on the process chamber.

  In order to increase the resistance to plasma, the process chamber of the semiconductor manufacturing equipment used for the etching process by plasma is made of anodized aluminum as a base material, and the inner wall is made of ceramics such as alumina ceramics, yttria ceramics, zirconia ceramics. Thermally sprayed and coated ones are often used. In such a process chamber, the ceramic part is weak against acid and the anodized aluminum part is weak against acid and alkali and is very corrosive, so it cannot be cleaned with chemicals. They were wiped off with a cloth soaked in alcohol or water, or rubbed off with an abrasive tool.

  However, these methods cannot sufficiently remove deposits, and if a polishing tool or the like is used, the surface of the ceramic portion or the anodized aluminum substrate surface may be damaged.

  On the other hand, in addition to such a physical removal method, a method of removing deposits with hydrogen peroxide in a heated state is known as a cleaning method for a process chamber made of an anodized aluminum substrate (for example, Patent Document 1). According to this method, it is described that the anodized aluminum oxide surface of the process chamber is not damaged, but a ceramic coating portion was formed on the anodized aluminum base surface by thermal spraying. Matters related to cleaning process chambers are not described. Furthermore, there has been no known example relating to chemical cleaning of a process chamber made of an anodized aluminum substrate having a ceramic coating portion formed by thermal spraying.

  Therefore, it has been desired to develop a cleaning composition capable of removing and cleaning the deposited deposit without damaging both the ceramic portion and the anodized aluminum portion.

JP 2001-127035 A

  An object of the present invention is to provide a cleaning composition that selectively removes deposited deposits without damaging a semiconductor manufacturing apparatus, and a cleaning method using the same.

  As a result of intensive studies on the removal of deposits deposited on the surface of a member for a semiconductor manufacturing apparatus, the present inventors include an organic acid containing an inorganic acid and / or a carboxylic acid, a fluoride, a hydrophilic organic solvent, and water. The composition for cleaning a semiconductor manufacturing apparatus member comprising: selectively deposits deposited without damaging a semiconductor manufacturing apparatus member, particularly a member coated with a ceramic coating on an anodized aluminum base surface. As a result, the present invention was completed.

  The present invention is described in further detail below.

  The cleaning composition in the present invention comprises an organic acid containing an inorganic acid and / or a carboxylic acid, a fluoride, a hydrophilic organic solvent, and water. However, this excludes the case where the inorganic acid and the fluoride simultaneously correspond to hydrofluoric acid.

  In the cleaning composition of the present invention, the inorganic acid is not particularly limited, but carbonic acid, bicarbonate, boric acid, iodic acid, nitric acid, sulfuric acid, hypobromous acid, hypochlorous acid, chlorous acid, Peroxo acids such as perchloric acid, nitrous acid, oxosulfuric acid, hydrobromic acid, hydrochloric acid, hydrofluoric acid, hydroiodic acid, hydrosulfuric acid, etc., peroxonitric acid, peroxosulfuric acid, peroxodisulfuric acid, etc. It is preferably at least one selected from the group consisting of acids and the like. Other inorganic acids can be used, but they are expensive and are not industrially advantageous.

  Among the above inorganic acids, it is preferable to use one or a combination of two or more from the group consisting of sulfuric acid, nitric acid or hydrochloric acid from the viewpoint of the ability to remove deposits and cost, and nitric acid is used alone. Is most preferred. As nitric acid, high purity commercially available for electronic materials can be used, but industrially available one may also be used.

  In the cleaning composition of the present invention, the organic acid containing carboxylic acid is not particularly limited, but acetic acid, acrylic acid, propionic acid, benzoic acid, phthalic acid, oxalic acid, glutaric acid, adipic acid, malonic acid. , Succinic acid, maleic acid, fumaric acid, tartaric acid, malic acid, and citric acid. Other organic acids including carboxylic acids may be used, but they are expensive and are not industrially advantageous. Among the organic acids including the carboxylic acid, citric acid is preferable from the viewpoint of the ability to remove deposits and cost. As citric acid, commercially available high-purity products for electronic materials can be used, but those commercially available may be used.

  In the cleaning composition of the present invention, the fluoride is not particularly limited, but is preferably at least one selected from the group consisting of hydrofluoric acid, sodium fluoride, potassium fluoride, and ammonium fluoride. . Other fluorides may be used, but are not industrially advantageous because they have low solubility in water or are expensive. Of hydrofluoric acid, sodium fluoride, potassium fluoride, and ammonium fluoride, hydrofluoric acid and ammonium fluoride that do not contain metal are particularly preferable. As the hydrofluoric acid and ammonium fluoride, those having high purity commercially available for electronic materials can be used, but those commercially available may also be used. Fluoride is effective for removing the Si component contained in the deposit, but also facilitates removal of the resist polymer.

  In the cleaning composition of the present invention, the hydrophilic organic solvent is not particularly limited, but from the group consisting of alcohols, ethers, formamides, pyrrolidones, ketones, lactones, esters, and sulfoxides. It is preferably at least one selected. Specifically, for example, alcohols include methanol, ethanol, isopropanol, butanol, ethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, cyclohexanediol, cyclopentanediol, glycerin, ethylene glycol monomethyl ether, diethylene glycol. Examples include monomethyl ether, triethylene glycol monomethyl ether, propylene glycol monomethyl ether, and diethylene glycol monobutyl ether. Examples of ethers include diethylene glycol dimethyl ether, diethylene glycol diethyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, tetrahydrofuran, and Hydropyran and the like, formamides include N-methylformamide, N, N-dimethylformamide and the like, and pyrrolidones include N-methylpyrrolidone, N-ethylpyrrolidone and 2-pyrrolidone, Examples of ketones include acetone, methyl ethyl ketone, cyclohexanone, diacetone alcohol and the like. Examples of lactones include propiolactone and butyrolactone. Examples of esters include ethyl acetate, ethyl lactate, butyl lactate, and acetoacetic acid. Examples of the sulfoxide include dimethyl sulfoxide and methyl ethyl sulfoxide, and at least one selected from these is preferable. Among the hydrophilic organic solvents mentioned in the above specific examples, from the viewpoint of the ability to remove deposits and cost, among the group consisting of methanol, ethanol, isopropyl alcohol, tetrahydrofuran, N, N-dimethylformamide, acetone, dimethyl sulfoxide. It is preferable to use 1 type or 2 types or more in combination, and it is most preferable to use acetone alone. As the acetone, high-purity commercially available for electronic materials can be used, but those that are commercially available may be used.

  In consideration of the fact that the object to be cleaned is used in the manufacturing process of the semiconductor element, the water used in the cleaning composition of the present invention includes ionic substances such as ion-exchanged water, pure water and ultrapure water, particles, and the like. What was reduced as much as possible is preferable.

  In the cleaning composition of the present invention, the ratio of the organic acid containing an inorganic acid and / or carboxylic acid to the fluoride, the hydrophilic organic solvent and water is not particularly limited, but the removal rate of deposits on the member surface In consideration of damage to components and components of the member, production of the cleaning composition, capital investment, etc., the amount of organic acid including inorganic acid and / or carboxylic acid is 0 with respect to the total amount of cleaning composition 0.1 to 20% by weight, the amount of fluoride is 0.01 to 5% by weight, the amount of water is 0.01 to 20% by weight, and the balance is preferably a hydrophilic organic solvent. More preferably, the amount of organic acid including acid is 2 to 10% by weight, the amount of fluoride is 0.1 to 3% by weight, the amount of water is 1 to 10% by weight, and the balance is a hydrophilic organic solvent.

  If the amount of the organic acid including inorganic acid and / or carboxylic acid is less than 0.1% by weight, the removal rate of deposits is not industrially slow, and if it exceeds 20% by weight, the coated ceramics and anodic oxidation In some cases, damage to the aluminum substrate is increased, which is not preferable.

  Also, if the amount of fluoride is less than 0.01% by weight, the removal rate of deposits is too slow to be industrial, and if the amount of fluoride exceeds 5% by weight, the coated ceramic and anodized aluminum substrate Since damage is increased, it may not be preferable.

  Further, if the amount of water is less than 0.01% by weight, there is no problem with the cleaning power itself, but it is not practical because it is very expensive to produce a cleaning composition, and the amount of water is 10% by weight. If it exceeds 1, damage to the coated ceramics and the anodized aluminum substrate becomes large, which may not be preferable.

  The cleaning composition of the present invention can be used for cleaning deposits or deposits composed of inorganic substances, organic substances, or both, which adhere to the surface of a member inside a semiconductor manufacturing apparatus in a semiconductor element manufacturing process. It is possible to clean the semiconductor manufacturing equipment made of the material, but in particular, coating by spraying ceramics such as alumina ceramics, yttria ceramics, zirconia ceramics on the anodized aluminum base ( For example, it can be suitably used for a member provided with 1.0 to 5000 μm).

  In using the cleaning liquid composition in the present invention, cleaning can be performed by bringing it into contact with a member of a semiconductor manufacturing apparatus that is the object to be cleaned, but the method of bringing the object to be cleaned into contact with the cleaning liquid composition is not particularly limited. In addition, any known method can be used. For example, it can be carried out by wiping with a sponge impregnated with the cleaning liquid composition, immersion in the cleaning liquid composition and / or spraying, etc., but cleaning by immersion is particularly preferable in terms of improving workability and simplifying the equipment. .

  Examples of the dipping method include a method of immersing the object to be cleaned for each structural unit or a plurality of structural units in the cleaning liquid composition, and performing a cleaning treatment. Oscillation, ultrasonic or air bubbling can be combined. In addition, as a cleaning apparatus used for these cleaning methods, a generally known apparatus can be used. Moreover, there is no restriction | limiting in particular in the drying method after wash | cleaning a washing | cleaning target object, Any well-known methods, such as warm air drying and reduced pressure drying, can be used.

  The cleaning temperature in the cleaning method of the present invention is not particularly limited, but 10 to 50 ° C. is necessary because it is necessary to satisfy any of the conditions for reducing damage to members, good cleaning properties, and reducing utility costs. 20-30 degreeC is preferable especially. Further, the cleaning time in the cleaning method of the present invention may be appropriately selected depending on the amount and composition of deposits on the member. However, from the viewpoint of reducing damage to the substrate and improving work efficiency, it may not exceed 8 hours. Preferably, 10 minutes to 5 hours are particularly preferable.

  Since the cleaning liquid composition of the present invention is used in an apparatus for manufacturing a semiconductor element, the impurities derived from the cleaning liquid composition must be avoided in the apparatus as much as possible. The inorganic acid and / or A solution consisting only of an organic acid containing a carboxylic acid, a fluoride, a hydrophilic organic solvent and water is sufficient.

  However, it is a component that can be washed cleanly from the surface of the member by a simple method such as water washing, and other cleaning liquids and various additives can be blended as long as the effects of the present invention are not impaired. Other cleaning liquid components include hydrocarbons and hydrofluorocarbons, and examples of additives include corrosion inhibitors and surfactants.

  Examples of the corrosion inhibitor include, but are not limited to, phosphoric acid-based, carboxylic acid-based, amine-based, oxime-based, aromatic hydroxy compounds, triazole compounds, sugar alcohols and salts thereof, and the like. However, two or more types may be used in appropriate combination. Examples of the surfactant include cationic, anionic, nonionic, and fluorine-based surfactants, which can be used alone or in combination of two or more.

  ADVANTAGE OF THE INVENTION According to this invention, the cleaning method of the member for semiconductor manufacturing apparatuses used in the manufacturing process of the semiconductor element and contaminated was provided. In the present invention, by using a cleaning liquid composition comprising an organic acid containing an inorganic acid and / or a carboxylic acid, a fluoride, a hydrophilic organic solvent and water, it is weak against acids and alkalis and is very susceptible to corrosion. In the past, Si deposited in an etching process or the like without particularly damaging a member for a semiconductor manufacturing apparatus in which a ceramic coating was applied to the surface of an anodized aluminum substrate, which could not be cleaned with a chemical chemical, Deposits such as resist polymer can be removed.

  In the cleaning method of the present invention, it is possible to perform cleaning only by immersing, so there is no need to install an ultrasonic cleaning basket or the like, and furthermore, the cleaning temperature is 20 to 30 ° C., which is the same temperature as room temperature, Utility costs can be reduced.

  In the present invention, an organic acid containing an inorganic acid such as nitric acid and citric acid and / or a carboxylic acid, a fluoride such as hydrofluoric acid and ammonium fluoride, and a hydrophilic organic solvent such as acetone are available at a low price. In addition to being superior in cost performance because it has a sufficient cleaning ability, it is excellent in safety and workability because it does not use hydrogen peroxide solution that requires attention to handling. A method for cleaning a semiconductor manufacturing apparatus.

  Hereinafter, although the washing | cleaning method of this invention is demonstrated by an Example, this invention is not limited to these. In order to simplify the notation, citric acid was denoted as “CA”.

Examples 1-3, Comparative Examples 1-2
Anode removed from a semiconductor manufacturing apparatus used in a plasma etching process, which is a manufacturing process of a semiconductor element, the surface of which is contaminated with Al and F as elements derived from deposits, and a coating having a thickness of 200 μm made of yttria ceramics A process chamber made of an oxidized aluminum substrate was cut into a length of 30 mm, a width of 14 mm, and a thickness of 12 mm to obtain a test piece. This test piece was immersed in each cleaning liquid composition prepared in the liquid composition shown in Table 1 and held at 25 ° C. for 1 hour, and then the test piece was taken out, washed with water and dried. The removal state of the deposit was examined by quantitative analysis using EPMA (X-ray microanalyzer), and the damage of the substrate surface was examined by SEM (scanning electron microscope) observation of the surface. EPMA was manufactured by HORIBA, Ltd., trade name “EMAX5770W”, and SEM was manufactured by JEOL Ltd., trade name “JSM T220A”. In addition, the Al content in the quantitative analysis by EPMA before cleaning was 0.9% by weight, and the removal state of the deposit was evaluated as follows.
○: Al was detected by EPMA less than 0.1% by weight or not detected.
X: 0.1% by weight or more and less than 0.9% by weight of Al was detected by EPMA.

Moreover, about the damage of the base-material surface, it evaluated as follows by SEM observation.
○: The anodized aluminum part and the part coated with yttria ceramics are unchanged compared to the unused parts.
×: Both the anodized aluminum part and the part coated with yttria ceramic are roughened, chipped and corroded.

比較例３
実施例１〜６で用いた試験片と同様のものを、８０℃に過熱した３１％過酸化水素水に３０分間、浸漬した。その結果、陽極酸化されたアルミニウム部分、イットリアセラミックスによりコーティングが施された部分共にダメージはなかったが、付着物が除去できなかった。

Comparative Example 3
The same test pieces used in Examples 1 to 6 were immersed in 31% hydrogen peroxide solution heated to 80 ° C. for 30 minutes. As a result, the anodized aluminum part and the part coated with yttria ceramics were not damaged, but the deposits could not be removed.

Claims (3)

Nitric acid is 0.1 to 20% by weight, fluoride is 0.01 to 5% by weight, water is 0.01 to 20% by weight, and the balance is isopropyl alcohol or acetone. Cleaning composition. The composition for cleaning a member for a semiconductor manufacturing apparatus according to claim 1, wherein the member for a semiconductor manufacturing apparatus is obtained by applying a ceramic coating to an anodized aluminum surface. The member by which the contaminant which originated in manufacture of a semiconductor element adhered to the surface of the member for semiconductor manufacturing apparatuses with the cleaning composition of the member for semiconductor manufacturing apparatuses of Claim 1 or 2 is made, and the said member A method for cleaning a member for a semiconductor manufacturing apparatus, comprising: